Gotoh-125SD-OTA cut short by 100mm.

This is the preparation for the cutting.  There must be always a clue to enable even at the hopelessly difficult situation in challenging something.
After cutting short, the difficult task of making the inner thread on the end will follow. But I have the innovative solution, either.

機械が無いとか、キャパを超えるとか言うのは、言い訳です。　本気で考えれば、大抵解が見つかるものです。　何事も工夫次第。　この後に続く、末端内ネジ切りにも秘策があります。