Need Info on Splicing into Existing Tach for Spindle Info

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SteveHGraham
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Need Info on Splicing into Existing Tach for Spindle Info

Post by SteveHGraham »

Here is a question for electronics people. I am trying to find the answer myself, but it can't hurt to ask.

I am trying to fix my CNC mini-lathe up for threading. That means it needs a spindle sensor. When I got the plans, a sensor was included in the BOM, so I bought it, assuming I would figure it out later.

Now that I'm taking a closer look, I think I will not need the sensor. The plans are for a mini-lathe with no RPM meter. My lathe already has one, so the spindle has a ring on it with a hole in one location, and the ring passes through a caliper-looking thing which must be an optical sensor.

Here is what I'm wondering: can I just cut into the RPM sensor wires and feed a new line to the board controlling the lathe? The board will accept spindle information, so that's not a problem. The problem is that I don't know what kind of signal comes out of an optical sensor, whether it needs power, etc. I don't know if the type of signal that emerges from this thing will make my controller happy.
Every hard-fried egg began life sunny-side up.
Zerobeat
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Re: Need Info on Splicing into Existing Tach for Spindle Inf

Post by Zerobeat »

Just taking a wild guess, but I think you may have a Hall Effect sensor rather than an optical. I'd also guess that both controls would experience issues sharing the sensor.
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SteveHGraham
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Location: Florida

Re: Need Info on Splicing into Existing Tach for Spindle Inf

Post by SteveHGraham »

I've been researching. Right now it looks like two slotted optical switches and a second wheel with two notches will do the job.

I've been using Mach3 to try to get the lathe working, and apparently, most people using Mach3 thread with a single spindle sensor. Unfortunately, I sprang for a nice board that insists on two sensors at 90 degrees to each other. I'm not sure I understand it yet, but the optical switches are my current focus.
Every hard-fried egg began life sunny-side up.
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