Automatic Blast Gates using a Drill Motor

[Thomas Marr]

I'm sure most of us have seen Jim Halbert’s automatic blast gate video:
http://www.youtube.com/watch?v=7zlNimxZgqw

I'd like to build the drill motor version of these gates for my dust collector system. Unfortunately, there are no details in the video about the electrical controls. I assume micro switches are used to limit travel and a current sensing relay is used for on/off operation. But that's about the limit of my electrical engineering expertise.

Are there any plans available for this system?

[Dan Friedrichs]

I attempted to build an electrically-actuated version using a leadscrew (rather than the lever arm that Jim is using), so encountered the same problems with travel limiting, etc. I used two microswitches (one at each end) and two diodes to open the circuit once the gate was fully open/closed. Current sensing is non-trivial, but there's a need for it, because the gate could bind and the motor could stall.

This probably isn't what you want to hear, but I eventually gave up on mine. The whole idea of using electrical actuation makes the design much more complicated than necessary. Alan Schaffter's version using pneumatic actuators is a much simpler, superior solution that avoids virtually all of the problems with the electric version: no need for travel limiting (just get the right size actuators), no worries about stalling, no need for mechanical linkages, etc. Plus, if you're thrifty with finding parts, it can likely be built cheaper and MUCH faster.

[Thomas Marr]

I do like the pneumatic design. However, I have my DC piping and electrical under the slab (I don't like things hanging from the ceiling). Consequently, it would be inconvenient to run the air.

[Ole Anderson]

I do like the pneumatic design. However, I have my DC piping and electrical under the slab (I don't like things hanging from the ceiling). Consequently, it would be inconvenient to run the air.

I am not following, either way don't you need to run something new, control/power wires or pneumatic tubing?

[Thomas Marr]

I am not following, either way don't you need to run something new, control/power wires or pneumatic tubing?

No...I have 120v right beside the blast gate. So I can plug in a transformer to power the DC drill head.

[Jim Neeley]

Thomas,

Were you not also planning on auto-starting your DC? What were your plans for communicating the start signal from the tool to the DC?

There are different techniques, I'm just curious. :-)

Jim

Jim

[Thomas Marr]

DC starts via wireless remote control. I don't like to cycle the DC on and off a lot if I'm just moving between machines. Therefore, I've avoided the micro switches on the blast gates for DC activation.

[Lornie McCullough]

It seems like we should be able to build our own pneumatic cylinders using multiple sizes of pvc pipe, etc.

But I cannot find anyone who has done it....except for a few Halloween prop sites....

Have any of you made your own??

Lornie