1

Topic: Y-axis belt slipping

Hey guys,

My Y-axis has been slipping recently, and I have come to the conclusion that it was because one of the "gears" connected to the belt (not on the axis connected to the motor, the other side of the belt) was not turning on the screw. I also noticed that the whole screw was turning, even though it's not supposed to (just the gear is supposed to), so how would I "loosen" the gear so that it can turn on the gear? Would I just have to clean it and then lubricate it? I made the mistake of using WD40 on it, which I later learned I shouldn't use, so could that be why the "gear" was stuck?

Thanks!

2

Re: Y-axis belt slipping

Sounds plausible.

It's not too big a deal to take of the idlers (brackets and all). I'd suggest you clean them (soap and water to get rid of any oil residue), dry, check for wear (score marks or out-of-roundness on the bolt or inside the pulley - anything unusual post it up here!), and if all OK apply tiniest little bit of grease (general purpose lithium grease same as the slides is fine) to the inside of the pulley (just a dab, spread it around in there), reassemble and make sure the bolts through the pulley are done up firm enough to not turn (careful not to distort or crack the bracket though!).

If they are worn out or still a problem, there are a few threads floating around on this forum that deal with improving / fixing the y axis. Start with a look at some of these, see if any take your fancy!
http://www.soliforum.com/topic/2671/sol … ent-guide/
http://www.soliforum.com/topic/2361/all … onversion/
http://www.soliforum.com/topic/6020/pul … from-wear/
http://www.soliforum.com/topic/4073/bel … -2-techie/

SD3. Mk2b + glass, heated enclosure, GT2 belts, direct drive y shaft, linear bearings, bowden-feed E3D v5 w/ 0.9° stepper
Smoothieboard via Octoprint on RPi

3 (edited by ronsii 2014-04-16 04:32:43)

Re: Y-axis belt slipping

Have you tried removing the screw yet? it may just need some cleaning and lube... there could be a burr inside of the gear where the setscrew threads are and this may have galled up the idler screw because the idler screw itself should not be turning.

EDIT: Grob beat me to it wink

4

Re: Y-axis belt slipping

ronsii wrote:

EDIT: Grob beat me to it wink

Wonderful problem to have, too much help! wink

SD3. Mk2b + glass, heated enclosure, GT2 belts, direct drive y shaft, linear bearings, bowden-feed E3D v5 w/ 0.9° stepper
Smoothieboard via Octoprint on RPi

5

Re: Y-axis belt slipping

grob wrote:
ronsii wrote:

EDIT: Grob beat me to it wink

Wonderful problem to have, too much help! wink

Kinda reminds me of the local hardware stores around here, you aren't in the door five minutes and already at least 5 people have offered to help you find something smile

6

Re: Y-axis belt slipping

I'll work on cleaning up my pulley and bolt later on, good thing I finally found out why my prints have been shifting. Thanks Grob and ronsii smile

7

Re: Y-axis belt slipping

Hello. Did you ever solved your problem? After a bunch of upgrades on my printer my Y-axis is slipping sad

8 (edited by LdyMox 2014-06-23 12:48:50)

Re: Y-axis belt slipping

My Y-axis has been skipping really bad for the last two weeks. I take things apart, redo the belts (I followed that video of redoing the belts)  and it fixes it for a print or two and then back to the same problem. I have started to just stop 3D printing as much because of the effort I need to put in just to get one print to come out.

Tammy
Solidoodle 2
E3Dv6 Hotend, MK5 v6 version, Glass Bed, Anti Z backlash slop nut, SureStepr SD8825 1/32 Extruder Driver, makeshift breakaway plexiglass case; . L-Cheapo 3.8 Watt Laser Attachment w/Custom built enclosure
From Buffalo, NY, USA

9

Re: Y-axis belt slipping

Well that's not good.  Adjust the VREF for that axis.  I would bet if you grabbed it with your hand while it's moving you can make it skip fairly easily.   Turn it up just a hair.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

10

Re: Y-axis belt slipping

When I get home I give it a try. Hopefully that just it, I had not touched the VREF for the y-axis. I thought my belt were misaligned since I had started printing at 150 speed slider and I thought I threw everything off. Not that I always print at higher speeds but the problem did happen shortly after I tried the faster speed for my Nylon test. I was worried that going at 150 speed slider ruined something at this point.

