WMAC Group build - Impressivo

MikeSeale wrote:
I see in the instructions that you can go for the servo exits on top of the wing or underneath and see you've gone 'down under'. I think I'll do the same but wondered if there is a reason for this other than personal preference.

I assume going on top of the wing would be to protect the linkage and horn when landing, which I would think would be sensible when landing on grass.

flyingpete wrote: Blimey Jon that is blast from the past!! Last time I saw one of those was at Beaulieu in the mid 70's

Definately a piece of modelling history Pete, been reading up a bit on it, Hanno used it to win his first Worlds in 1977! So it would probably have been around the late 70's over here. When I started out in F3a in '86 I think, my old mate Phil Mitchell was flying one, covered in nylon and painted as I remember, it weighed a ton but still flew really well. The kit is really nice and it's going to turn out much lighter than the originals, should be fun

Jon said

I assume going on top of the wing would be to protect the linkage and horn when landing, which I would think would be sensible when landing on grass.

Just a thought provoked by the comments about getting the servos into the rather thin wing. How about putting them in the fuz and driving the elevons with torque rods just like we did in the old days of a single aileron servo?

I've not yet got my kit but looking at the pic of the model PhilC let us think he'd built it certainly looks a possibility. I suppose flutter could be a problem but as the elevons are not in the draft of a prop it should be ok if the torque rods are strong enough to resist twisting.

David

Hi Dave

I don't think torque rods would be a good idea in this type of model - Its a recipe for elevon flutter !

Haven't collected my kit yet but i can't imagine that the original 11mm x 23mm servo footprint can't be opened up to 12mm x 24mm of which there are many cost effective digital MG servos with 2g/cm torque available.

Got my kit and shortly after admiring the superbly machined parts my glue started to dribble from its nozzle resulting in a completed fuselage crutch assembly. However, i am holding off fixing the rear former R9 for the motor because mine has not arrived yet.

Q. Has somebody in the build group got both kit and motor and if so please advise if the Motor profile fits this bulkhead or would it be better to make one specific to our elected motor.

Motor bulkhead fits the motor perfectly...just glue it together and the motor will slot straight in when it arrives, Kevin.

Fitting 12mm servos will require a little modification. By the look of it, ply parts F19 and F20 create a 'frame' for a 9mm servo and then balsa parts F21, F22 and F23 closes the structure before covering. F20 is 1.5mm in from the profile of the ribs and it wouldn't take much to drop this part down to the rib profile which would give an additional 1.5mm for the servo thickness. The inside of balsa part F22 could then be sanded 1.5mm at one end to clear the servo. I'm not going to order any servos yet, but here are some options to ponder...

Savox 0255 = £16.45 Metal gear, 1BB, digital, 12mm

New power XL-17MB = £10.99 Metal gear, 1BB, digital, 11.6mm

Ripmax SD150 = £15.95 Plastic gear, no BB, analogue, 9.1mm

I've used all of the above in one model or another. The SD150's are currently driving the ailerons in my F5B model...the one that does 150mph+. Food for thought?

Mike