I3 Prusa knock off help please

OK, moving the topic out of the introductions.

I am in Oakville, playing with this now… hardly worth it printer, but the models I need to make are not complicated or detailed.

I am just manually leveling the bed using the paper technique. But for example getting better advice on how to set that up would help. I think I set my Z-minimum to 1mm correct?

I have marlin 1.1.2 firmware. I am using PLA I bought from 3d Printing Canada :wink: its ok, it was on sale, so again… not worried on quality of print… just more getting it going again… I had this working pre-pandemic… messed something up when moving it… now I cannot remember what needs to be fixed… I have not done it enough for this to be retained.

Does not look like we can upload pics in this forum, or I would show you what I am dealing with.


Absolutely, Pic is worth a thousand words, Go for it.

This is the printer I have.

My build is OK, what I am not sure on is setting up the leveling… correctly. and the Extruder seems to shudder or slip or too tight? not sure how to adjust it properly.

This is my actual machine - couple of “upgrades” - really just need to figure out - how to set it up (leveling, offset etc)

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To adjust your extruder it should start loose, then tighten it down until with an energized stepper motor you cannot easily pull the filament out of it. In most cases, it will leave a little toothed track down one side of the filament but not enough to grind it. Run an extrusion test on it and once it’s predictable you are good to go. It’s one of my thoughts it needs to be tight enough but not too tight… Not sure if that sentence is helpful or not.

Bed levelling is pretty straightforward, unless you have a BLtouch you don’t have to worry about the offset, should ideally be zero if no BLtouch.

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SO I do the paper in the corners thing…

One thing I notice I have marlin 1.1.2 firmware - when I click disable stepper motors I get no response… I can move the bed… so I guess it OK, dont want to do any damage.

When I AUTOHOME it sets Z at 4mm - So when I do the paper thing… I take it down to 1mm and then adjust the bed correct?


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Z min should be 0, not 1. Once at zero you would paper level it which technically would put the physical bed at Z=0.02 but as far as the printer is concerned it would be at Z=0.

Past that it should print, Quality is a different issue. Im assuming you do not have BLtouch?

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No … no Bltouch. I understand the factory Autosensor I have sucks - senses the metal plate, and has a hard time if you have glass or a building pad on the metal. So I went back to manual… if you get manual right… then you should not have to do it each print… so not that big of a deal once you figure it out.
OK… so Z should be at 0… ok… Ill have to check that. Auto home puts it at 4mm.

When downloading firmware - do you download a firmware that is supposed to have your printers settings in it already?? Auto home for example does not seem centered on the X… Y seems good…


IN the build for the i3 prusa version. It says to set the Z axis endstop to 1mm.

Now I have marlin 1.1.2 on this printer right now. I found a website with a config file for this printer for marlin 2.0.7 - dont yet know how to upgrade it.

But question on config - setup… Mine has an Z offset of -1… AKA… I guess Z end set to 1 - but offset makes it zero to the table… minus the .02 from the paper? No idea if this is correct as no instructions on setup in the firmware.

Now when I take it to 1mm on the motors… I can put 1mm worth of paper in… and still reduce the nozzle -.7mm till I have a good pull on the paper. Paper was measured with a caliper.

SO… my Z axis switch is too low by .7mm correct? I am asking because my base layer does not exist really… but when I got building the benchy started looking like the tugboat whistle again :slight_smile:

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That sounds right to me, I agree that your switch may be too low.

I have not gotten any experience with building PRUSA firmware but from what I can understand what you have seems logical.

Re-reading it… I guess it is too HIGH by .7mm.

So I think I will put the 1mm of paper in… bring the nozzle down till I get drag on the paper. Then I will set my Z-switch so it just clicks at that position.

Found a good adjustable z-switch mount on thingyverse… have to have a working printer to make it though :slight_smile: LOL


Hey James

Yes, you are correct, it’s high by .7 in your example which means your Z offset would have to be set as a negative. I don’t think you would be able to “dial” in an exact trigger on an end-stop switch, there are just too many variables. Personally, I would recommend Leaving it as a set position and using baby step or Z offset to dial in exactly what you need for your situation.

Mechanical stuff I know… I am a hardware guy… G-code and firmware settings etc… thats stuff not so much… but I can see… if my offset right now is -1mm aka set at 1mm and offset brings it to 0… Then if I set the offset to -1.7 with what my test was… it should be 0…

SO… my question is… Do I really want 0 — or IF I set my offset to -1.6 and then do my paper test… using the bed screws… that will give me my .02 (1 sheets of paper) and really .02 is what I want for zero… correct?