Mike Chantler

used DevWingFoam to setup the panels and sections: Imported Paul's plan to set it out. Airfoil is HQ 2.5/10 which is not one I have come across before (it's not specified in the plan but I seem to remember reading somewhere that this is what was used and by eye seems an ok fit with the drawings).

So cut the 6 sections for the wing, actually think it might be easier using a swing arm and physical sections for this, as left the stepper motor machine at 1m width - at which you start to lose some accuracy at the edges, so took me two goes for the first wing. Of course you have to align and glue the beds together as well, which took more time than I expected - and began to think I might be faster doing built-up balsa 🤔 Prefer this Technic glue stuff to others as it sands more easily. Now ready for skins.

Beautiful looking plane, now thinking spitfire camouflage is slightly dowdy 🙂 And I obviously don't get out of the Pentlands enough to recognise PSS fliers lol

Ha! crossed posts 🙂 Nice vid!

Guess that is the 202 in your pic? looks very nice 🙂 Good to hear about the good performance and many thanks for the generous offer. At the moment I'm determined to carry on a bit with Fusion 360 as it's become a bit of a challenge for me, but I would not be surprised if I did not throw it in the 'delete bin'! It's such a frustrating process when learning from scratch. However, in 2 or 3 weeks I may come back to you for that offer if it's still available. PS Coincidently I have Paul Jansses’ original T33 – he has an amazing number of designs.

Have decided to have a go at build Paul Janssens' Spitfire 🙂 He did a plan for it in QFI Aug/Sep 2000, it's on Outerzone and there's an RCGroups build log. I was kind of intrigued by the multi panel foam wing that he used to make the elliptical shape and I get the feeling that his planes are designed to fly in lighter lift which suits our gentle hills better. However, I can't bring myself to do the lost foam technique so I'm going to build the fuselage differently but have not decided quite how yet! Thinking about carving the fus from XPS made me think that it would be quite a challenge to get the exhaust/engine head blisters right as quite a few of my fuselage carvings have come out as bananas 🤔 So plan is to do wing exactly as plan. But, very naively, I thought I'd 'knock up' a 3D model in Fusion 360 😩to see what it looked like as there aren't very many good cross sections around for the nose. Now I know why the Spitfire was expensive to build - every surface seems to be a complex curve that has to fit very carefully with all the other complex curves. And I have found lofting extraordinarily challenging to say the least!!! Anyway - wings will be conventional foam/veneer, but fuselage will be a mixture of 3D print (at least for spinner and exhausts/blisters) rear fus carved from XPS and tail feathers may be sheet as per original design.

Yes, and thanks for the tips. I maybe should of made the void filler a better fit: Problem is that it fall off quite quickly at both the front and back. But will be more careful with the void filler next time. Mike

So I was lazy and tried the prototype directly in a bottle with heat gun 🙂 Trouble is, it's actually quite a small canopy and needs quite a bit of heat to shrink onto the plug which has distorted the plug but not as much as you would think given the level of heat used. Interestingly you could see the pattern of the 3D print support structure beginning to emerge 🙂 The bit that killed it was a wrinkle I could bot get out (green). So before I attempt to smuggle plastic into the oven I'm going to try dividing the plug up into bits to reduce the shrinking requirements: So am now printing: Green bit is front canopy, purple is support so I don't melt the corners of the plug as much as I did last time 😊

Many thanks for all the suggestions guys. MUCH appreciated 🙂 Yes, I am rather worried about the PLA melting, but am now very tempted to sand with say 500 git (?) and then have a go with a bottle! Afterall, I only need one canopy 🙂

Help! I have just managed to get fusion 360 to generate a rough spitfire mk24 canopy shape (took ages as first attempt at lofting 🙄). Had not really got as far as to thinking about how to use it to form the canopy!! as I was using it to come up the (for me, very steep) learning curve on the 3D modeller. Had vague thoughts of using Easycomposites XCR epoxy coating resin to produce a mould and then tool but this seems overly complex. Am tempted to try sanding and then covering in polymeric vinyl or easycoat x 3 as suggested above. I'm a bit worried about covering it without wrinkles as it is quite curvy.: Printed with in PLA with .4mm nozzle and .3mm layers. Likely to try plastic bottle and heat gun to start as I think I deconstructed the vacuum box 😞 Any suggestions as to covering material, approach or other useful threads very much appreciated!

