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Jilles Smits 1/3 K7 Build

Posted: 16 Jul 2020, 21:36
by calypso22
Hi Everyone, this is my first post so don't expect great things. It is also only my 2nd scale project, I feel the amateur among many professionals, please bear with me. Last October I began building a 1/4 scale Charlesworth Ka7 from Mr Evans, that was maidened with a tow in May, looked really great in the air with that forward sweep, and after much advice from the assembled, the 2 pilots were removed and a little packing placed under the tail. The next three flights were much improved, in fact the vario did begin beeping a couple of times! I took the model home without a scratch and since then the pilots have resumed cockpit duties and a large chunk of lead from the nose has gone to compensate. So with enthusiasm bursting all over I have now taken delivery of another Ka7 but the 1/3 scale this time, again from Cliff. I believe Im the first customer. The fusalage is well under way and requiring all of the bench, its enormous!. Touch wood all is going reasonably smoothly and construction I have found far less complicated than the previous model having lots of click together formers and longerons. Still requiring plenty of thought before the next piece is glued in however....I am really enjoying the build, and having the door to the hangar straight off the kitchen it is easy to slip away for a few minutes while the potatoes are boiling and no one is watching. When I have worked out how to show you a picture I will post again.
John Harvey- Dartmoor Slope Soaring Club

Re: Jilles Smits 1/3 K7 Build

Posted: 16 Jul 2020, 22:12
by Peter Balcombe
John,
When writing your post, there a couple of tabs below the text entry box (Options & Attachments).
Click the Attachments tab & then the Add button to be able to select your required image from your device/PC.
The image should then load & give you a green tick mark. If another symbol then too large or other problem.
Note that the image needs to be sized to no larger than 800 pixels in largest dimension (100k or so max).

I normally add one at a time so that you can see which one causes a problem if any difficulty.
The ‘inline’ option puts the image in the text wherever the text cursor was at the time.
You can enter a useful caption name if you want.
The preview option lets you see what finished post should look like.
Peter

Re: Jilles Smits 1/3 K7 Build

Posted: 16 Jul 2020, 23:17
by calypso22
Many thanks Peter, will check it out, technology and electric things not my thing, I leave it to others to tell what to do as indeed you kindly have.
By the way have we met at the WMSA XCs anytime in the past?
John

Re: Jilles Smits 1/3 K7 Build

Posted: 17 Jul 2020, 08:57
by Peter Balcombe
John, we may have met as Chris Bowles & a few Dartmoor lads used to come to our Open XC comps, but I’ve not been to these for a numbers or years now & I’m afraid I cannot put a face to the name.
Good luck with the build. Jilles’ designs are very good.
Peter

Re: Jilles Smits 1/3 K7 Build

Posted: 18 Jul 2020, 20:02
by calypso22
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First mistake, I deleted my draft..doh! Hopefully you can see my pic of initial fuselage construction. So far all has been reasonably straight forward. I'm right at the aft end now and trying to make sure the fin aligns vertically with the wing seat, hence the clamped on level. I am one for using my eye and if it looks right I reckon it probably isnt far off. I hope that my primary efforts at building scale will inspire other beginners to have a go, this forum certainly shows there are plenty of experienced builders happy to share tips and encouragement in bucket fulls.
John

Re: Jilles Smits 1/3 K7 Build

Posted: 18 Jul 2020, 20:10
by calypso22
I think picture didnt work...try again.
John
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Re: Jilles Smits 1/3 K7 Build

Posted: 04 Aug 2020, 19:39
by calypso22
Hi all, here is a progress report on the Ka7. My first pic showed what I thought was a fuz well on the way to completion. In fact twas a mere skeleton, there was and still is a lot more work envolved..I should have realised. Having said that further construction has been reasonably straight forward and now things are really taking shape. All the .8mm ply cladding is on now and as someone who does not like waste Ive attempted to manage the cutting and jointing but not compromise strength and rigidity. The structure is now the size of a small hen house but remarkedly light..I think!
As before, getting construction in the right order needs thought. I will build the rudder next then offer up to the fin before adding fin .4mm ply sheet to ensure rudder LE is correctly covered by the sheet overlap and movement unobstructed. I have glued balsa sheet between the nose longerons where it was to be clad in ply sheet. This will be sanded, filled and glassed instead, as suggested by Jilles (thanks) in a post about a similar build, sorry can't remember where on SSUK I read it, there is so much info out there!! I hope the pic doesn't break any rules but my other half is trying to be involved and interested. Seriously enjoying lock down!
John
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Re: Jilles Smits 1/3 K7 Build

Posted: 04 Aug 2020, 19:42
by Cliff Evans
Blimey, that's coming on John.

