Adjustable mandrel not adjusting

[maxwell_smart007]

My PSI adjustable mandrel seems to have seized. I was making a Baron, and tried to change it to make a Sierra, and the mandrel shaft is stuck in the collet. As I turn the nuts to loosen the collet, the nut and shaft turn simultaneously...

I tried spraying some white lithium grease in there, and taking some lock-jaws and 'carefully' turning the mandrel shaft, but I can't get it to budge, and don't want to bend anything by being too aggressive...

SO, am I missing something?

Andrew

 

[Russianwolf]

with the collet loose, tap the end of the rod with a mallet. nothing too hard, just enough to break loose the CA, laquer, or grit that is making it stick. I've had it happen several times.

 

[cowchaser]

Mine seized also but is a csusa model. After loosing the nut I had to pull mine out further instead of pushing it in. When I tried to push it in it seized up more. Of course this was only my solution.

 

[jhs494]

Mine did the exact same thing.
I removed it from the lathe took the threaded cap completely off, and turned it over and tapped out from the other end.
It left a small mark on the shaft, which I just filed back smooth after. I now know not to tighten so much.
Just thinking while I am typing, I wonder if perhaps a small amount of Never Seize on the outside of the collet would prevent this from re-happening?

 

[jptruett]

I have to remove the nut and then pull the shaft and collet from the rest of the mandrel. Then I can slide the shaft in the collet to the length I want and reasseble. No big deal to me now that I know what to do.

Jerry

 

[Rifleman1776]

You need a bigger hammer.
Actually, try some solvent for whatever might be on the shaft. Acetone for CA, laquer thinner for laquer, etc.

 

[jrc]

They all do this. The easiest way is to start by putting a large bushing and tubes on the rod and the brass nut and tighten it. Then loosen the mandrel nut and it will push out and loosen the rod. The mandrel nut hole is larger than a 7mm bushing. I have a small thick washer that is placed first on the rod between the mandrel nut and the first bushing and when I turn the last one before changing sizes while the turned and finished pieces are still on I loosen the mandrel nut. Don't forget to back off the tail stock.

 

[jrc]

Did anyone try it this way? I've done it this way since the sierra's kits came out.