# Vacuum chucks



## Woodturner1 (Aug 3, 2011)

I would like to install a vacuum chuck and being about a cheap as they come, I would like to do it as inexpensively as possible. 

This sort of equipment is new to me so at this point I don't know what I don't know. I'm think I'm looking to learn the following. If not feel free to tell me what I need to know.

1) Can a basic air compressor be used to create vacuum or is a vacuum pump the appropriate equipment. I ask because a compressor would serve additional purposes in my shop. A vacuum pump would be single purpose. What size would be appropriate? I see CraigsList offerings for compressors measured in gallons, so is that the standard or should some other measure be applied?

2) If a basic air compressor can be used would the compressed air need to be run through some other apparatus to convert compressed air to vacuum? 

3) Finally do you have a recommendation for a good value chuck?

Thanks, Brian


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## davesplane (Apr 26, 2010)

this company makes vacuum generators that would work for this application.
http://www.vac-cube.com/


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## john lucas (Sep 18, 2007)

The least expensive way the I know of is to use a older Automotive air conditioning compressor as your pump. the you have to supply a motor and of course rig up the mounting. some plumbing, valves and a Vacuum gauge and a bearing to attach it to the lathe and your in business. I did that about 10 years ago and it cost me about $50. there are complete plans in American woodturner about 10 years ago. If your a member of the American Association of Woodturners you can access all the back issues and find it.
You can use what is called a Venturi vacuum system with an air compressor. Standard Venturi style systems that are inexpensive don't work very well. They take huge volumes of air and are extremely noisy. There is a system sold by Craft supplies that will work with smaller compressors and is not noisy. It's starting to get pricey however.
http://www.woodturnerscatalog.com/s...Vacuum_Chuck_System___holdfast_complete?Args=


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## Woodturner1 (Aug 3, 2011)

Thank you both, Dave and John. I haven't decided which approach to take as yet. The home built or the ready made. I'll keep the board posted.


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## Dave Paine (May 30, 2012)

*Lot of information available on the internet*

The other replies have links to options for using compressed air with a venturi device to get the vacuum source. I learned something new about the Vac cube. Interesting.

No sense in re-writing information which is well written on the internet. Check out Joe Woodworkers site.
http://www.joewoodworker.com/veneering/v2-about.htm

Joe has a lot of the details you are looking for. Good documentation, pictures and references.

You will need
a) A means to create a decent vacuum namely > 20in Hg. 30in Hg is a perfect vacuum.
b) An adapter for the lathe where you attach the vacuum tube. The tube is stationary, the lathe head is not, so you need a sealed bearing adapter.
c) A manifold to control the vacuum. Turn on, turn off, alter amount of vacuum.
d) A vacuum chuck head. This is what holds the piece while you turn.

Air compressors are useful in the shop as you mentioned. However, you need a lot of air to generate the vacuum needed for turning.

Air compressors have the following main statistics
i) Motor horsepower. Look for actual not "rated". Check the Amps of the motor, this is the real number. Higher the HP, the higher the max flow.
ii) Maximum CFM (Cubic Feet per Minute) at a given pressure. The higher the pressure the lower the max CFM. If you go the venturi route check the minimum CFM and pressure needed.
iii) The size of the surge tank typically in gallon. This aids in storing compressed air so that the compressor does not need to run continuously - assuming your discharge is less than the max CFM at the pressure you are running.
iv) Lubricated vs non-lubricated. I personally prefer lubricated. This is more up front cost, but will be quieter and last much longer.

A chuck for vacuum use is very different than one for normal turning. I purchased a 6in vacuum chuck head from HoldFast. Not cheap, but very well made.

I tried to make my own. The 4in PVC one runs true. My 6in attempts did not run true so I purchased the HoldFast.

I have a Beall spindle tap which was my way to make the threaded insert to glue into the PVC fitting. Just more challenging to get this to run true than I expected.
http://www.leevalley.com/US/wood/page.aspx?p=57074&cat=1,330,49238


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## john lucas (Sep 18, 2007)

Dave I found that you usually have to true up any vacuum chuck you make. I have been using plastic decking material as the base for the chucks. tap that with the beal, install it and true it up. Then I cut a groove to fit different sizes of PVC and glue that in. Those usually only take a tiny bit of truing to make them run accurately.


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## Dave Paine (May 30, 2012)

*I may have made my chuck heads the wrong order*

John,

I was expecting to true the vacuum head. I may have used the wrong order.

I tried the PVC fitting, then made the wooden plug and glued it in place, then re-trued.

I then drilled the hole. Still true.

Last step was the tapping, which then caused it to not run true.

I think you are right, make the plug, drill then tap, and true the plug for the fitting, then glue and re-true fitting if needed.

Live and learn.


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## Woodturner1 (Aug 3, 2011)

You guys are a terrific resource. Dave, your detailed explanation and references, and the subsequent exchange with John have given me good direction. Now it's time for me to research the references and begin to hunt and gather the necessary parts. Thanks.


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