Vacuum hold down unit

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Jan 20, 2019, 07:37 AM
Bellevue Woodshop

Vacuum hold down unit

Vacuum pod unit

Vacuum is a great way to secure work pieces, on the cnc, or on your workbench as well.
Inspired by Festools vac-sys, I decided to build a similar system for my workbench, for a loooot less money then the expensive commercial one.
I wanted it to be a simple construction, with a single operating lever for both direction of movement.
As you can see in the build video, I already have an old steel unit, that works great, but I loved the challenge to try to replicate it.
I also made plans for it so that anyone can build it.
the pods can be custom made in any shape and size to fit personal preference or product.

Its built from plywood, A piece of tubing, some pneumatic connectors, and a switching lever for the vacuum on/off.
The vacuum pump is a compressor salvaged from an old fridge.

If you want to see how to make a homemade vacuum pump from a fridge, take a look a Sam`s Workshop Diary`s new thread here on HTN, you can find it here: http://www.homemadetools.net/forum/h...uum-pump-71121

Personally, I just ripped the compressor out, and connected the hose to the inlet. (a little less work:):))

Here is a video of the vacuum pod build:

https://www.youtube.com/watch?v=fr0cNaUyXMw&t=

Best regards
Roy
Jan 20, 2019, 08:48 AM
wizard69

Nice work. Festool isn’t even close to my range of price acceptability. Especially for something of such simplicity. Thanks for the well done video.
Jan 22, 2019, 02:22 PM
PJs

Outstanding video and build, Roy. Curious of what kind of vacuum pump is required, like a refrigeration pump?. Thanks for sharing another great build with us!

PJ
Jan 23, 2019, 08:45 AM
Bellevue Woodshop

Thanks for the kind feedback PJ. I just used any old refrigerator compressor. Yanked it out of the fridge and cut the pipes. Just connected the pipe on the suction end to the hose, and voila!!! I have heard it is wise to put a drop of oil in the inlet from time to time, but I have never done it. I have had mine for years and its been running for hours and hours. A couple of times I have actually forgotten to switch it of, as it is extremely quiet. Nad It has been running for a couple of days. It was hot, but still pumping:):)
Jan 23, 2019, 01:25 PM
PJs

Quote:

Originally Posted by Bellevue Woodshop

Thanks for the kind feedback PJ. I just used any old refrigerator compressor. Yanked it out of the fridge and cut the pipes. Just connected the pipe on the suction end to the hose, and voila!!! I have heard it is wise to put a drop of oil in the inlet from time to time, but I have never done it. I have had mine for years and its been running for hours and hours. A couple of times I have actually forgotten to switch it of, as it is extremely quiet. Nad It has been running for a couple of days. It was hot, but still pumping:):)

Thanks Roy, my pleasure. I figured as much. I was trying to consider the inches of mercury to the area/volume of the vacuum plates. Assuming you could get 27"mg with your compressor that would be about 13PSI and your disc is around 10" diameter which would give you about 1021lbs of holding power in tensile...depending on the seals of course. That is pretty impressive...but all dependent on what your compressor will actually produces. Even at 15"mg that would be ~7PSI and result in 578lbs of holding power in tensile, shear would be another factor. Hopefully my math is in the ball park. ~¿@ Lots of other factors to consider but impressive none the less!

The main thing about refrigeration compressors imho, is maintaining your oil level on an open ended system because they will put a small amount of oil vapor into the shop without a baffle or muffler. The pump gets most of it lube from the oil bath...a drop or two in the inlet may help with the valving in the long run, but not necessary, imho.

Thanks again for your post and response!

PJ
Jan 25, 2019, 08:52 PM
DIYer


Thanks Bellevue Woodshop! We've added your Vacuum Hold Down Unit to our Workholding category,
as well as to your builder page: Bellevue Woodshop's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/homemade-vacuum-hold-down-unit"> <img src="/uploads/220419/homemade-vacuum-hold-down-unit.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/homemade-vacuum-hold-down-unit">Vacuum Hold Down Unit</a> <span> by <a href="http://www.homemadetools.net/builder/Bellevue+Woodshop_2">Bellevue Woodshop</a></span> </div> <div class="tags">tags: <a href='http://www.homemadetools.net/tag/holding'>holding</a>, <a href='http://www.homemadetools.net/tag/vacuum'>vacuum</a> </div> </div> </div> </div>