Manual Pulse generator?

[phantomcow2]

I am really wanting to get one of those handwheels for my CNC conversion, where I can manually move the machine around the 3 axes. At work we have them on all CNC mills, they are great. I am not quite sure how to make them work though...
What I know is that you need a manual pulse generator, and an encoder. I have the encoder.

Can somebody comment on what is needed for this to work? How do you configure it to the stepper drivers? Can any step and direction driver handle it, or do you have to connect it to the PC?

[ger21]

If you're using mach3, you just wire it to the input pins on the paralel port. You can make an MPG from an encoder, or you can buy them ready to go.

Here's one. http://rogersmachine.net/MPG/heatsink.html

[ViperTX]

ger21....is there any way to perform the same function with MACH3.....

[phantomcow2]

I am all for DIY.
Do you know of a schematic for the mpg?

[Al_The_Man]

Originally Posted by phantomcow2 What I know is that you need a manual pulse generator, and an encoder. I have the encoder.

Traditionally the resolution of a MPG is 100 pulses per rev, and from there a resolution multiplier is used as to the degree of movement/pulse.
A straight encoder will work, but the nice feature of the regular MPG is the indent, so that you have the tactile feedback per increment.
Al.

[phantomcow2]

I'de like to be so that I can adjust the resolution from .0001", .001", and .01" per increment if possible. I will want to get teh full blown MPG

[ger21]

You can pretty much use any encoder and just wire it to the parallel port and it will work in Mach3. If the encoder count is low, though, you may have some issues with smoothness. Apparently, most people spend the $100-$150 bucks, because it's tough to find 100 count encoders.

Just wire up your encoder and start playing with it.

http://www.machsupport.com/MachCusto..._cheap_encoder

Also see page 73 of the Mach3 manual.
http://www.machsupport.com/documentation/M3M1_84-A2.pdf

[Al_The_Man]

Originally Posted by ger21 because it's tough to find 100 count encoders.

Koyo sell 100 count fairly cheap, Also Sumtak Used to sell them complete with indent, but they seem to have downsized their US operation.
Al.

[pastera]

http://www.usdigital.com/products/ls7183-ls7184/

Use the ls7184 and a 47ls04 (inveter) to get to a step/direction output

Aaron

[phantomcow2]

Thanks for the replies all.
What I am confused about is, what do I actually make for a circuit? You have the handwheel, what is the circuit behind this handwheel? What do the knobs actually turn?

[Al_The_Man]

Just a normal encoder output, you only need the A&B channel not the inversion if it has it (/A &/B), also the marker pulse is not required so leave those un-connected.
The only other thing to watch for is if the encoder is 5v-TTL or 24v or open-ended, basically three types.
If you are using a parallel port input then TTL or open-ended with a pull up to 5v should work, unless someone has found different.
If you are not sure what an encoder output looks like, do a search for quadrature encoder output.
Al.