911hillclimber

Plane is now ready for the first flights this year. After some messing getting the snakes in and glued into position, finding out my '5 minute' epoxy is closer to 25 hours to set, and adding a full 200 Grams of weight right tucked-up into the nose motor box everything works, no binding and just might be nose heavy at 80mm C of G. Bit of an effort but pleased with my plane, all in cost about £40 inc purchase. of the bare plane at Weston Park 2 years ago. Such a nice design. I think it is a Flair version, but still not too sure but has corrugated steel gussets on the undercarriage which is a give away I think. With the cold spell now coming to a brief end it is back to classic car maintenance next week... As ever on here, thank you all for the help and advice.

The servo throw the elevator +/- 15 degs, or about 12mm up/down. That seems about right to me, but I can increase those values to add about 50% more. The rudder is dramatically more, a good +/- 30 degs.

Thank you Peter for this insight. Previously, I've had suggestions that 90mm back from the leading edge is a good spot. The 'plan' I've seen on google shows 70mm C of G. The nose ballast needed is quite a difference between the two spots. I think I'm over-thinking all this (I an a novice to all this as you may have realised!). Currently trying to sort the snakes out. The ones from 4Max are really nice, but the slippy inner plastic cables (must have a lot of ptfe in them) ate too large to pass through the existing outers in the plane. This means the whole of the 4Max snakes are inside the plane. Great, except i need crimp-on 2mm threaded ends for the servo end, the snakes come with one enge crimped on with steel thread and clevis. Of course you can super glue to the ptfe inner wire so need some crimp-on ends. Local model shop is closed today so this has stalled the plane's progress. Nothing really going to plan!

Thank you for your post Pat. I'll closely read it after this post! The motor is a big thumping Overlander T4240/10, a motor bought a long time ago and never used, so thought I would put it in this 60. It weighs 241 gr with steel mount, prop and nut. It scres to the original IC motor mount hole like yours. The ESC can take 3 and 5 cells but is big compared to the WOT4 unit. The prop is an 11 x 7e, it was bought because the Junior 60 upgrade (from IC to elect) on the 4Max website lists it as right for the plane. The motor looks a bit big for the model, but you don't HAVE to use full throttle! I'll try to post pictures tomorrow. Graham. Edit: Just looked at the thread Pat. Are all Belair wings bolt-on?. My 60 is made for classic rubber bands front and rear. The undercarriage bulkhead wood will not allow the battery to be in the engine bay, the power cables and charger lead would be almost level with the front of the wing. Maybe my plan is a Flair kit or even a Ben Buckle kit?

Sorry, can't edit my post above, but made a steel prop nut as long as a dare without this plane looking like Pinocchio's long nose.. Had to machine the bar down to 19.5mm dia to seat onto the prop hub. The nut weighs 54 gram and the prop 20. All bolted on and the battery in the cabin the plane needs: C of G @ 36% of chord (90mm from leading edge, chord is 10"/250mm): 114 grams ballast. C of G @ 28% of chord (70mm), ballast needed is 199 grams On the Belair plan the spar is 50mm from the leading edge. Seeing as the ideal C of G is not clear I think 150 grams of weight in the box below the motor is a good starting point. (?)

Just for interest; If I remove the 166 grm 3S 2200 battery and put it where the prop goes on the motor, the fuselage just about balances out, slightly tail down. I cannot see an 'elegant' way to get the battery further forward. Even cutting the nose about a lot to get the battery vertically and in front of the undercarriage bulkhead, the plane needs 155 grams of lead in the bottom of the nose under the motor. I'll leave it as it is now and load the nose under the motor and leave the battery inside, vertically behind the undercarriage bulkhead.

That's good to read! Being used to a foam WOT4e this plane feels like a lead weight, but I flew a 4 stroke/ balsa version last year (plane my buddy was flying) and the plane few really well in the 10 mph gusts typical of our air field on a very good day. I have a set of 4 x 3 cell batteries that fit all the planes I have somehow amassed over 4 years, but doubt i can find room now for a fatter battery, I guess a 5 cell 2200 is longer than the 3 or probably larger in all dimensions. Today, I think I'll tidy the plane up and get the radio all working, drill the prop to 8 mm dia shaft and machine the brass/steel nut which will add yet more balance, "every little helps".