Re: Jilles Smits 1/3 K7 Build

Posted: 04 Aug 2020, 20:16
by calypso22
Thank you Cliff.
John :)

Re: Jilles Smits 1/3 K7 Build

Posted: 30 Aug 2020, 20:33
by Cliff Evans
My 1/3 Jilles K-7 nearing completion thznks to Rich Vale.
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Re: Jilles Smits 1/3 K7 Build

Posted: 03 Sep 2020, 20:29
by calypso22
Cliff, this is the one that was awaiting the paint shop I'm guessing. I know another yellow K7, and that colour flys very well! My JS 1/3 is progressing a little each day with the elevators complete, beautiful structures, and I recently obtained 2 KST wing servos that fit nicely into the tailplane servo trays. The home made release is about to be fitted to the nose block then to the fuz, filled and sanded. I see lots of fabulously covered and painted models with striking designs...would be interested to know how to achieve the basics of a reasonable finish, however it will be some months before the paint brush is needed. Thanks.
John (calypso

Re: Jilles Smits 1/3 K7 Build

Posted: 03 Sep 2020, 23:46
by Cliff Evans
John, hopefully it will end up something like this!
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Re: Jilles Smits 1/3 K7 Build

Posted: 04 Sep 2020, 15:03
by calypso22
WOW!! Now I am inspired, what a fab-u-lous colour scheme, better carry on building.
John

Re: Jilles Smits 1/3 K7 Build

Posted: 04 Sep 2020, 15:08
by calypso22
Cliff, still not 100% sure, is that a model or full size. The wing weight appears modellish....brilliant pic.
John

Re: Jilles Smits 1/3 K7 Build

Posted: 04 Sep 2020, 19:06
by Cliff Evans
calypso22 wrote: 04 Sep 2020, 15:08 Cliff, still not 100% sure, is that a model or full size. The wing weight appears modellish....brilliant pic.
John
Full size!

Re: Jilles Smits 1/3 K7 Build

Posted: 25 Sep 2020, 23:24
by calypso22
Hi to all interested parties, more progress on the K7 build, but not as much as I would have liked..not enough time in the day! The tail department is complete now and I'm reasonably pleased. However I did not pay enough attention to the position of the elevator hinge line/axis and prematurely glued in the Robarts to one side in the incorrect position (in my humble opinion). The elevators still move up and down but not in the 'ball and socket' way if you get what I mean. I may have to revisit this as the build goes by and it gets on my nerves. Still its a lesson learned for next time.
Wings next, thanks Cliff for advice on where to start, unfortunately I have lost your email, can you, or anyone else please offer some words of wisdom here. My bench will just take one wing if I clear the clutter off. My preference is to make each wing in one piece, think it will fit in the Honda. It would be good to improve on the previous K7 wings construction/method which caused me some head scratching with lining up ribs. I have had one plan studying session until my eyes started popping but need more time to understand.
Thanks for looking
John
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Re: Jilles Smits 1/3 K7 Build

Posted: 25 Sep 2020, 23:44
by Cliff Evans
Lay the shear webs flat on the building board and glue a piece of.8mm py over the joint but make sure that you do not go top to bottom as you have to get the spars on. Whilst the web is on the board, glue the bottom spar to web and clamp overnight. you can now slot the ribs onto the web and add the top spar. Easy!

Re: Jilles Smits 1/3 K7 Build

Posted: 26 Sep 2020, 20:40
by calypso22
Thanks for that Cliff, I will get back to you when all becomes clear. I will now put parts to advice and hopefully exclaim '' Of course it's easy and so obvious!''
John

Re: Jilles Smits 1/3 K7 Build

Posted: 11 Oct 2020, 13:26
by Cliff Evans
Richard Vale has been busy with my K7!
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Re: Jilles Smits 1/3 K7 Build

Posted: 11 Oct 2020, 14:35
by Peter Balcombe
Very nice Richard.
Is that rattle can or spray gun application?

Re: Jilles Smits 1/3 K7 Build

Posted: 11 Oct 2020, 17:06
by Cliff Evans
Spay gun!

Re: Jilles Smits 1/3 K7 Build

Posted: 11 Oct 2020, 18:10
by RobbieB
Spay gun!!!

Wot, you did the cat at the same time.................?

