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ASK13 1/3 Scale**

Posted: 21 Dec 2020, 09:48
by Peter Balcombe
A short kit of a new design from Jilles Smits arrived today, so no excuse for idle fingers over the next few months ;)

A lo..ot of laser cut parts ((all bagged) & several drawing sheets covering fuselage, wings, tail, canopies (full & cabriolet), airbrakes etc. on separate sheets. (Drawings arrive folded, but I like to roll them for use).

Conventional woodie construction with 0.4mm ply wing D box skins & 0.6mm skins on the relevant fuselage parts.
Build options include choice of canopy type and with/without nose wheel.

I should receive a bundle of strip wood for spars etc. tomorrow, so can make a start - probably on the tail feathers.
Short kit contents
Short kit contents

Re: ASK13 1/3 Scale

Posted: 22 Dec 2020, 10:04
by Peter Balcombe
First up on the building board is the Stabiliser which slots together to form the structure shown below. Just needs a couple of spruce spars & tips to be to be added, plus 0.4mm skins to complete.
Two thin wing servos fit into the centre section from below, driving each elevator half separately.
85464F35-4FF1-4C1D-AB15-D15CE69C6A2E.jpeg

Re: ASK13 1/3 Scale

Posted: 22 Dec 2020, 20:18
by Cliff Evans
This is the scheme I have in mind!
130913-romanin-002.jpg
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Re: ASK13 1/3 Scale

Posted: 22 Dec 2020, 20:45
by Max Wright
This is one for me to watch, Peter. 8-)

Is that Finnish registration on the prototype, Cliff?

Cheers

Re: ASK13 1/3 Scale

Posted: 22 Dec 2020, 21:24
by chris williams
Hmmmm, very similar to this one...
D-0754_04 copy.jpg

Re: ASK13 1/3 Scale

Posted: 22 Dec 2020, 23:49
by Cliff Evans
Yes, similar

Re: ASK13 1/3 Scale

Posted: 23 Dec 2020, 07:35
by patte de loup
Some other pics of this glider here:
http://www.aeroclub-alpilles.fr/galerie ... pt2013.htm
Pat'

Re: ASK13 1/3 Scale

Posted: 23 Dec 2020, 07:57
by Max Wright
Beautiful shots!

Thanks for posting, Pat. 8-)

Re: ASK13 1/3 Scale

Posted: 23 Dec 2020, 08:00
by Cliff Evans
patte de loup wrote: 23 Dec 2020, 07:35 Some other pics of this glider here:
http://www.aeroclub-alpilles.fr/galerie ... pt2013.htm
Pat'
Yes, I have those pics. Have tried to contact the club to see if they have any more including cockpit detail but alas no answer. I called the club on the phone but nobody spoke English and my French is at best crap! If you have an in there and can get some more info I would be extremely grateful.

Re: ASK13 1/3 Scale

Posted: 23 Dec 2020, 09:32
by B Sharp
Pretty in pink!
I liked the K13 a lot, it was a nice old lady to fly. I must build one some day.
I will watch this build with interest.
Brian :)

Re: ASK13 1/3 Scale

Posted: 23 Dec 2020, 11:20
by Peter Balcombe
With the spruce hinge spars added to the Stabiliser, attention turns to the elevator halves.
Whilst the Stabiliser was build horizontal, using the rib building tabs to keep everything flat until the top skin has been added, the elevators & rudder are built vertical on their respective ply strips.

The elevator strips are 0.8mm ply, so these need to be held flat on the building board whilst the ribs are added (until the 1/2” x 1/8” spars are fitted). The TE is shown as a 4mm Balsa core (notched for each rib TE), sanded to profile & then capped with 0.4mm ply skins to give a 2mm thick TE.
After trying this approach on the LH elevator, I decided to try a slightly different approach on the RH one in order to give a better defined TE when profiling.
Thus although most of the RH elevator TE is comprised of a separate trim tab, the tip section TE core will be made from a strip of 0.8mm ply laminated between two 1/16” Balsa strips.
When profiled, the Balsa will be sanded back to the ply edge. The 0.8mm ply core, plus two 0.4mm caps should give a solid & straight 1.6mm thick TE.

It’s also worth noting that, in common with other CNC cut builds, the CNC parts are often a slightly different size from the printed plan - due to paper print linear errors being greater than the very much more accurate laser cutting.
This difference is more obvious on span-wise parts.
However, the answer is to use the laser cut parts as the reference, using the plan as a guide to enable some hand cut parts to be correctly resized, rather than cut from the plan.
If everything is cut from the printed plan, then there shouldn’t be an issue as everything will be out by the same percentage error.
49E53750-A82D-4DBD-9627-984B43177D6C.jpeg

Re: ASK13 1/3 Scale

Posted: 23 Dec 2020, 19:35
by patte de loup
Cliff Evans wrote: 23 Dec 2020, 08:00
patte de loup wrote: 23 Dec 2020, 07:35 Some other pics of this glider here:
http://www.aeroclub-alpilles.fr/galerie ... pt2013.htm
Pat'
Yes, I have those pics. Have tried to contact the club to see if they have any more including cockpit detail but alas no answer. I called the club on the phone but nobody spoke English and my French is at best crap! If you have an in there and can get some more info I would be extremely grateful.
Hi Cliff,
In my mind the best way to catch up some further info should be to contact Gerard himself (GPR). He is closed to to the club:
lesgpr#@#free.fr (take out the #).
BTW I also made a drawing for my best friend at the same scale of this beauty and this one flies very well with 12 kg of weight .
My friend has also some pics about the cockpit ( located in Strasbourg ). Please tell if you need it ;-)
Pat'

Re: ASK13 1/3 Scale

Posted: 24 Dec 2020, 00:20
by Cliff Evans
Thanks Pat.. I have emailed Gerard. Would you see if you can get the cockpit details off of your friend please.

Re: ASK13 1/3 Scale

Posted: 24 Dec 2020, 09:51
by patte de loup
Following this link;
- https://forum.spmc-modelisme.fr/viewtop ... f=9&t=5177
- https://spmc-modelisme.fr/
the ASK13 building of my friend

Re: ASK13 1/3 Scale

Posted: 24 Dec 2020, 09:59
by Peter Balcombe
The basic structure of the tail feathers is quickly completed once the spars and TE cores have been fitted.
I have also built up the fin structure on the rearmost fuselage former.

No excuse now to make a start on the larger bits - once I get a longer building board setup indoors :)
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Re: ASK13 1/3 Scale

Posted: 24 Dec 2020, 18:11
by Max Wright
Looking excellent, Peter. 8-)

I'm following along.

Cheers

Re: ASK13 1/3 Scale

Posted: 24 Dec 2020, 18:29
by Peter Balcombe
Well what a day :D
Realised after looking at the fuselage plan & laser cut bits that as several fuselage formers had building tabs on them & there were also plenty of laser cut longeron parts, it was going to be possibly to build the front half of the fuselage structure on my 4ft board 👍

First off, you need to decide whether or not you are building to have a front wheel or not. Once decided, select the front formers with a ‘W’ suffix for front ‘Wheeled’ variant, else ‘S’ suffix for Standard varian without front wheel.

So, after making sure that all interlocking slots slide together ok, I started by assembling the building tabbed formers to the two forward keel pieces (starting from F2 & working back to F11). Note that you may find it easier to first remove the cross pieces between the tab extensions, otherwise you will need to start with Former 6 as otherwise it will only go over the keel pieces from the front.

