Summary

Simple transformer bobbin that I made to wind custom power transformers for tube amplifiers. I sized it to use laminations from salvaged junk power transformers. It prints in two pieces to minimize need for supports. Just glue it together when finished. I added a lip to keep the sides from bowing out due to tight windings. Works fine for power, chokes, and audio output service. I do not recommend PLA if you expect your transformer to get hot.