DIY Vacuum Clamping System

[Bob D.]

There are a couple companies that offer a vacuum clamping system for woodworking. They are real time savers and can do things that are near impossible with mechanical clamps. But they are expensive with some approaching $1000 for a basic setup. They are very nice when routing an edge on a workpiece and for quickly grabbing and holding (and releasing) your work.

I found this homebrew clamping system that looks pretty good. Maybe not as good as that $1000 system but still might be worth considering. I have not built one and don't really plan to, and I have no plans to lay out over $1k for the Festool Vac-Sys or one of the other expensive brand vacuum clamping systems like the one Rockler offers for $600 for the pump and clamping pods and all the other bits you need to plumb it up. But I thought this guy did a nice job of creating his own version. He shares the plans on his website. More info in the video.

Maybe if I had a cheap source for a vacuum pump that wasn't so noisy I needed earmuffs to use it I might make something. I wonder how long one of those cheap HF HVAC vacuum pumps would hold up.

[MAS]

I wouldn't be afraid to try the Harbor Freight single stage vacuum pump. https://www.harborfreight.com/25-cfm...ump-61245.html
It's only $72 after applying the standard 20% off coupon.

This isn't the quietest option as you need to have an air compressor run, however their cheap venturi vacuum pumps work well. $14.40 with the 20% off coupon https://www.harborfreight.com/air-va...ors-96677.html
if you take the case apart you can unscrew the pipe that has the refrigerant ports and screw in a 1/4" NPT fitting of your choice.
the working part of that pump is just plastic as well so it's not to hard to get the NPT fittings to screw in.

I have a couple of these I've modified and use them to bleed brakes, suck out oil ect. as I didn't want to risk damaging my MasterCool 2 stage pump

[Bob D.]

I found a lab vacuum pump intended for vacuum filtering and other lab applications on Amazon. It is small, but very quiet at <40dB and is supposedly rated to run continuously. It also is low power drawing only 20 watts @ 120v. They claim 10L/minute which to me sounds like it might be enough since a vacuum clamping system is only a few feet of tubing and the small volume of the clamp area so I would think it would draw down fairly fast. There are two other models at 15L/min and a 30L/min which are more money of course. I wouldn't want to be waiting 30 seconds for the clamp to grab the wood. It's more money than the HF evac pump but very quiet and compact.

Lab Portable Oilless Diaphragm Vacuum Pump 10L 15L/min with Rubber Tube: Amazon.com: Industrial & Scientific

These clamp pods from v-clamp look interesting.

[Bob D.]

I'm looking into buying some bits to try this out. I'll post my findings here once I have it all together and working. I figure I can return or resell the stuff if it doesn't work to my satisfaction or it's a total bust. Might lose a few bucks but that's the price of trying, gotta put some time and money at risk if you want to make things happen.

Look at Elon Musk. He said not long ago that when he started SpaceX he had 8 employees including himself. After their first three rocket tests failed on the launch pad he was out of cash and could only scrap up enough money to fund one more try. If that one failed SpaceX would have been bankrupted. But the fourth time was the charm and the rest is history.

Now my playing around with some vacuum crap is nothing like that at all, not trying to say that. Risk is risk, it's all relative to the size of your wallet. :-)

[Bob D.]

I decided to get that little vac pump from Amazon and give it a try. It's easy enough to return stuff now that you can drop it off at Kohl's and the wife likes the $5 Kohl's cash you get when you make an Amazon return.

So the pump IS tiny at only about 8"W x 5"H x 5" deep. It easily draws 25" Hg in just a second or two so should work well enough for this application. The pump is very quiet. You can hold a conversation over it without raising your voice. It's made to use in a lab where it will run all day long for vacuum filtering. So I'm not worried about running it for a half hour or more at a time. There is no oil to change and that is another reason I went with this style pump. I did do one mod to the pump. As supplied it came with a barb fitting to connect a hose to. I removed that and installed a push-connect fitting for 1/4" OD poly tube and ditched the rubber hose. To do this I had to remove the back cover from the case and it was easy to install the fitting I needed. I did have to enlarge the hole through the cover slightly using a step bit.

Those V-clamps I referenced above in post #3 are meant to be used with an air compressor not a vacuum source so they are not a good match for this pump. I don't have a compressor in the basement shop nor did I want one because of the noise. So I looked around and bought a pair of vacuum pads from Rockler which were on sale. I already had some push connect fittings and 1/4" tubing so was good to go there.

The Rockler clamp pads come with some fittings and a short length of tubing and also the hardware to secure them to a T-track so I set them up on the side of my Festool MFT/3 clamping table which has a t-track slot built in and ran the tubing temporarily over to a workbench where I had the vacuum pump set up.

On the table I ran the tubing over to a toggle valve that I mounted on the corner of the table. I want to have a footpedal eventually but still looking for what I want. For now from the valve the tube runs down the leg and under the floor mat over to the bench where the pump is. Not sure I will keep the tube run this way so for now it's attached with some blue tape, but I have some cable clip that I think will work here if I decide to keep this configuration and could also use ty-raps if the clips don't work out.

So I fired it up and it grabs the board immediately. After a couple seconds it has drawn down about as far as it will go. The surface of the wood or whatever you have in the clamp affects how much vacuum the pump is able to draw. Rougher wood surfaces allow enough in-leakage that you might only get to 23" Hg but that is still more than enough to hold the workpiece for sanding or routing or for hand plane use. I was able to lift up the end of the table just holding on to the wood you see in the photo. I found that MDF while it appears smooth does not seal that well but you can hold on to it.

In the end I have about $220 invested for the pump and the pair of clamps. If I had to buy some tubing and fittings plus the valve then maybe another $25. That's a lot less than those commercial systems but no doubt not as versatile or powerful. I bought the smallest of the three pumps (10 Liter/min) of this design which costs me $170. The 15L/min pump was only $30 more and might have been worth it. The 30L/min pump is $260 and probably the best but as a trial I went in cheap. I guess I could return the 10L pump for the 30L version, but it's $90 more and I don't know how much I will use this.

[Bob D.]

I'll add links to other DIY vacuum clamping systems as I find them.

Here's one I found on the Fine Woodworking site.

Shopmade Vacuum Clamps - FineWoodworking

[Bob D.]

Here's another

DIY Vacuum Clamping System • WoodArchivist