TarHeelTom

Be interesting to see how repeatable these are. I’ve bought several types of micro switches from different manufacturers, as I’ve had one bad switch (sticky) on my Bridgeport. Finally found a source (Allied, I think) for the original Honeywell switch and bought one. $160 Oooouch. But, it works, and works well. My best indicators only read to 0.001, and the Honeywell switch is repeatable to less than that. The repeatablility is important to me, as I have a fixture bolted down to the table, and if I can home to a precise position, it saves me having to dial in the position with an edge finder, which is a slow process.
But the price is right on these, $0.99 each, so I ordered some.
Overall, I think I like the Hall effect switches better, especially if I can find a way to mount them where they are protected from swarf. They are, of course, magnetic, but I rarely cut any steel on the Sherline, so that’s not a problem.

Thanks again.

>>>Spindle control is of interest, but not something I’m going to worry about. I have provisions for it on my Bridgeport, but it just never has gotten anywhere near the top of the stack. But getting 0 to 10 vdc doesn’t sound that hard. Seems to me that a pwm signal looks a lot like a DC signal with lots of ripple. What if you just put a diode on the pwm output, then a capacitor, then a drain resistor. Wouldn’t that look just like a 0 – 10 VDC signal? I may try breadboarding something like that this evening.

Started to build a mock-up of the PWM to DC converter, but then decided to google it first. Here’s a link to a very simple way to do it. Of course, this simple circuit only gives 0 to 5 vdc, but there are ways around that.

http://www.instructables.com/id/Analog-Output-Convert-PWM-to-Voltage/

Tom

The plug on the controller end of my stepper cables is a 5 pin DIN plug, but I don’t remember ever having the cables loose from the steppers, so really don’t know how many wires are in the cable. But it appears that only 4 plus ground are used at the controller end of the lashup.

My Sherline has no limit or homing switches on any axis. But I would like to add them. Probably Hall effect switches. Not possible with the existing controller, as there are no inputs at all, only the stepper outputs and the parallel cable from the computer. Joe didn’t bother to add limit switches or homing switches on the Sherline as he was under the impression that running into the physical limits on the Sherline would not hurt anything. And he’s generally right.

Spindle control is of interest, but not something I’m going to worry about. I have provisions for it on my Bridgeport, but it just never has gotten anywhere near the top of the stack. But getting 0 to 10 vdc doesn’t sound that hard. Seems to me that a pwm signal looks a lot like a DC signal with lots of ripple. What if you just put a diode on the pwm output, then a capacitor, then a drain resistor. Wouldn’t that look just like a 0 – 10 VDC signal? I may try breadboarding something like that this evening.

But my question is still a simple one. Do the stepper drivers on the tinyg have enough ooomph to run the Sherline steppers. Once you get yours hooked up and running, let me know.

Thanks

Tom