Just remember to fit the 1/16” ply main wheel guard between the keel pieces before you fit the rear formers as the laser cut guard is tabbed.
Remember to fit F2 & F3 the correct way around to have the servo on the RHS.
Remember also to fit the horizontal plate between the root ribs whilst fitting the appropriate formers to avoid locking this out as it slides between a horizontal slot in one former & is tabbed into others. (I fitted the M4 wing retention bolt captive nuts into this plate before installation).

Once I had the formers in place, I could add the laser cut forward & canopy base longerons to tie everything together, followed by the 4 joiner tube guides between Formers 9 & 10, then the root ribs.

I fitted the Former 1/1A lamination last of all, noting that the 2 keel pieces will need to be curved inwards a bit to get the correct spacing for the former slots.

The pictures below show the structure without root ribs, the joiner supports & then the forward structure with all CNC bits fitted.
There are just 2 additional spruce longerons to add on each side on the forward section & these will be fitted once the rear part of the fuselage has been built on. Additional tabbed formers at the rear & internal horizontal plates will ensure that the rear section is square & straight with the front.

Well, that’s it for a couple of days whilst I negotiate extra space with local Management ;)
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Re: ASK13 1/3 Scale

Posted: 28 Dec 2020, 17:13
by Peter Balcombe
Whilst workspace negotiations were ongoing I was able to add the longerons to each side of the forward section. These 36” length were scarfed over 2” & left in place to mate with the rear sections. Note that the lower longeron runs the full 2.5m fuselage length!
The few remaining forward fuselage CNC parts (wing joiner tube slots, root ribs etc) were also added, together with the forward sections of the rear top & bottom keel strips & a couple of formers to hold these in the correct places.
A3C3646F-7177-438A-9044-652349F613F0.jpeg
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Once extra space was available I set up my longer building board (old draughting board, split in two & joined end to end).
Now I could add the remaining formers and rearmost keel piece, plus 0.8mm ply internal shoulder height cross plates, using a centre-line, the tabbed formers and notched cross plates to make sure everything was true.
Once all formers were in place, I could add the upper spars running from fin to cockpit opening, followed by the upper parts of the rear formers & the rear section of the top spine.
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A nice touch from Jilles is the centre pointer on the tabbed CNC cut formers. This greatly eases alignment :)
BE5A7FF6-13ED-4BE9-B82F-E1D2F37E8A53.jpeg
The Cabriolet canopy has also been assembled in the cockpit opening to ensure a good fit when skinned.
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Re: ASK13 1/3 Scale

Posted: 28 Dec 2020, 19:15
by Max Wright
This build looks like a lot of fun, Peter. 8-)

Re: ASK13 1/3 Scale

Posted: 29 Dec 2020, 10:36
by Peter Balcombe
Hi Max, yes the parts are going together very nicely indeed :)
Although there aren’t many stripwood longerons in this build, they easily gently bend to follow the fuselage lines without the need for any steaming - so very easy to build indoors at this time of year.

With the basic rear fuselage parts together, it time to add the tailplane seat before it’s locked out by the side longerons. The two hold-down assemblies (F19, 19A, 20, 20A plus P1s fitted with M4 captive nuts) can be pre-assembled & then slipped into place under the upper longerons used to support the 0.8mm BR2R top plate.
F20A also notched into the keel. Line up the hold-assemblies with the holes in the top plate & double check by bolting on the tailplane seat (STS).
(I forgot to fit a Cyano soaked balsa support block above the captive nut, so will need to do something after the event :o )
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Re: ASK13 1/3 Scale

Posted: 31 Dec 2020, 12:11
by Bovin
It is going to get a big glider! Nice build! The kit looks very sophisticated :).

Vincent

Re: ASK13 1/3 Scale

Posted: 31 Dec 2020, 12:12
by Peter Balcombe
Tow release servo plate
Tow release servo plate
Last few bits of main structure now added, including rear longeron sections, wing root skin supports etc., plus removeable tow release servo plate now secured with screws.
With the tailplane seat now complete, I trial fitted the stabiliser together with elevators & rudder structures taped on - just for fun ;)
Root skin support
Root skin support
With the basic fuselage structure now more or less complete, this will now be put to one side whilst a start is made on the wings.
Root skin support
Root skin support
Tow release servo plate
Tow release servo plate
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Rear spine joint doubler
Rear spine joint doubler

Re: ASK13 1/3 Scale

Posted: 06 Jan 2021, 20:09
by Peter Balcombe
On with the wing ....
Once the 1st pair of main spars spliced up from 1/2 x 1/4” Spruce strip to make the full 2.5m length, these should be tapered on the front edges from about inboard end of the aileron to give 1/4” Sq. at the tip (as detailed on the drawing detail sketch).
In parallel, the 2 main spar web pieces are joined & then the lower spar glued to the front of the web, aligned with the spar lower edge.
It is worth checking that the ribs can be slid onto the spar web/lower spar before using any glue as I find that the slots on both need to be cleaned up to remove cutting char deposits & also angle the rib slots a little to allow these to take up the required non-90 degree angle to the spar.
With the spar assembly positioned over the plan, the ribs can be glued in place, using the building tabs on most ribs & bottom of spar web, it is easy to check everything is seated & the ribs are angled correctly. Addition of the false leading edge sections allow the individual rib angles to be set up nicely.
Note that in common with most large printed plans, the CNC cut parts are of slightly different size, so the plan is used for information & a guide to the arrangement, rather than a precise mirror.
I tend to start by the fitting a few ribs to set the basic structure shape & then fill in spaces with the remaining ribs.
Note that all ribs can be dropped in from the top - although you need to remember to fit the servo plates between two pairs of ribs as they are fitted!
So far, I have fitted most of the centre section ribs as shown below.
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Re: ASK13 1/3 Scale

Posted: 07 Jan 2021, 01:38
by Jilles
Some comments on Peter's remarks on slots and drawings
Ply is manufactured with a tolerance like any other manufactured item e.g. 1.5mm ply can be between 1.4-1.6mm When 1.5mm ply is specified I make in general 1.6mm slots in the nc parts. Sometimes parts meet under an angle and the slots needs to be even wider. There are NC cutters that can be programmed to cut bevels etc but would be very expensive.
In principle I do not make the slots wider for angled parts but leave it to the builder to adjust. than there will be a neat fit, making the slots wider to fit the angled part could result in a sloppy fit.
Printed large drawings on paper are a pain. They shrink or expand due to temperature and moisture. When you print the LH and RH wing they both are the same but you build one wing first and start the other 2 weeks later there will be a difference. There is the option to print on a polyester type of print media but at a price. Another advantage is that glue will not stick to it. The material is transparent so you can use both sides of the same wing drawing for LH and RH wing.
In the past when drawings were printed on a drum from a transparent original the paper print was on the outside of the drum making the print 3mm longer per meter than the original.

Cheers

Jilles

Re: ASK13 1/3 Scale

Posted: 08 Jan 2021, 10:39
by Peter Balcombe
Thanks Jilles.
All of the ribs have now been fitted to the initial structure, plus the top aileron hinge spars & facing and the top brake box area support spars.
Adding the root end ribs needs a bit more care as although the building tabs give a vertical reference & the nose tabs define the location on the false LE, the drawing/measurement has to be used to used to ensure ribs remain parallel to the others as there is no notched spar web inboard of R6. However, the rib notches for the drag spar can be used as an alignment check as you go.
Note that the root rib is set at the dihedral angle of 4.5 degrees as shown in the plan detail sketch. Small tapered ply spar web pieces (W13) are provided to fit between R1 & R2 so these can be initially used as gauges when adding the root rib R1.
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Re: ASK13 1/3 Scale

Posted: 08 Jan 2021, 11:14
by RobbieB
Jilles wrote: 07 Jan 2021, 01:38
'....................Printed large drawings on paper are a pain. They shrink or expand due to temperature and moisture. When you print the LH and RH wing they both are the same but you build one wing first and start the other 2 weeks later there will be a difference........'

