pulse air valve

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gruszie
Posts: 10
Joined: Sun Dec 25, 2016 9:37 am

pulse air valve

Post by gruszie »

This is probably a strange question but I was wondering if there is something out there that will allow my air compressor to make small pulses of air on the material that I am engraving to blow off the dust created while engraving. I am doing some reverse engraving on some material and currently I am using a mister without the oil to blow air on the material to blow off the dust while engraving. I was wondering if there is a valve of some sort that will blast a pulse of air every 10 seconds or so to clean off the material being engraved. Having a constant flow doesn't allow me to supply enough air pressure to clean off the material without emptying the air compressor. A small blast every 10 seconds or so will allow me to apply maximum air pressure without taxing the compressor too much. Some of these engravings take hours to do and standing around for hours just isn't possible. If anyone knows if there is a device or valve that can do this, I would appreciate it.

Rando
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Joined: Tue Jan 06, 2015 3:24 pm
Location: Boise, ID
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Re: pulse air valve

Post by Rando »

Boy do I have an awesome solution for you! I do exactly that with my mister.

I use a standard air solenoid like this (12V driven):

https://www.amazon.com/HOSL-Electric-Re ... id+air+12V

and then I hook that up to one of these dual timers. They mean "dual" as in the first time is the "on" time, the second is the "off" time.

https://www.amazon.com/DROK-Dual-MOS-Mo ... mer+module

Note: If you get that specific one, you want mode 16.... Their instructions are, to say the least, a bit confusing. :mrgreen:

And finally, so that my mister only runs when the router is on, I use one of those wall-wart USB chargers to give 5V to a small relay that gates the current going to the solenoid. You want the gate in the solenoid circuit, instead of in the timer's power circuit, so that you can set the timer running, and it will keep running between toolpaths, but it will not blow while the machine is idle, and will just do the right thing when you run the next one.

If that's confusing in any way, just give a yell and I'll work up a schematic...assuming i don't already have one around here.

The above, of course, uses shop-air as the source. If you want, rather, to use like a shop-vac's exhaust output, then just wire the timer's high-current relay output into the vac's power, and skip the solenoid. Just be sure to keep your fingers away from the live wires! I'm more partial to a solid-state relay, since they often have the protective devices to handle the vac's inductive load. Something like this:

https://www.amazon.com/Solid-State-Rela ... B00MEKHTLC

To route the air into the area permanently, I use the loc-line products (http://www.loc-line.com/), in the larger size, attached to the z-axis carriage, and working it's way down underneath. A picture of that will help. The blue/green and orange bits are the loc-line. The purple hose is the mister, which has both an air tube and an internal lubricant (Kool-Mist) channel. It sounds like you already know about those.
20170423_160950.jpg
Now, for my chip-blower, I do the same thing when engraving: 1.5s on every 20min. But, the way I got that was a bit, well, "excessive" :D

http://www.cncsharktalk.com/viewtopic.php?t=5303

Many of my runs are long as well, and I have to continuously run ~100CFM into those air nozzles to get the chips out. So, the blower I use is one of these:

https://www.griotsgarage.com/product/ai ... rom=Search

That sucker is LOUD, but it's also way powerful, and will run for days and days and days, and not drain a PSI from your shop air :D.

Regards,

Thom
=====================================================
ThomR.com Creative tools and photographic art
A proud member of the Pacific Northwest CNC Club (now on Facebook)

gruszie
Posts: 10
Joined: Sun Dec 25, 2016 9:37 am

Re: pulse air valve

Post by gruszie »

Thanks for the input I ordered the 12 volt air valve and a timing circuit off of ebay and wired it together and BAM! that did the trick. I can set the timing value to anything that I want and the valve works great. Thanks for the input, it really helped out

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