Crazy Vacuum chuck ?

[Jack Mincey]

I know that the first vacuum chucks where done with shop vac's so here is my question. Say you have a 2 1/2 hp cyclone in your shop. If one was to hook up a vacuum chuck to this duck work, could it be used to hold the vacuum needed and have enough vacuum left to use for dust at the lathe at the same time. I know using a 2 1/2 hp motor just to use for a vacuum chuck would be crazy, but if you are using the dust collector for dust and have enough vacuum to operate a vacuum chuck it might be worth a try.
This is just a crazy thought I had the other day.
Jack

[Bill Bolen]

I think your question is one of those "now why didn't I think of that" jobbies! Since the vac is running anyhow why not? I think the main trouble using a vac to provide the vacumn is not having a bypass to allow air to enter the shop vac at all time. (Motor burn out) but you are using the vac too so that problem is solved. I'd love to hear how this works out for you...Bill...

[Steve Schlumpf]

Jack - not to take anything away from your idea but I don't see how that could possibly work. Example - my vacuum system hooked up and running - open the air bleeder value (used to regulate vacuum) all the way - would be the same as having one leg of your system dedicated to the vac chuck and the other leg dedicated to sawdust. No way to maintain vacuum...

I'm not an engineer but I know the guy who owns the local Holiday Inn.

[Chris Haas]

i agree with steve. a shop vac system is more designed for cfm, not acutal vacuum as measured in inches. i read somewhere that a typical shop vac will only pull 5-10 inches max. thats without any other lines open.

[Dave Ogren]

Jack,

A good industrial shop vac. will pull 120 inches of water. I have seen a conversion chart between water and mercury but can not remember where. And then you have the cooling factor of the shop vac. motors.
The idea is great though, and heck someone has to be the first.
I don't think that there is anyway to vacuum chuck your beautiful cherry burls anyway. Good luck.
Dave Ogren

[Jim Becker]

Your cyclone operates at very low static pressure...ie, very low vacuum. Not gonna work well at all. You need high static pressure like a vac would provider. But a real vacuum pump is generally best for the purpose, IMHO, and can be relatively inexpensive if you buy surplus.

[Leo Van Der Loo]

120" of water is equal to about 10" of Hg (mercury) roughly 1/3 of total vacuum HTH

[Richard Madison]

Dave,
120" H2O is only about 10'' Hg vacuum. Others have written that 18-20" Hg vacuum is sometimes required.

[Jack Mincey]

Thanks for the info everyone. Like I stated it was a crazy ?, I might still try it at my school shop. We have a system that lefts 4 50 gal. drums off the ground when it is turned on. It is an old sock tower system that has a 15 or 20 hp motor on it.
Thanks again,
Jack