Servo motor resolution

[thissideup]

Hey guys, I posted this in the p cam section but never got a reply. I’m planning to convert a bench mill to cnc using a spare set of plasma cam parts I have. Not ideal I know but it’s free and will be a fun experiment. I’m curious though how to time the resolution. My screws are 10 turns per inch, .100 per turn, if I set motor to screw cog ratio to 1:2 that should equal .001 per step (assuming my plasma cam motors are 200 steps per revolution?) but what’s got me stumped is the resolution setting, I’m not sure how to do the math on that so that 5 turns of the motor will equal 1” of travel or should I say 1” of movement will equal 5 turns... maybe I should go 1:1 and get into the .0005 territory

[acourtjester]

Ok there is a simple way to do this if you are using Mach 3 to drive the mill. After you assemble each motor you can calibrate it by using the "Steps Per inch" calibrations for each axis. You will be asked to enter a distance like 0.500" then you measure how far it move and enter that into the box in the next page. Mach 3 will calculate the number of steps it will need to move 0.500" for you and put it into the motor drive location for that value.
There are many video on how to do this on YouTube for you to view. You can change the steps per revolution to effect the ratio for the overall distance and the velocity and acceleration to make it move the speed you want after.

[thissideup]

I plan to go totally plasmacam to start including software. Not ideal I know, mainly just looking to drill patterns so I can use it to touch down with a centring drill to mark the spot, I’ll play with it like a router as well and use kerf width to set the offset for the thickness of the cutter. If this goes remotely well I’ll be getting a Bridgeport and do a full conversion with either mach 4 or Linux.