HELP! Endstop problem in Marlin

Greetings Team,

Okay, here is the background information. A few months ago I purchased a used Micromake D1 delta printer. The original owner stated he could never get the print head to work correctly. After fussing with it for a while, I figured there had to be something wrong with the print head. Rather than continue to mess around with it, I decided I was going to move my laser head over to this printer so I didn't have to switch between 3d printing and laser engraving on my Wanhao i3. I could use my i3 for 3d printing and then use this delta for laser engraving. I've already got my laser mounted, and that part works great.

Here is the area that I'm having an issue with. I have my gcode set up so that it homes first, then it comes down to the point where the endstop (Z MIN) mounted on the print head (now a laser head) is activated, then it moves back up 76mm and then it can start laser engraving. The reason for this is it would allow me to laser engrave on any height object, but always keep the distance between the surface being engraved on and the laser head at the optimal 76mm. Now, the firmware that originally came on the delta was Repetier, but I was continually having memory problems with the printer because the firmware took up like 93% of available memory, so I decided to try switching over to Marlin to see how that would work.

I have Marlin installed, and the movements of the printer seem okay, I know there are a few settings that I need to tweak, but that is not where my problem lies. My issue is this, homing works fine on all 3 axis so I know that the X MAX, Y MAX, Z MAX endstops are working fine. After homing, the print head moves down to about 190mm and stops, which is fine. I've moved the print head back up to Z230, then tell it to move to Z170 and while it is moving, I am manually activating the Z MIN endstop, but Z doesn't stop moving, it just keeps moving down to the Z170 position where it will stop. I'm doing this to test and make sure that the Z MIN endstop will activate and stop the print head at that point.

I have done an M119 and the X MAX, Y MAX, Z MAX, Z MIN all show OPEN. Then I have done an M119 while holding the Z MIN endstop and it will show that Z MIN is TRIGGERED, so I know the endstop is working, and I already know the 3 MAX endstops are stopping the head, so they are working, I just can't figure out why when the Z MIN endstop is activated that it doesn't stop the head from moving down, it just keeps going. I'm sure this is a setting somewhere in Marlin, but I can't find where it is.

I had this process working in Repetier, but I would prefer to use Marlin if it can be figured out. Again, I'm sure it is just a setting somewhere in Marlin, so I'm hoping someone can take a look and figure out what I've got set wrong.

Any help would be GREATLY appreciated!!!

My configuration.h file is attached as a txt file as the forum wouldn't let me post the contents here, kept giving me a message to shorten my message.

With Delta's, they typically home to Z-Max. But after that... whether it respects Z-Min is a setting in the Configuration.h file. (Software Endstops) Also, Probe Clearance setting may be coming into play.
A video might be helpful to see what it is up to.

Okay, so I was asked to post a video of the problem.

Here is the link: [youtu.be]

Thanks!

I think that 'middle position' it goes to is close to the

#define MANUAL_Z_HOME_POS 250 // Distance between the nozzle to printbed after homing

But, you have:

#define Z_MAX_POS MANUAL_Z_HOME_POS

So... basically, you are claiming the Z axis has 250 mm of print envelope in the Z direction. And it is homing to that location. Except... because it homes to max, it has to back off of the max number 250 mm.

Edited 1 time(s). Last edit at 10/28/2017 12:06PM by Roxy.

So, over the weekend I reflashed the Repetier firmware, and I was able to get the printer to stop when the Z_MIN endstop was triggered, so I know it is not a hardware issue, it is a setting in the Marlin firmware. Due to the lack of replies to my request, it doesn't look like anyone else knows how to fix this problem either. Guess I'll keep working with the Repetier firmware and see if I can get it working better. I like Marlin better and was hoping to use it, but can't seem to get any resolution to this.

In configurtion_adv.h you will find:

/**
* This option allows you to abort SD printing when any endstop is triggered.
* This feature must be enabled with "M540 S1" or from the LCD menu.
* To have any effect, endstops must be enabled during SD printing.
*/
//#define ABORT_ON_ENDSTOP_HIT_FEATURE_ENABLED

But won't that just abort the whole print process entirely? So if I had in my precode for it to go to G0 Z0, then when it hit the Z_MIN endstop, wouldn't it just quit there and never go to the next line of my gcode?

In config_adv.h there is an option to 'only check endstops while homing'

un-comment this

// If you want endstops to stay on (by default) even when not homing
// enable this option. Override at any time with M120, M121.
//#define ENDSTOPS_ALWAYS_ON_DEFAULT

Help me obewan, you're my only hope........

Sorry, couldn't resist.

Okay, I found the option you mentioned and commented it. I did not find the endstops always on default option, so I added it to the config_adv.h section, and compiled and I didn't get any errors.

The only check endstops while homing option, commenting that out helped SOME, but I still seem to have a problem. Now when I issue a G0 command to have the print head move down, and when I trigger the Z_MIN endstop, what happens is that as soon as it is triggered, the print head slows down, but it continues to move about 5mm before it actually stops. You can hear the motors change speed to a crawl, but it continues to move downward for about 5mm then it will stop. What I really need is for the print head to stop immediately when that Z_MIN is triggered. I've scanned over and over again the Marlin code and I can't find anything that would cause this to happen.

I'm really hoping you can help me with this. I'm not even kidding when I say I've been working on trying to get this fixed for about 10 days now and while I'm making very slow progress, I really need to get this fixed.

Any suggestions?

Thanks,

Bryan

I am having similar issues - did you ever find a solution?