No problem, be sure to post your results, especially your threading
Hood

I most definitely will!

I have a few extra Hall effect switch sensors laying around, and some magnets,

I use a Hall effect sensor and below is a link to how it's mounted. Works great,but, if one needs to purchase new it's cost
may be pricey.

http://www.machsupport.com/forum/index.php/topic,12484.msg82818.html#msg82818

You should check the spec info for the sensors you have. The sensor must be able to proivde / sense index at spindle speeds you will be using.
Can't remember details but a few sensors I have were not adequate.

RICH

Rich,

Thanks for the link.

Your solution looks great.

My hall effect sensor is a cheap $3 sensor that I was planning on using on a little DC motor to make my own encoder way back when that I never got around to.

I am quite certain my sensor will be able to read the magnet at any speeds I need to for threading, my concern is more whether the output signal will be acceptable for my G540/Mach3 combo.

I would need to look at the G540 info but you could always just go to designated pin for the index.
RICH

Rich,

I'm not sure what that means, do you mean that there is a designated spindle index pin on some parallel breakout boards?

Guys, one more question I just thought of.

My hall sensor is actually an analog output, I am wondering if this will be a problem for Mach3? I suspect that Mach3 is looking for a digital 1 or 0 type input?

If so, I suppose I could take an arduino and write some code to convert my analog output to a digital signal, but i'd rather not if I don't have to.

Yes, digital would be needed. Unless you really like messing with the aduino you would be better spending $10 and getting an opto.
Hood

Yeah, makes sense.

Darn, was really hoping to see some threads this weekend!

Thanks again.

I really want to cut some threads this weekend. I was going through my electronics stash and found some goodies.

I have a LED infared emitter and a phototransistor.

I made up a small circuit with a few resistors and hooked it up to an extra arduino I have not in use right now.

I wrote code that reads the analog signal from the phototransistor, and if it's above a threshold variable I set, it sees white, and I set a digital pin high, if it sees black, it goes below a lower threshold and I set the digital pin low.

I tried it on a little DC motor I have lying around and it's working well.

Going to try to hook up that digital pin from my arduino to my G540 and mach3 and see if this works later today. If it works, I will make a black disk with one white stripe on it and put it somewhere on my spindle and mount my phototransistor/emitter setup to read it.

Hopefully this works, I will post back when I get a chance to play around with it.