auto calibrating X Y steps per mm
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I'm trying to set up an autocalibration routine for my CNC that runs on startup and was thinking it would be possible to drive a tool into an axes probe in a known location and save that as a tool offset then drive it into a second probe of a known distance to probe X and calculate the sterps/mm from that. does anyone believe this to be possible
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@jengland said in auto calibrating X Y steps per mm:
I'm trying to set up an autocalibration routine for my CNC that runs on startup and was thinking it would be possible to drive a tool into an axes probe in a known location and save that as a tool offset then drive it into a second probe of a known distance to probe X and calculate the sterps/mm from that. does anyone believe this to be possible
Why would you want to do that?
Is the steps/mm going to be changing because of some different hardware being swapped in and out?
Normally you can calculate what the steps/mm should be.
Frederick
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@fcwilt because I run an open-source project for a 3d printed CNC and creep issues can be a problem causing different steps/mm a few weeks after first building. it also helps new builders at the end of the day set it up as it can be done with the click of a button rather than by themselves.
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@jengland My guess is you'll need some kind of unchanging reference of a known length. For instance, two switches 'exactly' 500mm apart, and initally measured by some other means. You can then drive the carriage (or tool or, other part of the machine) into one switch, pull the current position from the object model and store it as a variable, do the same for the other switch and then compare the difference in position to your reference. If it differs by some amount, update the Steps/mm for that axis automatically.
Microswitches are cheap but might not be suitable because of their repeatability error. Maybe you'd want to create a switch using two conductive points, like some cncs use for tool offsets:
https://shop.carbide3d.com/collections/accessories/products/bitzero-v2?variant=32936948236349