Have to stop now while the snakes arrive soon I hope. Everything is in place now to move the weight forwards as above. The conclusion of all this is at 70 mm spar position from the leading edge the additional nose wight is 290 grams to be added, that's 15 Oz or nearly a pound! Nothing I can see to make this less, so it will have to be so. Bit dissapointed, but watched a YouTube video of a similar plane and R/C electric on a new build Junior and the flyer had to keep strapping lead strips to the nose to get it to glide 'flat' and fly. He seemed a very experienced flyer. Pics to follow when all done and cleaned up.

The 're-conversion' is going (too?) well. The ESC and it's wire lengths (not generous) sort of dictated the layout. The hole from the servo space by the engine bearers has been enlarged to 20 x 15 mm and the motor leads can pass into the engine bay well with some length to connect and the excess tucks away down into the engine bay side cheeks, The lead to the battery and Rx are now inside the servo bay and playing at being the plane's dash board. The cooling I hope will be ok.... The battery now stands vertically and is in-between the engine bearers and sits on the sheet balsa base by the under carriage and neatly protrudes in the right place to link to the ESC and Rx yet right up (bar 5mm) to the rear of the bulkhead of the engine bay. I know this means removing the wing to change batteries, but no big deal. Having removed the attempts of the previous builder(s) of the plane i have the original servo mount holes deep into the servo bay. Using the FMS servos (which are a mighty 10 grams with horn and 100 mm long leads) this servo platform of the original needs to come up a good 20mm to align the servo horns to the existing snake tubes and avoid as much as possible any 'out-of-straight' passage of the wires from the horns to the entry of the snake tube. I can also site the servos 10mm aft of the C of G, so not too bad.

I'm sorry this has generated a some discord. I think I'll come back when I have a 'result' and can show what I've done and the weights needed to balance the plane around the wing spar. Certainly the experienced flyer at the Club's field will only buddy Tx with me if he is happy with the balance which has been on the deepest of the wing section on my foam models, so on this design the spar which is 70mm from the leading edge. That will be the aim: to CofG at 70mm knowing I can balance either side of that but be nose heavy if anything. I'll add some pics if I can remember how to post on this forum.

Yes, and that negates the need to un-band the wing every time to change the battery. Plan now is to action all these excellent suggestions. Current FMS servos to the very front, either side of the vertical LiPo 3S 2200 battery, bottom hatch install. Snakes to the rear surfaces. Steel or brass prop nut Minimal I hope nose weight dropped into the engine nose box.

This plane was all built and drilled for an IC engine but the engine etc was never installed, hence never flown. The control links were not in the plane, just the servos on a rough ply plate. As it is all covered (rather well) I don't want to cut open holes other than a breather hole to help cool the ESC. I was/am hoping such a hole will allow threading the snakes through. I've just ordered 2 x 36" snakes with fittings from 4Max. 36" will get me from the tail surfaces to the prop, so I can get the servo's right forward and also mount the 3S 2200 battery vertically right up against the bulkhead so weight will be as far forward of the CofG as I can get it. Must admit, the servo's taken from the foam plane do seem very small, but the change around will be better in the long run and as said, remove the need for much of the additional nose weight. Quite like this type of tinkering on these planes, so all good in my book. +++++++ Thought I would own =up and say I have just looked deep down in the fuselage and the two outer tubes for the snakes are all glued in place inside the balsa frame... What a bonus! Just need to feed the steel wires in and terminate to the surfaces and servos once mounted far forward.

That was the conclusion I had almost reached this afternoon as the only way to shift weight to the front. I think your suggestion will make life better. On other builds I've made the classic wire/balsa runs from servo to surface links, possibly as light as you can make such runs. With the snow on it's way, could be a good time to change things round.

Interesting. This model was built and never flown and was full of Futaba radio servos etc. I scrapped an FMS Kingfisher and re-used the servos from that, mounted in the tail similar to yours but 'hidden' under the tail plane and long wires back to the Rx I was not sure that was lighter, but easy conversion and I knew it would all work with my DX6, the main reason for the change over. I've ordered a big box of weight strips. Will look at the CofG articles too as this will make quite a difference to the nose weight mass. Looks like the elevator movement is about 15 deg up and 12 deg down.

All good stuff, keeping it simple is the very best! As to nose weight... I am amazed how much will be needed to get the CofG under the wing spar, , 16 Oz seems about right, a huge weight but I'm comparing it all with my WOT4e that floats in the air. Not sure where to find such a load of weights other than a pile of the stick-on strips. I need to get this sorted before anything else. I very much appreciate this advice from you all, thank you.