I have a project where I think an Arduino could be put to good use. It involves reading the hydraulic presure developed in a bottle jack used in a hydraulic press.
The problem is that the pressure developed can be up to 10,000 psi and though sensors in this range are available they are prohibitively expensive for this project.
Gauges are availabe quite reasonably though.
OK, so I have a gauge with a pointer that moves. I’m thinking if I would couple that to a potentiometer somehow that I could Have the Arduino read the potentiometer.
The problem is how to couple the pot to the gauge pointer. I’ve thought of taking a pot apart to loosen it up as much as I can (there are several tutuorials on the net about how to do this - it’s kind of common for muscians to want to be able to adjust pots on their instruments with just the brush of a finger) and just JB welding the end of the pot to the gauge pointer base. I’d have to rig up an anchor for the body of the pot though.
I also have a couple 10K pots with solid shafts (no split in the end, no ridges, etc. they’re just aluminum round) and I’ve considered cutting them shorter and drilling a hole in the end and then removing the pointer and putting some epoxy in the hole and shoving it down on the gauge pointer shaft. Again, I’d need to rig up an anchor for the pot body. The problem is the pin shaft is pretty small and drilling a small hole exactly in the center of the pot shaft may be challenging.
I’ve also wondered if I could just bend the end of the pointer up and then install a flat disc on the pot shaft and put a hole in the outter edge of the disc for the bent portion of the pointer to fit into. This method may be a little sloppy but would help negate the need for having the pot and the pointer shaft exactly aligned.
In my net search for ideas I ran across a YouTube video that shows how a gauge works. It appears it’s a coiled tube that moves a geared linkage that meshes with gears on the shaft. The geared linkage isn’t exactly straight but it’s not overly curved either, so I’m also wondering if I couldn’t rig a linkage from it to a straight slide pot.
I’m wondering if I’m not re-inventing the wheel here though and I just don’t know the right words to put into the search engines to find what I’m looking for.
Does anyone know of an inexpensive off the shelf device to do this? Or have an idea for an easily fabricated gauge/pot coupler?