cnc lathe

Miss Rebekah

so i made a cnc lathe with a duet, it has a live tool in Z no Y axis. two spindles 3 tools setup like a gang tooling lathe that never moves i gave each tool a work offset tool one is G55 tool two G56 etc. so i could move each tool individually to account for wear etc.... no threading no constant surface speed just 2 axes and a live tool. its to help a doctor friend of mine cut small hypodermic tubing and face and deburr ends uses a small Dremel with a fancy diamond cut off wheel. a 30 deg engraving tool and a #0000 center drill . it surprisingly works well for its intended purpose. except for 2x glitches i cant get by. I got X to read diameter by halfling steps and lying to it.

First how can i just have Z and X axes? i don't need Y don't want it to even be an option i currently have a g92 Y0 in my config to just fake it out. ive tried to make the user experience as idiot proof as possible since i am journeyman machinist and a doctor or some office flunky will be cutting tubes with it not me. ive played with moving it just like a though nothing bad happens, id still like to get rid of it.

I have a spindle speed sensor its just an optical endstop im not asking for PID or CSS lol.... how can i divide the number of pulses by 4 in the config? just wannna be able to see actual rpm in DWC surfacefeet per min is important in this application.

for the live tool in Z i defined a tool and added two spindles to it. so i can run both at same time. i have to use m3 p1sxxx then m3p2sxxx.

Axis skew correction rocks on a lathe just build it best you can sweep indicator add line of code all square i was out of square .004 inches over 100mm just bolting it together(yes I need a metric test indicator)

dc42

@miss-rebekah said in cnc lathe:

First how can i just have Z and X axes? i don't need Y don't want it to even be an option i currently have a g92 Y0 in my config to just fake it out. ive tried to make the user experience as idiot proof as possible since i am journeyman machinist and a doctor or some office flunky will be cutting tubes with it not me. ive played with moving it just like a though nothing bad happens, id still like to get rid of it.

Currently there is no way to hide the Y axis. It is possible to hide the Z axis, so you could rename your Z axis to Y; but then you would need to change your GCode files.

I have a spindle speed sensor its just an optical endstop im not asking for PID or CSS lol.... how can i divide the number of pulses by 4 in the config? just wannna be able to see actual rpm in DWC surfacefeet per min is important in this application.

The best I can suggest is that you configure a fan (you don't have to actually connect it) and configure the port that the optical sensor is connected to as the tacho for that fan. You will then get an RPM readout. However, fan tachos normally produce 2 pulses per rev, so the RPM reading you get using a 4 pulse per rev sensor will be twice the actual rpm.

for the live tool in Z i defined a tool and added two spindles to it. so i can run both at same time. i have to use m3 p1sxxx then m3p2sxxx.

Axis skew correction rocks on a lathe just build it best you can sweep indicator add line of code all square i was out of square .004 inches over 100mm just bolting it together(yes I need a metric test indicator)

Thanks for sharing!

Miss Rebekah

@dc42
thanks DC42 your active participation on these forums is why i bought 2 duets. its actually working quite well for what I'm doing with it except for the above mentioned features. skew correction does have one big downfall on a lathe that is drilling you get x and movement instead of just all z i ended up popping it loose and squaring it the correct way. i made an aluminum tool holder to hold a tiny boring bar it had to be on centerline so i put drill in spindle and drilled it on the lathe itself. during dry run i saw the x stepper moving.

i did find another glitch if a start a spindle M3P0S5000, then send M3P0S8000 in iso g code and every machine tool i have used the spindle should accelerate to 8000rpm on my duet 2 on this lathe it wont change speed. it will if i give it M5 then send M3P0S8000. its the same in a program, console and DWC. I'm using heater 3/4 2000hz pwm the duet does not change pwm value. id like to be able to ramp up the spindle rpm without stopping m3 sxxx g4 p500 m3sxxx+1 etc.... bug,feature or operator error? i would think with ability to change rpm without stopping and a spindle tach knowing where your at in X constant surface speed would be possible pretty easy. i only code in g code for a living though

Miss Rebekah

@miss-rebekah

i figured it out since I'm using work offsets for tools i wasn't calling a tool number once i did that m3 works