Tammy
Solidoodle 2
E3Dv6 Hotend, MK5 v6 version, Glass Bed, Anti Z backlash slop nut, SureStepr SD8825 1/32 Extruder Driver, makeshift breakaway plexiglass case; . L-Cheapo 3.8 Watt Laser Attachment w/Custom built enclosure
From Buffalo, NY, USA

11

Re: Y-axis belt slipping

I would highly doubt speed had anything to do with it.  150% of slow is still slow wink

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

12

Re: Y-axis belt slipping

You say turn it up a hair. Is clockwise or counterclockwise turning it up?

Tammy
Solidoodle 2
E3Dv6 Hotend, MK5 v6 version, Glass Bed, Anti Z backlash slop nut, SureStepr SD8825 1/32 Extruder Driver, makeshift breakaway plexiglass case; . L-Cheapo 3.8 Watt Laser Attachment w/Custom built enclosure
From Buffalo, NY, USA

13

Re: Y-axis belt slipping

LdyMox wrote:

You say turn it up a hair. Is clockwise or counterclockwise turning it up?

Clockwise.
Don't break it wink

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

14

Re: Y-axis belt slipping

I'll try to not break it this time..:P

Tammy
Solidoodle 2
E3Dv6 Hotend, MK5 v6 version, Glass Bed, Anti Z backlash slop nut, SureStepr SD8825 1/32 Extruder Driver, makeshift breakaway plexiglass case; . L-Cheapo 3.8 Watt Laser Attachment w/Custom built enclosure
From Buffalo, NY, USA

15

Re: Y-axis belt slipping

This seems an appropriate place to post this little story:

About a week ago I upgraded to ball bearing carriages and M5 z rod, and after the big reassembly (every moving part was removed from the frame at one point...) I had a weak y-axis, which I finally fixed by realising that I hadn't tightened up the set screws on my direct-drive coupler. I'd spent a whole afternoon chasing VREF, alignment, cleaning of rails, belt tension... Felt like such a fool!

After a bit of a break, flash forward to last night - I had the m3x50mm problem with lawsy's carriage, so the extruder was held on mainly with tape. Last night I was trying to print a variation to replace it, but somehow couldn't get rid of slips in the x axis. Now this never happened before, so I thought maybe the ball bearings were still wearing in a bit and a bit sticky, was feeling like I might have bitten off a bit much all at once.

Starting to worry a bit, given I'm trying to print a case for a clock as a present by wednesday, and I've already been in trouble for late delivery, so every hour counts...

This in mind, I tuned VREF to get a good sound and a bit more force (figuring the bearings may have changed the sweet spot), and being overzealous / in a hurry nearly cooked the x motor - but it was still slipping (particularly badly when the driver tripped out on thermal).

I then added a desk fan and a heatsink to the x driver, as a matter of desperation. Still slipping.

Let everything cool off (more time wasted), retuned VREF back down to run cool as possible, looked good for a bit then... Still slipping.

Sliced the model at 30 mm/s (SimCity Turtle Mode - so useless) to reduce the forces (good for the wobbly extruder though). Still Slipping.

While leaving the x motor to cool back down another couple of tries later I thought I might jam a multimeter thermocouple in there to see how it was doing (too hot to touch still).

At this point I noticed the x pulley was riding right against the flange, so decided to lift it up a little. When I put the allen key in the set screw to loosen it, I notice it's already loose. DUUUUUUUHHHHHHH!!!!

I think I need a label on the front of the case: "CHECK YOUR SET SCREWS."
Also: "IT'S LATE, YOU'RE TIRED, GO TO BED."

SD3. Mk2b + glass, heated enclosure, GT2 belts, direct drive y shaft, linear bearings, bowden-feed E3D v5 w/ 0.9° stepper
Smoothieboard via Octoprint on RPi

16

Re: Y-axis belt slipping

It's good to know I'm not the only one that has those kind of moments big_smile

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

17

Re: Y-axis belt slipping

I think adjusting the Y-Axis VREF seemed to help, well thus far. At first it made it way, way off. Seems now I am just getting the slightest y-wobble on my prints. Is there an easy way to Y-Axis VREF besides keeping printing objects as you tweek the VREF?

