My New Vacuum Chuck

[James Combs]

A couple weeks back I posted a vacuum pump tool gloat. I now have it in service. This post will give you an overview of how I got it up and running.

This first set of photos is the modification of the spindle hand wheel on my Jet 1642.

The first photo is the main valve/bypass valve and gauge assembly. The 1/4" nipple mates with the 1/4" coupler in the next two photos. I had several of the bearings in the second photo from years past (hence the rust) and used one of them for the coupler bearing. It has a nice flexible plastic seal. I turned a seat in the hand wheel for the bearing and turned the coupler to a press fit in the bearing.

In the fourth photo I have the pump hooked up and on with the spindle plugged I get 26+inches of Hg. The fith photo shows the remote on-off switch for the pump which is placed on the far side of the lathe just outside the chip curtain. When the curtain is closed it keeps chips off of the pump and the rest of the shop. The next post will deal with pump.
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[James Combs]

These photos show the pump and filter unit. With the connection hose dead ended into a vacuum gauge I get a full 29" of Hg. The Home made filter unit uses a replaceable automotive filter. I will detail it in a different post. I had read of complaints about oil vapor smoke from vacuum pumps so I have added an oil extraction filter to the output port. I will post latter as whether or not it works.


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[Steve Schlumpf]

James - Congrats on getting your system up and running! Everything looks well thought out and the system should serve you well! I am impressed with the Hg you are pulling! Don't believe I ever got more than 23 or 24 Hg with my mine.

Thanks for sharing your design! Have fun using it!

[James Combs]

This is the actual chuck. I found an old piece of coupler and turned and taped it as a face plate. Mounted a piece of MDF to it and grooved it for a modified PVC clean-out. The first photo shows all the steps I went through to make the chuck. The other photos just blow up a few of them up for detail. Next post is the filter.

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[James Combs]

To prevent dust and dirt from getting sucked into the pump I needed a filter. Checking on line I found them but they were from $40 to $100. I figured I could make something much cheaper. Here is my version at about $20 to build and $4.95 to refill. The refill is for a, I believe, a Saturn. It is 2 or 18 micron oil filter. I really couldn't tell the rating from the specs but some online discussion forums pegged it at 2 and 18 depending on manufacturer. This one should be a 2 but not positive. It too uses a PVC cleanout as well as a PVC reducer and a short length of 3" PVC pipe. Two o-rings seal the filter and adhesive back foam seals the lid. Turned UHMW parts create the seats with o-ring seals and the spring keeps tension on the o-ring seals. The green o-ring on the filter comes with it but I am not using it as a seal only as a centering locator. That is UHMW in the bottom of the PVC canister fitted and glued into a notch milled into the side of the bottom funnel (PVC reducer), another piece of UHMW (w/spring) is fitted to the top of the filter (snaps onto it or onto it) and a third piece forms a lip on the clean out lid and contacts the foam seal. Next Post is "In Use"

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[James Combs]

Here you can see the chuck being tested then in use. The first two photos is just a piece of laminated MDF placed against the main chuck face. In the third photo I have just finished sanding a recent HF and will be reversing it for tenon removal. In the fourth photo I have install a smaller adapter (again from PVC) to the main chuck face and have reverse mounted the chuck and bowl and am transferring the bowl to the v-chuck. Looked for a separate OP for the reversing chuck adapter.

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[Peter Fabricius]

James;
That is a really nice system. You are very lucky to be able to use a Metal Lathe. I have access to one but it sure would be nice to have a Metal working section to my shop.
Well done, 26 inches is more that some bowls can stand. Perhaps your pressure relief valve should be opened a bit when you have thin walled bowls.
Peter F.

[James Combs]

James;
That is a really nice system. You are very lucky to be able to use a Metal Lathe. I have access to one but it sure would be nice to have a Metal working section to my shop.
Well done, 26 inches is more that some bowls can stand. Perhaps your pressure relief valve should be opened a bit when you have thin walled bowls.
Peter F.

Agreed, I will be using the bypass valve to reduce the vacuum on thinner items. It will induce a leak in the system reducing the maximum vacuum. The few items that I have run with the 3" adapter hold nicely at about 20" Hg.

[Dan Forman]

That's a really nice, and well thought out system you have there.

Dan

[Jeff Nicol]

James, You went all out on your Vacuum System and it looks like it will do the job. I still have my old beater ex-Dehumidifier pump system that I have not used in over a year. I found out I work much faster with jam chucks and only seem to think about the vacuum when I have a piece where the bottom may be weak or soft when turning it down to the nub before carving it off and hand sanding to finish. Maybe some day I will use it more, have fun with yours.

Great job,

Jeff

[Alan Trout]

James,

That is a very nice setup. You were very crafty the way you put it together and you should be proud. Well Done!

Alan

[Baxter Smith]

Great looking job James! They are very convenient!

[David Reed]

Way cool addition to the shop. I've gotta get one built also . . . soon.

[Jim Burr]

That looks like it came out of a box it's so well assembled. You mechanical guys just kill me!! Superior work JD!!

[John Furjanic]

James, Hi
You have quite the setup there and was wondering if you could provide some more details about your oil mist filter? I have the same make vacuum pump and am currently trying to finish my vacuum chuck system. Did you make or by the componets used.

Thanks,

John

[John Keeton]

John, you should PM JD in the event he does not check this older thread. I am sure he would share his information.

