What do I need to add to turn threads

I am about to rebuild my shopmaster eldorado which was converted to CNC several years ago, but has had issues the last couple years. I havent been able to figure out the issues and decided it will be easier to start from scratch and build it myself.

When I do this I want to add a reluctor wheel or whatever is needed for LinuxCNC to read RPM and be able to turn threads.

Any suggestions on what to get and how it should be integrated? And advice on setting up the config?

Or links to info on this topic, i have had no luck finding anything relevant.

You need an encoder with an index pulse once per rev of the spindle. For rigid tapping you need a differential encoder.

JT

No eBay APP ID and/or Cert ID defined in Kunena configurationThanks, Can you share a link to get me looking in the right direction?

would this work if i made a sensor disk with a single slot/hole?

Don't have a clue if that will work and don't know what a shopmaster eldorado is. I don't think a single slot would work you need an A and B and a single Z (index) per rev. Have you looked in the Documents in the Hardware Examples section? Do a google search for rotary encoder.

JT

ElDorado is a 3in1 mill/lathe I am using steppers to drive the axis. Everything I have read confuses me more so I thought i would ask here. I found some threads with this type sensor being used, but not much info on how.

Did you read the Hardware Examples section of the Documents?

linuxcnc.org/docs/2.7/html/examples/spin...ml#_spindle_feedback

Looks like you need A and Z to single point thread.

JT

okay, i didnt find those documents, i will do some reading

It is possible to thread with just a single pulse-per-rev. It is better to have more, but you do always need the single-pulse-per-rev channel.
Does the lathe have any gears on the spindle? You can add a gear-tooth sensor to get several pulses per rev, and possibly use a second (or third) sensor on a keyway to get the once-per-rev pulse.

The lathe is run from a series of belts, the only gears we the original threading gear set up which i never used.

here is what im dealing with
drive.google.com/open?id=10P6yM2mA6uabLPSY8lxa_EZj_yo1x0sl3A

and this is the controller mess i need to redo and clean up
drive.google.com/open?id=1lWs5Ii5x4ljl0JxhRheHjJOPeuD7fFSzcQ

Is that a Mesa 7i43 in the bottom left?

And, what ratio to the spindle speed do the two unused threading gears turn at?