Vacuum chucking success!

[Tony Trigg]

Hi,

I acquired a secondhand vacuum pump and bag press a few months ago and have only just got round to sorting the rest of the system. Pleasantly surprised by how well it works so I thought I'd share my experiences.
I turned an aluminium shaft, on the wood lathe with three little coves to fit three O rings that were a snug fit within the spindle, (Spindle bore approx. 16mm on my 3520B) much trial and error required to get the sizing right, and a little Vaseline for lube helps. Used a mixture of HSS cutters, sharpened as they would be for use in a metal lathe, as well as a standard skew and spindle gouge. Another O ring also sits tight up against the handwheel (I feel the more the merrier) and a hole bored through the middle, drilled out in the usual way with a Jacobs chuck in the tailstock. Sealed bearings are required and I used a couple that I had in stock.
Once again using what I had available, an old Nylon (some sort of plastic) material roller (another thing that I knew there was a reason for keeping) was hollowed out to fit the outside of the bearings. The inner part of the nylon was drilled out and the hose barb was screwed in.

Fittings, gauge and valve purchased and fitted together with PTFE tape and off we go. Used a sintered exhaust silencer as a filter below the quarter turn valve and then this was attached to the lathe using one of the belt cover bolts, which makes it easily removable.

Very poorly produced video making the adapter (and you'll be able to find others on the manifold and chuck)
Adapter Video

More chucks to make. further details to follow.

 

[Tony Trigg]

And a video of the Vacuum Manifold

I wanted to retain the option of using the pump on the vacuum press bag (or even some other uses in the future) so went for a quick release connector to connect to the vacuum pump.
All fittings were put together using PTFE tape, and the whole thing was fitted to a board that I chose to mount on the lathe using one of the belt cover screws, it could just as easily clamp somewhere suitable or screw to the wall next to the lathe.
I ended up with a mixture of ¼” and ½” BSP fittings to tie it together. A quarter turn valve is used to dump vacuum (or let air in depending on which way you look at it) this connects to the bronze exhaust silencer being used as a filter (when I open the valve air goes IN and I wanted to do my best to keep dust out of the pump, it will destroy it. (intention is to connect a filter to the pump inlet at some point)
Flexible pipe goes on the hose barbs to join the manifold to the adaptor. A cup of boiled water will soften the pipe end to allow it to be pushed onto the brass barbed fittings.

 

[John Legg]

I love it. Mainly because I just picked up a dual Gast Pump unit (2 different sized pumps coupled together on either side of the motor shaft) with the intention of ultimately converting it into a vacuum chuck. Originally used as part of a mail sorting system.

Baby steps and it will probably take a year or two to get it done at my pace of work (s l o w).

 

[John K Jordan]

Tony, nice design and machining! Good clean fun! Your video is good.

I keep a variety of plastic and metal stock around - might sit for years but when I want to make something, it's there!
I have a metal lathe and mill but use the wood lathe a lot for turning aluminum and brass. So far I've done one club demo on turning metals. (from machining I learned to love Dykem Blue for layout with calipers!)

I also like the set of o-rings, I get them from Northern Tool in both metric and imperial sizes (along with other variety hardware sets, pins, clips, hose clamps, spring, etc.) - amazing how often I reach for these things.

I had thought about making and adapter for a Jet 1642, read the stuff from Joe Woodworker, but didn't fall in love with the design. Bought a pump and parts from him to make a regulated reservoir clamping and bag press. His vacuum tape is excellent.

Vacuum Chucking Lathe Projects with Vacuum

www.joewoodworker.com

Then I bought a used 3520b which came with a vacuum pump and a commercial adapter (plus a variety of vacuum chucks) so the need evaporated!

I like the way you put a stop step on the aluminum with an o-ring just before the bearings.
Are your bearings a press fit in the hole for sealing? It's hard to get the ID right on such a hole with hand tools! I use a small spring-loaded internal caliper that lets me feel for the high and low spots.

Just curious, what's the reason for the cove on the OD near the end of the plastic?

JKJ

 

[Tony Trigg]

Tony, nice design and machining! Good clean fun! Your video is good.

I keep a variety of plastic and metal stock around - might sit for years but when I want to make something, it's there!
I have a metal lathe and mill but use the wood lathe a lot for turning aluminum and brass. So far I've done one club demo on turning metals. (from machining I learned to love Dykem Blue for layout with calipers!)

I also like the set of o-rings, I get them from Northern Tool in both metric and imperial sizes (along with other variety hardware sets, pins, clips, hose clamps, spring, etc.) - amazing how often I reach for these things.

I had thought about making and adapter for a Jet 1642, read the stuff from Joe Woodworker, but didn't fall in love with the design. Bought a pump and parts from him to make a regulated reservoir clamping and bag press. His vacuum tape is excellent.

Vacuum Chucking Lathe Projects with Vacuum

www.joewoodworker.com

Then I bought a used 3520b which came with a vacuum pump and a commercial adapter (plus a variety of vacuum chucks) so the need evaporated!

I like the way you put a stop step on the aluminum with an o-ring just before the bearings.
Are your bearings a press fit in the hole for sealing? It's hard to get the ID right on such a hole with hand tools! I use a small spring-loaded internal caliper that lets me feel for the high and low spots.

Just curious, what's the reason for the cove on the OD near the end of the plastic?

JKJ

Thanks for the kind words John.
I'll take a look at Joe Woodworkers site, but I'm in the UK so not sure if delivery is an option.

The bearings were a push fit into the hole, I turned a little taper on the internal face when close to the correct diameter then squared that up. Guess it helped that there was a little 'give' in the nylon type material.

As to the little cove, it wasn't necessary but I was thinking that somewhere to grip the adapter if it were to get jammed in the headstock or maybe it would help with storage.

 

[Tony Trigg]

I love it. Mainly because I just picked up a dual Gast Pump unit (2 different sized pumps coupled together on either side of the motor shaft) with the intention of ultimately converting it into a vacuum chuck. Originally used as part of a mail sorting system.

Baby steps and it will probably take a year or two to get it done at my pace of work (s l o w).

S L O W is my middle name. I bought the pump months ago thinking I'll get round to it, the need for something to hold the beech bowls was my motivation to actually get it done.

Beech Bowls showing the vacuum in use

 

[Larry Copas]

That is quite similar to the one I made nine years ago. The biggest difference is I added a grease seal in front of my bearings. That's the black thing in front of the bearing. I had read that the vacuum would suck the grease out of bearings even though they are sealed. After nine years my "O" rings look terrible from sliding in and out of the spindle but they still work.


Don't get trapped into buying vacuum chucks, they are so easy to make and work really well. I have em from 3" up to 20" in diameter.

 

[Tony Trigg]

Lovely job @Larry Copas, I hadn't considered that the vacuum could pull grease out of the bearings.
Unless I'm looking at it wrong surely the seal should be on the other end?