One of the reasons I build large wings like this:

IMG_0010.JPG

Not quick but no errors.

Re: ASK13 1/3 Scale

Posted: 09 Jan 2021, 11:54
by Peter Balcombe
With the top drag spar in place, the remaining root spars can be cut & epoxied into place.
Then, when the top has been completed, the wing is briefly turned over to fit the lower drag spar - again fixing with epoxy.
Once the epoxy has cured, the wing will be turned back to sit on its building tabs whilst the drag spar web pieces are attached.
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Re: ASK13 1/3 Scale

Posted: 09 Jan 2021, 18:58
by Keith
Peter why are you using so much epoxy, when pva is fine?

Re: ASK13 1/3 Scale

Posted: 09 Jan 2021, 19:09
by Peter Balcombe
Keith,
I’m only using it on the root spar system & joiner tube joints for maximum strength in these higher stress areas.
Only other place I tend to use it is when splicing spars - for same reason.
I use Aliphatic glue everywhere else for wood joints (because it sands nicely if required) & white PVA for applying ply skins using the ‘ironing’ method.
Peter

Re: ASK13 1/3 Scale

Posted: 10 Jan 2021, 06:51
by Jilles
For my PVA is a no no to structural items, Like Peter epoxy and Aliphatic glue is what I use and PVA only for planking to be able to use the iron on method. Aliphatic glue also sets faster so you can go on with the project. PVA is not moisture proof and will let go in time. Not a problem for indoor projects but I live near Brisbane Australia, most of the time hot and humid. From experience the UK is not that dry either. I intend to fly my gliders for a long time. PVA also stays a bit rubbery what is not handy with sanding
Here we can get a special PVA for exterior use that may be more moist resistant. I tried this once but it does not work so well with the Iron on planking method.

Cheers

Jilles

Re: ASK13 1/3 Scale

Posted: 10 Jan 2021, 09:47
by Trevor
Whilst I too am a fan of Aliphatic glues, mainly for their superior sanding qualities, I'm also very happy to use PVA for internal joints. As for its longevity, I have several models over 30 years old, all built using PVA, and the glue joints still seem pretty sound to me. I've had at least three PVA-built models take serious duckings at some stage or other. They've all dried out perfectly well without falling apart.

That said, if I'm building a model nowadays which is intended to fly off water, I'll usually use a water resistant Aliphatic in preference!

Re: ASK13 1/3 Scale

Posted: 10 Jan 2021, 10:37
by Keith
Ok thanks for the replys guys.

Re: ASK13 1/3 Scale

Posted: 11 Jan 2021, 19:48
by Peter Balcombe
The wing structure is more or less complete now apart from the TE and brakes.
The drawing shows a balsa core TE which is sanded to profile & capped with 0.4mm ply skins.
However, I am going to try an alternative approach of using a ply core as the jam in a balsa sandwich. This will give a hard (& hopefully straight) TE.
So.. currently I am making up a 2.5m long TE strip, ready to notch to accept the ribs.

Meanwhile, I have started on the airbrakes which are standard top & bottom Schemp Hirth types, installed in two brake box sides glued directly to the wing ribs. The plan shows the brakes being actuated in the normal way via a pushrod from a nearby servo, but Cliff is developing a ‘direct drive’ arrangement which I will be trialing on this build.
The brass brake arms are replaced by 3D printed alternatives, but the twist is that one of them has a square drive shaft connection to a close coupled servo who’s shaft is on the same rotational axis.
All this should become clearer over the next couple of days, but in the meantime, I have assembled the 1st pair of blades and fitted the 3D printed arms with bushes & checked they all have the same centres etc.
You should be able to see the square drive shaft in one of the photos below. This rotates nicely in a 5mm brass tube.
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Re: ASK13 1/3 Scale

Posted: 13 Jan 2021, 19:28
by Peter Balcombe
As there is no airbrake box structure as such on this design (front & rear faces only mounted directly to rib notches in the brake aperture) I decided to check out the brake operation in a standalone box assembly before committing to wing installation.
Thus I made a simple Liteply box with the same internal dimensions as the final brake blade aperture & same pivot hole centres. The box was stiffened by edgewise strips of liteply along top & bottom edges of front & rear face.
I also fitted the four 3/4” x 3/16” vertical stiffeners - one at each main pivot hole on each side.
I fitted 5mm brass tubes in the arm centre holes in order to bush the 1/8” square brass drive tube at one end & 4mm pivot pin at the other (3/16” tubes used normally, so not much different.
I also fitted short 5mm bearing tubes in the box walls at the driven end to act as bearings for the square tube.
The blade fitting were 5/32” tube& 1/8” rod as per drawing.
The pics below show the LH box fitted with blades from both front & rear.
At the driven end, the 1/8” drive tube is fitted with a compatible servo-like disc, which can then be driven from any servo/arm using a simple twin peg coupling.
A small servo is mounted so that it’s shaft/servo disc axis is on the brake arm/coupling disc centre.
The servo is a K&S PDI-HV0903MG which has 2Kg torque at 6v, 2.6Kg at 7.4v.
I tested using a 5 cell NiMn pack.
Hopefully, Cliff will be able to put up a video clip of the brakes driven from a servo tester in cyclic mode.

I’ve also fitted a section of my sandwich TE strip to the outer wing section. (I had forgotten the taper break at the inboard end of the aileron, so could have made the TE unit in 2 shorter pieces) 😏
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Re: ASK13 1/3 Scale

Posted: 13 Jan 2021, 20:09
by Cliff Evans
Here is the video of said air brakes.


Re: ASK13 1/3 Scale

Posted: 13 Jan 2021, 20:52
by SedB
That runs very smooth by the looks of it! Nice to see how i's constructed, thanks for sharing!!

Dan

Re: ASK13 1/3 Scale

Posted: 14 Jan 2021, 00:44
by Cliff Evans
3d printed arms and drive wheel.

Re: ASK13 1/3 Scale

Posted: 14 Jan 2021, 10:12
by Keith
That would save some time a effort, some pre assembly pics would be helpfull.

Re: ASK13 1/3 Scale

Posted: 14 Jan 2021, 11:58
by Peter Balcombe
Which bits do you mean Keith?
The blade units or assembly to arms etc?
Peter

Re: ASK13 1/3 Scale

Posted: 14 Jan 2021, 12:16
by tjarko
Very neat solution.
With a strong servo with good ball bearings, the brake arm might be directly bolted to the servo arm even.
This avoids the need for carefull alignment of servo and brake axes.

Re: ASK13 1/3 Scale

Posted: 14 Jan 2021, 12:36
by Peter Balcombe
Hi Tjarko,
The drive pivot square tube/axle needs to be accurately located in order to allow the 2 arms to rotate smoothly as will cause extra friction or binding to occur at some point during rotation as is the case for any Schemp-Hirth brake setup.
I have used a peg & slot coupling between the servo disc & the square tube drive disc to achieve a degree of flexibility in the coupling, so the servo just needs to be notionally centred.
I just connected the discs before marking & drilling small starter holes for the servo screws, then screwing the servo into place.
Peter

Re: ASK13 1/3 Scale

Posted: 14 Jan 2021, 12:50
by Keith
Hi Peter, the arms and drive assy.

