Ruined threads on spindle

[BradyWatson]

Get an ER torque wrench. It's the only way to do it right.

Chasing threads with a thread file is fine. A motor repair shop would do exactly that.

Unless it's an ATC spindle or 5hp+ Colombo, the spindle is considered disposable. For example, I borked the threads on my spindle 15 years ago and they wanted $800 for a replacement main shaft - no bearings. Bearings were another $700 and none of this included an ounce of labor. I thread filed it and that spindle is still useable today... although it's getting time for new bearings.

[Pscdouglas]

I love this phrase: one quarter turn past "snug" is BROKEN!

[GWG_CNC]

Repair of damaged threads on the Spindle of the Stinger II.pdf We are a guild so have many trainees learning CNC programming and machining on our machines. In January and February 2023, we replaced our old machine with a Stinger I and Stinger II. Soon afterwards, a trainee cross threaded the spindle of the Stinger II, requiring a cheater bar to remove the collet nut. The attached pdf describes the process we used to repair the threads.

David Dewease CNC Coordinator at Greenville Woodworkers Guild, Greenville SC

[keithrhyde]

My suggestion is a Musclechuck which eliminates which after installation eliminates the removal of the collet nut. Just one allen screw to tighten and much easier to change bits. I have one on my Stinger and router table and I love it. I am old with arthritis in my hands and I can still use it. I have never had a bit come loose. Joey will give you a 10% discount if you have a Camaster CNC. FWIW

https://www.usroutertools.com/category-s/343.htm