vac hold downs --using vac pucks

[stan kern]

Would anyone know size of vac pump would be required to run say 4-6 pucks double sided
(suck on the table and the workpiece)(puck size about 6in diameter
We tried to substitute a large shop vac but that did not work ,the vac started to heat up

[Mike Heidrick]

More important than vac size is volume of air you want to move - how much cfm and inches of mercury pressure at that cfm.

I have an ebay found 3hp FPZ regenerative blower vac pump with a FPZ relief valve and solberg filter and manifold I made in PVC and ball valves - it is all 2" NPT and I have 4 zones - 1 plumbed to the table and the others awaiting a new spoil board. I can easliy suck through face surfaced edge sealed 1/4" LDF and hold down a 6"X12" or larger wood part. I have a grid in the MDF spoil board with the PVC flush with the bottom of the grid.

One day I will hook up my 20HP roots blower setup with 4" NPT - will be in a new bldg though. That pump is HUGE.

What size are the ports on the puck you want to use? You really need an aux tank and solenoid setup for many of those pucks so your compressor does not run 100% for most pucks. If you cut through you are done though for most of them.

A real deal setup is a 10+HP VTLF Becker vacuum pump that is about 170cfm and 25Hg. Get out the checkbook. The vanes in it cost more than I paid for my ebay vac!

Low Res Video of my setu




Eventual vac pump

[Jerome Stanek]

You would not need a very big unit for that as long as you have good gasket material.

[Rich Fennessey]

A normal shop vac can not pull vacuum table duty for very long. There is not enough air flow to cool the motor. If the shop vac seems to be powerful enough, then get a Fein Turbo vac. It has a separate motor cooler and will run indefinitely without overheating. This is all based on research because I'm working on a solution myself.

It sounds like you might want a special jig with gaskets instead of pulling through the MDF. A high vacuum, low cfm system, (as low as 5 cfm) might suffice. Pumps for this are usually in the low hundreds of $. You can use a small tank as a vacuum reservoir. There are some posts on camheads.org regarding this. I recently bought a 17 cfm 10-4 Torr 1 HP Welch vacuum pump to implement a gasket jig setup. Only concern I have is that the pump is made to run at very high vacuum and will overheat if there is a lot of leaking. As a spoilboard vac system, I'm looking at buying the Fein Turbo 3. My 4x8 table is plumbed with 4 vacuum zones, so likely only use one or two zones at a time. I also don't have a shop vac (use broom or dust collector to clean up) so it can be used for that too.

Depending on your setup, you'll want to adjust your tool pathing. The last cut through should be thin and slow, especially for small items, since you will be creating vacuum links as you cut through (for the spoilboard vacuum)

[gary l roberts]

Try Shopbot forum... search for vac hold downs and system. There are several solutions and home build units.

[AL Ursich]

I bought a continuous duty Veneer Vacuum Pump that I am in the process of making into a Vacuum sled for my CarveWright. I will also wire in a Vacuum Switch into the Sled tied to the cover switch circuit to shut down the cutting in the event of a loss of vacuum.

Has anyone tried a Veneer Pump on Pucks?

AL

[stan kern]

go to joe woodworker (google) you will see what he recomends.
He also has puck info