Does anybody have an unbiased opinion on the Extra 300 by I.A.D Model designs?

I'm still building mine and have only one concern.

My wing joiner seems a bit flexible, a little concerned that it will flex or break under some mild aerobatics. It has a foam wing and it seems the wing tube in the wings are compressing the foam. When I join the wing then bolt it to the plane, have it inverted , then lean on the wings the centre gap opens about 2mm. The kind of load I think would be in a mild climb. I'm sure it would snap doing square loops or something similar. In my mind there should be no flex or movement at the join. What do think?
I've made the control surfaces slightly larger for 3D but do you think of the 3D capability??


Kevin

Kevin,
I don't know about the Extra 300 that you have but I have the 45% Cap 232 (ex Ali Machinshi that he displayed at Sandown etc). Its a fantastic plane. the wing is foam internally with a large aluninium tube as a spar so sounds similiar in construction. Ali did over 200 flights with it and if anything was going to break it would have done it by now. Why don't you speak to IAD for reassurance.
John

Hi John,

Thanks for that. My wing tube is about 17mm in OD and about 500mm long and not in the centre of the wing, it's towards the top of the of the surface. Ive seen an older design and it had a 25mm tube and about the same length. I tested the rigidity of it and it felt like a one piece wing.
I spoke to Ian at IAD and he said it's a foam wing, it's bound to flex and compress. It just doesn't seem right to me. I'll continue to build it and fly it.

I was actually contemplating to join the wing so it's in one piece, stronger and lighter.
Thanks for the info.

Kev

Dear Kevin


You are condeming the model before trying it. there are lots of extra's flying with this wing tube which is 6061 t6 alloy.

I take it this is the same model you gave to someone to build and he made a total hash off it?

The wing tube is near the top of the wing at root in order to place the end of the tube as near the centre of the wing as possible, (have you ever seen a wing fold down the way?) as the top of the wing is flat and the tapered thickness gives the efect of slight dihedral.


The tube used is the same tube Installed the same way in my Serpent jet of which I know of several with 30lbs turbines fitted, and I think a jet with this size of turbine will pull higher G forces than any aerobatic model.

You will probably have noticed by the lack of replies the only problem is in your imagination.

No , no issues at all..............

Flown all season, flys great..... and its been put through it's paces, elevator and rudder were enlarged for 3D purposes, but that was my choice, and Iain was very helpful in this respect.

Hi Ian,
I didn't think there was a problem with the aluminium tube, just the fact the insert tube flexes in the foam. I thought it might tear through the surface. Maybe the fact that the twat I had doing the work on the plane did damage to the wings by leaving them in the sun...(not to mention all bad work he did)....

As you know they were left in the sun and split the veneer.
I put the thread on here only to confirm my suspicions , if no one had problems then maybe the foam is a bit more spongy in places because of the sun expanding it.... I don't know... but it does flex a lot with very little weight..

It's not far from being covered, taken a shed load of hours to get to this point though... No thanks to that wanker that called himself a "professional commission model plane builder"

Anyway thanks for your help, don't take it personally.