Mini Drak Fins by billyd

Last crawled date: 3 years ago

I don't like Coroplast for wing fins so I decided to print mine. I used ABS on a 100 degree c bed with PEI covered with glue stick. An easy way out would be to use PETG. PLA is not great long term in sunlight. If you're having trouble with the fins warping after taking them off the bed, use a covering iron on high (for ABS) and slide it over the concave side of the warp. After a little experimentation you'll learn how to get it flat.
The big fin just BARELY fits on the bed (see the photo) so you need a big printer to print this, just a little smaller than 12" square room on the bed is required.
I printed this at .2mm layer height and .5mm print width. Also I used 2 layers on the bottom and 3 layers on the top with 15% infill in S3D. This is the bare minimum to keep the part roughly watertight (or the appearance of) and minimize weight. With these settings the big fin weighs about 24 grams more than the stock Coroplast fin of the minidrak.
The good news is if you can print this they look way better than the coroplast fins.
ps The big fins are designed for Harvard Store's Oring wing joining method. So the notch on the fin is a little taller and narrower than the stock Coroplast. But it will likely work with the stock method of velcro anyway.
*Update 6-2-2017 Added split big fin files to print in two pieces on smaller printers. Sand and use goop to join them. One set has notches for easy alignment and more gluing area, but may not look as nice.