Re: Jilles Smits 1/3 K7 Build

Posted: 11 Oct 2020, 20:37
by Cliff Evans
I think I need a new keyboard!

Re: Jilles Smits 1/3 K7 Build

Posted: 11 Oct 2020, 21:16
by Peter Balcombe
Cliff Evans wrote: 11 Oct 2020, 20:37 I think I need a new keyboard!
One with larger keys :lol: :lol:

Re: Jilles Smits 1/3 K7 Build

Posted: 12 Oct 2020, 06:31
by Max Wright
Peter Balcombe wrote: 11 Oct 2020, 21:16
Cliff Evans wrote: 11 Oct 2020, 20:37 I think I need a new keyboard!
One with larger keys :lol: :lol:
. . . and bigger spaces between them . . . :shock:

Re: Jilles Smits 1/3 K7 Build

Posted: 08 Nov 2020, 13:22
by calypso22
Hi all, I'm back and managing to stay clear of all the worldly mayhem by hiding in the man shed. Have tried to progress the build a little every day and now have the rudiments of a wing (that'll be one side) I have made a couple of mistakes along the way but hopefully have learnt the lessons and the second wing will be easier and quicker. One such error was not ensuring the webs/ sheery things were glued accuately at 90 degrees to the bottom spar thus allowing the ribs to slot on tabs flat to the board fwd to aft. Also tapering the spar to the tip was new to me and easier than I imagined with a sharp razor plane. Anyway with some tweeking I'm very happy with a nice straight enormous wing which feels really stiff!!
At this stage the TE is going to be added but I cant quite work out the best way to approach the 0.4 ply and balsa sandwich and produce a strong attachment to the ribs, the ribs only appear to be slotted into the balsa core by circa 3mm, am I reading this right Cliff? . Last years Charlesworth K7 employed a similar method, this was very strong even without the carbon interior strip but I never the less managed to distort/lift the TE when tightening the film covering in one area.
All considered I reckon the build is moving fwd faster than imagined and Spring 21 Covid allowing may see me looking for the right maiden conditions. Actually I am already looking at the next project! Regards John
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Re: Jilles Smits 1/3 K7 Build

Posted: 08 Nov 2020, 13:59
by robert-woolley
Good progress John. Are you sure your car is long enough? I look fwd to seeing it up L.H at next years aerotow.

Re: Jilles Smits 1/3 K7 Build

Posted: 08 Nov 2020, 15:18
by Cliff Evans
Just waiting for some decent weather to get her outside to put the decals on (thanks Barry) and get CG where I want it.
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Re: Jilles Smits 1/3 K7 Build

Posted: 08 Nov 2020, 15:57
by calypso22
If it wont go in my car Robert I know somebody's it will Mr Bowles! Trouble is if things stay the way they are I will not be accompanying it.
John

Re: Jilles Smits 1/3 K7 Build

Posted: 08 Nov 2020, 16:00
by calypso22
That looks absolutely stunning Cliff, dont tell me it lives in that shed!
J

Re: Jilles Smits 1/3 K7 Build

Posted: 08 Nov 2020, 18:32
by Chris Bowles
Looking good John, think the transport costs have just gone up 😎😎
Chris

Re: Jilles Smits 1/3 K7 Build

Posted: 08 Nov 2020, 23:26
by calypso22
Hello Chris! perhaps I will need a roof box, better get a tape measure out. For the time being I've hung the first wing up and started building the spar for number 2 before while construction is still fresh in my mind. I made really sure I was not starting to build the same wing, but even then I nearly stuck the sheer web on the wrong side of the spar....doh! There is only one place to be during lock down....the man shed, oh and the drinks cupboard is pretty good too.
John