Re: ASK13 1/3 Scale

Posted: 14 Jan 2021, 13:28
by Cliff Evans
3d printed drive arm for ASK-13 air brake
3d printed drive arm for ASK-13 air brake
3d Printed servo coupling for ASK-13 air brake
3d Printed servo coupling for ASK-13 air brake

Re: ASK13 1/3 Scale

Posted: 14 Jan 2021, 14:22
by Peter Balcombe
Ok Keith, hopefully the following will do the job:

One pic below shows the blade parts (with internal ply spacer discs fitted, plus the 3D printed arms (with 5/32” bearing tube fitted at blade pivots & 5mm brass tube fitted at non-driven centre pivot - driven arm has a 1/8” square drive slot included in the printed part) for the as yet unbuilt RH brake assembly. 1st pic also shows the 3D printed drive disc + servo & std output arm fitted with 2 screw pegs for drive coupling to the 3D printed drive disc.

The other pics show back & front of the LH brake assembly installed in the test brake box, with & without the servo in position.

As per the standard plan arrangement, the blades are attached to the arms using 1/8” brass pins & then held in place with dabs of epoxy on the outside.
The non driven arm rotates on a fixed 4mm pin (could be secured on final installation with dabs of epoxy).

A short length of 1/8” brass tube is secured into the 3D printed disc at one end & pushed through driven arm via short 5mm O.D. brass bearing tubes epoxied into each side of the brake box wall. (The 1/8” Sq. brass tube runs nicely in the 5mm tube bearings).

If the square drive tube is fixed into the drive disc, then it cannot go anywhere as the servo stops it going one way & the brake box, the other.
The separate servo/drive discs arrangement allows any servo to be coupled to the square drive, rather than having to print correctly splined/fine detail drive discs for each servo option.

(The standard plan arrangement uses brass sheet arms with 3/16” & 5/32” brass tubes for main pivot & blade pivots respectively - everything being soldered together to ensure perfect alignment before separation into the bushed arms.
The pins are then 5/32” & 1/8” respectively for main & blade pivots)
1/8” square brass tube is slightly too big across the external diagonal to fit in a 3/16” (4.76mm) tube, hence the move to 5mm tube & 4mm pivot pin for this direct drive option.
Forward side of box
Forward side of box
Rear side with servo
Rear side with servo
Rear side showing drive disc
Rear side showing drive disc
Set of CNC & 3D printed parts
Set of CNC & 3D printed parts

Re: ASK13 1/3 Scale

Posted: 14 Jan 2021, 14:33
by Keith
Thanks Peter, i have the same setup on my Jaskolka a mate has made me some 3d arms and i have made new moulded blades, (ill post pictures soon) i like the drive system and will try and incorporate it in my Jaskolka. Nice build of a nice kit from Cliff.

Keith

Re: ASK13 1/3 Scale

Posted: 14 Jan 2021, 20:39
by Peter Balcombe
Ok, getting ready to fit the brake blade assembly into the 1st wing .....
As there is very little room between the front 0.8mm brake box side & the main spar web, I decided to fit the 2 vertical main pivot support strips, drill through to the correct size for my installation (5mm & 4mm) & dry fit the 5mm driven end bearing tubes before fitting the brake box sides. Note that the support strips are not full width as they go between the 1/8” wing surface spars.
I couldn’t see how I was otherwise going to be able to accurately drill the holes through the support strips once in the wing!
I can now at least tweak the holes in situ if needed once hole alignment is checked, before fixing the tubes in place.

One pic below shows the rear box side with the support strips in place, drilled & tube in place, whilst the other shows the front side clamped in position in the wing.

Note that it is imperative that the 0.8mm sides sit cleanly onto the rib tabs, else the resultant gap to accept the blade assembly will be smaller than expected!
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Re: ASK13 1/3 Scale

Posted: 15 Jan 2021, 14:53
by Peter Balcombe
The first airbrake is now installed in the wing & operational :)

As expected, the resultant space between the two brake box faces produces a rather neat fit for the blade assemblies.
I ended up shaving a little off of the arm pivot bosses in order to get them to slide in (11.5mm).
However, the axles lined up nicely & the arms rotate well - at least until the blades start going into the box when there is a little bit of rubbing due to the blades being not exactly central/perfectly straight & the gap being only 2mm larger than the nominal blade width.
This area will need a little attention later, but is basically ok.
Note that I needed to re-position the servo with long axis parallel to the wing surface to keep the support plate edges under the wing surface.
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Re: ASK13 1/3 Scale

Posted: 17 Jan 2021, 21:27
by jack
very nice work peter,l am about to take delivery of a k-13 kit from cliff....,will post a build blog as l go,the brake set up is a neat addition,....l have his petrel finished and ready for paint,just cant get it to him :evil: ,the k-13 looks to be a good deal bigger though ;) ;)

Re: ASK13 1/3 Scale

Posted: 17 Jan 2021, 22:51
by Peter Balcombe
Hi Jack,
Yes you will need a bench that is 2.5m or so long for both the fuselage structure (without rudder) & each wing.

I’ve now put together the basic structure on each part except for the RH wing. Everything seems to fit nicely & the design seems well thought out.
You just need to be very careful to get the brake blades nice & straight in the vertical plane as I’ve found on the 2nd brake assembly build. If the 2 sets of blades do not come together nicely in line, the bottom of at least one blade will hit the outside edge of the box! ( I’ve just taken apart & re-assembled one assembly because the non-driven pivot arm was slightly off square ;)

The root end handful of ribs are only registered by notches in the false leading edge (rather than also by the main spar web), so you need to position these carefully to ensure the root rib is at right angles to the joiner tubes.

Happy building,
Peter

Re: ASK13 1/3 Scale

Posted: 19 Jan 2021, 11:02
by Peter Balcombe
A little more done on the fuselage.
I had forgotten to add the rear fuselage internal. Cross bracing between formers F13 &. F18, so this has been done. Note that this goes as the waist stringer (S2) level. Together with the upper CNC ply plate & the upper fuselage skin, this forms a strong box structure to resist rear end flex.

Fuselage servos now fitted (rudder horn length to be extended) & tow release.
Meanwhile, the main joiner tube & rear incidence pin tubes have been installed.
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Re: ASK13 1/3 Scale

Posted: 24 Jan 2021, 10:46
by Peter Balcombe
A little bit more progress in that I have fitted small plates in the rear fuselage to support the rudder C/L guide tube exits.
I have also fitted a removeable shelf above the tow release servo to carry a brace of batteries in due course.
The plate sits on a pair of cross-rails & is secured by sliding into a slot at the front & a couple of easily accessible screws at the rear.

0.6m ply skins have been cut for the upper nose section & forward turtledeck section, so they should once I have added some balsa glueing doublers to the front of the canopy hoop.
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Re: ASK13 1/3 Scale

Posted: 24 Jan 2021, 17:06
by Peter Balcombe
Jilles’ detailed aerotow release assembly now fabricated less the rear retaining pin.
Pics below show the main tube & crosspin, plus internal carrier for actuation pin.
Front view of assembled unit also shown. Tow loop is directed by angled wedge up behind crosspin where the actuation rod comes forward to go through loop, trapping it between actuation pin & cross-pin.

