After installing a BL Touch on a Workhorse, is the backlash calibration with the cube toast or does it still work?
Backlash calibration will no longer work with a BLTouch, this is because the sense line ordinarily used for the backlash calibration will now be connected to the BLTouch.
Lulzbot is now selling a Taz Pro S, which has the option of adding a BLTouch. They also sell a BLTouch that is mounted to a printed plate that inserts behind the single extruder and connects to the ports that the second extruder and servo on the dual head usually connect to (I think the Workhorse has these ports as well, in case a Workhorse owner wanted to add the dual print head).
Anyway, Lulzbot must be using separate pins for the BLTouch and the backlash cube (which I think is the same as the bed leveling washers).
I have not been able to find the pinouts in any literature provided or posted by Fargo Manufactoring (are they still supportive of open source?) However, the photos show approximate pin locations in the connector, allowing for some experimentation)
I would be fairly easy to hack the hardware to allow both backlash compensation and BLTouch to work, but my question is this…
Do those who use backlash compensation think it adds to print quality? From my recent reading, I’m not sure it does. If not, is it worth the effort to re-impliment it.
I can’t say I noticed any decrease in quallity after adding the BLTouch to my Taz Pro.
Still thoughts/opinions are appreciated, as I have been considering making the effort to re-impliment the backlash compensation so I can perform side by side comparisons.
Since I no longer work for LulzBot, I no longer have access to the kind of insider information I used to have. Thus, I’ve always felt that Drunken Octopus was meant for older printers and accessories, not newer generation releases from LulzBot. You are of course free to experiment, but this is not something I can feasibly do myself. Good luck!
When backlash compensation was originally implemented, it used the same pin in Marlin as the probe. For backlash compensation and the BLTouch to work simultaneously, it would be necessary for those features to use different pins. I do not know whether Marlin has been modified to allow this, or whether LulzBot is using some custom code to do this. In any event, the calibration cube is not necessary for backlash compensation. It is merely necessary to measure it. You could conceivably use the stock firmware to run the calibration cube routine, note down the backlash values, flash the BLTouch firmware, enter those values manually, and have the same effect.
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