Rumba and Auto-Bed level

[tsteever]

Thanks! I think the most confusing in all this has been the info I find all over the place on this. I can't keep it all straight! My Printer with enhanced firmware seems to work, just not the G28. I guess I could always run a G29 command after it but sometimes I am only printing a very small part and don't need the G29. Oh well, got some reading to do!

[tsteever]

Looking forward to following the thread that Roxy linked to. It can be found here. Looks like a good place that i should have found before all this!

Anyways, previously I had been reading the ABL and Enhanced Firmware thread in the firmware section and I came to this post. I am going to try and implement this tweak into my code to see if that helps. Basically it is adding another value to the G28 command which is what I thought may be missing. Hopefully it will work and Roxy has a chance to get the firmware sorted and streamlined. I think my confusion came from the so many different versions floating around. Would be nice to have a sticky "look here" thread.

[Roxy]

Thanks! I think the most confusing in all this has been the info I find all over the place on this. I can't keep it all straight! My Printer with enhanced firmware seems to work, just not the G28. I guess I could always run a G29 command after it but sometimes I am only printing a very small part and don't need the G29. Oh well, got some reading to do!

The more I think about it, the behavior of the G28 with Auto Bed Leveling is not a bug. The purpose of the G28 is to Home the axis. It does that. At the very end of the G29 the code compensates for the Z_PROBE_OFFSET. It would be very straight forward to make the G28 do that also.

[tsteever]

Found this post from Abu in the other thread and it seems to fix the issue. Not sure if it is a band aid or not but I can get the nozzle on the bed after a g28 now.


Pasted from here...

Do a G28, then a G1 Z0. Find out at what distance above the bed the nozzle stops. Let's call that number X.

Look for this section in Marlin_main:

if(code_seen(axis_codes[Z_AXIS])) {
        if(code_value_long() != 0) {
          current_position[Z_AXIS]=code_value()+add_homing[2];
        }
      }
      #ifdef ENABLE_AUTO_BED_LEVELING
        if((home_all_axis) || (code_seen(axis_codes[Z_AXIS]))) {
          current_position[Z_AXIS] += zprobe_zoffset;  //Add Z_Probe offset (the distance is negative)
        }
      #endif 

Change the "+= zprobe_zoffset;" to "+= zprobe_zoffset+X;" inputting the number you found earlier for X. On my printer, it was 4.

[Roxy]

Found this post from Abu in the other thread and it seems to fix the issue. Not sure if it is a band aid or not but I can get the nozzle on the bed after a g28 now.


Pasted from here...

Do a G28, then a G1 Z0. Find out at what distance above the bed the nozzle stops. Let's call that number X.

Yes, this looks correct. This should get the G28 and the G29 synchronized in where they think the nozzle is relative to the bed. One small caution: If the bed is tilted at a noticeable angle, the nozzle will be at a different height than the probe because the probe is offset from the nozzle. The G29 corrects this 'error'. The G28 does not have the bed angle information and it can't do the more accurate correction.

[tsteever]

Good to know! I'd really only be doing the solo G28 command on small prints that wouldn't need the ABL (Thin wall calibrations, etc...). I look forward to the dynamic build envelope settings being implemented if possible. Have the printer probe only the areas included in the Skirt would be a valuable addition to the feature. For now though it does appear to be working. This is with the Erik firmware not the beckdac firmware. I will see if I can't move these settings over to that as well.

What should be my next step? I know that there are some wondering/waiting to see if it was working. Should I just post my marlin folder in a zip?

[Chadd]

So what are the differences between this and the normal FW from Colin? I know that I saw auto bed leveling options in the FW, what didn't work with the original FW?

Good to know! I'd really only be doing the solo G28 command on small prints that wouldn't need the ABL (Thin wall calibrations, etc...). I look forward to the dynamic build envelope settings being implemented if possible. Have the printer probe only the areas included in the Skirt would be a valuable addition to the feature. For now though it does appear to be working. This is with the Erik firmware not the beckdac firmware. I will see if I can't move these settings over to that as well.

What should be my next step? I know that there are some wondering/waiting to see if it was working. Should I just post my marlin folder in a zip?

[sniffle]

So what are the differences between this and the normal FW from Colin? I know that I saw auto bed leveling options in the FW, what didn't work with the original FW?

marlin firmware is an ever evolving piece of software, with bug fixes and features being added all the time...

colin's firmware is like a snapshot in time, in the time since he made that copy of the firmware, many, many bugs have been fixed and features have been added not all of which will effect you or others but marlin is ever evolving into better and stronger code with features being added and refined daily

[Roxy]

Good to know! I'd really only be doing the solo G28 command on small prints that wouldn't need the ABL (Thin wall calibrations, etc...). I look forward to the dynamic build envelope settings being implemented if possible. Have the printer probe only the areas included in the Skirt would be a valuable addition to the feature.

I'm not sure what I think about the dynamic build envelope. I actually wrote a piece of C code to process the GCode and set the parameters. But I think we all agree it would be best to just have one standard script to do this that everybody uses. The big reason I'm not sure what to think about this topic is this:

Unless you have big imperfections in a few locations on your print bed, aren't you better off measuring the whole thing where you can get more accurate numbers that are spread out? Suppose you are only printing something with a 1" square foot print. Can you accurately measure a bunch of points withing that area to set the bed angle? Or would you be better off going way out to the edges to measure your points so you can set the bed level correction matrix more accurately?

[tsteever]

That I don't know. For the small stuff I have just been turning off the ABL and just using G28 in my custom code. I need to get the BeckDac working and my fear was the dynamic ABL stuff might cause troubles if I wasn't using the slic3r part.

Can I just load this firmware and ignore the dynamic ABL stuff and assume that it will work?