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

Kevin,

Here is what you need to do. On the CNC router that I designed, I left
about 4" of vertical clearance on both sides of the lead screw below the
table top.

You need to machine a piece of MDF where you would normally place your
spoilboard. Rout out a checker board grid pattern. The width of the slots
should be designed to accommodate a strip of closed foam tape. The tape will
go around the outside of the checker board pattern. On the bottom of the
table top and on one side (leave clearance for the lead screw) place a
flange with a 90 deg plastic pipe fitting. Wherever you place the flange,
drill a hole about the size of the pipe ( I would use a 3/4" pipe fitting)
through the spoilboard. Now you can add another pipe to the 90 deg fitting
so that it goes out the back far enough to clear the table. Then you can use
a flexible hose to your blower or shop vac.

The depth of the grid pattern should be such that when the foam gets
compressed it is down to the table top, but snug enough to make a good seal.

Bob Campbell
Bob@...
www.campbelldesigns.com
Breakout board
THC board sets
CNC router plans
Stepper Motors
VisualMill Basic

----- Original Message -----
From: "kdoney_63021" <kdoney_63021@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Wednesday, January 12, 2005 7:47 AM
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
>
>
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Robert Campbell" <bob@c...>
> wrote:
>> Kevin,
>>
>> what are the size of the parts? How many of the same parts would
> you be
>> cutting?
>>
>> What type material are you cutting?
>>
>> Basically you have two types of vacuum systems. One is the high
> vacuum low
>> flow system and the other is the high flow lower vacuum. For the
> high flow
>> system the vacuum should be around 15".
>>
> (snip)
>
>
>
>
>
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