I thought it time to reinstate the MO2a build thread, which sank when the old forum foundered...
Starting with the fuselage, the first half-shell is built up on the board...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 16 Jan 2021, 15:35
by Cliff Evans
Thanks Chris, we lost quite a few good builds at that time.
Re: MINIMOA MO2a 3.5 SCALE
Posted: 17 Jan 2021, 09:44
by chris williams
Once enough planking has been added to render the first side rigid, the half shell can be removed and the other side added. The cockpit side rails are laminated from strips of 0.8mm ply...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 17 Jan 2021, 09:46
by Cliff Evans
Is there going to be a 1/4 scale version soon?
Re: MINIMOA MO2a 3.5 SCALE
Posted: 17 Jan 2021, 09:47
by VinceC
This has to be one of the nicest gliders available. I am not a big fan of the Minimoa, but the Mo2a is something different
Re: MINIMOA MO2a 3.5 SCALE
Posted: 17 Jan 2021, 11:26
by chris williams
I should also mention that my drawing is based on Vince's excellent 3-view & documentation...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 18 Jan 2021, 10:02
by chris williams
With the basic fuselage structure complete, attention moves to the tailplane... The tailplane sits on jigging supports when the final sheeting is added.
Re: MINIMOA MO2a 3.5 SCALE
Posted: 19 Jan 2021, 09:48
by chris williams
Now the elevator can be made up by first drilling out the false LE to fit the tailplane, then build up the rest...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 20 Jan 2021, 09:45
by chris williams
Now the tailplane mount can be be built up. Square brass tubes were used for the elevator actuating system, but it's worth noting that these days I use a much simpler method with a carbon tube loosely located in order to discourage friction..
Re: MINIMOA MO2a 3.5 SCALE
Posted: 21 Jan 2021, 11:39
by chris williams
Now the top ply sheeting on the fuselage can be attended to...I used 0.8mm ply, but these days prefer 0.6mm...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 22 Jan 2021, 09:54
by chris williams
Time to make up the all-moving rudder and install the rudder cable guides. Unlike most sailplanes, the rudder guides exit out of the rear former, rather than the sides of the fuselage, so there's not a lot of room when connecting up...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 23 Jan 2021, 09:46
by chris williams
Some details now of the rudder mounting arrangement...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 24 Jan 2021, 09:40
by chris williams
Now it's time to start on the wings. These are built with my old method i.e. built in two panels, later joined at the gull break.
Re: MINIMOA MO2a 3.5 SCALE
Posted: 25 Jan 2021, 09:51
by chris williams
A good stage to check the progress so far...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 26 Jan 2021, 09:37
by chris williams
Now the outer and inner panels can be jigged up and joined together...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 27 Jan 2021, 09:11
by chris williams
Before the lower sheeting is added, a straight edge clamped to the aileron spar keeps the outer wing panel straight. Before adding the top sheeting, the two small parts of the inner panel TE are clamped to keep them parallel...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 28 Jan 2021, 09:44
by chris williams
After a quick dihedral check, the wing can be placed on the jigging supports and the top sheeting added...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 29 Jan 2021, 09:50
by chris williams
A quick progress check, then on with finalising the wing sheeting...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 30 Jan 2021, 09:16
by chris williams
Now it's time to sort out the fitting of the wing joiner box...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 31 Jan 2021, 08:31
by chris williams
A bit more work on the fuselage now, including adding a strip of 3mm sq spruce strip to form a rebate for the glazing, and sorting the hole for the landing light...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 01 Feb 2021, 09:54
by chris williams
With the skid glued on and the MPX tow release temporarily installed, attention can now move towards fitting the wings to the fuselage...
Note that the rubber retention bands sit closer together than usual, in order to hide their existence inside the joiner box assembly in the fuselage.
