Z-Stepper Motor issues and how to fix them
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HotKey
Nov 18, 2010, 10:08:34 AM11/18/10
to MakerBot Operators
For some weeks I've had the problem of the z-stepper motor getting
stuck (*brrrrrrrr* noise) when turning quickly (e.g. advancing from
one layer to the next).
When using the RepG control panel to move the z-stage: Values <120
worked fine, values >150 eventually lead to the motor not turning
smoothly, getting stuck, starting to buzzzzzz.
What I've tried to fix it (without solving the problem):
* Lubricating, lubricating, lubricating
* Using the printed "locking bearing" to fine-adjust the bearings
* Loosening up the screws that hold the bearings in place (locking
bearing only)
* Loosening up the bolts on the z-rods that are close to the bearings
* Increasing the z-stepper voltage
* Installing fans that cool the z-stepper motor (gets hot when doing
half-steps)
* Installing heat spreader on the motor driver boards
* Reducing the maximum z feed rate in machines.xml - doesn't help at
all since Skeinforge seems to ignore that
* Using the "cool" option which makes the z-stage travel upwards quite
smoothly once the orbiting has finished. Sometimes, though, it still
moves to fast - buzzzing.
NOTHING helped. The motor kept buzzing when moving up too fast.
Then I found that page: http://reprap.org/wiki/StepperMotor
I went on to Reichelt (a german electronics supplier) and got myself a
TRINAMIC QSH4218-51-049. That's a stepper that has the same profile as
the original MakerBot 50002 motor (but is much taller) and pumps out a
pleasing 0.49 Nm of force - that's twice as much as the original one.
The only problem was the shaft which is about .25mm wider than the
original - one quick lathing later it fit!
My problem is solved! But I have to see how it performs on longer
prints. It may "wear out" the stepper driver boards a bit more. But
that's a risk I'm willing to take!
I hope it helps some of you!
stuck (*brrrrrrrr* noise) when turning quickly (e.g. advancing from
one layer to the next).
When using the RepG control panel to move the z-stage: Values <120
worked fine, values >150 eventually lead to the motor not turning
smoothly, getting stuck, starting to buzzzzzz.
What I've tried to fix it (without solving the problem):
* Lubricating, lubricating, lubricating
* Using the printed "locking bearing" to fine-adjust the bearings
* Loosening up the screws that hold the bearings in place (locking
bearing only)
* Loosening up the bolts on the z-rods that are close to the bearings
* Increasing the z-stepper voltage
* Installing fans that cool the z-stepper motor (gets hot when doing
half-steps)
* Installing heat spreader on the motor driver boards
* Reducing the maximum z feed rate in machines.xml - doesn't help at
all since Skeinforge seems to ignore that
* Using the "cool" option which makes the z-stage travel upwards quite
smoothly once the orbiting has finished. Sometimes, though, it still
moves to fast - buzzzing.
NOTHING helped. The motor kept buzzing when moving up too fast.
Then I found that page: http://reprap.org/wiki/StepperMotor
I went on to Reichelt (a german electronics supplier) and got myself a
TRINAMIC QSH4218-51-049. That's a stepper that has the same profile as
the original MakerBot 50002 motor (but is much taller) and pumps out a
pleasing 0.49 Nm of force - that's twice as much as the original one.
The only problem was the shaft which is about .25mm wider than the
original - one quick lathing later it fit!
My problem is solved! But I have to see how it performs on longer
prints. It may "wear out" the stepper driver boards a bit more. But
that's a risk I'm willing to take!
I hope it helps some of you!
Will Brown
Nov 18, 2010, 2:41:29 PM11/18/10
to make...@googlegroups.com
Awesome! I was having the same issue and found that decreasing the Z belt tension helped (although it didn't eliminate the problem -- it's just much rarer now).
Does the stepper stick out beneath the front facing of the bot?
whb
Written on a phone. Please excuse typing errors.
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travis
Nov 18, 2010, 3:36:11 PM11/18/10
to MakerBot Operators
Try loosening the 180 and 360 vert bearings where they attach to the x
axis. I was having trouble with the z axis and it ended up being that
the z axis bars werent completely straight and when they'd try to
raise/lower the x axis they'd get in a bind. Loosening the vert
bearings gave a little leeway and it's a lot smoother.
axis. I was having trouble with the z axis and it ended up being that
the z axis bars werent completely straight and when they'd try to
raise/lower the x axis they'd get in a bind. Loosening the vert
bearings gave a little leeway and it's a lot smoother.
krst
Nov 19, 2010, 2:48:56 AM11/19/10
to MakerBot Operators
I've had Z-axis issues as described and tried a variety of fixes - but
the eventual solution involved fixing heat expansion. It seems that as
the chamber warms up (due to the extruder, but also with the HBP) the
acrylic Z-platform absorbs the heat and expands. The wider Z-platform
then presses against the Z-rods and has difficulty if the pressure is
too great. This is exacerbated if one or more of the Z-rods are
warped, such that the pressure is increased when the rod is turn in a
specific direction.
The two solutions that made a lot of difference were:
- Tilt the Z-platform by raising the nuts on one side. This makes the
machine look awkward, but it provides more room for the acrylic to
expand without causing pressure
- The warped Z-rod was taken out of the equation by simply removing
its nut on the Z-platform
These two moves virtually eliminated Z stuck situations. Give them a
try!
the eventual solution involved fixing heat expansion. It seems that as
the chamber warms up (due to the extruder, but also with the HBP) the
acrylic Z-platform absorbs the heat and expands. The wider Z-platform
then presses against the Z-rods and has difficulty if the pressure is
too great. This is exacerbated if one or more of the Z-rods are
warped, such that the pressure is increased when the rod is turn in a
specific direction.