The release will be fitted later once I have the nose cone to hand & forward fuselage skins fitted.
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Re: ASK13 1/3 Scale

Posted: 26 Jan 2021, 15:54
by Peter Balcombe
A start has been made on the upper fuselage skins using the recommended 0.6mm ply.
The slightly thicker ply is a fair bit tougher than the 0.4mm ply I’ve been used to, but is more picky about going around complex curvature.
As a result, I’ve had to do the upper nose section in 2 pieces & the forward part of the turtle-deck has split into 3 pieces over the wing root length. However, it looks as if I might be able to use larger pieces further aft.
I’m using the white PVA glue & hot iron technique.
The nose section has just had PVA applied to both sides of the joint, so I’m waiting for that to dry before starting the ironing bit to re-activate the glue with the ply in position.
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Re: ASK13 1/3 Scale

Posted: 26 Jan 2021, 17:49
by Peter Balcombe
And with the first bits done, rapid progress has been made to complete the upper left side skinning up to the wing TE.
On the flat sections, I used PVA, but have clamped them together wet. (Gives the option to use iron later if needed).
Right hand side under canopy frame & around wing root to do next, then completion of the rear fuselage :)
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Re: ASK13 1/3 Scale

Posted: 28 Jan 2021, 17:18
by Peter Balcombe
Upper fuselage skinning just about done - only rearmost fuselage side piece to do on RHS, plus pieces above tailskid.
With the upper skins virtually in place, the fuselage former building stand extensions can be removed.

You will see that in the end, i skinned in single former space sections on all curved areas (apart from the bit near the wing root, which I suggest others do in 2 sections) ;)
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Re: ASK13 1/3 Scale

Posted: 30 Jan 2021, 11:50
by Peter Balcombe
Upper fuselage skinning now complete, fin skinned and rudder C/L tubes epoxied in place, with wire outlet cleared.
Just the skin panel joints & fin LE to tidy up with a little bit of filler & that area is completely done.

Skinning the fin with the 0.4mm ply (as on the plan) was much easier than using the 0.6mm as used for the rest of the fuselage. I used one panel on each side of the fin (remembering to leave the small rear overhang for rudder hinge shroud) after putting a balsa doubler strip around the lower side of fin rib FR2 (to provide support for the front part of the skin LE as it curves in below that rib).
The fin skin could be pulled in around the faired off balsa LE infill, leaving just a small gap to fill at the LE once excess skin had been removed. I didn’t try wrapping the skin around the LE, except for the section below FR2 (which worked well).
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Re: ASK13 1/3 Scale

Posted: 30 Jan 2021, 12:50
by Bovin
Hi Peter,

Its looking good!
About the ply, there are strange differences, I had 0.4mm ply which was quite brittle and 0.6 which was more manageble. A German member of Retroplane had just the opposite, like you. It looks like there are differences in the fabrication of ply,

Vincent

Re: ASK13 1/3 Scale

Posted: 30 Jan 2021, 13:46
by Peter Balcombe
Vincent,
It probably depends on the orientation of the wood grain in each of the ply layers.
Usually our ply will happily bend in one direction, but less so in the other.
On curved areas, I therefore arrange the ply to bend easily over the curved surface, but when the surface curves in both directions, you usually have to reduce the width of the strip to cope with the amount of bend available.
Wetting the ply surface & then applying with a hot iron (to re-activate the glue) after letting PVA applied to both surfaces dry, gives a degree of steam bending as the piece is fixed.

Re: ASK13 1/3 Scale

Posted: 30 Jan 2021, 15:25
by Bovin
Hi Peter,

Thanks for your answer, but I like to explain what happened; most 0.6 mm I could bent with boiling water to a radius of 2-3mm, I am always astonished that it works,
IMG_1156.JPG


but I had some 0.4mm ply that cracked and delaminated when bending with boiling water. that why I mentioned it.

Vincent
IMG_1156.JPG

Re: ASK13 1/3 Scale

Posted: 30 Jan 2021, 16:18
by Peter Balcombe
Hi Vincent,
That makes more sense as small differences in the ply can probably make the difference between success & failure when dealing with tight curves such as you describe.

Re: ASK13 1/3 Scale

Posted: 30 Jan 2021, 17:50
by patte de loup
Herewith some pics of the ASK 13 which is located in Strasbourg ( East of France )
BTW , Thanks Cliff for your support ;)
Pat'
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Re: ASK13 1/3 Scale

Posted: 30 Jan 2021, 17:54
by patte de loup
And the 2 last ;)
Pat'
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Re: ASK13 1/3 Scale

Posted: 30 Jan 2021, 20:32
by Peter Balcombe
Many thanks for the pictures Pat.
They will be a great help in the cockpit area detailing. :)
Peter

Re: ASK13 1/3 Scale

Posted: 01 Feb 2021, 18:53
by Peter Balcombe
This build is based on a full size which has both nose wheel and tail wheel, so having built the forward fuselage using the required parts for the nose wheel option, it is time to turn my attention to modifying the rear end to take a tailwheel.

During my research for this (with many thanks to GeeWee & Lez Saker) I have discovered that the bottom of the finpost on the full size doesn’t taper as much as on the plan, where Jilles has simplified matters a little to provide a 12mm wide solid skid built into the rear keel - tapering the bottom of the finpost to suit.
However, if you wish to modify for a sprung skid or tailwheel, then the following might be of interest.

The base of the finpost on the full size is more like 85mm, so just under 29mm @ 1/3 scale.
The full size tubular framework at the keel is a single tube moving towards the rear from the mainwheel area until below the forward part of the fin, where it then splits into 2 tubes, each going back to opposite sides of the finpost base.
On gliders fitted with sprung skids, the skid is then attached to the bottom of the fuselage framework.
On gliders fitted with a wheel, the 2 tubes are replaced by a “tuning fork” type arrangement, with the tailwheel axle attached to the bottom of the “prongs” of the fork.
One image below shows a glider on tow, with the lower rear fabric “bulge” around the wheel aperture. Another shows the exposed tubular framework on a damaged glider - showing the “tuning fork” framework around the wheel.

I’ve currently cut out the rearmost keel section on my build & added a couple of “cheeks” to the bottom section of the finpost to reduce the taper to give 30mm width at the base. The intention is to insert a replacement ply keel assembly whose shape simulates the “tuning fork arrangement” onto which the wheel axle can be attached.
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Re: ASK13 1/3 Scale

Posted: 03 Feb 2021, 21:47
by Peter Balcombe
A new lower rear fuselage section has been fitted which transititions from the 4mm ply keel member to the widened (30mm) finpost base as shown below - trying to emulate the ‘tuning fork’ like shape of the framework on the full size a/c.
This plate is made from 3 layers of 1/8” ply & the centre of the wheel aperture is braced back to the upper fuselage longeron using 1/8” ply. The aperture is sized fora 70x23mm wheel which is virtually spot on 1/3 scale for the full size 210x65mm.
The edges of the plate have been faced with balsa & profiled to give a better gluing area for the skin panel to be fixed once the wheel fit has been checked & the axle plates fitted.

The wheel will be mounted on brass 2 axle plates yet to be made, slightly recessed & bonded to the sides of the ply plate, so that the plate replicates the full size external appearance as much as possible.
The wheel attachment appears to be a large bolt on the full size - at least from the pic below, although I’m sure there will be a locking device.

This lower section of the fuselage is fabric covered on the a/c in the picture, but I will probably skin the model with 0.4mm ply rather than 0.6mm to deal with the complex curvature at the forward end whilst still giving a smooth surface.
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Re: ASK13 1/3 Scale

Posted: 05 Feb 2021, 11:32
by Peter Balcombe
Thanks to input from GeeWee & Lez Saker at the Mendip Giding club, I’ve managed to find the attached info about the rear skid installation.
The skid is a simple length of approx. 20mm steel angle/sq. tube, bolted via flexible mount to the lower fuselage at the front & via a rubber shock mount, bolted to the lower fuselage at the back. A replaceable wear shoe is welded to the rear end. The rear shock out may be about 50mm wide & 100mm or so diameter (but see pics below).
The overall skid assembly is often covered in (to keep out field muck) using a vinyl type material, maybe secured to the skid by bindings through small holes in the skid.