[Greg Bender]

James,
definitely a very nice fab job, and Thanz for posting it in such detail. I really like the filter canister.Is 2 micron the perfered filter media for our type of application?
Greg

[John Giem]

These photos show the pump and filter unit. With the connection hose dead ended into a vacuum gauge I get a full 29" of Hg. The Home made filter unit uses a replaceable automotive filter. I will detail it in a different post. I had read of complaints about oil vapor smoke from vacuum pumps so I have added an oil extraction filter to the output port. I will post latter as whether or not it works.


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I read your post and found it rather interesting. I have a couple of questions and comments. From the photos, it appears that you have a rotary vane oil lubrucated and saled vacuum pump. That type of pump will generate the best vacuum levels. The next lower performance is the dry rotary vane pump, followed by piston pumps and then diaphram pumps. From the text, I think that you are using 1/4" NPT fittings but I can't tell what size hose you are using. In the testing and evaluation of vacuum pumps and vacuum chucking systems, I have learned several interesting things about them. The high vacuum level you measured is necessary but not sufficient. How accurate is your vacuum gauge? I have seen a wide variation in readings from the typical 2 1/2" gauges. What is your alititude? Here in Northern Colorado, I cannot get above 23 in Hg. Congratulations on having a good working system that you can use. Now for the rest of the story... To properly evaluate a vacuum pump or a vacuum system, one needs to measure both the vacuum levels and the air flow rates. In a perfect world there would be no air flow because we were able to get perfect seals and the wood in our bowls does not leak air. In the real world there are leaks and the vacuum levels achieved at the vacuum chuck, where it is needed, depends upon all sources of leakage. The biggest limitation in most vacuum systems is the plumbing and hardware between the vacuum chuck and the vacuum pump. I have measured data showing that this inbetween stuff lowers the maximum air flow from 5 CFM with just the pump to about 2.5 CFM when all of the rest of the system was in place. Recommendations; 1/4" NPT fittings are ok, use 3/8" hose with corresponding hose barbs, keep hoses as short as feasable, the rotary vacuum adapter should have the largest bore through it that you can get. After you have your system together, test it for leakage. The lamated MDF across the chuck is a good start but a bit heavy. To help in leakage testing, I put an isolation valve between the filter and the manifold. I placed a sheet of aluminum across the vacuum chuck on my system and closed the isolation valve and measured how long it took for the plate to fall off. Remember, rotary vane pumps will not hold a vacuum when turned off whereas piston and diaphram pumps will, hence the need for an isolation valve. The volume under test was that of the vacuum chuck, vacuum adapter, hoses, manifold, vacuum gauge and leakage control valve. I was and still am shooting for the max performance. When I first ran the fall-off test, the plate fell off at around 25 seconds. I hunted down and fixed the leakage in the system. Afterwards, my fall-off test increased to in excess of six minutes. (I got tired of waiting.) What this means is that we can take our good useable system and improve it to a great system which allows us to mount and turn items that would otherwise we could not.

John Giem

[James Combs]

Thanks for the great info John, it gives me some great points to look at to improve my system.


I read your post and found it rather interesting. I have a couple of questions and comments. From the photos, it appears that you have a rotary vane oil lubrucated and saled vacuum pump. That type of pump will generate the best vacuum levels. The next lower performance is the dry rotary vane pump, followed by piston pumps and then diaphram pumps. From the text, I think that you are using 1/4" NPT fittings but I can't tell what size hose you are using. In the testing and evaluation of vacuum pumps and vacuum chucking systems, I have learned several interesting things about them. The high vacuum level you measured is necessary but not sufficient. How accurate is your vacuum gauge? I have seen a wide variation in readings from the typical 2 1/2" gauges. What is your alititude? Here in Northern Colorado, I cannot get above 23 in Hg. Congratulations on having a good working system that you can use. Now for the rest of the story... To properly evaluate a vacuum pump or a vacuum system, one needs to measure both the vacuum levels and the air flow rates. In a perfect world there would be no air flow because we were able to get perfect seals and the wood in our bowls does not leak air. In the real world there are leaks and the vacuum levels achieved at the vacuum chuck, where it is needed, depends upon all sources of leakage. The biggest limitation in most vacuum systems is the plumbing and hardware between the vacuum chuck and the vacuum pump. I have measured data showing that this inbetween stuff lowers the maximum air flow from 5 CFM with just the pump to about 2.5 CFM when all of the rest of the system was in place. Recommendations; 1/4" NPT fittings are ok, use 3/8" hose with corresponding hose barbs, keep hoses as short as feasable, the rotary vacuum adapter should have the largest bore through it that you can get. After you have your system together, test it for leakage. The lamated MDF across the chuck is a good start but a bit heavy. To help in leakage testing, I put an isolation valve between the filter and the manifold. I placed a sheet of aluminum across the vacuum chuck on my system and closed the isolation valve and measured how long it took for the plate to fall off. Remember, rotary vane pumps will not hold a vacuum when turned off whereas piston and diaphram pumps will, hence the need for an isolation valve. The volume under test was that of the vacuum chuck, vacuum adapter, hoses, manifold, vacuum gauge and leakage control valve. I was and still am shooting for the max performance. When I first ran the fall-off test, the plate fell off at around 25 seconds. I hunted down and fixed the leakage in the system. Afterwards, my fall-off test increased to in excess of six minutes. (I got tired of waiting.) What this means is that we can take our good useable system and improve it to a great system which allows us to mount and turn items that would otherwise we could not.

John Giem