Use of G30 Z0 to achieve a perfect first layer (with grid level and nozzle based probe) February 18, 2017 08:07AM |
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Re: Use of G30 Z0 to achieve a perfect first layer. February 18, 2017 09:40AM |
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Re: Use of G30 Z0 to achieve a perfect first layer. February 18, 2017 10:08AM |
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Re: Use of G30 Z0 to achieve a perfect first layer (with grid level and nozzle based probe) February 19, 2017 02:41AM |
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Re: Use of G30 Z0 to achieve a perfect first layer (with grid level and nozzle based probe) February 19, 2017 04:55AM |
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Re: Use of G30 Z0 to achieve a perfect first layer (with grid level and nozzle based probe) February 19, 2017 04:59AM |
Registered: 8 years ago Posts: 3,525 |
Quote
o_lampe
Using the nozzle as probe has a logic conflict IMHO:
You have to heat the nozzle and wipe it clean before you know where Z=0 exactly is. With a stiff frame and solid bed, you can easily damage the bed surface.
What's your way of doing that?
Re: Use of G30 Z0 to achieve a perfect first layer (with grid level and nozzle based probe) February 19, 2017 06:40AM |
Registered: 8 years ago Posts: 601 |
Quote
DjDemonD
Quote
o_lampe
Using the nozzle as probe has a logic conflict IMHO:
You have to heat the nozzle and wipe it clean before you know where Z=0 exactly is. With a stiff frame and solid bed, you can easily damage the bed surface.
What's your way of doing that?
Hi O_lampe these are good points but its really not a problem.
-Yes I heat the nozzle but only to just below "ooze temp" for your filament so 130-160 deg C which should NOT damage your bed if contact is brief. Do not probe at full hot end temperature.
-I wipe the nozzle with my usual wire clippers.
-This works as the piezo probe triggers with minuscule force, I will put my jewellery scales on the printer and measure the probing force if it works.
-Your bed material has to be able to tolerate filament being deposited onto it at whatever temperature you print so I cannot think of many surfaces that won't tolerate 250 deg C briefly and we are using 160 at most.
-In the start gcode (or probing macro) you should have G30 (or G30 Z0) then immediately G1 Z5 or G1 Z50 whatever height you prefer to move to after probing, so you don't leave the nozzle on the bed hot.
As for the thermal expansion I did a few calculations:
The thermal expansion effect from say 160 to 235 is very small, even if we assumed the entire hot end was heated, an e3d v6 would go from 62.40345mm @ 160 deg C to 62.46092mm @ 235 deg C so only 0.06mm and that's if the whole thing was hot. In reality the heater-block and heatbreak up to the heatsink is 19.5mm, so the change is only 0.02mm. If you probed with hotend cold you would be expecting 0.06mm change in dimension from 20-235 deg C. So if worried probe with hot end cold, but bed at full operating temp, but add 0.06mm when printing to compensate for expansion.
Re: Use of G30 Z0 to achieve a perfect first layer (with grid level and nozzle based probe) February 19, 2017 08:14AM |
Registered: 8 years ago Posts: 5,232 |
Re: Use of G30 Z0 to achieve a perfect first layer (with grid level and nozzle based probe) February 19, 2017 09:07AM |
Registered: 8 years ago Posts: 3,525 |