I sometimes print with ASA on my H2C. When I do I always end up doing 2 cold pulls on each nozzle I use. Sometimes all of them. Is there a way to skip the homing on each pull as I really do not see the benefit of this action for a Cold Pull?
I am not aware of any bypass for homing.
It needs the homing to present tool head at an accessible location and enough height to execute the procedure.
They might however improve the firmware so when it knows its position, it doesn’t repeat the homing again.
But it’s safest to do homing every time to make sure the position is known and possible step skips have occurred.
That does sound like an opportunity to optimize the firmware as Gerrit stated, there isnt a reason to home more than once even if it changes nozzles it should know the location of the print head.
Should only do it once, not repeat it every time you do a pull, unless you exit the screen after each pull. I once needed to do 6 pulls on one nozzle, just hit retry after each one. When finished, I went to the other nozzle and it didn’t rehome either.
It is homing for each nozzle. I did have to run white PLA through the left nozzle 7 times to clear black ASA but I am pretty sure it had to home each time. Even when repeating it on the same nozzle.
It will only re-home if you complete, or stop the process. If you retry after pulling out the filament, it will go to the pull PTFE and then insert filament stages. If you complete the process, then it resets and will have to start from the beginning. I just completed a large ABS job with .6 nozzles and did a cold pull on them before putting them away. I normally run minimum 2 pulls per nozzle so I hit retry after pulling the filament out so it doesn’t reset. So don’t hit complete or finish on the last screen and it won’t rehome.
That’s fine for each nozzle but when running them on all 7 nozzles of the H2C is just seems like a lot of wasted time. I’d just rather it be a manual process and allow the motors to move freely. Not a HUGE deal, just inefficient.
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I haven’t done a cold pull on the C yet, but I do understand why it does it since it has to unload and fetch a new nozzle. Their programming on that sucks. When you unload a nozzle, it parks the head at #1 location at the rack. When you fetch, it does the same thing, so apparently the base coding is combining both the unload/fetch, and cold pull programming from the D and S and doesn’t use it’s own programming to remember the home setting, so has to rehome every time the head moves for something else. You would think it would since it fetches a new nozzle when changing colors while printing and doesn’t need to home. Thats coming from the slicer, so if the slicer can do that, why can’t the machine itself remember it’s home position during a cold pull?
It’s too bad you can’t manually pull the nozzle out on the right side easily like on the left. When I do a cold pull I do all nozzles on the left side unless that nozzle hasn’t been used since the last CP, then I do them all on the right. With 3 machines, .2-.6 nozzles, I tend to rotate nozzles and then have a cold pull party and just swap them out after each clean pull and just keep hitting retry on that side with the new nozzle. Saves a bunch of time between swapping sides and rehoming.
They could definitely improve their firmware and check if the stepper motors drivers are still active.
As soon as the drivers are powered off the position of the tool head is basically unknown.
I haven’t checked all the moments that the drivers are powered off, but at the end of a print job it definitely does.
But in some other situations, the drivers stay powered on infinitely to make sure the position is known after a pause for an error/warning.
On my Voron with Klipper, I created a macro for the homing that checked if the drivers were still active/home position still known and skipped the homing sequence if that was the case.
It saves 30 seconds on each homing cycle.
It should not be hard to implement something similar in the H2 series for that matter.
It seems that the homing is just being executed every time a G28 passes by.
On the other hand, missing a homing sequence for whatever reason can cause much more damage.
And what’s 30 seconds in a lifetime?
Did the first IN cold pull on my C and sure enough, homes on retry. The D doesn’t do this, so a bit weird BL has the C doing this.