Initial height with multiple hot ends

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peterbrown77
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Joined: Mon Mar 27, 2017 5:20 pm

Initial height with multiple hot ends

Post by peterbrown77 » Wed Feb 19, 2020 1:39 pm

I have 2 hot ends, one with a 0.50 nozzle and one with a 0.35 nozzle. I change them a couple times a week..... 0.35 for PLA, 0.50 for TPU.

I REALLY don't want to go through the whole bed leveling ordeal every time lol. The bed is level.

What I want to do is just issue a command that will drive the M2 to the center of the bed at it's zero height, slip in the feeler gage, and adjust the nozzle by loosening the SHCS on the hot end and letting gravity drop it down to the feeler gage. Tighten, and Bob's you mother's brother.....

Same thing if I'm using painter's tape or not...it's kinda thick.

TIA

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ednisley
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Re: Initial height with multiple hot ends

Post by ednisley » Wed Feb 19, 2020 1:55 pm

peterbrown77 wrote:
Wed Feb 19, 2020 1:39 pm
issue a command that will drive the M2 to the center of the bed at it's zero height
Something like this:

Code: Select all

G0 X100 Y125
G0 Z0
That assumes you have the XY origin set at the front-left corner, which I think is true for pretty nearly everybody other than me, that the platform is down far enough to not collide with the hot end, and that the axes have been properly homed.

For me, it's easier:

Code: Select all

G0 X0 Y0
G0 Z0
It is Good Practice™ to move XY first, then position Z, to minimize the damage done when a typo slams the nozzle into the side of the platform.

Setting the nozzle flat on the platform puts Z=0 on the surface, which makes perfect sense to me, which is why I've always done so. Various rituals involving shims / feeler gages / business cards put Z=0 somewhere above the platform, for reasons lost in the days when few folks knew how to properly adjust the Z offset.

airscapes
Posts: 443
Joined: Wed Jan 31, 2018 11:36 pm

Re: Initial height with multiple hot ends

Post by airscapes » Wed Feb 19, 2020 3:01 pm

G28; homes everything
G1 F1000 X100 Y125 Z0 ; move to center of bed at 0 height

There is a more complicated process I follow to set the exact staring height but the above gives you what you want and will work as you want. It is how I start the process, hot end up all the way in the mount, send those commands, put feeler under (clean nozzle) loosen screw till it drops and tighten it.

If you want the rest of the process for more exacting (time consuming) set up let me know as it is a bit to type out.
Hope that gets you were you want.
Doug

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