UNI Tape Alternative? West 713

[TMann]

Would the West Systems 713 e-glass tapes be a viable substitute for the traditional tapes offered by Aircraft Spruce?

 

It seems as though it would be a much more managable alternative.

 

Any Ideas/feedback?

[Lynn Erickson]

Would the West Systems 713 e-glass tapes be a viable substitute for the traditional tapes offered by Aircraft Spruce?

 

It seems as though it would be a much more managable alternative.

 

Any Ideas/feedback?

It might take a lot more plys to fill the spar trough. I believe the cross fiber can not be removed as with the roving tape

[TMann]

It might take a lot more plys to fill the spar trough. I believe the cross fiber can not be removed as with the roving tape

Yes, it would take more plies and you would have to recalculate the number and length of each ply:

full length plies = Outboard trough depth / .0125

Incremental lengths = Length / ((inboard depth - outboard depth)/ .0125)

 

Yes the cross threads are permanent which really helps to keep everything lined up nice. I know that Burt's original design used UNI which was 'flag-folded' and had cross threads. I was just speculating on how it would affect the finished spar cap as far as having a uniform finished surface that more closely followed the underlying contour.

[Lynn Erickson]

Yes, it would take more plies and you would have to recalculate the number and length of each ply:

full length plies = Outboard trough depth / .0125

Incremental lengths = Length / ((inboard depth - outboard depth)/ .0125)

 

Yes the cross threads are permanent which really helps to keep everything lined up nice. I know that Burt's original design used UNI which was 'flag-folded' and had cross threads. I was just speculating on how it would affect the finished spar cap as far as having a uniform finished surface that more closely followed the underlying contour.

I used this type in carbon on my landing gear legs and it tends to build up a crown in the center. the loose fiber type tends to lay down better and the loose tows will fit into the low spots better

[TMann]

I used this type in carbon on my landing gear legs and it tends to build up a crown in the center. the loose fiber type tends to lay down better and the loose tows will fit into the low spots better

I've worked with the 703 Carbon Fiber which I used for the spar cap in my new canard. It worked out so well it only took me about half the time I had spent previously with much better results. The tapes conform very well to the underlying shape of the trough.

 

The 703 is very similar to the 713 (carbon fiber vs e-glass) and the contrast of the experience is very apparent which is why I brought it up in the first place. The real issue comes down to the strength of the finished product.