Well. It worked great for 1 part. I built a 16" x 16" vauume hold down table. Turn on my shop vac and it held down really good for 1 part then my trusty Stanley shop vac died. I’ve heard other people using shop vacs with success. Guess I’m un lucky. The part was only about 6" x 3"
@hobbyhands - Clark, probably failed due to lack of air flow to cool the motor. They do get warm even not using it as a vacuum table.
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@hobbyhands @Heyward43 Heyward has it, Clark. If you want to use a shop vac, you need to find one that has a separate air stream for cooling. I know that Fein and Festool both do. Both are WAY out of my snack bracket, though. I’ve read that many of the wet/dry vacs will work, too, but I can’t swear to it. Peter on CNCNutz on youtube buys a new vac for his table after frying his previous one. That may help you to decide, too.
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Thanks. It actually worked really well. I am starting to look at these , but have to do some research to see how much cfm and horse power I will need. Not for a full table. I mainly do smaller parts.
Also it seems like a much quieter solution.
@hobbyhands I have a Gast 3.5 cfm vane pump that I use for the vacuum chuck on my wood lathe. I can use it to hold small parts on vacuum “pucks” that I made, and it holds very well. I tried it on a home made 16" x 16" vacuum table and it didn’t hold anything at all. I would think that the 5cfm would not be all that much different. YYMV though.
Some time ago, I found a YouTube video showing a fairly unique way to make a vacuum table that doesn’t require a high-volume vacuum pump and doesn’t require masking off the areas you aren’t cutting, either. In essence, the top is solid with 5/8" holes drilled half-way through the top, then a small 1.1mm hole drilled in the bottom of the larger holes all the way through. The small holes limit how much air is needed to be moved for form the vacuum while the larger holes on top hold the vacuum.
He made his from MDF, which isn’t the best choice as it is somewhat porous, something he pointed out in the two videos and how he corrected the issue.
For the curious the two videos can be found if you lock for CNCNutz episodes 210 and 211.
Some day, when I decide I want a vacuum table, this is the approach I’ll take.
Michael
@Myklhn FWIW, Michael, I used Peter’s (CNCNutz) plans to make a table. I found that my shop vac did not not move enough air to make it work on anything small. You likely saw that, in Peter’s episodes 243 and 244, he eliminated the through holes and relied on the porosity of the MDF to develop the holding power. He also fried a vacuum and replaced it with a more powerful one that had a dedicated cooling air stream.
@johanmikl Mickal: Thanks for your input, but as you know, that thread was started almost 2 years ago and no one has commented since then.
For my part, I moved on for two reasons. First, shop vacs that use a dedicated air stream to keep the motor cool are more expensive than I am prepared to pay. Second, no vacuum will be strong enough to hold down very small parts, which, in my particular case, is what I was looking to hold down. If you have a piece that is only a couple of square inches in size, even a perfect vacuum will only result in a downward force of just less than 30 pounds. Since it is possible to achieve a perfect vacuum, the actual downward force is considerably less than that. That is not enough to hold my pieces in place.
As an aside, the commercial shop where I put in time has a 15HP vacuum pump for its 4 x 8 foot vacuum bed. It will not hold down very small pieces.
Lastly, the link that you included in your post goes to an Australian refrigeration company’s web site. I don’t see the relevance.