Nick Cripps

That tailwheel retract is a work of art! The air pressure holding the retract down should provide some basic springing as well - clever design.

Dubro used to make a control horn that had a captive ball to which you attached a normal clevis and was available in various lengths. It appears to be discontinued now but they still offer this heavy duty version for large models: Heavy Duty Dual Control Horn

Yep, I'd do the same, Steve. It's also worth putting the wing in place and checking that the tailplane aligns when viewed from the front/rear.

You've not missed anything, Pat, no updates for a few days as I've been working on a different model and only putting the odd coat of dope onto Smoke Trail when I get chance. PM sent.

You're just not trying hard enough ?

Hi Pat, I've looked at the Tomboy plan today and realised it is much bigger than Smoke Trail and, with a built-up fuselage as well, would probably need at least 3m (possibly a bit more to allow for wastage). If you have that quantity available, please let me know the cost including postage and the easiest way to pay you. Regards, Nick

That's a very kind offer, Pat, thank you. I'm going to use the Litespan on this model but there's a set of parts for a Tomboy somewhere in a cupboard which I may build later in the year and could try it out on that. I'll measure it up tomorrow and send you a PM. Thanks also for the links to your threads, I'll have a good read of them.

After letting the test panels dry for a few hours, I moved onto the next stage: heat-shrinking to tighten the covering. Using a heat gun on the clingfilm and gently warming it as described in the video above, I found that the edges pulled away rather easily and clearly weren't really stuck down at all well. I decided that method wasn't for me so looked at the Litespan panel instead. I shrunk that with a covering iron turned up to about 125 deg C and this seemed to work well, with the covering still appearing to be attached firmly to the framework - success! I'd only covered one side of the panel and, holding it up to the light, the covering appeared to show some pinholes. Gently blowing through the surface confirmed it was not completely airtight, despite the instructions claiming so. I've now given it a coat of 50:50 non-shrink dope to seal the surface and, I hope, help to ensure the covering stays firmly stuck to the framework. I'll give it another coat tomorrow and see what it's like. With luck, the dope will not only seal the surface but also make it look even more like the tissue finish on the fuselage. A shame I won't get to try out the tissue over mylar method on this model. I'll give it a go another time but, for now, I need to get Smoke Trail finished so I can get back to the other model I've been working on, ready for the summer season.

I've put a couple of test pieces onto my scrap framework, both with the Poundland PVA used wet (no tissue paste). I have not thinned the PVA as it already has a very watery consistency straight from the bottle, much thinner than you would typically get in diy shop PVA. One panel is covered in Litespan and the other is covered with clingfilm, with the tissue to be added later. With both panels, I'm going to let the PVA dry before the next stage. Apparently, clingfilm is made from PVC or polyethylene and is typically around 10 micron thick and therefore thicker than the mylar I was planning to use (although still acceptable). The particular brand I have is stated as "non-PVC" so will be polyethylene which, as you know, stretches very easily - it will be interesting to see how it behaves with the tissue over it.

Thanks EB and Andy for your suggestions. I'll have to experiment with clingfilm but my initial thoughts are that it is thicker (hence heavier) than mylar and I'm not convinced that it has the same puncture resistance. I'll give it a try and see how it goes, it may be ok in conjunction with doped tissue. I didn't think 5-star/Starloc adhesives were still in business, Andy? Good thought, though, I think I may have some tissue paste somewhere. If I'm going to stick the covering down with wet paste then PVA should be just as good?

With the smell of cellulose dope pervading the workshop, I got my selection of lightweight tissue out to decide what colours to use. I'm going for the traditional coloured wings with black fuselage but I now have something of a dilemma over the wing covering itself. What I thought was a roll of thin mylar bought from SAMs some years ago turned out to be something else, a lot thicker and slightly opaque in colour. It looks similar to laminating pouch material (ie, adhesive-coated) but tests on a scrap framework showed it had little resistance to temperature and wrinkled easily, while still staying opaque. Not having anything else suitable as a base to tissue over, I now have to either order some mylar from Mike Woodhouse or change to a one-shot covering such as Solarfilm Litespan (which I already have in stock). Either way, I will need to find a suitable adhesive to stick the covering down as my jar of Balsaloc is just a solid lump! The obvious alternative is Deluxe Materials Cover Grip but have you seen the price? ? Some research shows that thinned PVA can be used (but my experiments so far with Poundland glue have been unsuccessful) or contact adhesive thinned with cellulose thinners. I will give that a try but if anyone has any other suggestions/experience, please let me know. So, back to the workshop, and some thinking to be done while I get high on dope fumes ?

All the woodwork has been completed with the fitting of the cabin roof and shaping of the nose. Also another small milestone has been achieved: first fitting of the engine. I knew that 8BA box spanner I bought 40-odd years ago would come in handy again: We're now ready for the first coats of dope to be applied...

There are 1 or 2 which appeal but looking at my stack of half-built models, let alone the unstarted kits, I think I've probably got enough for now. Thanks for the thought anyway.

Nice job, EB, you're making good progress.

They are all on your "to-do" list? ?

Even though it's only a small model, it's amazing how many little jobs there are to do and how much time it consumes, even when I thought I had finished the basic assembly. The upper and lower sheeting had plenty of time to dry so was trimmed and then sanded to shape, with just a little rounding of the corners. Next up, I cut out the fin, sanded it to shape and cut a slot in the upper sheeting to locate it. That meant I could loosely put the model together for the obligatory, morale-building, photo: And it even looks reasonably straight: Final shaping of the nose to do and it still needs the cabin roof to be added to the fuselage ahead of the leading edge. Then it will be time for covering, honest...

