vacuum tables

[Clockman]

Has anyone got advice on vacuum tables, either buying one or building one, I thought they would be better than clamps, which seem to be in the way all the time,

[martin54]

Really depends on the type of work your doing & what you want from a vacuum system, somewhere like CNC Zone might be a better place to ask something like this although I am sure there will be some Vectric users who can offer advice & help.
It wouldn't be practicle for me to build a full table system but I do sometimes use vacuum fixtures for various projects, these are just jigs made from MDF that I can clamp on the machine table. I have a small vacuum pump that I bought years ago for carbon fibre work that works well for this sort of thing but wouldn't be much good for profile cutting unless I left an onion skin on the parts.

[garylmast]

I guess it's what a person's preference is. I bought a new CNC with the vacuum system, but turned around and sold it within a few weeks after I got it. It was just too much noise. I think the sound of a 747 Airplane in my shop would of been quieter.

Gary

[TReischl]

Sort of depends on what you are doing, size of work for example, and what you are doing.

I built a pair of low profile vises quite a few years ago and they work well for a lot of things I do.

Everyone can offer a lot better advice if you tell us what you are typically cutting, or if you are like me, a wide variety of things. In addition to the vises I also built up a clamp system for the machine that has worked well over the years. And then sometimes I just screw things right to the spoilboard. How to clamp things depends on what you are doing, there is no magic solution.

[wilkigr]

I built the one shown on Peter Pasuello's youtube site CNCNutz. After playing with it for a couple of weeks, I came to a couple of conclusions:

1. I would not use it enough to justify the cost of a very expensive shop vac. Cheaper ones have no cooling air in situations where the incoming air is almost completely blocked, as in "vacuum table", so they burn themselves up very quickly.

2. I thought that I could use a vacuum table to hold down the jigsaw puzzle pieces that I cut from 1/2" MDF sheets. The table did hold down the sheet, but the pieces were too small to offer enough surface area for my weak shop vac to hold down.

3. Like martin54, I have small vacuum pods that I can attach to my Gast vacuum pump. They work extremely well for smaller projects. My pump is not big enough to handle a vac table, though.

[Leo]

I have made the pods, or, one pod.

I have a couple of jobs that I could really use vacuum clamping. I went to Rockler and bought some of their pods.

I used 2 of them for the first time yesterday. WOW - I was very impressed.

I bought a Robilar?, Robinar? vacuum pump, 1 hp. It doesn't really matter so much as long as it has the capacity needed. I would say that the Rockler vacuum clamping system would be a VERY good choice.

For mine, I have an on off switch on my control panel. I mounted the 2 Rockler pods on my machine with some alignment stops.

I have 9 pieces to make with 2 operations. I ran all 9 3D carving operations first. I clamped a 2x6x24inches on the pods and flipped on the switch. BOOM - CLAMPED - SECURELY. The parts did NOT move at all.

I ran all 9 pieced one at a time.

Next, I changed the cutter and ran the 9 pieces for the cutout operation.

YES - it was a bit of money.
YES - I am WELL pleased
NO - I am NOT sorry
YES - I would do it again.

[Rcnewcomb]

Vacuum is the best hold down solution except when it's not.

I've used a vacuum table as well as vacuum pods. In either case good gasketing can make a world of difference. Get the thinnest gasket that will work for the job. All Star is a great gasket vendor with lots of good information.

If you are cutting sheet goods with larger pieces such as cabinet doors the a vacuum table is great. We were able to adjust the feed rate so that the chips would pack back into the slot so there was minimal loss of vacuum so no need to tabs to hold the pieces in place.

With the vacuum table you can start with something as simple as a shop vac, or you can go with a high horsepower rotary vane pump, i.e. something that can move a lot of air. Be sure to mill off the shiny layer on both sides of the LDF or MDF that you use as your bleeder board. A thicker bleeder board actually works better than a thinner one. Seal the sides of the bleeder board. Sanding sealer works well.

For smaller pieces a vacuum pod may be a good solution. They are easy to make:

• get some thicker plastic
• (optional step) cut a very shallow slot around the top for the gasket material
• cut a hole in the center of the top of the plastic material
• cut a hole from the side the meets up with the first hole
• screw in a vacuum hose connector
• apply the gasket material

With a vacuum puck more vacuum is needed, but air movement is less critical. I found a used Gast pump that worked well.

If you make a lot of the same parts then custom fixturing is well worth the time.

I recommend reading this article: The BradyVac II – A Production Vacuum Fixture on a Shoestring Budget

[martin54]

I bought a Robilar?, Robinar? vacuum pump, 1 hp. It doesn't really matter so much as long as it has the capacity needed. I would say that the Rockler vacuum clamping system would be a VERY good choice.


Think you will find it's a Robinair Leo but you were close
I have the same brand although I bought mine a long time before I ever owned a CNC machine

[Clockman]

Thank you all for the advice, I will look into all suggestions, I just had a quick look at the Rockler pods, not expensive but shipping and tax to the UK is a killer, I will look at making them or getting some in the UK, the noise was something I forgot to consider, I have now got some reading to do, I would like to be able to do the profile cut while it was held down with the vacuum, so a lot to read up on,

[Adrian]

I had one when I first started as everyone said it was a necessity on an 8x4 machine but the noise really put me off not to mention it's another running cost to factor in. People in the States laughed me at when I said that on another forum but they use electricity (UK electricity cost was twice USA at the time) and have motors that need replacing eventually.

For the last 15 years I've just used clamps and never had an issue with them.

[Ken Rychlik]

It depends on what you mostly cut. For flat sheet goods, it's wonderful. If you cut odd size non sheet good stuff, it doesn't do a well. Mdf is fine for me, but many use phenolic, aluminum, and other waterproof options. I have done vacuum boxes with built in mufflers that help a LOT with the noise. For anyone wanting to cut down on noise, you can find mufflers for the dust collector as well. That was a great investment for me.

[litzluth]

I started with a 20x24 vacuum table from an ebay vendor who proudly says "made in USA." The table wasn't milled correctly and they basically said "too bad." (You have to kind of wonder how ebay manages to give someone a 100% positive feedback score when they haven't had 100% positive feedback. Maybe if you pay enough to be a featured vendor they forget all the bad stuff). I had to attach a dead flat piece of milled aluminum to the back of it to make it work.

I have found vacuum pods pretty useful. There are lots of places to buy the vacuum pods.
I bought the V4 venturi/tank based vacuum system kit (which requires a decent sized compressor to run) from this outfit and it works very well. https://www.veneersupplies.com/categori ... ess__Kits/

[Phil]

This is from a thread on the Shopbot forum.
http://www.talkshopbot.com/forum/showth ... Vac-system

Phil

[Clockman]

Thank you all, the more I read about a vacuum set up the less I want to build one, it is only a hobby for me, but hopefully, I can make some money soon, so I think I will stick with clamps for now, low-level clamps if I can find some

[martin54]

Thank you all, the more I read about a vacuum set up the less I want to build one, it is only a hobby for me, but hopefully, I can make some money soon, so I think I will stick with clamps for now, low-level clamps if I can find some

I haven't found a "one size fits all" clamping system, I tend to decide what I think might work best on a project by project basis & go with that so even if you build a vacuum table you may find you don't use it as often as you might think
Earn some money first & then build your vacuum system using that money
What do you mean by low level clamps? I use wooden clamps quite a bit, make them from plywood offcuts using a file I think Adrian posted a few years ago