[Greolt]

My CNC router is pretty much up and going. (just gotta get a better spindle)

However you pretty soon realise that securing material to the table is a whole new can of worms.

Screw it down. Clamps don't reach far from the edge. Double sided tape. There has to be a better way. (nuts)

I'm going to have a go at making a vacuum hold down thingy.

I had a piece of acrylic (I think that's what it's called) 20mm thick that someone gave me. A bit beaten up but OK.

Got some quarter inch rubber stuff. Sort of foam rubber with an external skin.

Drew up a grid pattern in my cad program. 30mm squares with 3mm radius on the corners. 5.25mm channels in between.

Generated a toolpath in sheetcam. Didn't know how hard to push the 1/8th endmill I had.

So I went 1000mm per min. RPM? About half speed on the cheapy little router that is my temp spindle. Sounds like it's about to explode if I go faster.

1mm depth of cut. Could have gone deeper I think but I did not want to break the only little end mill I had seeing it was the weekend and couldn't get another.

Set my machine going and went and watched TV. Took about 90 mins.

[Greolt]

Drilled an inlet. Maybe that should be called an outlet.

Fitted a quick release air coupling.

Have no vacuum pump yet. I want to see how well this works before splashing out the hard earned on one of those.

So I pressed the little shop compressor into service. Connected up the hose to the inlet side just to see what will happen.

Well it worked @#&%* brilliantly. :banana: No way that piece of board was going anywhere.

Sucked it down like you wouldn't believe. Well a lot of you would of course as you've had plenty of experience with vacuum tables.

Now where am I going to get one of those nifty little vacuum pumps like they have in the US ?????

.

[Geof]

...So I pressed the little shop compressor into service. Connected up the hose to the inlet side just to see what will happen.

Well it worked @#&%* brilliantly. :banana: No way that piece of board was going anywhere....

Now where am I going to get one of those nifty little vacuum pumps like they have in the US ?????

.

Why not keep on using a little compressor? I was planning on experimenting with one sometime but I would be happy to learn from your experience.

[Greolt]

Yeah I am thinking about that Geof.

They can be had quite cheaply here. I thought I could reverse the head and hook it up permanently that way.

Have to replace the presure switch with a vacuum type and guage as well.

Then you would have a all in one unit with a good size reservoir.

Don't see why it would not last just as well as when it is compressing.

It's real noisy though.

A silencer on the air out port would maybe help a little bit.

Greg

[sailfl]

You are aware of this site?

http://www.joewoodworker.com/veneering/welcome.htm

He has a whole thing about vacuum press and pumps you build.

[Greolt]

Had a look at that Sailfl. Good site. Lots of info.

Unfortunately the most important or at least the most expensive part is the pump.

We have different voltage here in Aus.

And changing our dollars to yours then paying freight makes things very pricey.

[sailfl]

I completely understand about the cost thing. But I thought you might like to look at the information. That is part of the price you pay for living down under.

[ger21]

Not sure what the shipping would be, but you can get a 220V pump from www.surpluscenter.com for $89 US. I just got one the other day.

[Geof]

In the days when all car engines were carburetted with vacuum operated winshield wipers you could just run a tube out to the vacuum connection on the intake manifold and leaving it idling in the driveway.

[Greolt]

Not sure what the shipping would be, but you can get a 220V pump from www.surpluscenter.com for $89 US. I just got one the other day.

Hey thanks for that Gerry. I have requested a shipping price.

What are you using it for? Do you think it will keep up with vacuum clamping as above?

In the days when all car engines were carburetted with vacuum operated winshield wipers you could just run a tube out to the vacuum connection on the intake manifold and leaving it idling in the driveway.

We're showing our age now aren't we Geof.

I remember they used to slow to a crawl when you put your foot down and go like the clappers as you eased off.

[Geof]

Hey thanks for that Gerry. I have requested a shipping price...

Make sure you are sitting down when you get the shipping price. That is if they will give you one. We ship metal parts to Sydney (Allambie Heights) and it costs a few penneis.

[ger21]

It was $17 to ship to Detroit, probably at least $75 to ship to you. I should also mention that although they are advertised as new, mine was a bit banged up. Consider them "unused". They are not in any factory packaging, so may be dented a little. Mine does work fine, though.

Anyway, I'm going to use it for both veneering and a hold down system, whenever I finally get my router done. I was already using a Joe Woodworker venturi setup, but it puts a strain on my compressor. I'm going to set it up just like the JoeWoodworker system.

I hooked up the Gast pump to my reservoir in place of the venturi, and it pulled 26"Hg pretty quickly. If you get a very good seal, it should work just fine. The Joewoodworker site has a small section on clamping, and he uses the same system as for veneering. http://www.joewoodworker.com/veneeri...umclamping.htm

At work today I was making a new set of vacuum pods for our router. If I get a chance this week, I'll try to make a small clamping jig to try with the new pump.

For good quality gasket material, check out www.allstaradhesives.com

[Geof]

I just went online to UPS and got a shipping quote for 50lbs from Chicago to Sydney. Around $400 so now you know what the upper limit should be.

[ger21]

It says 31 lbs I think, but I don't think it's that heavy.

[Geof]

Yikes!! I also looked up US Postal Service rate; $340. Which surprises me.

[epineh]

Here is a crazy thought (yes I am full of them ))

If by chance you had access to a working CNC router :stickpoke

You could possibly cut out a simple multi bladed impeller design similiar to a standard vacuum cleaner's, make a matching housing, keeping things simple, 2D outlines, and hook up a motor, something like one of those small fan motors they use on coldroom's you MAY be in business... might be worth a try.

Of course you would have to find someone who had a CNC router heh

Russell.

[Geof]

Here is a crazy thought (yes I am full of them ))

If by chance you had access to a working CNC router :stickpoke

You could possibly cut out a simple multi bladed impeller design similiar to a standard vacuum cleaner's, make a matching housing, keeping things simple, 2D outlines, and hook up a motor, something like one of those small fan motors they use on coldroom's you MAY be in business... might be worth a try.

Of course you would have to find someone who had a CNC router heh

Russell.

You will not get enough vacuum. A really good multistage centrifugal fan will pull a static negative pressure of maybe 1/3 of an atmosphere. This is not really adequate for vacuum holddown unless you are working with large intact areas.

[Greolt]

Eloid you posted a PM to me with a question but I am unable to answer via PM because your inbox is full.

So I will respond here.

Look at the pic in the post,

http://www.cnczone.com/forums/showpo...99&postcount=2

You can see that I have temporarily hooked my hose to the side of the compressor head that usually sucks the air in.

It normaly just has a filter on there.

And I also temporarily disconnected the side that goes on to the tank or pushes the air out.

Hope that is clear.

Greg

[Greolt]

The Surplus Center have said approx shipping cost is $160

So all up it would be about $335 of our Aussie dollars. I think I will keep looking for a second hand one here.

But for now I am going to get one of these cheap air compressors and turn it into a "joe woodworker" style of unit.

I won a cheap vacuum switch on ebay so the rest should be easy. I'll let you know how I get on. :wave:

Greg

[Greolt]

Well I got myself a 2 hp compressor, direct drive, 30 liter tank for $50.

Brand new, the plastic shroud over the motor / compressor had been cracked in shipping.

Repaired and good as new. Well it doesn't look as good as new but....

Directly attaching a fitting to the head (the suck side) works like a dream.

Got a gauge. vacuum switch, check valve and a couple of other bits coming from an ebay purchase and from JoeWoodworker.

Can't see why it won't work to make it cycle on and off using the air tank to hold the vacuum.

So we'll see. Just gotta wait on that international post.