[BUILD] Making a Carbon Fibre Wing: Part 2 - The Spars

The second installment in manufacturing a carbon fibre wing for use on a race car. This video fixes the pattern I screwed up in the last one and then focuses on the manufacturing of the spars which will take the main loads in the wing.
Per my usual procedure:
The build starts straight away.
The lessons learned start at 18:50
The materials being used:
- Kinetix R246 / H126
- 300gsm biaxial Stitched Carbon Fibre (Easy Composites)
- 200 GSM 2x2 Twill Carbon Fibre (Beyond Materials)
If you have any projects you want help on hit me up through my website contact page and we shall see what we can do. www.chapmaneng.com
The wing calculator spreadsheet is available through my website at: chapmaneng.com/tools/ If you have any questions or suggestions about it please drop me a line.
The airfoil data came from: www.airfoiltools.com/
X-Foil information is at their website here: web.mit.edu/drela/Public/web/...
Did I say check out my website? I like it, I made it (it needs work) www.chapmaneng.com

[@ross4742]

Great videos

[@carbonarne675]

I liked the wetpack debulking

[@DanielWilliams-oi4ss]

So I didn't do the calcs myself, but I am broadly familiar with how much carbon the aviation guys are using, and it seems like your wing is pretty dramatically overbuilt? (Not stating, asking). Looking over your spreadsheet, it seems as though the deflection can't possibly be that high. I'm trying to use an online calculator to check.
EDIT: Again, I may be doing something wrong, but simplifying to do a box beam with uniform load (which the arc of the carbon ought to be superior to?), I get a deflection of .308mm with 1772 N/m load distribution, .135m span, 1.6mm thickness, and Modulus of 45 GPa.

[@CEWManufacturing]

It is pretty overbuilt, however, the deflection "between spars" (which I assume is what you are referring to as it is the 0.135m span on the sheet) is the theoretical deflection of the unsupported skin under load, not the whole wing itself.
With the foam still in there I suspect that number is completely meaningless now. However I was originally contemplating melting the foam out to have a hollow wing. In that case, the skin between the spars would have been a solid beam with 1.6mm thickness, 0.135mm span and unit length (as it makes the calculations easier to use unit length and load/unit length). I don't think it is unreasonable for sizeable deflection there.
The free end and center of struts deflections are the overall deflection of the wing, and they are substantially smaller. But that assumes the load is completely shared across the whole wing cross section, not locally applied.
Does that make sense? I'm happy to be wrong, if you think differently please let me know.
As for the overbuilding, I did originally start this as a learning project for myself, I was then going to test the wing at the end to verify my model and see how the whole thing ended up. As you're probably tracking from watching my video, the wing ended up bigger and with a mate instead.

[@kendallt909]

The clamp and spring to maintain tension were great ideas.
With the glue, I would use a cheap small paint brush to spread it over your surface evenly for a better glue joint

[@CEWManufacturing]

Thanks for the comment. I'm probably going to use the same glue on the next video to join all the bits back together, even though I said it took too long to cure....

[@___Chris___]

The video is interesting, but I see a problem with this construction method: you have limited control over the fiber direction. It probably won't matter for this application, because it seems over-engineered anyways, so this is just a general observation in case strength is more of an issue (like in airplane wings). You would want longitudinal direction for the upper and lower spar surface, but vertical or even better bidirectional in 45/45° diagonal orientation (or triaxial) for the vertical connection part. You can't have all that be winding the same cloth in that 'C' shape. What I would have done: rectangular spar cross section, with two separate types of cloth: longitudinal stripes of unidirectional cloth for the upper and lower surface and then wrap triaxial cloth around the entire thing (the vertical parts don't need to be very strong, so very few layers of triaxial would do the trick).

[@CEWManufacturing]

Thanks for taking the time to comment.
You can still get good fiber orientation control with an open, wet, hand layup (routan aircraft are testaments to that), however you won't get the same level of precision as you would with prepreg (and cnc tape placement etc).
Specifically on the points you raised about the spar: it was well over engineered, this was done because I was exploring the construction method and was only intending to make a smaller section, but somebody wanted it knowing the limitations of what I was doing so this is how it ended up.
The spar c channel was a quasi isotropic layup with a higher weighting towards the 45degree fabric I was using. If I was doing it again I would probably lower the number of layers in the vertical surface (maybe take it to 2x biaxial and 1x twill) and then use a unidirectional tape on the spar caps.
I wasn't trying to make the most materially efficient wing here, but rather go through the process from start to finish. When I make another I will refine it and it will be better than this one.