The photos below show a couple views of a skid & rubber mount when removed from the a/c, plus a sketch showing some dimensions of the full size arrangements: wheel version at top & skid version beneath.
Note that sizes on the sketch are a 1:1 scale.

I hope this is useful to anyone looking to make either revision to the standard plan design.
Peter
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Re: ASK13 1/3 Scale

Posted: 06 Feb 2021, 09:09
by Jilles
well this is one option, probably a local retrofit/invention like front and tail wheels
The original skids on the K4 up to K13 Schleicher models were a spoon type structure from spring steel, bolted straight to the fuse, the spoon under the rudder no rubber in sight

Re: ASK13 1/3 Scale

Posted: 06 Feb 2021, 09:12
by Jilles
hard to find pictures of skids on the internet but attached should give some idea what I meant in previous post

Re: ASK13 1/3 Scale

Posted: 07 Feb 2021, 20:54
by Cliff Evans
3d print of tailskid rubber. Printed using ninjaflex which is a flexable rubber type filament. You can print so that it is really squishy or make it as hard as neccesary to emulate the real thing. Thus has been printed so that it emulates the real thing.
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Re: ASK13 1/3 Scale

Posted: 08 Feb 2021, 09:38
by catwok
Nice bit of detailing Cliff... Are they available to buy and do you make them in all sizes?

Re: ASK13 1/3 Scale

Posted: 08 Feb 2021, 09:41
by Cliff Evans
I am only limited by the size of the printing bed, what scale do you require?

Re: ASK13 1/3 Scale

Posted: 08 Feb 2021, 10:21
by catwok
33% and 40% if possible :D

Re: ASK13 1/3 Scale

Posted: 22 Feb 2021, 19:48
by Peter Balcombe
Picture of the previously featured full size tailskid parts re-assembled back onto the glider after refurbishment.
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Re: ASK13 1/3 Scale

Posted: 26 Feb 2021, 14:05
by Peter Balcombe
With a bit of sunny weather upon us & the 2nd wing structure now at the same build state as the 1st, it’s time for a trial assembly ;)
Next job is to prepare the balsa spar caps & False LE for applying the top skin.
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Re: ASK13 1/3 Scale

Posted: 26 Feb 2021, 14:34
by Barry_Cole
Brian will be after you about that grass!!! :shock: :shock: :shock: :shock:

BC

Re: ASK13 1/3 Scale

Posted: 26 Feb 2021, 15:56
by Peter Balcombe
Barry_Cole wrote: 26 Feb 2021, 14:34 Brian will be after you about that grass!!! :shock: :shock: :shock: :shock:

BC
You should have seen it before I cut it :lol: :lol:

Re: ASK13 1/3 Scale

Posted: 26 Feb 2021, 17:02
by Max Wright
It's a beautiful thing, Peter.

Almost a shame to cover all that lovely work. 8-)

Re: ASK13 1/3 Scale

Posted: 27 Feb 2021, 08:58
by B Sharp
The grass is Ok Peter. Keep the cut hight high for the first cut, a quick scarrify and a spring feed to finish!
The aeroplane is not looking too shabby either.
Brian. :D

Re: ASK13 1/3 Scale

Posted: 07 Mar 2021, 17:34
by Peter Balcombe
A metal bashing day today ;)
All horns, wing retainer clips, brass tailwheel support plates plus first of the main wheel support plates made, so just the 2nd mainwheel plate & front wheel plate (as indicated by the paper templates) left to do tomorrow.
(The tailwheel plates are my design & I decided to use 1mm Brass rather than Aluminium in order to get strength from thinner plate as these will be attached to outside of the wheel box framework as per the full size. With 0.6mm ply fuselage skins, only the very bottom parts should be visible. (On the full size, the wheel brackets are welded to the outside of the tubular framework which is fabric covered as shown below).
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Re: ASK13 1/3 Scale

Posted: 09 Mar 2021, 12:43
by Peter Balcombe
All 3 wheel axle supports now fitted & wheels checked for fit.
The nose wheel is a 3.5” Dubro mounted on a 4mm axle, the mainwheel is a 110mm FEMA mounted on a 6mm axle & the tailwheel is 67mm, mounted using a M3 hex headed bolt.
The tailwheel brackets are sandwiched between the 1/8” ply plates visible in the photo & the 0.8mm external skin yet to be fitted.
Front wheel
Front wheel
Main wheel
Main wheel
Tail wheel
Tail wheel

Re: ASK13 1/3 Scale

Posted: 16 Mar 2021, 09:08
by Peter Balcombe
All 3 wheels now fully installed and the lower fuselage skins fitted.
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Re: ASK13 1/3 Scale

Posted: 21 Mar 2021, 18:15
by Peter Balcombe
Operations have re-commenced on preparing the wings for skinning in the outdoor workshop as a result of the warmer weather, but meanwhile the tail control surfaces have also being prepared for application of the limited skins.
The rudder pinless hinges have been fitted together with internal guide tubes for the long piano wire pin, then the LE fitted & shaped. Rudder C/L horn also fitted & boxed in with block balsa.
The elevator LE strips have also been shaped & the horns epoxied in.

Although Jilles’ plan shows a bottom horn on the elevator trim tab, coupled with trim pushrod attachment to the side of the fuselage under the tailplane, I will revert to a scale upper surface trim horn & try to ensure a similar anti-servo action (tab moving in opposite direction to the elevator).
I have obtained some shots of the trim tab horn & connections on a full size ASK13 based at the Mendip Gliding Club (many thanks Lez), plus a couple of dimensions for the trim tab horn, so watch this space.
Elevator horns fitted
Elevator horns fitted
Rudder hinged
Rudder hinged
Trim tab from root
Trim tab from root
Trim tab horn from top surface
Trim tab horn from top surface
Trim tab pushrod to fuz bellcrank
Trim tab pushrod to fuz bellcrank

Re: ASK13 1/3 Scale

Posted: 21 Mar 2021, 19:02
by GeeW
Anti-servo tab moves the same direction as the control surface....just saying.

Gordon

Re: ASK13 1/3 Scale

Posted: 21 Mar 2021, 19:12
by Peter Balcombe
GeeW wrote: 21 Mar 2021, 19:02 Anti-servo tab moves the same direction as the control surface....just saying.

Gordon
Thanks Gordon,
I meant the other one then :oops:

Re: ASK13 1/3 Scale

Posted: 02 Apr 2021, 13:54
by Peter Balcombe
Despite the recent lack of posts, I’ve been busy prepping & skinning the wings & now have them pretty much done.
The pics below show that one wing is nearly done apart from adding rib cap strips & shaping the LE/tip block, whilst the 2nd isn’t too far behind.
I will fit the LE strips on the 2nd wing today.

Note that the servo cables are routed through the D box, so don’t forget to install these before closing up with the lower skins - I nearly did, but remembered as I was ironing on the outer skin section. I managed to fish a wire through the inner section to save the day ;)
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Re: ASK13 1/3 Scale

Posted: 02 Apr 2021, 20:44
by Max Wright
"Note that the servo cables are routed through the D box, so don’t forget to install these before closing up with the lower skins - I nearly did, but remembered as I was ironing on the outer skin section. I managed to fish a wire through the inner section to save the day ;) "

Thanks, Peter. That makes me feel a lot better. :lol:

It's all looking excellent. 8-)

Re: ASK13 1/3 Scale

Posted: 04 Apr 2021, 19:02
by Peter Balcombe
Mr Murphy said that if you don’t secure the servo leads at the servo end, they will find their way back into the D box when you move the wings to turn them around :lol: :lol:

Re: ASK13 1/3 Scale

Posted: 10 Apr 2021, 12:05
by Peter Balcombe
Wings & tail feathers now fully skinned & just need a bit of preparation (including servo hatch installation) before covering can commence.
Meanwhile, an alternative elevator trim tab has been fitted & the starboard elevator temporarily hinged to try out tab movement. It appears that the tab pushrod effective centreline needs to go on the same side of the elevator hinge line as the tab horn in order to get tab moving in the opposite direction to the elevator. (Hence reason that Jilles has used a bottom horn to get opposition movement)
I will investigate a bit of pushrod kinking to try to achieve the same effect with a top horn - after all the full size manages to achieve it with the tab pushrod attaching to a crank just inside the upper rear fuselage.