No criticism intended, Steve. I guess it comes down to how closely you want to replicate the original and we all have our own views on that. And, despite what I said, if I was building one I would probably move the tailplane up as it looks so vulnerable on the bottom of the fuselage!

I would suggest that you keep the tailplane in the same position, it's part of the character of this model. Moving things around and redesigning the back end makes it a different model in my eyes. I put a castoring tailwheel on a Wot4 some years ago - it was a nightmare! Maybe my rudder skills weren't very good back then but it was almost impossible to keep in a straight line on take-off. I fixed it by adding a 2nd bracing wire which allowed the leg to flex a bit so I could steer it on the ground without the model getting away from me.

Feeling a little more upbeat about the fuselage now and have made progress by gluing the top sheeting to the rear of the fuselage and adding the side cheeks to infill between the engine bearers and the fuselage sides at the nose. Here it is weighted down while the glue dries: You can also probably just make out the ply pockets to hold the undercarriage torque arms and the scraps of liteply which will be under the lower sheet to take the u/c screws. And here are the aforesaid undercarriage legs, obviously overlength at this stage: I also shaped the front deck ahead of the cabin from 1/16" sheet which was wetted and wrapped around a suitable former: I'll finish off the lower fuselage sheeting later today, leaving just the front deck and leading edge support piece to complete the basic fuselage assembly. Then it will be onto final sanding ready for covering but that will have to wait until later in the week as I am away again for a few days.

Thanks, John, she did have a good day with various family members visiting or calling via Zoom. Anyway, the build. It isn't going too well but I'm soldiering on regardless. As I mentioned, I always seem to struggle with fuselages and the "small" misalignment was worse than I thought. When I drew the sides together at the tail there was a mismatch of over 1mm which meant that I had to hold the sternpost vertical and accept that the sides were not at the same level horizontally. I toyed with scrapping the fuselage and starting again but thought I'd try and rescue it first. It's not my best work but I have now joined the sides and added the remaining formers, after which I planed and sanded down the sides to match and spent some time recutting the tailplane mount so it was parallel to the wing. I decided that I would change the undercarriage arrangement to piano wire rather than the plan design which uses a banded-on, 20swg dural undercarriage, mainly due to the sheer effort involved in hacksawing, filing and bending up the dural. Often, free-flight power models like this have a one-piece wire undercarriage sewn and glued to a suitable fuselage former but this gets in the way when sheeting and sanding the underside of the fuselage. I've chosen to use two 14swg piano wire legs which locate in vertical slots behind former F3 (at the leading edge) in the style typically seen on Peter Miller's designs. To do this, I made up some ply "pockets" to hold the top of the legs vertically up against the rear of the former and will then clamp the legs to the underside of the fuselage once all the covering has been completed. Not much to show from these efforts, I'll take a few pics tomorrow when I hope to progress onto sheeting the fuselage top and bottom.

Now for the part I always dread doing: assembling the fuselage. I decided to try a different approach this time by tacking the 3 main formers (all the same width) to the right-hand fuselage side with cyano. After the firewall was tacked in place, the hardwood bearers were fed through to help with the location of F2 and then given a squirt of medium cyano. The rear former was held square and cyano run along the rear joint line and Superphatic along the front: I then laid the left-hand fuselage on the building board and placed the other side, complete with formers, over the top. After checking in several locations that all was square, cyano was run along each join to hold it all in place with the help of some suitable weights: After leaving it to dry for a while, the fuselage was removed from the board and the tail drawn together to check alignment. Hmm, not perfect but acceptable - perhaps it's not such a difficult job after all ? Next task is to run some epoxy to form fillets along the join lines of the plywood formers and the hardwood bearers but that will have to wait until after I'm back from visiting my dear old Mum on her 90th birthday tomorrow ?

There are several ways to transfer the plan shapes onto wood, I just used one that I've used many times in the past. Cutting out the plan and gluing with a Pritt stick works well, or you can lay a photocopy of the plan face down on the wood and use a hot iron to transfer the pattern. I'm sure there are other ways too. I'm sure this tip is well known, but when using thin sheet over a structure such as sheeted leading edges or, as in this case, fuselage sides, it is better to sand the outer surfaces to a good finish before assembly. The reason being that if you try to do it afterwards, the sheeting bows under the pressure of the sanding block and you risk sanding too much off the areas supported by the underlying structure. Thinking about it, I should have put the sanded faces together and leave the unfinished faces to the outside. I could than have more easily transferred the former positions onto the inside face.

Back home and a start was made on the fuselage. There are 3 formers cut from 1/16" ply with the remainder being 1/8" balsa. Former F3 will be glued between 2 spruce uprights against the rear face of F2 and then the small, v-shaped, piece glued across the top which will support the leading edge of the wing. For the fuselage sides, I first "finish" sanded 2 sheets of 1/16" balsa then taped them together by the edges with the sanded faces on the outside. I use the time-honoured method of pricking a pin through the plan onto the balsa beneath and joining the dots with a biro before cutting the parts out with a scalpel. Oops, just realised I'm missing former F1A. I'll get that cut out and start the assembly tomorrow.

Here you go, John, here's the other end of the bench: And this is the other bench: No exciting piccies from today's efforts, I'm afraid, all I did was to glue in the centre ribs and the wing centre section sheeting and then finish off shaping the tailplane. These are both done now ready for covering which I'll start when the fuselage is complete and all the doping can be done together. That's all for now as I'm off to the Lake District for a few days, hopefully doing a bit of walking if the weather cooperates.

Good progress, EB. Must be all those early starts...