Electric Clamp?

[rycodog]

LOOKING FOR SOME KIND OF ELECTRIC CLAMP. I AM USING IT ON A HOMEMADE CNC AND NEED IT TO OPEN AND CLOSE SEVERAL TIMES THROUGHOUT THE COURSE OF THE TOOL PATH. JAWS NEED TO OPEN ROUGHLY 1 1/2" TO 2" . ANY IDEAS AT ALL WOULD BE MUCH APPRECIATED. THANK YOU.

[mwestern]

Try connecting a dc motor to a C-clamp. C-clamps can be bought at any hardware store. The metal is cast iron and relatively easy to drill/mill.

Mark

[tsalaf]

You might want to try a pneumatic clamp with an electric solenoid controlling the airflow to open and close the clamp. A cheap alterative, depending on the direction of clamping force, would be to use a DeStaCo over-centre clamp coupled to a pneumatic cylinder.

[ger21]

I'd go the same route tsalaf suggested. you can pick up a MAC valve on ebay that will turn your air on or off from your controller. All you need is the pneumatic clamp.

Gerry

[rycodog]

Lots of food for thought, thank you. Mark, knowing nothing of electronics, how would I get the dc motor to turn off when it opened/closed the clamp all the way? Another foolish question...how do I tie the DC motor into a plug receptacle. (before u laugh at me remeber I'm a carpenter, not a electrician Thanks again for the responses.

[rycodog]

Also, what is a MAC valve, and how do they work.

[mwestern]

I suggested the dc motor and c-clamp because it would be really inexpensive. But it is just an idea; I have not tried this with a c-clamp. I have done this with a lead screw.

Sounds like you don't have much electronic hardware at you disposal. What I would do is get a small motor and a small power supply from radio shack (depending on the size of the clamp you need).

If you were operating it manually, you would just set up some toggle switches so that you can run the motor forward and backward. You could also put limit switches at the end and beginning of the lead screw’s travel. Still this would only cost a few bucks (except for the power supply). I have a 5 Vdc power supply I bought from Radio Shack for less than $20.

If you want to have it operated by your cnc software; you will have to figure out which pins on your parallel port you can control from your software (you need two, one for forward and one for reverse). Then use an H-bridge to control the direction of the motor. You can find schematics for H-bridges on the net.

[ger21]

Originally posted by rycodog Also, what is a MAC valve, and how do they work.

Basically just an air valve that is opened and closed electrically. You can wire it to a relay and have your controller open and close it with M codes.

Gerry

[rycodog]

Thank you, Gerry. I may try that.