Meanwhile, the canopy moulding has arrived! I think I will use it to grow some tomatos :D
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Re: ASK13 1/3 Scale

Posted: 11 Apr 2021, 17:38
by Peter Balcombe
Well, I didn’t use the greenhouse for tomatoes after all.
Today was spent hinging the glazed canopy using the method similar to the full size & as used on my 1/4 scale build.
I solder brass tubes onto pieces of brass plate (tube centreline offset from plate centreline to allow the two mating hinge plates to be recessed into fuselage & canopy frame)
In this case I used 3/32” brass rod, 1/8” OD tube & 0.8mm plate.
The hinges are set at same centres as Jilles’ plan hinges, but they allow the canopy to be slid off towards the nose & easily replaced by the Cabriolet canopy (just like on the full size).
The brass pins will be fixed into the canopy tube side later.
The canopy frame hinge plates are initially fixed with epoxy with the parts aligned, then screwed inserted for added security once the hinge has been opened up. These screws are visible in the hinge close-up shot.

The canopy moulding shown yesterday was also attacked with a disc cutter to remove the curved moulding from the vac formed sheet surround. (The removed moulded canopy thickness varies between 0.035” & 0.055” as measured near the edges in a few places by my trusty micrometer. It was nearer 0.062” at the edges of the surrounding sheet - hence the cutting disc ;) )

With the canopy frame sat inside the moulding, it is clear that there is still plenty of ‘meat’ to trim off all round.
(Note that the moulding still has protective film in place on both sides.)
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Re: ASK13 1/3 Scale

Posted: 16 Apr 2021, 21:16
by Peter Balcombe
Canopy locking mechanism fitted as used on 1/4 scale version and similar to that used on the full size.
2 photos show rear & front locks.
A single 16g rod slides in the fuselage mounted (LH) tube, engaging in the canopy (RH) tubes with forward travel.
Not shown in forward area photo is an additional tube connected to an external release tab which passes through a slot in the bottom of the canopy frame. This tube is fixed to the rod just aft of the forward catch.
Rear canopy catch
Rear canopy catch
Front canopy catch
Front canopy catch
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Re: ASK13 1/3 Scale

Posted: 18 Apr 2021, 13:00
by Peter Balcombe
Canopy moulding now cut to shape in a couple of steps, principally due to the moulding thickness which made cutting with my large scissors or scalpel a no-no until the trimming stage.
First a rough cut around the canopy frame with a disc cutter, then a closer cut using a fine tipped soldering iron as a hot knife got me to the final trimming stage.

As you can see, I have replaced the central ply canopy cross member with a 4mm carbon rod which is a lot narrower and closer to the front of the rear cockpit instrument panel binnacle (as on full size). The rear cross members will get the same treatment & I will also fit an 1/8” doubler to the top edge of the frame to increase moulding gluing area along the sides.
The finished frame will be painted prior to attaching the moulding.

Note that thecanopy i moulded with a translucent protective film on the inside surface & a clear film on the outside.
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Re: ASK13 1/3 Scale

Posted: 18 Apr 2021, 22:56
by Max Wright
That canopy is looking great, Peter. 8-)

Re: ASK13 1/3 Scale

Posted: 19 Apr 2021, 14:46
by patte de loup
great master piece , not easy to make ;)
Pat'

Re: ASK13 1/3 Scale

Posted: 20 Apr 2021, 15:08
by Peter Balcombe
Once cut to shape & with centreline reference marks (masking tape) on front & rear of fuselage & canopy moulding the canopy went on without a problem - just hold the sides of the canopy away from the glue until front & back centres are correctly aligned.
Pleased with the result - just a little final trimming to do.
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Re: ASK13 1/3 Scale

Posted: 20 Apr 2021, 21:32
by catwok
Really nice Pete, I picked mine up from Jack at the weekend and can't wait to do the finishing bits and pieces.

Re: ASK13 1/3 Scale

Posted: 21 Apr 2021, 13:05
by Peter Balcombe
Trial assembly today for a rough balance check to see how much church roof can be squirrelled away in the reinforced nose cone.
I reckon that I can safely put 1.5-2Kg up front, so time to make some lead block to epoxy into place.
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Re: ASK13 1/3 Scale

Posted: 22 Apr 2021, 12:44
by Bovin
Really nice canopy, no distorsions, if I am using the right terms for that.

Vincent

Re: ASK13 1/3 Scale

Posted: 24 Apr 2021, 20:22
by Peter Balcombe
Many thanks from your nice comment Vincent.

Meanwhile, the often stressful task of cutting the clear view screen apertures & fitting the screens using 3D printed runners has been greatly eased by using a cutting template which can now be supplied by Cliff.
The template can be temporarily clipped to the canopy frame & the holes cut using a sharp scalpel without the usual need for very careful measurement.
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Re: ASK13 1/3 Scale

Posted: 01 May 2021, 21:30
by Peter Balcombe
The model is currently being covered in Ceconite using dope as the adhesive.
This works well if the material is laid on as smooth as possible, then tacked around the perimeter with dope before gently taking out any wrinkles/bubbles with gentle iron heat & securing all wood supported areas. Then shrink open areas to taste & seal the weave with dope.
You may need to go over areas several times with the iron as the material does relax a bit as it cools down.
All parts except the ailerons & one side of the fuselage are currently covered, so hopefully, I can assemble for some pre-paintshop shots in a couple of days (when I can find a dry & relatively calm day next week!).

However, it’s worth noting that whilst getting close up & personal with the 0.4mm ply skins used on parts of the model (fin, tailplane & wings) it is apparent that although the skins went on ok, there are areas where they have taken up a less than smooth profile, with a few small hollows now evident
This is most noticable on the top half of the fin (where I have filled the worst of the skin hollows) and on a couple of wing D box rib bays.
I suspect the largish rib spacing & thin ply skin, coupled with compound curves has come into play in these areas, so builders may want to consider adding extra internal support such as riblets, else lightwieght foam inserts cut to profile using a small Hotwire cutter across pairs of normal ribs.

Re: ASK13 1/3 Scale

Posted: 05 May 2021, 14:33
by Peter Balcombe
The airframe is now covered, with all control surfaces hinged.
It’s now over to Cliff for the paint shop activities.
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Re: ASK13 1/3 Scale

Posted: 06 May 2021, 09:13
by IanT-White
Peter , really impressed with your model , re light weight Ceconite , used it on several models .
John Rickett passed on a good tip and that was to apply a coat of the thinned Super Seam cement ( from LAS Aerospace) to the outline and under cambered part of the ribs and let it dry.
Drape on the Ceconite and reactivate the cement with a brush and the Super Seam thinners ( MEK ) brushed thru the fabric , best wear gloves as you press it down .
This gives a good "grip" and once the fabric is stuck down you can apply a thinned coat of the cement to the outline , again thru the fabric and let it dry before doping the model .
Re your wrinkles !! , or should I say the wrinkles on your model ( only joking ) I was disappointed to see wrinkles in the 0.8mm ply covering on a scale power model , I had used some ply that I bought quite some time ago and it was probably "wavy" before I applied it .
John Rickett is my inspector for the C.A.A. over 25 kg models and during an inspection of the model , when I mentioned the wrinkles , he said congratulations , just like a full size aircraft !
Best regards Ian Turney-White

Re: ASK13 1/3 Scale

Posted: 06 May 2021, 11:00
by Peter Balcombe
Hi Ian,
I originally tried the LAS Super Seam Cement on the first couple of models I covered with Ceconite, but found it a real pain to use as it dries in a matter of seconds. However, your tip of just applying an initial border, letting it dry & re-activating sounds as if that would be a good way.

