Vacuum system types

[Roger Chandler]

Could some of you folks give me some help with a vacuum system as related to the type.

What is the advantage or disadvantage of a vacuum pump over a venturi system like the Hold Fast system, if there are any? I already have a compressor, and it would be less expensive and faster to use the Hold Fast system, but is it as safe as a vacuum pump system?

What are the major differences, and or advantages or disadvantages?

With much appreciation, I await your kind responses!

 

[Steve Worcester]

A pump is considerably quieter.
Check the CFM requirements of the venturi to see if it will get you as high as you want/need.

Here is another thread on it

http://www.aawforum.org/vbforum/showthread.php?t=2871

 

[john lucas]

Venturi systems in general are noisy and require huge amounts of air. That is not the case with the Holdfast system. It is not noisy. I don't remember the air requirements but it was a lot less than the early venturi systems I looked at. That being said it does require an air compressor.
Electric vacuum systems go from fairly quiet to really quiet. They are physically larger since the motor is quite a bit larger. Not a problem since either style can be mounted away from the lathe.
What is important for vacuum chucks holding wood is the CFM that it will maintain. I could not find that for the Holdfast. The Oneway rates theirs at 4.5CFM. This is important because some woods leak vacuum and the various compressors need to be able to keep up or you have to find some way of sealing the leaks.
The Holdfast system is fairly inexpensive compared to buying the electric versions. The downside would be if your compressor can't keep up. I think it said 2.5cfm at 55-60psi for the compressor. The good side is you get everything you need besides the compressor for the one price. With electric versions you often have to buy your own vacuum gauges, valves, etc.
I have never owned the Holdfast system so I can't comment on that. I have played with it and was very impressed. I have a Ghast vacuum pump and homemade system that I've used for years with great success. I've also worked with the Oneway system and think it is very good if not great.

 

[Roger Chandler]

Thanks!

Thanks for the input! I have done further research and talked with some knowledgeable folks, and I now feel comfortable with the Hold Fast system. My compressor is way more than adequate, and the air consumption is pretty low anyway.

This system will be easier and faster to set up for me, and will not take up much room in my already cramped shop, so I think it is the correct way to go for my situation.

Keep the wood spinnin' 🙂

 

[Doug M Jones]

Holdfast is a good unit.

I bought the Holdfast system at the symposium in Richmond. According to the gauge I can pull a vacuum in the low 20's which holds everything well on my Jet Mini. If I get overly aggressive or have a catch, the mounted piece will move but it takes some stupidity on my part. I run mine with a Porter Cable pancake compressor and it has no problems keeping up. Someday when I graduate to a "big" lathe with larger bowls I may need more horsepower but it serves me well for now. On more porous woods, I do need to put a coat of sanding sealer on or it will pull air through the wood and not hold well at all.

 

[Roger Chandler]

I bought the Holdfast system at the symposium in Richmond. According to the gauge I can pull a vacuum in the low 20's which holds everything well on my Jet Mini. If I get overly aggressive or have a catch, the mounted piece will move but it takes some stupidity on my part. I run mine with a Porter Cable pancake compressor and it has no problems keeping up. Someday when I graduate to a "big" lathe with larger bowls I may need more horsepower but it serves me well for now. On more porous woods, I do need to put a coat of sanding sealer on or it will pull air through the wood and not hold well at all.

Good info Doug,

I appreciate you responding. My compressor is a 25 gal with a 5 hp motor,so it should do really well. The sanding sealer for porus woods is a good idea.