I saw someone write here a while back that the only point of limit switches was to be able to home the machine at the end of the day. I’d like to shed some light on this.
The limit switches allow you to operate based off a consistent 0,0 location. Upon homing, you can work from the same spot every time. Index your material off of a jig, and make the home location your work zero, and you can resume a cut without material loss if you encounter an error. Even if the torch snags a tip up and moves the sheet, you can re index, home, and start your file from the line of code the error occurred on.
Even more, let’s say you started your cut in the middle of the table with an unknown relative 0 like a madman (which I do all the time) and fire control freezes after a pause to fix a tip up. Well, I wrote down the machine coordinates, and the work coordinates, then subtracted them from each other to find the machine 0 I had started with. This ended up being X11.378, Y-1.355. Now, because I could not just type that into fire control, I had to use a combination of continuous jogging and 1/16 steps to get it to those coordinates to set my work zero where it had been. Luckily my material never shifted. I couldn’t get it dead on, but I was within .002 of each. Resumed my cut and you cannot tell I lost my zero and restarted in the middle. Took about 5 minutes to get back to zero and save the cut.
In the future, if I need to start a cut in the middle of the table on some scrap, I’ll probably move the torch from home by 1 inch increments then position the sheet accordingly to make it easier to get back to my exact work zero based on machine coordinates.
Firecontrol rarely gives me issues, I believe this was just a fluke from me pausing right as the torch was about to fire. Otherwise, every other pause worked fine, and I run firecontrol off a tiny cheap stick pc. Yes the limit switches kill a tiny bit of your workspace, but your table stays dialed in. Depends on what this ability to salvage a cut is worth to you. If you’re doing a giant sheets of tons of parts or huge signs, then the limit switches can pay themselves in one salvaged cut.
Just getting primed, 16g mild steel. Hypertherm 45xp with fine cuts, book specs.