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

thingiverse

If you own a laser cutter/engraver, it's crucial to monitor the current flowing into the tube and keep it within the manufacturer-recommended safe operating limits. Failing to do so can result in premature death of the extremely expensive tube. Many machines lack this feature, so we add it ourselves. Personally, I was misled by anecdotal advice suggesting that if I kept the power percentage of my 100-watt cutter at 70% or below, I would be fine. Unfortunately, WRONG! At 70%, the current draw of the tube is approximately 29ma, which, according to RECI, will lead to premature failure of the tube. They recommend keeping it at 25ma or less always! Without a meter, I wouldn't have known until it was too late. Different tubes have varying allowable current levels, but the principle remains the same. This mount is designed for 85C1-size meters, which are widely available online (I chose the 30ma full-scale model). It's a simple part to print, and orienting it with the meter opening on top will yield the best results. The finished assembly attaches to the face of the laser cutter housing, so you'll want to run the wires out through the provided slot or the back if there's a hole available. Ensure that you have enough wire to comfortably reach the appropriate attachment points within the laser electronics. For mounting, I used 3m double-sticky automotive tape to secure this assembly to the front panel of the sheet metal box. Remember, extreme caution is essential when working with the electronics in your cutter, as there are high voltages that can be lethal! If you're not comfortable working inside these machines, find an expert to assist you. Good YouTube videos are available on how to connect the meter. Additionally, a very accurate model of the 85C1 meter is available from Grabcad. Update: I've added a modified design called "Housing inverted," which allows for mounting the meter at a 180-degree angle, plus it includes wire cutouts on both sides that you can ignore if you cut a hole in the chassis. This enables mounting the meter on top of the cutter (or on the front), oriented appropriately. The updated design is slightly deeper to accommodate the meter's internal components.