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Custom 3D Printed Carbon Fiber Bike Frame

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Step 18: Extra Layups (and Avoiding the Temptation to Do Them)

Picture of Extra Layups (and Avoiding the Temptation to Do Them)
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2012-05-26-465 (Medium).jpg
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If after demoulding and sanding you find that there is a delamination, ridge, pocket, or void, have no fear. Simply grind or sand away the damaged area and add new layers as mentioned in the previous steps.

In my case, I decided that I wanted to do something a bit nicer with the edges of my lugs, get a sharp clean edge,  and feather them into the tube a bit more smoothly. I could have done this with some sanding, but I was lazy and wanted to do it by adding material instead. I cut some thin ribbons of fiberglass and carbon fiber tape of varying widths to create the transition, and then laid up a larger piece of the twill weave carbon for the outer layer. After that, I wrapped in compression tape as I'd done for the dropouts.

This turned out to be a big mistake. Getting nice uniform layups without the moulds was trickier than I'd thought, and I ended up with a bit of a lumpy mess. The carbon fiber had also slithered around a bit as I added the compression wrap (the key is to let the epoxy set up a little bit before doing this, rather than immediately after the layup). The end result was a bit of an aesthetic nightmare, exactly the opposite of what I'd hoped for, and in trying to fix some minor imperfections meant that I needed to do a huge amount of sanding to get back to the point I'd started at.

Learn from my mistakes, and avoid the quick fixes. Getting a nice finish on your parts will usually require some measure of sanding no matter what, so do it nicely the first time instead of doing it twice.
 
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