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X Axis binding on pre-print start  

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dennis.c
(@dennis-c)
Active Member
X Axis binding on pre-print start

I just completed my build of the Mk2 a couple days ago. I just started having a problem with the X axis only binding up on the pre-print calibration. If I apply firm pressure in the direction X is to go it moves fine and once the pre-print calibration is done it prints exceptionally well. I have examined all obvious factors. The belt is sufficiently tight, the bearing guide bars are parallel, the belts are not obstructing anything.

It appears to me that the settings for the X Axis move are too aggressive and it is using the two parallel bars to put up or downward pressure causing it to lose steps and error out.

Again this is ONLY on the pre-print calibration and after I get past that it prints very, very well. Is there something I am missing and should check or is there a firmware change that can be made to decrease the step/direction speed in G code to keep it from binding?

DC

Veröffentlicht : 09/01/2017 3:46 am
Nigel
(@nigel)
Honorable Member
Re: X Axis binding on pre-print start

Skew. Check it. That is often the case.

Nigel
Life is keeping interested and excited by knowledge and new things.

Veröffentlicht : 09/01/2017 6:37 am
dennis.c
(@dennis-c)
Active Member
Themenstarter answered:
Re: X Axis binding on pre-print start

I have checked everything I can conceive. I tightened the belt last night and it started working fine when it was warm. The print failed though when the X needed to move fast to the next point and jammed up. Today the extruder belt clamp broke so now I am dead in the water. I need to get a new piece to get it going. When the belt is off the extruder assembly moves perfectly back and forth on the axis so I don't think "skew" is an issue here. It is starting to look like the X axis stepper is not functioning properly.

Veröffentlicht : 15/01/2017 6:41 pm
PJR
 PJR
(@pjr)
Antient Member Moderator
Re: X Axis binding on pre-print start

Dennis

The 2 screws int the right hand X-Idler housing should only just be touching the ends of the rods. If they are too tight or too loose, the X bars can twist out of alignment.

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…

Veröffentlicht : 16/01/2017 9:38 am
thomas.b9
(@thomas-b9)
Active Member
Re: X Axis binding on pre-print start

I have the same exact issue. Switching to High Powered mode will actually let me complete calibration just fine, only in Silent mode will the X-axis bind (which sucks, I really only use it in Silent mode...)

I've tried tightening all the belts and screws for the assembly, oiling the rods, tensioning the belt, loosening and tightening the smooth rod holder screws, and checking skew (funnily enough, it gives me a rating of perfectly perpendicular!! wtf??). None of that has worked. Unless it's a problem with my belt being too tight or something, I have no idea how this could happen.

Veröffentlicht : 16/01/2017 8:59 pm
simon.p
(@simon-p)
Trusted Member
Re: X Axis binding on pre-print start

I have the same exact issue. Switching to High Powered mode will actually let me complete calibration just fine, only in Silent mode will the X-axis bind (which sucks, I really only use it in Silent mode...)

I've tried tightening all the belts and screws for the assembly, oiling the rods, tensioning the belt, loosening and tightening the smooth rod holder screws, and checking skew (funnily enough, it gives me a rating of perfectly perpendicular!! wtf??). None of that has worked. Unless it's a problem with my belt being too tight or something, I have no idea how this could happen.

could be the end of your y belt sticking out a bit and making it hard to reach the y end stop

Veröffentlicht : 16/01/2017 11:00 pm
dennis.c
(@dennis-c)
Active Member
Themenstarter answered:
Re: X Axis binding on pre-print start

I swapped the X axis stepper with the Y axis stepper and checked all of the connectors on the Rambo. The X axis still had issues. I then noticed that the belt was rubbing up against one of the walls on the stepper mount/belt guide. It was about 2mm and was likely contributing to the binding. I had three stand-offs and mounted the stepper with them to get the 3mm or so needed to improve the belt path. I then took a digital caliper and measured the X axis from the bed and made sure they were within a mm. I ran PLA through it and it had a little binding. I adjusted the two screws that adjust tension on the X axis and found that there is a very, very small sweet spot. I had to failed bed calibrations and had to adjust the limit switch bump some to get proper connection with the limit switch. I then ran a V2 calibration print and got that dialed in. I changed over to ABS and did a 1" cube test print which worked without binding on the X axis.

I was then able to run a real print and got my first two ABS prints done. I had some lifting on a corner but I can deal with that as I probably didn't have the bed cleaned properly. So, for right now my problem appears to be fixed. I still need to print a X carriage replacement so I can get rid of the aluminum bracket I had to attach to hold my belt.

In retrospect I believe there is an issue with the belt path on the X axis stepper motor bracket and I think I had tension too tight with the two screws. Does anyone have belt path rub and need to offset stepper? There should be some updates to the guide that discusses the fine tuning of the two tension screws.

Veröffentlicht : 17/01/2017 5:56 am
ChinookTx2
(@chinooktx2)
New Member
Re: X Axis binding on pre-print start

How does moving out the X motor using standoffs change belt alignment??? Can't you simply adjust the pulley to line up the belt?

Veröffentlicht : 17/01/2017 6:33 pm
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