Vacuum chuck design

[Tom Godley]

Sticking with my usual way of building something -- I spend too much time thinking and buying all the parts -- only to have to do something else.

This then allows me to return at a future date to a big box in the corner of my shop that will contain ALMOST everything I need to do whatever I started out to make in the first place.

I unfortunately just found - through a link provided in my other thread -- pictures of what others have built as veneer presses and vacuum chucks. I do believe that some must work for NASA!!

Has anyone found a benefit to install an air tank (using PVC pipe!) for the chuck -- or do you just let the pump run. I would think that this would then require a pressure switch when used as a chuck.

I purchased one of the Gast 0253 units with a 110v 1/4 motor - I am just wondering if I should design in the ability to do some veneer work.

I may want to do it in 10 years or so :)

[Jim Becker]

I use my Gast pump both for vacuum chucking at the lathe as well as for using vacuum bags for veneer work.

[Richard Madison]

Tom,
Am no expert, but believe that the pump runs continuously. The function of a "vacuum" tank in the system is to give you a few milliseconds to catch your workpiece if the power fails and the pump stops.

[Don Eddard]

A lot of turners don't use the vacuum reservoirs. They just let the pump run continuously. For veneering and pressing, though, the reservoir (and pressure switch, as you mentioned) does away with the need for the pump to run continuously for the entire clamping time. The reservoir isn't necessary for turners, but it does no harm that I know of.

[Jeff Nicol]

I use a high quality stainless ball valve that I can turn off when I have reached the amout of vacuum to hold the piece I am turning. If there are no leaks it will hold for a long time. Most of the time the vacuum is used to finish something and the run time is not very long. I have never done any veneer work with a bag but I think they are sealed very well and the pump should not have to run all the time.

I use a foodsaver vacuum sealer for meat, fish, cheese etc and once the vacuum is pulled and sealed it stays until you open the bag or container.
So the same principle.

Jeff

[Jim Becker]

A lot of turners don't use the vacuum reservoirs. They just let the pump run continuously. For veneering and pressing, though, the reservoir (and pressure switch, as you mentioned) does away with the need for the pump to run continuously for the entire clamping time. The reservoir isn't necessary for turners, but it does no harm that I know of.

I agree with this and frankly, tend to shut off the pump for short periods of time when veneering, too, if I seem to have a good seal. It let's the pump cool and cuts out the noise. I don't have a reservoir on mine.

[Jim Kountz]

www.joewoodworker.com

Will tell you all you need to know.