Why Prusa does not add auto bed leveling feature to i3 MK3/S?  

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

Posted by: @prusanewuser

Hi, why this feature is not added?

Automatic mesh bed leveling is a basic feature of the Mk3 series.

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

The original Prusa i3 Mk3/S/S+ all have auto bed levelling and X-Y geometry calibration features installed in their firmware.  This is why the printer performs calibration on first power up; it checks that the X and Y axis movements are perpendicular, that there are no problems with the x, y, and z axis movement, the heatbed and  hotend heater and thermistors work and that the various fans work and performs an initial auto bed level and initial z height adjust for your particular steel print sheet type.

Auto bed levelling is normally called by the starting gcode commands in your gcode print file as generated by PrusaSlicer for an i3 MK3/S/S+; specifically the line:
G80 ; mesh bed leveling

If you use another slicer or pre-supplied gcode then this gcode command could be missing from the file and the i3 MK3/S printer will print without performing auto bed levelling first.

Notes:

• if you have different types of steel sheet build plates (smooth, powder coated, or satin) then you need to set your printer's z-height adjust separately in the menu for each type as these sheets have different thicknesses. you then just choose the sheet type you're using for that build before you start the print.
• after maintaining or modifying the printer you should perform at least a manual printer calibration run as you may have changed the printer geometry in the X, Y or Z. 

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

For other printers I have used, auto leveling was done automatically. I guess when I talk about the Prusa i3MK3/S, I should call it auto Z first leveling? 

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

Are you talking about bed leveling and surface correction, as in the fine tuning of the Z position to compensate for irregularities in flatness and such, or are you talking about the Z calibration to establish a good working general Z position?

With some machines, both are accomplished by that tedious multi-iteration process of futzing around with manual leveling screws and test prints.

With the I3, you set the Z calibration with whatever build plate you are using and the machine and the Pinda will do the fine tuning.

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

Maybe he is talking about this kind of nice feature available on the bear SKR firmware, you just adjust the Z level once, manually make the nozzle touch the bed, and the height read by the PINDA becomes the Z_offset.

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

I agree as to why Prusa does not add auto leveling that can auto adjust to the change in the use of the smooth plate vs the textured one.

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

It does. You select your plate on the printer and z-offset is kept in memory for 4 différentes plates. 

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

Posted by: @airsyspro

I agree as to why Prusa does not add auto leveling that can auto adjust to the change in the use of the smooth plate vs the textured one.

There are two separate adjustments:

• Bed leveling accounts for inconsistencies in flatness over the print area. Automatic mesh bed leveling on the Prusa does this for every print by measuring the distance between the probe and between 9 and 49 test points.
• Live-Z or 1st layer adjustment calibrates the optimal distance between the nozzle and 1st layer. This is what you seem to be referring to.  This is not only dependent on the distance between the probe/nozzle and the bed, but also the bed texture, filament type, and other factors. Without an array of expensive sensors, the printer has no way of "knowing" what a good 1st layer looks like. Even then, it might not suit many users' tastes.

So the answer to the OP's question is that Prusa printers already provide automatic mesh bed leveling. The answer to your question is that there is currently no inexpensive and reliable way of detecting differences in the 1st layer quality for consumer-grade FFF printing. Providing multiple slots to save individual Live-Z settings is a good approach for different surfaces and requires minimal effort on the user's part.

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

@bobstro Clearly sometimes (often) I wonder if the question conceal something simple or complex. 🤨  You are so good for the complexe side of the reply 😊 

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

Posted by: @jsw

Are you talking about bed leveling and surface correction, as in the fine tuning of the Z position to compensate for irregularities in flatness and such, or are you talking about the Z calibration to establish a good working general Z position?

With some machines, both are accomplished by that tedious multi-iteration process of futzing around with manual leveling screws and test prints.

With the I3, you set the Z calibration with whatever build plate you are using and the machine and the Pinda will do the fine tuning.

Most of the time when I contacted Support, they asked me to do several Z  First Layer Calibration:

https://help.prusa3d.com/en/article/first-layer-calibration_112364

It looks like for the i3 MK3/S, getting a good Z First Layer Calibration is important.

I guess in other printers that I have used (e.g. https://www.tiertime.com/up-plus-2/ , Stratasys uPrint SE Plus)

this is skipped or part of the auto leveling. 

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

Posted by: @prusanewuser

I guess in other printers that I have used (e.g. https://www.tiertime.com/up-plus-2/ , Stratasys uPrint SE Plus)

this is skipped or part of the auto leveling. 

It depends what other printers. The UP Plus 2 is a Mini sized printer at a Mk3 price. The Statasys are higher still. The answer to the original question is pretty obvious: Cost. I don't know the details of what they provide, but if they have more profit margin to work with, it's not surprising they can provide more features. It's also easier to ensure consistency on a smaller 140x140 build plate. I know Tiertime is highly proprietary. Stratasys isn't exactly heralded as leaders in open source. They may have patented bed leveling technologies as well, precluding widespread use. Tiertime has some very nice support interface features as well, but those are not open-source so not available for other printers. 

With many other printers, you just live with the inconsistency. At the lower end, users routinely put up with 0.3mm or thicker first layers, using rafts and brims for every print, slathering the bed with glue or hairspray or other workarounds for poor 1st layer consistency.

The answer to the question of calibration is that there is currently no inexpensive and reliable way of detecting differences in the 1st layer quality for consumer-grade FFF printing. If you're willing to step up to "prosumer" or commercial-grade equipment, other options are available. Providing multiple slots to save individual Live-Z settings is a good approach for different surfaces and requires minimal effort on the user's part.

RE: Why Prusa does not add auto bed leveling feature to i3 MK3/S?

@bobstro

Ahh, your reply does make a lot of sense and I appreciate you taking the time to educate me on my above question.