New members, please check your spam folder for activation email.

Schleicher ASH31 4m

Let us all watch your new project progress.
MartinE
Posts: 122
Joined: 28 Oct 2021, 14:36
Location: Essex

Re: Schleicher ASH31 4m

Post by MartinE »

Outer wing wing joiners bonded into the inner wing sections - all the pins line-up and move smoothly (phew, no faffing around to be done).

You can just see the white wire conduits, in their slots (Thanks for that suggestion Kenneth). I think I'll fill the gap with some balsa, then sand smooth.
Attachments
20220424_095358_001.jpg
MartinE
Posts: 122
Joined: 28 Oct 2021, 14:36
Location: Essex

Re: Schleicher ASH31 4m

Post by MartinE »

Note that all the wing joiners are mounted in between the upper & lower spar caps.
MartinE
Posts: 122
Joined: 28 Oct 2021, 14:36
Location: Essex

Re: Schleicher ASH31 4m

Post by MartinE »

Wing top surface bagging:

I decided in the end to use Mylar (as I already had it).

First photo shows pre-primed Mylar (rolled up), tissue paper, breather fabric & 106gsm carbon fibre (bias).

I used a roller to apply the resin, this gives even distribution and does not move the cloth.
Using the tissue paper, instead of 25gsm glass was much easier (Thanks again Kenneth).

And the into the bag for 18hours.
Attachments
20220430_140657.jpg
20220430_141126.jpg
20220430_144932.jpg
MartinE
Posts: 122
Joined: 28 Oct 2021, 14:36
Location: Essex

Re: Schleicher ASH31 4m

Post by MartinE »

What I didn't show was the wing foam negatives top and bottom, fully weighted down.

The wings came out of the bag this morning and (as expected) they're certainly not moulded wing smooth, but definitely my best bagged wings. Still some slight dips and ripples.

The tissue paper has eliminated any pin holes, which is great.

On to the underside shear webs, spar caps, etc.
Attachments
20220501_090613.jpg
20220501_090606.jpg
MartinE
Posts: 122
Joined: 28 Oct 2021, 14:36
Location: Essex

Re: Schleicher ASH31 4m

Post by MartinE »

On to the undersides;

2 slots are cut, down to the top spar cap - 1 straight & 1 wavy. Resin is then injected into the slots and then pre-cured/trimmed lengths of bias carbon fibre are slotted in.

The wave should give compression and shear strength.

The spar caps, from carbon tow (and resin), are then laid on top.
The wings are then bagged.
Attachments
20220507_133441.jpg
MartinE
Posts: 122
Joined: 28 Oct 2021, 14:36
Location: Essex

Re: Schleicher ASH31 4m

Post by MartinE »

While the wings cured, i started on the tail servos. Both tucked inside the vertical tail.

Holes cut either side of the rudder mount and the foam dig out. Then 2 mounts made that allow me to install servos from the rear.
Attachments
20220508_115911.jpg
20220508_104900.jpg
Kenneth Paine
Posts: 12
Joined: 14 Nov 2021, 09:50
Location: Cheltenham

Re: Schleicher ASH31 4m

Post by Kenneth Paine »

MartinE wrote: 07 May 2022, 15:25 On to the undersides;

2 slots are cut, down to the top spar cap - 1 straight & 1 wavy. Resin is then injected into the slots and then pre-cured/trimmed lengths of bias carbon fibre are slotted in.

The wave should give compression and shear strength.

The spar caps, from carbon tow (and resin), are then laid on top.
The wings are then bagged.
Good progress Martin; I am glad my tissue paper idea worked for you.

Interesting shear web set-up. Did you borrow the wavy shear web idea from James Hammond who includes it in his designs? I am not convinced yet; if forced to cut two shear web slots I would choose straight cuts at the front and back of the spar cap to make a (torsion) box spar.

How did you cut the slots to the top spar? Any interesting jigs and tooling or just by hand?

Kenneth
MartinE
Posts: 122
Joined: 28 Oct 2021, 14:36
Location: Essex

Re: Schleicher ASH31 4m

Post by MartinE »

Test
MartinE
Posts: 122
Joined: 28 Oct 2021, 14:36
Location: Essex

Re: Schleicher ASH31 4m

Post by MartinE »

Hello Kenneth,

Sorry for late response, been having issues posting & now away on holiday.

Yes the idea was from Mr Hammond. Works very well.

Martin
MartinE
Posts: 122
Joined: 28 Oct 2021, 14:36
Location: Essex

Re: Schleicher ASH31 4m

Post by MartinE »

Yes I did think about a way to cut since wave slot, but to be honest, just did it by eye.
Not sure how much difference an accurate done wave cut would make.
Post Reply