Autobed level servo twitches every 2 minutes. Video.

[voodoo28]

I too had trouble with Makergeeks ABS.

Bought it. Let's see if that helps. Hope it does. Also bought some red abs the one I got from makergeeks had too much bubbles. And I want to print the Itty bitty flex with no problem and good quality.

[voodoo28]

I think the Metal Gears might actually be too strong in case of a bed crash...could break your X Carriage instead of the servo giving way...Just a thought. Then again...the torque of the servo is not much.

Hexatronics HXT 900 here. looks the same as the towerpro but holds up much better. If buying again I would go for one with metal gears.

[rhonal89]

My ABS was a surprise package. Not sure if that had anything to do with the quality they send you. Maybe that's the way they get rid of the bad filament they have. I'll give your servo a try. Hope that fixes the problem. For now I have another servo left to try.

I think the Metal Gears might actually be too strong in case of a bed crash...could break your X Carriage instead of the servo giving way...Just a thought. Then again...the torque of the servo is not much.

[Roxy]

I've been waiting for this to come up here, had this problem last Summer. No one on any of the forums I frequent had a solution, several diagnosed it as RF interference, but none of their suggestions fixed it. I limped by for a month until it caused a particularly catastrophic print failure (ripped the probe off and almost started a fire). After weeks of Googling I still couldn't find any answers, but then I located this post. That is your answer, ABL has worked like a dream ever since. If it does work for you, be sure to thank jamesdanielv; that's the only real solution to this problem I've ever seen.

Good find! And here is some more info: https://github.com/MarlinFirmware/Marlin/issues/1885 This thread references a thread at the Arduino group where the root problem is discussed: http://forum.arduino.cc/index.php?topic=312869.30

If this 'twitching' is happening on every print, this may not be the issue. (But it could be!) What is happening is there is a 'bug' (The Arduino group says it is not a bug) where the detach() function doesn't check the state of the control signal going to the servo before disconnecting from it. If it is disconnected while in a high state some bad things happen. First, the last pulse of the pulse train going out to control the servo never ends. Or, from another perspective the control line stays high instead of being low like (some people claim) it should be. There are no standards for how these R/C servo's are supposed to do things. Depending upon the brand (and how much money you spend) you are going to get different behavior.

This is marked as a 'bug' and Marlin is going through a bug fix phase right now. I suspect in 2 or 3 weeks this will be ironed out. But for right now, here is something else you can try instead of switching servos. You can try changing the retracted and engaged angle numbers by one or two or three in each direction. Probably, you will be able to find a number where it is stable. I had to do that with my cheap eBay Tower Pro servo (that cost me $4.75 with shipping from China).

[rhonal89]

I guess is what you just posted. It doesn't happen on every print sometime I'll would print 2 or 3 items next print the servo would be crazy. Sometime the servo arm would move more than what you just sow on the video. Thanks for the info. And autobed level sometime don't work look at adamfilip he created a thread also. I posted some video. But I can deal with that stop and restart until it works.

Good find! And here is some more info: https://github.com/MarlinFirmware/Marlin/issues/1885 This thread references a thread at the Arduino group where the root problem is discussed: http://forum.arduino.cc/index.php?topic=312869.30

If this 'twitching' is happening on every print, this may not be the issue. (But it could be!) What is happening is there is a 'bug' (The Arduino group says it is not a bug) where the detach() function doesn't check the state of the control signal going to the servo before disconnecting from it. If it is disconnected while in a high state some bad things happen. First, the last pulse of the pulse train going out to control the servo never ends. Or, from another perspective the control line stays high instead of being low like (some people claim) it should be. There are no standards for how these R/C servo's are supposed to do things. Depending upon the brand (and how much money you spend) you are going to get different behavior.

This is marked as a 'bug' and Marlin is going through a bug fix phase right now. I suspect in 2 or 3 weeks this will be ironed out. But for right now, here is something else you can try instead of switching servos. You can try changing the retracted and engaged angle numbers by one or two or three in each direction. Probably, you will be able to find a number where it is stable. I had to do that with my cheap eBay Tower Pro servo (that cost me $4.75 with shipping from China).

[cub22908]

But for right now, here is something else you can try instead of switching servos. You can try changing the retracted and engaged angle numbers by one or two or three in each direction. Probably, you will be able to find a number where it is stable. I had to do that with my cheap eBay Tower Pro servo (that cost me $4.75 with shipping from China).

This makes sense now for me. When I switched microswitches my extend/retract numbers changed a little bit which is probably the reason my movement problem went away! I still had other crazy things during the auto bed leveling sequence that were also solved when I got rid of the recommended microswitches.

[rhonal89]

I received the servo voodoo28 recommend and am still getting the same servo movement. Exempt this time is down. Servo is backward. I did couple of changes to the page roxy posted and no luck. Could it be something with marlin 1.0.2. That's the only firmware I have try other than makerfarm. I try roxy one and when it flashed servo twitches like crazy. I guess bad configuration on my part on that firmware. Also changed the value by one and still happens.

[voodoo28]

Have you tried the Marlin from Clough42' site? You could use the Itty BItty single extruder ..and just change the E steps to match your original and make any other changes needed. I am currently using the Flex Extruder Marlin form his site. If you want to..PM me your original Marlin Config and ill try to match it up for you with the version from C42's site.

[rhonal89]

Alright thank you!! Am on my way to work right now. Let me try what you said when I get home today. If am still having trouble I'll send you a pm.

Have you tried the Marlin from Clough42' site? You could use the Itty BItty single extruder ..and just change the E steps to match your original and make any other changes needed. I am currently using the Flex Extruder Marlin form his site. If you want to..PM me your original Marlin Config and ill try to match it up for you with the version from C42's site.

[voodoo28]

Ok no prob, What board do you have?

Alright thank you!! Am on my way to work right now. Let me try what you said when I get home today. If am still having trouble I'll send you a pm.