I think that I might have been John Greenfield that suggested using dope & that works very well, allowing any sagging areas to be gently shrunk to tauhten before applying dope there.
Peter

Re: ASK13 1/3 Scale

Posted: 06 May 2021, 11:47
by IanT-White
Peter , its often best to use the method that suits you , one of the things I found , was that the Super Seam cement worked best when well thinned.
As you say John Greenfield successfully uses dope ( mainly on Diatex ) .
Personally I found that the Super Seam cement gave a stronger bond , but its what ever "floats your boat " !!!
Best regards Ian Turney-White

Re: ASK13 1/3 Scale

Posted: 06 May 2021, 11:56
by Barry_Cole
IanT-White wrote: 06 May 2021, 11:47 But its what ever "floats your boat " !!!
Or maybe whatever flies your glider...

:lol: 8-) :lol: 8-)

BC

Re: ASK13 1/3 Scale

Posted: 06 May 2021, 12:29
by IanT-White
Wasn't there a flying boat glider ???
Best regards Ian Turney-White

Re: ASK13 1/3 Scale

Posted: 06 May 2021, 12:59
by Cliff Evans
IanT-White wrote: 06 May 2021, 12:29 Wasn't there a flying boat glider ???
Best regards Ian Turney-White
sea adler.jpg

Re: ASK13 1/3 Scale

Posted: 06 May 2021, 16:08
by Barry_Cole
And as if to prove it:-



:lol: :lol: :lol: :lol:

BC

Re: ASK13 1/3 Scale

Posted: 06 May 2021, 17:35
by IanT-White
Superb model, quality of construction something to aspire to .
Ian Turney-White

Re: ASK13 1/3 Scale

Posted: 07 May 2021, 08:14
by john greenfield
I actually use "Balsaloc" to attach the covering as you can just iron the covering on with a low temp iron (not hot enough to shrink the covering but enough to activate the Balsaloc). Once attached I brush dope around the edges and any undercamber to lock the covering to the structure and then start the shrinking process with a hotter iron.

AEB

Re: ASK13 1/3 Scale

Posted: 07 May 2021, 10:37
by Peter Balcombe
Thanks John, that sounds an even better way to get started :)
Peter

Re: ASK13 1/3 Scale

Posted: 07 May 2021, 20:06
by Barry_Cole
john greenfield wrote: 07 May 2021, 08:14 I actually use "Balsaloc" to attach the covering as you can just iron the covering on with a low temp iron (not hot enough to shrink the covering but enough to activate the Balsaloc). Once attached I brush dope around the edges and any undercamber to lock the covering to the structure and then start the shrinking process with a hotter iron.
AEB
How do you get to the under camber, after you have sealed the edges??

:? :? :? :?

BC

Re: ASK13 1/3 Scale

Posted: 07 May 2021, 21:13
by Peter Balcombe
Barry_Cole wrote: 07 May 2021, 20:06
How do you get to the under camber, after you have sealed the edges??

:? :? :? :?

BC
Just leave the covering slack enough to be able to get it to reach the under cambered ribs Barry, then shrink to tighten once secured. :roll:

Re: ASK13 1/3 Scale

Posted: 07 May 2021, 21:58
by Peter Balcombe
Prototype 3D printed seat checked for size.
Improved ones with full scale cutouts to be fitted in due course.
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Re: ASK13 1/3 Scale

Posted: 08 May 2021, 07:59
by john greenfield
Barry_Cole wrote: 07 May 2021, 20:06
john greenfield wrote: 07 May 2021, 08:14 I actually use "Balsaloc" to attach the covering as you can just iron the covering on with a low temp iron (not hot enough to shrink the covering but enough to activate the Balsaloc). Once attached I brush dope around the edges and any undercamber to lock the covering to the structure and then start the shrinking process with a hotter iron.
AEB
How do you get to the under camber, after you have sealed the edges??

:? :? :? :?

BC
I attach to the root and tip first and then starting at mid chord work forwards and backwards attaching it to the undercamber before securing it to the leading and trailing edges !!

Re: ASK13 1/3 Scale

Posted: 16 Jun 2021, 14:00
by Cliff Evans
Paint job coming on!

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Re: ASK13 1/3 Scale

Posted: 15 Jul 2021, 16:05
by Cliff Evans
Paint job done just decals to add.


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Re: ASK13 1/3 Scale

Posted: 15 Jul 2021, 16:43
by StephenB
What a striking model, beautiful job as ever Peter.

Re: ASK13 1/3 Scale

Posted: 15 Jul 2021, 17:58
by Peter Balcombe
Paint job isn’t mine , but nice work anyway :)
Should look even better once the decals are on.
Peter

Re: ASK13 1/3 Scale

Posted: 16 Jul 2021, 15:10
by Cliff Evans
Finished!


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Re: ASK13 1/3 Scale

Posted: 16 Jul 2021, 18:46
by catwok
Beautiful looking model Cliff, mine will only come out after sun set now!

Re: ASK13 1/3 Scale

Posted: 17 Jul 2021, 14:45
by Jus Gordon
Beautiful model, well done Peter & Cliff!

Re: ASK13 1/3 Scale

Posted: 20 Jul 2021, 10:18
by B Sharp
That's a fine job Peter. Well Done!
Brian.

Re: ASK13 1/3 Scale

Posted: 27 Jul 2021, 16:13
by SedB
Gorgeous!!

Daniel

Re: ASK13 1/3 Scale

Posted: 28 Jul 2021, 07:24
by Mike F
Pretty in pink....

Re: ASK13 1/3 Scale

Posted: 07 May 2022, 03:32
by Gordon McLean
Peter Balcombe wrote: 07 May 2021, 21:58 Prototype 3D printed seat checked for size.
Improved ones with full scale cutouts to be fitted in due course.

8CE8CDED-7731-4C40-872F-0249E8993212.jpegDC28E1E8-3C60-4562-ACC8-B8387B36BEB5.jpeg
Hi Peter...I am just getting around to starting my kit...Is there any chance that you may.be printing additional seats?

If so, I would be interested in a set.

Thanks in advance.

Gordon

Re: ASK13 1/3 Scale**

Posted: 07 May 2022, 04:08
by Max Wright
It is very nice, Cliff. 8-)

Re: ASK13 1/3 Scale

Posted: 07 May 2022, 08:44
by Cliff Evans
Gordon McLean wrote: 07 May 2022, 03:32
Peter Balcombe wrote: 07 May 2021, 21:58 Prototype 3D printed seat checked for size.
Improved ones with full scale cutouts to be fitted in due course.

8CE8CDED-7731-4C40-872F-0249E8993212.jpegDC28E1E8-3C60-4562-ACC8-B8387B36BEB5.jpeg
Hi Peter...I am just getting around to starting my kit...Is there any chance that you may.be printing additional seats?

If so, I would be interested in a set.

Thanks in advance.

Gordon
Email sent Gordon.