Pneumatic Blast Gate

A pair of workshop solutions for those who like to tinker.

SHOP OWNER: Larry Verhoff

    When I installed my new Oneida 3-horsepower dust collector last summer, I of course had to put in new PVC pipe. This is the only type I would consider using, for reasons I’ll mention later. Then I had to make 4" and 6" blast gates. After using them for a while, having to open and close them manually became a real chore. I would forget to either open or close them. Closing them wasn’t too big of a deal, but if you forget to open them, it makes having dust collection senseless!
Pneumatic Blast Gate

    I realized what I wanted was a way to somehow make them work automatically. This thought had been on my mind for a while anyhow, but the questions were how and also make it “dummy-proof” at the same time. About this same time, someone posted about automatic openers and found something by Jim Halbert. He used electric solenoids, which I guess worked very well, but things had to be just right or the solenoid would stick part way and burn up and that is just not for me. I would need something more “dummy-proof”.
Solenoid Valves

    So, I went back on my 20 years of maintenance experience and came up with the idea of running them by air, supplied by a small compressor. I went on eBay and bought a bank of six solenoid valves and some six and eight-inch pneumatic cylinders with a 1 1/16 bore. I added some airline from Lowe’s and went to work.
Pneumatic Blast Gate

    I made different gates to accept the air cylinders, ran my airline, hooked up my solenoid valves and the compressor. The first one I hooked up was my DeWALT sliding compound miter saw. First, I tried using a button I would push to open the valves, and was hooked up to an off delay relay so it would hold the gates open for about ten seconds. Well, that began to really annoy me. Soon, I installed a limit switch on the SCMS. You can see it just below the motor. The switch has an arm on it that contacts the motor, so just as soon as I start to pull on the motor; it closes the circuit to the solenoid and opens the gates. When I put the saw back to its home position the relay still holds the gates open for whatever time I want it to stay.
Pneumatic Blast Gate Pneumatic Blast Gate

    This is the fourth time I’ve had to make some kind of change to my DC system. This is the reason why I like using PVC. It is so much easier to work with, in my opinion. I just got my tablesaw hooked up this past week and plan to hook my other machines up over the next few weeks. I need to get my Granddaughter’s baby bed made in between times. Between all this, I am constantly figuring different ways of doing things.
Pneumatic Blast Gate

    I have also included pictures of the homemade router raiser I put together about seven years ago. I’m somewhat surprised it still works well. The heart of it is just a right of left angle gearbox that I got from work quite a few years ago before they tossed them away. Pneumatic Blast Gate

Pneumatic Blast Gate

    I’ve also located them on eBay, which usually lists them for about $30. They usually identify them as right-hand gearboxes. I believe one company, Tool O Matic, the type mine is, calls them floating-shaft gearbox because the shaft "floats" or slides up and down through the gearbox. The vertical shaft has to go up and down with the router and connect to the router raising mechanism. I hope someone can use these ideas; because they sure helped me become lazier, err… I mean efficient!

. . . Larry Verhoff



This is the place to share views of your shop, woodworking tips and methods,
mug shots, special tools or machines, finished work--you name it!
    We prefer digital images via e-mail, but prints or transparencies will do. Include your name, address, phone number and a paragraph or two explaining the photo(s). Not every entry will be used, we reserve the right to edit for length and clarity, and we will not return photos.

P.O. Box 493
Springtown, PA 18081