Auto_Bed_Leveling: Enhanced G29 command

[AbuMaia]

A few problems. I use Ubuntu Linux, so I haven't yet figured out how to make a shortcut for Arduino ( I do have 1.0.5), which I start from the terminal (command line). Second, When opening your Marlin.pde file, *only* the Marlin.pde file is loaded, none of the others.

[Roxy]

OK, instead of a drag & drop to open the sketch... Almost for sure the Linux version of Arduino will let you open it by browsing to it. This will sound a little bit paranoid but I would delete a semi-colon or something to cause a syntax error in one of the files. I've had problems with Arduino using what ever I last opened and having it build the wrong thing. If you cause a syntax error in one of the files, and it complains about it during the build, at least you will know its working on the right code base.

[AbuMaia]

I got Arduino working, got all the files loaded properly. Fixed the baud rate setting, and uploaded to the printer. Y axis still moves when the Z axis raises. The problem of not being able to print from an SD card is now fixed, however.

[Roxy]

The baud rate is not supposed to matter on the USB-to-Serial interface. I saw that was different but left it at the stock value. Are you saying it didn't work at that value?

If the SD card is working correctly now, most likely that is because of the pin definitions in Pins.h There are some conflicts on some of the controller boards with the duplicate usage of the SD card pins.

What you have right now is a totally stock and unaltered version of Marlin. Just to be clear, you are saying the Y-Axis is OK at the end of the G28 but when the G29 starts the Y-Axis moves as the Z-Axis raises? Knowing that exact answer will help limit the places we are looking for the problem. If this is true, I've attached the current Marlin_Main.cpp file you are using with some debug printouts in the relevant areas. It would be helpful to rebuild and post what it says. And it will pause after every print out so you should be able to determine at what point the Y-Axis starts moving. I think this will give us almost all the information we need to understand what is going on with your machine.

But before you do that:

Can you do a G28 and check that it behaves as you think it should. And then issue a M114 ? You have the following values:

#define FRONT_PROBE_BED_POSITION 30
#define Y_PROBE_OFFSET_FROM_EXTRUDER -7.7

If the M114 is reporting Y to be equal to 0.0 at the end of the G28 I would expect it to move the nozzle 30+7.7 mm before doing the first probe. Is there something wrong with what I'm thinking?

[AbuMaia]

No, the Y axis moves during Z lift during G28.

Issuing an M114 after a G28 gives me:

>>>G28
SENDING:G28
>>>M114
SENDING:M114
X:0.00 Y:0.00 Z:10.70 E:0.00 Count X: 0.00 Y:0.00 Z:10.70 (still using stock marlin without enhanced bed levelling)

Issuing a G29, the LCD reports first probe position as X0 Y37. Pronterface reports Bed x: 30.00 y: 30.00.

[Roxy]

So I'm confused. We had that debug info printing in the G28 command and it was reporting that the Y-Axis was staying at 0.0 and at the very end of the G28 the Y-Axis was still at 0.0?

[AbuMaia]

Yes. Y axis homes, gets set to 0, then while Z axis moves before extending the probe, Y axis also moves, about 10mm, but stays set at 0. So Y axis coordinates are offset by 10mm after a G28, before G29. That's why, when doing the last row of levelling probes during a G29, the probe is right on the edge of the glass (197mm) while the LCD reports it at 187mm.

[RobH2]

Hey Roxy, this in an incredible and valuable thread. There is an amazing amount of expertise being conveyed here.

However, it's gotten quite daunting if someone finds it and wants to digest it. I think it would be a lot of work but do you think it would be possible to make a single post that consolidates all of the advice and tweaks that this thread represents? Your code has evolved during the course of the thread and it's confusing what's new and what's old at times. If you could post a summary and directive it would be really helpful. That would make a good "Sticky." Then we could continue a separate thread that addresses individual issues and continuing problems.

Just a thought.... Really nice work and amazing guidance!

[Roxy]

Thanks for the kind words... Yeah, this thread has grown too big for its own good. Probably it should be broken into 5 or 6 smaller threads. The problem is I am too darn busy. And what I'm thinking is both the M48 Z-Probe Repeatability code and the Enhanced G29 Bed Leveling code need to be repackaged so they can be folded back into the main code base. Somebody suggested (asked) if that had been done and explained the steps to make that happen. I can't find that now. I've been looking at any thread that has GitHub and Put in it.

But anyway, I'm thinking of trying to fold the M48 Z-Probe Repeatability code back into the code base first. The reason is it is smaller, less controversial and has less conflicts with the existing code base. If I can get that 'absorbed', then I was going to try to get the bigger, fatter Enhanced G29 incorporated.

The problem is... I can't find that post with the step by step directions. And if I remember right, it was in some thread that was related, but not actually in one of these sticky threads.

Maybe if the person that typed in those steps sees this message, they can say "Its over here..." ????

Arrrggghhhh! It sucks when you know what you need is within grasp, but you can't quite grab it!!!

[RobH2]

Arrrggghhhh! It sucks when you know what you need is within grasp, but you can't quite grab it!!!

Yea, I know. That's sort of where I was coming from. I've been watching this closely and I've even gotten confused. I too remember the "step by step" directions but can't seem to find them either. No problem that you are busy. One day when things calm down maybe you can condense it but don't worry about it now. If someone on the web happened to randomly find this thread though I think they'd be very confused and move on. What they'd never realize is what a treasure trove of valuable info it is, if you can sort it out.

I'm sort of busy too but I may take a stab at reading it all the way through again and trying to pull out the final results to make a single post.