Re: Jilles Smits 1/3 K7 Build

Posted: 08 Apr 2021, 17:02
by calypso22
Hello Everyone, I'm afraid I was rubbish at this posting business, the last post on this build being last year! Well the K7 is finished now, started it last July.
You were right Cliff it's a lot of model. I havent built anything so large before, oh there was a garden shed once. Overall a thoroughly enjoyable pass time and anyone else thinking of doing similar should not feel incapable, my building skills are only moderate and I have no specialist equipment, but I have plenty of friends willing to help and offer advice, oh and lend things. You do need space though, my single garage only just sufficed and a little hangar rash did occur turning items around.
The laser cut parts (loads of them) are a godsend, I did not use a jig, was I supposed to? Lots of eyeing up and a straight line on the bench. Nothing is too fiddly with a big kit and no different really to the construction of a much smaller model but I did use a lorra lorra white glue and surprisingly little epoxy....it all feels very stiff so here's hoping. When it came to covering I had an idea in mind to spray paint the solid sheet areas and film cover the open structure, however getting a neat edge between paint and film was tricky, however self adhesive trim line worked magic...are you all cringing yet? The canopy would make a good poly tunnel but really finishes the model off. It is hinged and button magnets hold it down firmly ( I hope) as with the rear canopy which should also be hinged. I confess to using commercial top spoilers, the excellent ply ones supplied were beyond me...sorry Cliff. Now for the nitty gritty she weighs in ready to fly at circa 12.3 kgs and I reckon the wing area is around 20+ sq ft...how does that seem? I did need a lot of lead up front well over 2k...I hate to think what you are all saying. Anyway the K7 sits in the hanger awaiting a willing tug pilot and what will be will be. Its been a fantastic year of building..lets face it we couldn't do much else! Good Luck to all other maideners!
Regards
John ( Harvey) Dartmoor Chaps
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Re: Jilles Smits 1/3 K7 Build

Posted: 08 Apr 2021, 19:28
by Cliff Evans
Looks great John. Look forward to seeing her in the air. Well done.

Re: Jilles Smits 1/3 K7 Build

Posted: 08 Apr 2021, 20:44
by calypso22
Thanks Cliff, I am informed Tuesday may be 'D Day' Gulp!! I have a pilot on the way, Maggie is making clothes as we speak. Mike a good friend 3D printed the head, hands and shoes for me. I just wish it was warmer, can't relax when I'm freezing and the fingers do not work so well.
John

Re: Jilles Smits 1/3 K7 Build

Posted: 08 Apr 2021, 20:53
by Cliff Evans
You will be fine.

Re: Jilles Smits 1/3 K7 Build

Posted: 08 Apr 2021, 21:11
by robert-woolley
Your finished K7 looks great John. Will this be a Little Haldon Maiden? Be sure to get some photos please. Or even some aerial video. I have a Runcam you can borrow if you are over our way before Tuesday. Any pics or video will make a great introduction to this seasons flying on our club website.

Re: Jilles Smits 1/3 K7 Build

Posted: 09 Apr 2021, 07:43
by Cliff Evans
robert-woolley wrote: 08 Apr 2021, 21:11 Your finished K7 looks great John. Will this be a Little Haldon Maiden? Be sure to get some photos please. Or even some aerial video. I have a Runcam you can borrow if you are over our way before Tuesday. Any pics or video will make a great introduction to this seasons flying on our club website.
You could also post the photos and video here!!

Re: Jilles Smits 1/3 K7 Build

Posted: 10 Apr 2021, 00:27
by Jilles
the 12.7 kg is not a problem but is as it should be
I had to add 0.8 kg weight just in the c.o.g of my new Ka8 to make it fly properly. Before adding this extra ballast it did not flew right
lots of inputs to keep it level. A indication that the wing loading is too low.
With the extra weight is goes now very stable even in windy conditions
Large scale needs large weight. (within reason)

Re: Jilles Smits 1/3 K7 Build

Posted: 10 Apr 2021, 09:30
by calypso22
Thanks very much for your input Jilles, that is reassuring. One thing you may wish to comment on is the wing to tail incidence. I borrowed a meter to check this but it was not broad enough to measure at the wing root so I fixed it at the nearest useable point which was right up at the inner point of the aileron. Must admit I struggled a bit using the instrument but got a positive reading of about +3.5 to 4 degrees, do I need to recheck/adjust with some help before committing?
John

Re: Jilles Smits 1/3 K7 Build

Posted: 11 Apr 2021, 03:22
by Jilles
with all my designs I have a 3 degree difference between wing and stabilizer incidence measured over the mean chord of the profiles. With NC laser cut parts there should be no reason to adjust this on the model, subject to that it was assembledand built square and level. No harm in checking of course. there was never a need for me to adjust one of my models that I did built myself.
Note if the incidence is measures from the bottom of the wing profile the result will be 4-4.5 degrees

Re: Jilles Smits 1/3 K7 Build

Posted: 11 Apr 2021, 19:22
by calypso22
Many thanks Jilles for your advice. All these snippets of info from you and the guys here build to a much more comprehensive understanding of what is required for a successful build and consequently...flight. Onward and upward!
John

Re: Jilles Smits 1/3 K7 Build

Posted: 12 Apr 2021, 10:03
by robert-woolley
And dont forget some tranquillisers to steady the joysticks John. 😀

