SS pen mandrel from PSI

[wa2crk]

Hi gang;
Spent most of yesterday and today in the shop (garage) turning a few things for an upcoming craft fair. This was the first time I used the Penn State pen mandrel and the mandrel saver together. Things seemed to be going quite well but I was getting some vibration that I thought was unusual. I stopped the machine and got a different lathe tool and when I started the machine again the mandrel was spinning off center where it threaded into the spindle adaptor. A quick inspection revealed that the mandrel had unscrewed itself from the spindle adaptor. So I put it all back together and after a few minutes turning it happened again. When the mandrel unscrews itself it is not apparent as you work.

Well this looks normal!!!
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But this is what you see when you retract the quill.
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I think that I will go to Ace Hdwr in the AM for some Loctite for the mandrel and hopes it works out. Note that this does not happen if a standard live tailstock center is used cause the tailstock prevents the mandrel from moving.
This is probably not too dangerous but it might cause some ruined work.
I actually like the PSI mandrel system as well as the mandrel saver. I have a feeling that the Power Pro's constant adjusting of the spindle speed may be the cause of this movement, but time will tell.
Bill V

[wa2crk]

Don't know why the first "normal" pic did not load but here it is again.

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Sorry
Bill V

[terrydowning]

It's not specific to Power Pro. My "greenie" does it sometimes too (but not always). A bit of loctite and it has not happened since.