This is for those tiny crimp on dupont connectors that fit inside the plugs that plug into the RAMPS board. Tolerances on this are TIGHT! don't feel bad if you can't print a working one. This isn't going to crush the connector tight but it is enough to get those little tabs to start folding in the right way so you can squish it flat with some needle nose pliers. You can also give the crimper a smack with a hammer to close the jaws tighter after you've closed it as much as you can by hand. Feel free to mix this up and make a stronger one if you like. You can get the uncrimped connectors and plugs at places like banggood.com for about $7. The real tool is available there too for $17. Print it solid. With some swearing and a magnifying glass you can make your own custom plugs!Print it solid. Not a substitute for a real crimper but better than nothing. Put together with a 2mm machine screw.