need input on diy vacum

[thesaent14]

can some one help me out to get some plans for a diy vacum sytem so i can make it for my machine


thanks to all in advance

[Greolt]

Do you mean dust extraction or vacuum hold down?

If hold down then there is all sorts of systems depending on what you want to secure.

For what I have done for my small machine have a look at this thread.

http://www.cnczone.com/forums/showthread.php?t=34537

Greg

[SRT Mike]

Originally Posted by thesaent14 can some one help me out to get some plans for a diy vacum sytem so i can make it for my machine thanks to all in advance

We used a venturi vacuum nozzle that we got, I believe, at McMaster.com. It has three ports - in, out and vacuum. It just uses shop air and creates a vacuum on the port when air is put in the IN part and flows to the OUT part. It would pressurize a 14x14" plate within a few seconds.

The plate itself was just a plate with multiple holes drilled and slots milled in the top to form a grid pattern with each grid square being about one inch. Then you just buy gasket-on-a-roll from McMaster and push it into the slots in the plate to form whatever shape you need and drop your part on it.

We then made it a bit fancier, using a 4" piece of PVC about 4 feet long to make a vacuum chamber to help keep the vacuum constant, and used air solenoids on the chamber so we could electronically apply and release vaccum. Then you can interface that with the machine and control the vacuum plate using M-codes.

Works pretty well, but you need to be mounting a smooth surface. You can also buy pretty cheap plastic vacuum plates and Ive heard good things about them.

Good luck

[thesaent14]

nice guys thanks for all the info is there a way i can see some pictures of this system


thanks

[SRT Mike]

Originally Posted by thesaent14 nice guys thanks for all the info is there a way i can see some pictures of this system thanks

I dont have any pics of our setup (and it's currently disassembled in boxes near the mill) but go to this site to see the general idea

http://www.workholding.com/Vacuum_Chucks.html

You can also do a google search on "Vacuum chuck" and you will get tons of pics and sites to check out. Basically you machine the criss-cross pattern to create a bunch of little posts, and every so often you put a hole for vacuum. Then you use gasket-cord to section off a portion of the plate and allow a seal to be made. You close off the other vacuum holes (maybe with a set-screw with an o-ring under it) and leave the one under your part open. When your part is on the gasketed-off area, and you apply vacuum, it get sucked down and held tight. The rubber gasket makes a nice seal and the little posts that stick up touch the bottom of your part once the gasket compresses a little from the part being pulled down, leaving a nice flat straight fixture that can be machined on all sides.

We had a local CNC salesman stop by and try to sell us one of these things. He dropped off some big-name vacuum chuck but after looking at it, it was so simple (and his was so expensive - around $4,500) that we just made our own from about $300 worth of materials.