Vacuum system adapter, which one ?

[Amaury Graulich]

Hello woodturners,

I am planning to install a vacuum system on my lathe. The main problem is choosing the right adapter for my lathe. After removing the handwheel, the M25 thread is quite short (photo) behind the nut. Is it long enough to screw on the Oneway adapter? Or should I choose the Holdfast adapter? Do you have any other suggestions?
Thanks,
Amaury

 

[john lucas]

I had the handwheel of my powermatic bored to fit tge bearing in use on my vacuum system. Works so well I filled the handwheel of my midi kathe with wood and bored it to fit the bearing. A closed cell foam washer seals it. Very fast to install and remove getting your lathe back to normal operation. I don't have a photo of my powermatic handwheel but here is the midi adaptor.

 

[Dean Center]

Some spindles don't have adequate thread for a screw on adapter. The Powermatic 3520 that John Lucas shows is one of those. Oneway makes a special adapter for the Powermatics, since they are very popular in the US. I can't tell what brand of lathe you have, but you could ask Oneway if they have something that might work. Some vacuum systems do not require a threaded adapter at the outboard end, and so would work for you. Odd-not had one, but they may be out of business. Robust has solutions. Frugal probably has solutions. There are also lots of do-it-yourself solutions that you could read about if you do a Search on the forum here. Personally, I would not recommend the venturi vacuum method, as I think a vacuum pump is a much better solution, though some folks use them successfully.

 

[John K Jordan]

Oneway makes a special adapter for the Powermatics, since they are very popular in the US.

The vacuum adapter for my PM3520b is made from aluminum and has two O-rings which seal the smooth bore inside the spindle handwheel end - just put a tiny smear of silicone grease on the rings for smooth insertion. Unfortunately I don't know the brand since it came with the lathe. Would be easy to make one, especially with a metal lathe.

I've seen several designs for making vacuum adapters and all the pieces needed. One I remember is from Joe Woodworker:
https://www.joewoodworker.com/veneering/vacuumchucking.htm

Long time ago I bought a good vacuum pump from him. Although I didn't need to make an adapter, it was nice to be able to get all the pieces from one place to set up a vacuum chuck and vacuum press. Joe was also great to discuss things by phone.

JKJ

 

[Jim Reynolds]

Another resource is Doc Green's article Rotary Adaptor for a Vacuum System

I own his book Fixtures and Chucks for Woodturning. He goes in to the construction of a vacuum system in great detail in this book. I highly recommend this book.