Current (ma) panel meter mount for Laser Cutter/Engraver

thingiverse

If you own a Laser cutter/engraver you owe it to yourself to monitor the current to the tube and keep it within manufacturer-provided safe operating limits. Failure to do so will cause early death of the VERY expensive tube. For some reason most machines lack this feature, so we add it ourselves. Speaking of my own usage, I believed the anecdotal advice I received that if I kept the percent of power of my 100 watt cutter at 70% or below I would be fine. WRONG! At 70% the current draw of the tube is about 29ma, which (according to RECI) will result in premature failure of the tube. They say to keep it at 25ma or less ALWAYS! Without the meter I would have never known until it was too late. Of course different tubes have different allowable current levels, but the concept is the same. This mount is for 85C1-size meters, commonly available online (I chose the 30ma full-scale model). It's a simple part to print, orient with the meter opening on the top. The finished assembly attaches to the face of the laser cutter housing. You'll want to run the wires out the right in the provided slot, or out the back if you have a hole. Make sure you have enough wire to comfortably reach the appropriate attachment points in the Laser electronics. For mounting I used 3m double sticky automotive tape to affix this assembly to the front panel of the sheet metal box. Important: Use extreme caution when dealing with the electronics in your cutter, there are high voltages that can be lethal! If you're not comfortable with working inside these machines, find an expert to help. Good youtube videos are available on how to hook up. Also a very accurate model of the 85C1 meter is available from Grabcad. Update: I have added a modified design, "Housing inverted" that has the ability to have the meter mounted 180 degrees the other way, plus I've added wire cutouts on both sides, which you can ignore if you cut a hole in the chassis (eek!). This allows mounting the meter on TOP of the cutter (or on the front), oriented appropriately. It is a bit deeper allowing for the meter "guts".