Re: MINIMOA MO2a 3.5 SCALE
Posted: 01 Feb 2021, 12:00
by Keith
Lookin good Chris, could you please tell me where you get you servo cable from on the roll? Thanks
Keith
The wing root fairings are finalised the usual way with filler...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 03 Feb 2021, 11:37
by chris williams
Back to the wings now and it's the flaps & spoilers...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 04 Feb 2021, 10:05
by chris williams
Now for the tricky bit: the canopies...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 04 Feb 2021, 12:45
by Barry_Cole
Are you having a lay in these Days? These posts are getting later and later.
BC
Re: MINIMOA MO2a 3.5 SCALE
Posted: 04 Feb 2021, 12:50
by Peter Balcombe
Barry_Cole wrote: ↑04 Feb 2021, 12:45
Are you having a lay in these Days? These posts are getting later and later.
BC
It’s to give him more time to do the tricky bits Barry
Re: MINIMOA MO2a 3.5 SCALE
Posted: 05 Feb 2021, 00:33
by chris williams
Continuing with the canopies...(This early enough for you, Barry?)
Re: MINIMOA MO2a 3.5 SCALE
Posted: 05 Feb 2021, 09:22
by Barry_Cole
That's better, mustn't let standards slip..
BC
Re: MINIMOA MO2a 3.5 SCALE
Posted: 06 Feb 2021, 10:09
by chris williams
With the canopy parts stained, time for a regular progress check...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 06 Feb 2021, 16:33
by Dave Mackintosh
Beautiful!
Re: MINIMOA MO2a 3.5 SCALE
Posted: 07 Feb 2021, 10:09
by chris williams
Thank you, Dave... the front canopy can now have the ply sheeting added and the whole shebang faired into the fuselage. Note that the balsa former for the top of the canopy was for the PETG moulding, which is available from Sarik Hobbies...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 07 Feb 2021, 11:40
by Martin Gough
Chris could you explain how you go about making the canopies,
what materials etc.
Re: MINIMOA MO2a 3.5 SCALE
Posted: 07 Feb 2021, 13:26
by Cliff Evans
I now finish all my canopies with Novol two pack polyester finish. It is not affected by the heat of the vacforming at all. The Plugs are made from MDF so, nice and solid. Just spray directly on to your plug and flatten off with 320 grit then finish with 6-800 grit.
Novol Polyester two pack spray filler.
Re: MINIMOA MO2a 3.5 SCALE
Posted: 07 Feb 2021, 17:17
by chris williams
I have always made my plugs/formers from blue foam, wrapped in parcel tape, glassed with mat & polyester resin, then finished off with filler etc. Trouble is, you have to make sure that the glass and mat is thick enough to prevent the heat from melting the foam during the pulling process.
Barry from Sarik will verify this...
(The balsa plug on the MO2a was possible because it was so small)
Re: MINIMOA MO2a 3.5 SCALE
Posted: 07 Feb 2021, 23:50
by Jolly Roger
chris williams wrote: ↑07 Feb 2021, 17:17
I have always made my plugs/formers from blue foam, wrapped in parcel tape, glassed with mat & polyester resin, then finished off with filler etc. Trouble is, you have to make sure that the glass and mat is thick enough to prevent the heat from melting the foam during the pulling process.
Barry from Sarik will verify this...
(The balsa plug on the MO2a was possible because it was so small)
Yes, very upsetting when the plug is crumpled by the vacuum machine. 5 layers of 100gsm cloth and resin over blue foam nowhere near strong enough.
Re: MINIMOA MO2a 3.5 SCALE
Posted: 08 Feb 2021, 09:52
by chris williams
Last job now: the ailerons... Note that the aileron false LE is drilled out against the wing for the hinges before construction commences.
Re: MINIMOA MO2a 3.5 SCALE
Posted: 08 Feb 2021, 09:57
by Martin Gough
Hi Chris
Thanks for the canopy advice, I take it you need to allow for the
thickness of the canopy material.
Regards Martin.
Re: MINIMOA MO2a 3.5 SCALE
Posted: 08 Feb 2021, 11:30
by chris williams
No, not really, but you do have to extend fore and aft to allow for cutting off the ends...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 08 Feb 2021, 13:03
by Peter Balcombe
chris williams wrote: ↑08 Feb 2021, 11:30
No, not really, but you do have to extend fore and aft to allow for cutting off the ends...