Re: Jilles Smits 1/3 K7 Build

Posted: 12 Apr 2021, 20:30
by calypso22
Hi Robert, yesterday at the Okehampton MFC would have been ideal for the maiden had I been totally prepared, as it was an aerotow with my old and trusty Alpina Magic had to do. My attempt to produce a 1/3 scale pilot is progressing, Maggie is dressing him as we speak. The head, hands and foot wear (Doc Martens I'm told) were 3D printed by Mike Ford and have been painted with acrylics, the limbs are robart hinged dowel and the body is foam...I'm mildly optimistic it will do. Chris Bowles gave me a neat tip to keep the canopy from dropping over.
John
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Re: Jilles Smits 1/3 K7 Build

Posted: 19 Apr 2021, 03:26
by larrikin
Cliff Evans wrote: 08 Nov 2020, 15:18Just waiting for some decent weather to get her outside to put the decals on (thanks Barry) and get CG where I want it.
Cliff Evans wrote: 09 Apr 2021, 07:43You could also post the photos and video here!!
Speaking of posting photos, Cliff, did you ever get the decals on the '7?
That scheme is really nice, it'd be great to see it finished.
Thanks
David

Re: Jilles Smits 1/3 K7 Build

Posted: 19 Apr 2021, 07:25
by Cliff Evans
No I didn't I have passed the model on to someone to finish, just have not got the time! Will try to get some photos when it is done.

Re: Jilles Smits 1/3 K7 Build

Posted: 28 Apr 2021, 09:00
by Cliff Evans
Johns K7 had its Maiden yesterday! All went well. This is the email report I had from John.

Morning Cliff, well I finally maidened the K7 yesterday! A very light westerly and warm..perfect. The tug was an electric WOT4. Unfortunately the chap who was going to video had to shoot off early but he kindly left the camera for us. I have returned the camera for the results of our amateur efforts. if it is rubbish we will film again.
However, the K7 lifted very quickly and thereafter the flight was fantastic. Not much lift around this time, but she floated about majestically and really looked the part. Boasting...my initial landing was one of my best ever, really steady approach, small bounce left the wheel spinning and down...brilliant. My next 2 landings we will not talk about, but heather is nice and forgiving!
I will get some pics or video to you asap but here is a couple to prove I'm not fibbing. Thanks for all the support, next project...🤔

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Re: Jilles Smits 1/3 K7 Build

Posted: 28 Apr 2021, 09:26
by robert-woolley
Well done John and to your pilot tailor Maggie.

Re: Jilles Smits 1/3 K7 Build

Posted: 30 Apr 2021, 10:19
by Bovin
Congratulations with your first flight, your comments sounded very well and I hope to see the video!


Vincent

Re: Jilles Smits 1/3 K7 Build

Posted: 30 Apr 2021, 16:47
by calypso22
Thank you very much Vincent for your comments. I have just today sent Cliff the maiden video and hoping he can post it for me as I am a dunce at the computor/IT technology, really hope it works. The flight was at Little Haldon near Teignmouth. This site was an aerodrome a long time ago but is now a nature reserve. It has a westerly slight slope,North south and East west rough grass runways and looks right across to Dartmoor...spectactular backdrop for gliders and all models actually, particularly scale. On maiden day last Tuesday there was barely a breeze but coming from West it gave a nice bouyant feel. Chris Bowls and his 5mtr scratch built Pilatus maidened first late morning. An eventless tow but a great flight. Circa 20mins I think. Then my turn with K7. I was nervous to say the least, lets face it non of us want a spectacular failure after all the hours and money invested. However the launch by Martin Tonkins's electric Wot4 went smoothly lifting off very quickly, as did release. I added a few clicks of up to slow things down and my heart rate slowed as well! I had the vario installed but had forgotten to connect my RX and head phones, so that scuppered any beeps. She looked really stately up there and handled very easily, lovely smooth turns etc. Shortly came the downwind and cross wind legs and for me a really controlled approach (judge for yourself of course) touchdown and small bounce and in....very happy. I suppose I need to experiment now with Cof G which at present is around the LE at the canopy. There is circa 2.5k of lead up front but perhaps some of that could be loaded onto a lorry and taken away. Thanks to Jilles and Cliff for a wonderful project and model and all the advice along the way, and if I can do it so can almost anyone.
John

Re: Jilles Smits 1/3 K7 Build

Posted: 30 Apr 2021, 17:54
by Cliff Evans
Here is Johns maiden flight with the K7 from Jilles Smits. Supplied by Laser Cut Sailplanes.