Saving G29 Bed Level Correction Matrix to EEPROM

[DarkAlchemist]

I don't think anyone is saying this will be a one-time set-and-forget feature. Why do you think I went to find a way to run a G29 from the LCD on a standalone printer?

You would be surprised at how many are looking for a one time set and forget ABL.

The fact is I have ran into a few who have been able to do it then suddenly it stopped printing correctly and I lol'd and had to explain it to them. Guess what I got in return? "Oh, no it can't be that my printer is perfect and you're an idiot, etc..." I then hear that ABL sucks and is just trash by the same people who discounted what I said and said I was an idiot. 2+2=4 so I suspect they found out I was right but are so stubborn they have to blame ABL when in fact it is because of the way our machines are built (to save money so everything is skimped on) and when you add heat and cool down then heat again factors I expect no less than the numbers to change.

So, this is why I had to say it so if someone stumbles onto this thread they will realize what they can and probably cannot do with this feature.

[AbuMaia]

This halloween I printed out a lot of pencil toppers to hand out. It would have saved a lot of time if I had had this code earlier, run one G29, print out all the toppers without having to G29 before each batch. That's the only case I can think of when I'll be using it, if I have a lot to print out and will be keeping the printer running and hot.

[DarkAlchemist]

This halloween I printed out a lot of pencil toppers to hand out. It would have saved a lot of time if I had had this code earlier, run one G29, print out all the toppers without having to G29 before each batch. That's the only case I can think of when I'll be using it, if I have a lot to print out and will be keeping the printer running and hot.

Exactly, or if you want to multi-color because the printer never will get cold. Trying to use this so you never have to g29 again will be an exercise in futility for most.

[AbuMaia]

I don't understand how this helps with multi-colour prints. I just pause the print with an M600 whenever I need to change colours.

[Fri]

This is awesome, thanks so much. Basically if the printer is good enough and you print at similar temps, you only have to G29 when you do something to the bed or don't get a good first layer.
I got to say that I wasn't able to get it to work when resetting the printer. When I connect to it and hit print, x homes, yes only x , hits the stop and goes right straight into the wall.
I have to M502 to get it back to work and loose the ABL matrix. On these two machines I am using chinese rambos and this may have something to do with it.
BTW, do you know of a way to erase the rom or the flash on the rambo (clean swipe) before flashing the fw again?

Thanks for all this great work

[Fri]

Roxy,
I tried this and was not too successful. I will try again when I get more time.
Now, how do I revert the eeprom back to where it was. I don't seem to be able to remove the ABL matrix from it. I flashed the firmware ( with and without eeprom enabled, but both without the code above). I tried M502 then M500, I also tried M500.

[Roxy]

Roxy,
I tried this and was not too successful. I will try again when I get more time.
Now, how do I revert the eeprom back to where it was. I don't seem to be able to remove the ABL matrix from it. I flashed the firmware ( with and without eeprom enabled, but both without the code above). I tried M502 then M500, I also tried M500.

You would need to have a version of the firmware that is not trying to save the Auto Bed Level Correction Matrix to the EEPROM. And then you could restore the default settings and save them. That would do it. Or you could change the version number of the EEPROM format at the top of ConfigurationStore.cpp so it doesn't trust the information in the EEPROM.

Alternatively... Add the M499 command to invalidate the EEPROM. It changes the EEPROM format version so the values won't be loaded until you do another save of the values to the EEPROM.

It can be found here: http://3dprintboard.com/showthread.p...4294#post34294

[Fri]

Thanks again Roxy,
I was able to get it back.

On another note. I have an issue on one machine since I changed the z offset on my viki lcd (this may not in anyway be related), but it is like that ever since.

I have the G28 deletion of plan bed leveling uncommented.

After g28 g29 the machine rests as it should in the far right corner. Now when I hit G28, it moves further back and right. Looks like it thinks it is home.
If I send a G x0y0 it goes to the home position, but it's not homeing (bouncing off the stops). If I lift z until the sensor goes out (I am using proximity sensors for z stop) it will home fine.
(It also homes fine if I don't do a G29 at all). Any ideas? I tried pretty much everything. It was working fine before.

[Roxy]

Thanks again Roxy,
After g28 g29 the machine rests as it should in the far right corner.

There isn't enough detail here. Is it going to the back far right corner? If you use a V option on the G29 such as G29 n 3 V it will not zig zag and the last point probed should be as far from the origin as possible. Can you redo it with a G29 n 3 v and report back?

Now when I hit G28, it moves further back and right. Looks like it thinks it is home.

It would be helpful to do a G28, a G29 and then a M114 to see where the printer thinks it is at. Then do a G28 and another M114 and see where it thinks it is at. That will give us some hints about what is going on.

If I send a G x0y0 it goes to the home position, but it's not homeing (bouncing off the stops).

That would make sense. You told it to go there. Not to home there. The homing code is special. It just starts heading there waiting for a limit switch to get pressed. Then it backs off and goes back towards the switch at a slower speed. But you are not giving it a home command. And my guess is if you look, the limit switches are pressed when you go to G1 X0 Y0

If I lift z until the sensor goes out (I am using proximity sensors for z stop) it will home fine.
(It also homes fine if I don't do a G29 at all). Any ideas? I tried pretty much everything. It was working fine before.

This is new information. What happens if you turn Z_SAFE_HOMING off? I don't know what code path it would follow (because I've never had an issue like this), but I can believe that the Z Probe firing could impact the X and Y homing.

[Fri]

There isn't enough detail here. Is it going to the back far right corner? If you use a V option on the G29 such as G29 n 3 V it will not zig zag and the last point probed should be as far from the origin as possible. Can you redo it with a G29 n 3 v and report back?

Yes, it is on the diagonal position opposite to HOME, I use 3 point grid N3V

It would be helpful to do a G28, a G29 and then a M114 to see where the printer thinks it is at. Then do a G28 and another M114 and see where it thinks it is at. That will give us some hints about what is going on.

G28, G29, M114 result is X190 Y175 Z1.65, when I hit G28 now, it goes straight into the wall. So I did a home X only, the x carriage moves approx 10mm away from the previous position (roughly 200 actual pos.) but the M114 reports X0



That would make sense. You told it to go there. Not to home there. The homing code is special. It just starts heading there waiting for a limit switch to get pressed. Then it backs off and goes back towards the switch at a slower speed. But you are not giving it a home command. And my guess is if you look, the limit switches are pressed when you go to G1 X0 Y0

You are right.

This is new information. What happens if you turn Z_SAFE_HOMING off? I don't know what code path it would follow (because I've never had an issue like this), but I can believe that the Z Probe firing could impact the X and Y homing.

True, but I cannot home without Z_Safe, the probe would be outside the bed. I did it anyway and and did a G29. Same result, it is in the right position 190,175,1.65, but when hitting home x it moves right or away from the last position.