Yup - thanks for the tips 🙂 I tried vacuum forming a while back and failed pretty miserably, so above hints and tips have rekindled my enthusiasm. I particularly like the taping off of redundant holes to increase the suction round the mould 🙂

Looks great, fantastic bit of building 🙂

The competitor: 545g was an earlier estimate - will double check.

Sorry for the radio silence, we've had about 6 Sundays of almost calm and one that was just gales. I've taken it up on the calmer days but I have also taken up an Arthobby Sky-V1.7 which I built just before the Slash. At the moment, and in these conditions, the Sky 1.7 is winning when I go to select the one to fly on the hill. The Sky is a little under 500g and is a very similar size and a similar 9% thick wing. In the recent conditions I've been very conscious of the weight difference and the fact that the Slash has a built-up wing. That and the T-tail and light-weight glass fus makes the Slash seem more fragile to me. This has made me more nervous of flying it in marginal conditions, with the thought of having to land it halfway down the hill if I misjudge things and get into a lot of sink low down. The Sky is I think also a bit better at tracking with it's longer tail moment. I'm just having too much fun with it at the moment, and it's very good at catching thermals 🙂 These are obviously highly subject thoughts, the other club member who has one is a much better flyer than me - so this may help quite a bit to get the best out of the Slash. Will keep taking it up in light conditions 🙂

From Silent Flight December/January 1997: he had a really series of articles in electric and silent flight mags 🙂 and see and see https://www.freeflightsupplies.co.uk/index.php/products/lightweight-covering-materials

After seeing some of these posts, I used 75 micron film directly onto of EPS on a 60" slope model. When it's really windy it gets lots of ballast and bad landings on the hill(!) Despite this it's surviving very well. I accidently started covering it with 150 micron film 🤔, and couldn't understand why it wouldn't go round the sub-trailing edge! Then I read the description on the packet! Model has 3mm cedar LE, 5mm square balsa sub-TE, carbon end caps and two 6mm carbon rod full length spars, the film gets lightly stretched across that frame work. (In a previous version I didn't have end caps or balsa TE - and not surprisingly the eps got a bit crushed after a while and the film looked awful) Thanks for all the info everyone 🙂

I use a cheap 12v vacuum pumps with veneer skins on EPS cores (see link below). On that model I added 25gm glass separately after bagging the skins, took me ages to get a good finish - never thought of using laminating pouches. I had tried bagging glass directly onto foam using thin mylar or similar - but got a very dimpled finish. Using it with glass/veneer combo sounds good though 🙂

Do you put skins + glass on all in one go, or in two stages?

Will post pics when rain allows!

Took Slash for quick maiden this morning but by the time we had walked to the slope (40mins) it started to drizzle, which was not of the forecast at all, just had time to launch and check basic trim, drizzle turned quickly to rain so we beat hasty retreat, it managed 4 or 5 circuits in VERY gentle slope lift and dampness without loosing height and that was all we could do before heading down the slope. Needed a little bit of up but that was about it. Will do a dive test etc when we get better weather!!!

Servos in and cable outers glued Used the kit hardware and tray. Servos are Bluebird BMS-125WV which are perfect length for the tray.

Although quite light it seems to nip around quite smartly 🙂 Box says MH32 mod, and for a built up wing it seems quite slim, so guess this helps.

Did more precise CoG check, and only needs 52g to balance at most reward recommended CoG so will add a bit for maiden. But weight coming out at circa 620g at this CoG 🙂 I'm not going to put a ballast tube in as I intend to use it only when my other aileron planes would just stooge around (and it's very lightly built!).

lol 🙂

Then had complete panic as could not find the wing-joiner - but was hiding in a safe place 🙄 Assembled as is = 400g. I kind of like the all black look, but it has picked up finger prints (!) Doing a quick CoG check with 100g 4xAA square pack as far forward as it will go indicates it needs at least 100g right in the nose. Add 50g for Rx, cables and servos etc takes weight to circa 650 say 700 if I don't get the nose weight as compact as I would like. Instructions say 680-750g so they are pretty spot on 🙂 Needs rudder & elevator servos, servo tray, rx, bat pack, and nose weight - but a pretty fast build for me.