And the bottom?
Re: MINIMOA MO2a 3.5 SCALE
Posted: 08 Feb 2021, 13:53
by chris williams
Actually, the secret is to make the whole former bigger than you require in the not unreasonable hope that the canopy will fit other gliders...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 08 Feb 2021, 14:25
by Cliff Evans
chris williams wrote: ↑08 Feb 2021, 13:53
Actually, the secret is to make the whole former bigger than you require in the not unreasonable hope that the canopy will fit other gliders...
A classic example of this is Chris's Skylark canopy. Would be hard to find something he has not fitted that to!
Re: MINIMOA MO2a 3.5 SCALE
Posted: 09 Feb 2021, 09:49
by chris williams
A few more details of the completed airframe before covering & finish...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 09 Feb 2021, 16:10
by Tom Pack
Very nice! Is that a landing light in the nose???
Re: MINIMOA MO2a 3.5 SCALE
Posted: 09 Feb 2021, 16:20
by chris williams
Yes, in the 1930's people were so keen on record breaking, that they were prepared to go on flying after sunset...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 09 Feb 2021, 16:41
by Peter Balcombe
Tom Pack wrote: ↑09 Feb 2021, 16:10
Very nice! Is that a landing light in the nose???
Tom,
I suspect that it is the sustainer motor shaft
Tom Pack wrote: ↑09 Feb 2021, 16:10
Very nice! Is that a landing light in the nose???
Tom,
I suspect that it is the sustainer motor shaft
And you would be wrong, it is indeed a light.
BC
Re: MINIMOA MO2a 3.5 SCALE
Posted: 10 Feb 2021, 04:57
by Tom Pack
chris williams wrote: ↑09 Feb 2021, 16:20
Yes, in the 1930's people were so keen on record breaking, that they were prepared to go on flying after sunset...
Yes but this is 2021 and some idiot somewhere might be doing just that......
Re: MINIMOA MO2a 3.5 SCALE
Posted: 10 Feb 2021, 09:48
by chris williams
Time for the End Game...the entire airframe is covered with Solartex. The translucent areas have two coats of clear lacquer initially, which is flatted with wet with 600 w&d, and then another single coat of lacquer, mixed with some matting agent, applied over the top. After that, the trim colours can be applied. The fuselage is sprayed with 2-pack primer, flatted, and top-coated with the main and trim colours, also mixed with matting agent...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 11 Feb 2021, 05:03
by Max Wright
It's looking excellent, Chris.
Re: MINIMOA MO2a 3.5 SCALE
Posted: 11 Feb 2021, 09:37
by chris williams
Thank you, Max... Now for the finished model details...
Decals supplied by the Super-Separator and Dandy Decal Corp (i.e.Barrington V. Smallpiece) (also, the detachable u/c)
Barry_Cole wrote: ↑11 Feb 2021, 11:40
I was just trying to keep the suspence going.....
Didn’t that go the same way as the half crown in 1971?
No that would be the sixpence......
Re: MINIMOA MO2a 3.5 SCALE
Posted: 12 Feb 2021, 10:28
by chris williams
In action, the MO2a has no vices, and on a calm day on the flat, seems to fly at near scale speed. It's hard to quantify if the flaps make much difference, but you certainly don't need them landing into a strong wind, as the glider darn nearly stops in mid air. The drop off dolly is mixed with the spoilers so you don't have to take your hands off the sticks during take off.
Re: MINIMOA MO2a 3.5 SCALE
Posted: 13 Feb 2021, 00:24
by chris williams
You can see the 'Moa in action here...
Re: MINIMOA MO2a 3.5 SCALE
Posted: 14 Feb 2021, 16:31
by Hansjörg Rothfuß
this video was the ignition for me, to build this marvellous glider......
Thanks Chris for the fantastic construction an the plan!