Tammy
Solidoodle 2
E3Dv6 Hotend, MK5 v6 version, Glass Bed, Anti Z backlash slop nut, SureStepr SD8825 1/32 Extruder Driver, makeshift breakaway plexiglass case; . L-Cheapo 3.8 Watt Laser Attachment w/Custom built enclosure
From Buffalo, NY, USA

18

Re: Y-axis belt slipping

LdyMox wrote:

I think adjusting the Y-Axis VREF seemed to help, well thus far. At first it made it way, way off. Seems now I am just getting the slightest y-wobble on my prints. Is there an easy way to Y-Axis VREF besides keeping printing objects as you tweek the VREF?

When is the last time you lubed the y-axis drive rod bushings?  It seems odd that you have wobble in the y-axis all of a sudden.  With the VREF you can adjust that while moving it with manual controls.  It's pretty easy to find the sweet spot if you add some resistance with your hand while it's moving (it will stall easier if too low).  If you get too high it will sound more like a groan.  Are you running a fan to cool the board?

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

19

Re: Y-axis belt slipping

No fan on the board, never seemed to need it before. I have lubed the Y-axis rods with the recommonded white lithium grease a few times recently and made sure there was no gunk messing with it.

The wobble in the X-axis started after I turned the speed up for my testing of nylon. I suppose there is an off possbility that the VREF was accidently bumped maybe and adjusted it slighty at the time.

I think I'm almost there. I am just getting a slight Y-wobble at times rather then great shifting. I just can't figure if I need to turn it up or down yet.

Tammy
Solidoodle 2
E3Dv6 Hotend, MK5 v6 version, Glass Bed, Anti Z backlash slop nut, SureStepr SD8825 1/32 Extruder Driver, makeshift breakaway plexiglass case; . L-Cheapo 3.8 Watt Laser Attachment w/Custom built enclosure
From Buffalo, NY, USA

20

Re: Y-axis belt slipping

Not the Rods... The bushings that the drive rod sticks through on the frame near the back on each side.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

21

Re: Y-axis belt slipping

Well I haven't lubed them. I can try that.

Tammy
Solidoodle 2
E3Dv6 Hotend, MK5 v6 version, Glass Bed, Anti Z backlash slop nut, SureStepr SD8825 1/32 Extruder Driver, makeshift breakaway plexiglass case; . L-Cheapo 3.8 Watt Laser Attachment w/Custom built enclosure
From Buffalo, NY, USA

22

Re: Y-axis belt slipping

LdyMox wrote:

Well I haven't lubed them. I can try that.

Just a dab will do ya... you can use oil on those so it can flow in there.

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

23

Re: Y-axis belt slipping

Argg that y-axis shift is back after a week and a half....curses! Maybe I need to switch to the replacement Y carriages I have seen around.

Tammy
Solidoodle 2
E3Dv6 Hotend, MK5 v6 version, Glass Bed, Anti Z backlash slop nut, SureStepr SD8825 1/32 Extruder Driver, makeshift breakaway plexiglass case; . L-Cheapo 3.8 Watt Laser Attachment w/Custom built enclosure
From Buffalo, NY, USA

24

Re: Y-axis belt slipping

I have to wonder if I have made my belts TOO tight but really hard to describe how tight they are, nor ask how tight they should be and expect a clear answer.

Tammy
Solidoodle 2
E3Dv6 Hotend, MK5 v6 version, Glass Bed, Anti Z backlash slop nut, SureStepr SD8825 1/32 Extruder Driver, makeshift breakaway plexiglass case; . L-Cheapo 3.8 Watt Laser Attachment w/Custom built enclosure
From Buffalo, NY, USA

25

Re: Y-axis belt slipping

LdyMox wrote:

I have to wonder if I have made my belts TOO tight but really hard to describe how tight they are, nor ask how tight they should be and expect a clear answer.

That's an easy test... Loosen them up a bit wink are you running a fan on your board?

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions