Kite Spar End Cap - PARAMETRIC - TPU

If you use carbon fibre or fibreglass spars in your kites, usually you need some sort of end cap to prevent the end of the spar rubbing and eventually pushing through the fabric.

Commercial end caps are usually PVC or similar rubbery material. They're relatively cheap, but you can guarantee that the size you need isn't in stock or you need one piece and the minimum order is 500 or the P&P is 20 times the cost of the end cap hahahaha! 

I bought the material and spars for a new kite about 20 years ago, and when I finally got around to building it this week I realised I didn't have any end caps. No problem, I have a 3D printer and some TPU now, so a quick bit of design in Fusion360 and I can print as many as I want in any size I want. And with the supplied F3D file here, so can you!

I have supplied STLs for 2mm and 3mm spars as that's what I needed. I gave them 2mm tips (beyond the end of the spar), 12mm coverage of spar (so 14mm total length), and 0.8mm wall thickness (two lines of 0.4mm nozzle).

I used a 3 line brim for adhesion. TPU bonds so well that this can't simply be peeled off, but I noticed that the first few layers of the model for some reason print a little fatter than the rest, so I took this into account and I cut off the brim along with about 2mm of tube with a sharp utility knife and that results in a perfect end cap with an overall diameter of under 2mm more than the spar diameter. 

If your requirement is for anything other than I've supplied, just edit the F3D in Fusion by going to fx Parameters and change whatever you like :o)  I could also add other sizes to this published model if needed, but Fusion is free for personal use so it's easy to install and tweak the file.

It would be great to see your makes, and possibly even your kites! I suppose it's possible you could use other materials to print these end caps, I just happened to have a reliable TPU which was ideal (Eryone Clear 95A Shore TPU). It's a good snug fit if you specify 2mm for a 2mm spar diameter. In PLA etc I expect you would have to add a little for clearance and then probably use a touch of threadlock superglue or similar to prevent it coming off unintentionally but still removable if needed.   

Please Like this model if you find it useful.

If you REALLY like it, https://www.buymeacoffee.com/gigabeast :o)