Groucho Duke's 38mm high power rocket launch tower

thingiverse

Use at your own risk. For the 29mm version and pictures of what the assembled tower looks like, check out this link: https://www.thingiverse.com/thing:2538353 This is a 3D printed end support for a launch tower designed specifically for high power rockets with a minimum diameter of 38mm. I've personally tested this design on one flight using a Loki J1026 motor and it worked flawlessly. It's still a work in progress, but everything has gone smoothly so far. This launch tower is built to fit over a standard 80/20 1010 square launch rail, making it easy to use at any launch without needing additional equipment. Be sure to check the fit onto the 1010 rail as some may have slightly different dimensions due to finishes or other factors. Bill of Materials: * Approximately 1kg of PETG or similar filament (I used http://amzn.to/2y7Z0zs) * 4x #10 machine screws * 8x #10 washers * 4x #10 lock nuts * 6x 1/4-20 x 4" lag bolts * 1x 1010 launch rail (or use your club's launch pad) * 2x aluminum extruded L * 3x 3/4" EMT conduit * Adhesive-backed Teflon tape (I used http://amzn.to/2wn9Hlc) Construction: - Print two of the parts, which will take approximately 40 hours each and about 0.6kg of filament. - Sand, file, buff, or machine the EMT conduit to remove any bumps that could damage your rocket. - Test fit the 3D printed parts on the 1010 rail, EMT conduit, and extruded L. You may need to sand, file, or Dremel a few things to get the perfect fit. - Trim the extruded L and/or EMT conduit to fit and deburr the ends so they'll slide onto the 3D printed parts (for my 4' extruded L, trimming the EMT conduit to 44-3/16" worked well). - Sand, file, or adjust the 3D printed parts as required. - Slide both 3D printed parts on the 1010 rail. - Screw the 1/4" lag bolts into place in the holes where the EMT conduit mounts. It's crucial to do this to avoid a catastrophic failure that could be deadly. - Tape one side of each EMT conduit with the PFTE/Teflon adhesive tape. - Support one end of the EMT conduit and slide it into one of the 3D printed parts, making sure the Teflon tape faces where the rocket will go. I used car washing sponges to prop up the EMT. Repeat for all three EMT conduit pieces. - Slide the other 3D printed part and EMT conduit into place. Depending on the fit, this may require some force. Use caution not to damage your 3D printed parts during assembly. If you damage them, throw them away and print new ones. - Once all three EMT conduit pieces are in place, slide the extruded L pieces into place. Drill 3/16" holes through the L using the holes in the 3D printed parts as a guide. - Use #10 machine screws, washers, and nuts to attach the L pieces to the 3D printed parts. - Test fit your rockets, inspect them, and get ready for launch!