# Specific 3D Printers, Scanners, & Hardware > RepRap Format Printer Forum > MakerFarm Forum >  Auto bed level

## tonybuckley

Anyone got any good links for the i3v.   I've seen zen masters vids for i3 but that slows things down a lot it seems?

Is this worth exploring?

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## cperiod

In practice, it doesn't slow printing down. The ABL normally runs after the heat bed gets to temperature and the hotend starts heating. I find that my ABL finishes right around when the hotend is at temperature.

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## Roxy

With Auto Bed Leveling, you get a good first layer almost every time.   It is well worth having just because of that.

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## cub22908

> In practice, it doesn't slow printing down. The ABL normally runs after the heat bed gets to temperature and the hotend starts heating. I find that my ABL finishes right around when the hotend is at temperature.


My ABL doesn't start until after both bed and nozzle heat up.  This does slow things down a bit,  I am set up per zen masters vids.  Anyone know what to change to get it to go after bed heats up and before nozzle?

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## cperiod

> My ABL doesn't start until after both bed and nozzle heat up.  This does slow things down a bit,


Okay, that *would* suck.It depends on your slicer, basically. With Slic3r, I just put my ABL commands in the "Start G-Code" section for the printer. However, that section isn't run until the heatbed is at temp and it's started the hotend warming up.I assume you're either not using Slic3r or perhaps an older version (I'm on 1.2.9), so you'd have to work out the right place to add ABL commands in your slicer. Assuming it's even possible.

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## cub22908

I'm using Simplify3d and the ABL command is in the Starting Script area.  I'll look around and see if I can put it someplace where it will run after the bed heats up.  Thanks.

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## Roxy

You should be able to tell your printer to start heating up but don't wait for that to happen.   Then do the ABL commands.  And then WAIT for everything to be up to temperature.   I can start cold and just about the time the 4x4 grid is probed, everything is up to temperature if I'm printing PLA.

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## kd7eir

I have always probed my bed with the hotend and bed at printing temperature. My theory being that things expand when hot so the measurements may be off if taken with everything cold. Am I just wasting my time?

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## Roxy

> I have always probed my bed with the hotend and bed at printing temperature. My theory being that things expand when hot so the measurements may be off if taken with everything cold. Am I just wasting my time?


Well...   That probably makes sense.   But if you are consistent and print the same way all the time...   It is easy enough to just adjust your Z-PROBE-OFFSET the right amount so the right thing happens.

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## cperiod

> I have always probed my bed with the hotend and bed at printing temperature. My theory being that things expand when hot so the measurements may be off if taken with everything cold.


I've read that the bed can noticeably flex between hot and cold, so I like to have the bed at temp; even before I switched to ABL, I'd warm the bed before doing a manual level. But I've never heard the same with the hotend. It seems unlikely, and waiting for the hotend to be at temp before starting ABL strikes me as a recipe for excess oozing.

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## Roxy

OK...   And remember, everybody's printer is different.  You could very easily turn on the bed and nozzle with Pronterface and let it heat up.    Do you get a different first layer if you do that compared to if you just start cold and let it heat up while the ABL stuff is doing it's magic?

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## cperiod

> Do you get a different first layer if you do that compared to if you just start cold and let it heat up while the ABL stuff is doing it's magic?


In all honesty, it never occurred to me to test that. My heat bed is always up to temp before I run the ABL, but ABL runs while the hotend is warming up. What I can say is that I haven't noticed a difference in first layer quality between the origin corner (where the hotend would be coldest during the ABL) to where the ABL ends (when it's near 240C). Nor would I expect to see the difference at the 0.2mm layer heights I print with; the linear thermal expansion of something the size of an alu/brass hotend heating to 250C is something like 0.005mm. I'd bet the retraction and extrusion forces and carriage wobble move the hotend more than that.

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## kd7eir

I've been testing today with just heating the bed before doing ABL and have not noticed any quality difference between that and heating both the bed and hotend. I'm not sure that there is any time difference from clicking print to laying down pla with either method as normally my bed heats first then the hotend, so I'm spending the same amount of time, just eliminating any possible oozing during ABL.

Tomorrow I will experiment with doing ABL cold.

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## Donziboy2

So what probes are you guys using?

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## kd7eir

> So what probes are you guys using?


I'm using a servo with the same microswitch that was being used for my Z axis

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## cperiod

Servo with microswitch. A different microswitch than stock, though, as I trashed mine resoldering a broken connector.

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