I had my air compressor go off in the middle of the night again last night so I finally ordered one of those ~1200 GPH air compressors for aquariums($45). And recently I saw a post about an air assist configuration with some valves to switch between full air assist for cutting and low air assist for engraving and keeping the lens clean. Made me wonder if these oscillating membrane based aquarium pumps can be regulated with a standard light dimmer switch?
The better ones do zero-crossing waveform chopping so often the basic 60Hz frequency is maintained.
I got nothing for you on the dimmer, but I can definitely relate to the 2am air compressor. Especially at my last house where the bedroom was right above the garage!
A lot of dimmers warn that they work only for resistive loads. I’ve never investigated why but could imagine back-emf shifting phase enough to make the dimming function not work right, for one thing. (Only intuition here, no knowledge.) I also dimly recall warnings that they can overheat driving inductive loads, so maybe fire danger? Any reason you wouldn’t use a fan speed control switch designed for inductive loads instead?
ya, not all the dimmers are choppers either. It’s been a while since I was into the dimmers and which brands had what internals. I built a coffee bean roaster out of a popcorn popper by breaking the fan off from the heater and putting it on a dimmer many years ago.
Yes, a fan control much like the one on my large extraction fan mounted on my garage roof would work too. Just a small single junction box is easy-peasy. Thanks for the reminder as I will try this using the fan controller by putting a power meter before the controller and look for a linear response without heating on the pump or controller.
The 1189 GPH pump pulls 46W full speed and I could slow it to 26W with the fan speed controller and then it would shut down. I did not notice any heating nor odd sounds at the low power. It still puts out more air then I’d like for the minimum but it’s untested and resistance in the airline might slow the flow enough to work.
New bearings arrive sometime tomorrow so I might get the machine working again on Sunday to do some testing.
I was thinking of a manual valve or just see if a cheap small aquarium pump would be enough air to keep smoke out of the lens cone. Two inline one way air valves would allow the 2 pumps to be "Tee"ed together and then it’s just a matter of leaving both on all the time and just turning off the big one for engraving or have each with their own power switch.
BTW, I could not see what that last link was for. It brought be to a page of ads.
I have seen users add muffin fans to the front of the machine to pull air across the cutting area.
I planned to do the same but it never made the “do it” list.
That may be enough air movement for you engraving and they can run all the time.
I’ve got a green house fan used to extract air from the K40 so that works great and for engraving I just prop the door open a 1/4" and a nice flow of air goes across the top of the work piece. All my work to lower the air assist is because my air assist is a combo lens cone and tube and I want just enough airflow to keep fresh air in the lens cone.
Yes that link works now and it’s been added to my wish list for my next batch of purchases. I had a small harbor freight regulator on my compressor line and it was set so low the dial did not register. But the spring water drain valve would sometimes need a little tug down to keep it closed and the new aquarium pump is right at the edge of where the regulator was. So VERY close to the same airflow/pressure I was working with before. I connected it up today and love how quiet it is even though it’s adding continuous noise instead of moments of very loud noise.
