RE: [CAD_CAM_EDM_DRO] Re: Need a vacuum system for acrylic sheets

Kevin,

Check these guys out...I use their gaskets.
Give them a call...they are experts at cnc vacuum
hold down systems.

http://www.allstaradhesives.com/products.htm

I think Bob Campbell knows a lot about vacuum hold down as well.

Venturis give very good vacuum but consume huge amounts of air.
I researched this a bit and found I would eat up all the capacity
of a 10 hp compressor for my application.

Some multi stage regenerative blowers can give about 3 pisg vacuum and
are economical.

My parts are small so I am looking for a rotary vane type vacuum pump.
Many use pumps like the Busch R5 series. These are typically 3-5 hp
and give 20-50 ft^3/min free air flow and almost perfect vacuums.
Sadly they are very expensive even used.
They are big enough for low leakage gasketed systoms. Systems that
use vacuum spoilboards without gaskets require larger pumps.

Leslie M.Watts
L M Watts Furniture
Tiger Georgia
(706) 212-0242

Main page:
http://www.lmwatts.com
Engineering:
http://www.lmwatts.com/shop.html
Cnc surplus for sale:
http://www.lmwatts.com/forsale.html
Carved signs:
http://www.lmwatts.com/signwp.html


-----Original Message-----
From: kdoney_63021 [mailto:kdoney_63021@...]
Sent: Wednesday, January 12, 2005 8:48 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: Need a vacuum system for acrylic sheets




Sorry, I should have been a little more specific.

I'm actually not cutting the 1/8" acrylic plastic sheet. I am
painting on it with dispensing valves and acrylic paint. I need to
hold the sheet flat (+- .1") against the surface of the table. The
sheets, as they come off the properly constructed storage racks, are
sometimes off by .5" by warping. I don't need high volume, except to
counteract the table leakage and I don't need high vacuum since I
only have 12 of the 1/4" bullet catches which allow the vacuum to
form inside of my multiple areas of
"Poron Quick Recovery Foam Strip, 1/8" Thick X 1/2" Wide".

I was thinking that this rubber was the wrong type, causing massive
leaks when I tried my new Gast vacuum pump but when I put my finger
over the vacuum inlet it didn't seem that strong so I assumed the
pump was the problem.

I then tried the wet dry vac and got no better result. Maybe my

"Bullet-Style Spring-Loaded Catch, Nonadjustable Mortise-Mount
Strike, 1/4"D X 3/8"L"

were too small to allow the vacuum to hold the piece?

Should I just remove the catches and cover the unused holes?

I've heard good things about venturi pumps. Any comments?

Kevin