Z home or - direction triggering failure.

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kdixon
Posts: 6
Joined: Mon Jan 13, 2014 9:00 pm

Z home or - direction triggering failure.

Post by kdixon »

Received my Felix 3.0 Monday and just completed the assembly and flashed to the latest .91 firmware. Tried printing the test part, but having trouble getting Z to home consistently, especially when attempting to print a part. When I first turn the printer on, or reset it, everything works fine. I can home in all 3 axis's, but after several minutes it will no longer home in Z. It makes a beeping sound and stops short of home. I can move in the Z+ direction without any problems, but as soon as I try to move in the Z- direction it will start to fail and then eventually will no longer even attempt to move at all in the Z- direction. It's as if the Z stepper motor is dead. If I reset, I will be able to home and move in the Z- direction again. But then, after a few minutes, the failures begin again.
I have tried adjusting the Z pot, but it makes no difference. I have yet to print a part as it fails to home in the beginning and attempts to print the part in the air.
Please help! Any suggestions would be helpful. This is extremely frustrating. I would really like to see what the printer will do. -Thanks in advance
Last edited by kdixon on Thu Jan 16, 2014 8:10 pm, edited 1 time in total.

andrewsi
Posts: 130
Joined: Mon Dec 23, 2013 1:26 am

Post by andrewsi »

How about the led on the mainboard for the z endstop sensor? Any change in brightness when the failure starts to kick in or relative to the behavior of the other endstop leds? It almost sounds like it's falsely triggering for some reason. Is there any foreign material in the gap in the z sensor?
__________________________________________
Andy Silverman, Technogeek in Seattle
Felix Tec4 Single-head

kdixon
Posts: 6
Joined: Mon Jan 13, 2014 9:00 pm

Post by kdixon »

No change in the the LED sensor when the failures begin; no dimming no triggering. As a side note, when Z is working correctly the sensor works flawlessly just like X and Y.
I also notice a bit of a hum that seems to becoming from the stepper motor when it fails. Sounds like it may be under load. When is starts to fail I have tried lifting the table to ease the strain on the stepper motor, but it make no difference. Once it starts to fail, it just continues to get worse until it no longer functions at all and the software reports the commands are waiting to be sent. It's seems like something is over heating and this is causing failures.

Do I have a bad stepper motor? Thinking I may swap the Z out with extruder and see if that fixes it. Any other ideas?
Last edited by kdixon on Thu Jan 16, 2014 8:11 pm, edited 1 time in total.

andrewsi
Posts: 130
Joined: Mon Dec 23, 2013 1:26 am

Post by andrewsi »

Obviously swapping two of the motors will isolate whether the problem is in the motor or elsewhere, so that may be an easy thing to try first. The thing you say that is a little suspicious is that the software reports commands waiting to be sent: I don't _think_ there is any feedback from the motor controller to the firmware that "yes, the steps have taken place" so that seems to imply some kind of electronic or communication failure.

I also found when assembling my 3.0 that I had to realign the frame pieces just slightly after installing the Z motor to have it all line up perfectly. You're sure the Z axis moves freely and doesn't bind anywhere? (Not likely, I'm sure, but thought I'd at least throw it out there.
__________________________________________
Andy Silverman, Technogeek in Seattle
Felix Tec4 Single-head

kdixon
Posts: 6
Joined: Mon Jan 13, 2014 9:00 pm

Post by kdixon »

Didn't think about the -Z- alignment. It does have more failures the closer it gets to home. May very well be an alignment issue. I'll check that out when I get home and report back. That's what is great about this forum; ideas and experience shared with others. Thanks for your feed back...
Last edited by kdixon on Thu Jan 16, 2014 8:11 pm, edited 1 time in total.

andrewsi
Posts: 130
Joined: Mon Dec 23, 2013 1:26 am

Post by andrewsi »

On an unrelated note, the bed carriage squealed horribly against the leadscrew after completion, until I lubed the screw with some lithium grease. Now the screw is silent, at least, unlike the whining motors. :-)
__________________________________________
Andy Silverman, Technogeek in Seattle
Felix Tec4 Single-head

kdixon
Posts: 6
Joined: Mon Jan 13, 2014 9:00 pm

Post by kdixon »

I applied a little grease the first time it acted up, but thanks for the advice. The more I think about it the more I suspect the Z alignment. Can't wait to get home a check it out.

kdixon
Posts: 6
Joined: Mon Jan 13, 2014 9:00 pm

Post by kdixon »

Update: Aligned the -Z- axis - no change. Still "homes" in mid air.
Tried swapping Z and Y opto sensors. The problem went away in the Z direction but, occasionally triggers home in the middle of the Y travel. The LED does not dim when it triggers in the middle of travel, but does operate correctly, LED dims, when Home is triggered by the vane.

So after all this, it would appear to be a bad sensor. I'll contact support for a replacement. Finally been able to successfully print parts. Just have to move Y neat home before the run. Thanks Andrew for your input!

andrewsi
Posts: 130
Joined: Mon Dec 23, 2013 1:26 am

Post by andrewsi »

Well, glad you got it figured out. More than likely it's just a bad solder joint on the back of the sensor or something to that effect so that it occasionally glitches due to vibration or something, triggering the home endstop behavior.
__________________________________________
Andy Silverman, Technogeek in Seattle
Felix Tec4 Single-head

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