The two solutions that made a lot of difference were:
- Tilt the Z-platform by raising the nuts on one side. This makes the
machine look awkward, but it provides more room for the acrylic to
expand without causing pressure
- The warped Z-rod was taken out of the equation by simply removing
its nut on the Z-platform
These two moves virtually eliminated Z stuck situations. Give them a
try!
Zip Zap
Nov 19, 2010, 2:56:53 AM11/19/10
to make...@googlegroups.com
Use the wobble arrestors in Thingiverse. For a quick fix, use MakiYoshida's wobble arrestor on one of your z-rods or use my double version of the same wobble arrestor.
http://www.thingiverse.com/thing:4668
http://www.thingiverse.com/thing:4668
From: krst <kerry.s...@gmail.com>
To: MakerBot Operators <make...@googlegroups.com>
Sent: Thu, November 18, 2010 11:48:56 PM
Subject: [MakerBot] Re: Z-Stepper Motor issues and how to fix them
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HotKey
Nov 19, 2010, 6:14:22 AM11/19/10
to MakerBot Operators
Wow! Never thought about expanding acrylic! That sounds pretty
comprehensible! This would REALLY be an issue that should be taken
care of!
But actually, when the motor got stuck, I turned the rods by hand -
and it went very smooth. At least so smooth that a standard 12V
stepper motor should be able to rotate it!
Well, now it's too late for me to try it out (and I'm too tired of
that issue already ;-) ), since the new motor just rocks! :-D
@Will: Yes, the motor is about 50mm tall which makes it stick out some
8mm from the top panel - Showing its 0.49Nm manliness :-D
On 19 Nov., 08:56, Zip Zap <zzap...@yahoo.com> wrote:
> Use the wobble arrestors in Thingiverse. For a quick fix, use MakiYoshida's
> wobble arrestor on one of your z-rods or use my double version of the same
> wobble arrestor.
>
> http://www.thingiverse.com/thing:4668
>
> ________________________________
> From: krst <kerry.steven...@gmail.com>
comprehensible! This would REALLY be an issue that should be taken
care of!
But actually, when the motor got stuck, I turned the rods by hand -
and it went very smooth. At least so smooth that a standard 12V
stepper motor should be able to rotate it!
Well, now it's too late for me to try it out (and I'm too tired of
that issue already ;-) ), since the new motor just rocks! :-D
@Will: Yes, the motor is about 50mm tall which makes it stick out some
8mm from the top panel - Showing its 0.49Nm manliness :-D
On 19 Nov., 08:56, Zip Zap <zzap...@yahoo.com> wrote:
> Use the wobble arrestors in Thingiverse. For a quick fix, use MakiYoshida's
> wobble arrestor on one of your z-rods or use my double version of the same
> wobble arrestor.
>
> http://www.thingiverse.com/thing:4668
>
> ________________________________
> To: MakerBot Operators <make...@googlegroups.com>
> Sent: Thu, November 18, 2010 11:48:56 PM
> Subject: [MakerBot] Re: Z-Stepper Motor issues and how to fix them
>
> I've had Z-axis issues as described and tried a variety of fixes - but
> the eventual solution involved fixing heat expansion. It seems that as
> the chamber warms up (due to the extruder, but also with the HBP) the
> acrylic Z-platform absorbs the heat and expands. The wider Z-platform
> then presses against the Z-rods and has difficulty if the pressure is
> too great. This is exacerbated if one or more of the Z-rods are
> warped, such that the pressure is increased when the rod is turn in a
> specific direction.
>
> The two solutions that made a lot of difference were:
>
> - Tilt the Z-platform by raising the nuts on one side. This makes the
> machine look awkward, but it provides more room for the acrylic to
> expand without causing pressure
> - The warped Z-rod was taken out of the equation by simply removing
> its nut on the Z-platform
>
> These two moves virtually eliminated Z stuck situations. Give them a
> try!
>
> --
> You received this message because you are subscribed to the Google Groups
> "MakerBot Operators" group.
> To post to this group, send email to make...@googlegroups.com.
> To unsubscribe from this group, send email to
> makerbot+u...@googlegroups.com.
> Sent: Thu, November 18, 2010 11:48:56 PM
> Subject: [MakerBot] Re: Z-Stepper Motor issues and how to fix them
>
> I've had Z-axis issues as described and tried a variety of fixes - but
> the eventual solution involved fixing heat expansion. It seems that as
> the chamber warms up (due to the extruder, but also with the HBP) the
> acrylic Z-platform absorbs the heat and expands. The wider Z-platform
> then presses against the Z-rods and has difficulty if the pressure is
> too great. This is exacerbated if one or more of the Z-rods are
> warped, such that the pressure is increased when the rod is turn in a
> specific direction.
>
> The two solutions that made a lot of difference were:
>
> - Tilt the Z-platform by raising the nuts on one side. This makes the
> machine look awkward, but it provides more room for the acrylic to
> expand without causing pressure
> - The warped Z-rod was taken out of the equation by simply removing
> its nut on the Z-platform
>
> These two moves virtually eliminated Z stuck situations. Give them a
> try!
>
> --
> You received this message because you are subscribed to the Google Groups
> "MakerBot Operators" group.
> To post to this group, send email to make...@googlegroups.com.
> To unsubscribe from this group, send email to
Mark Cohen
Dec 6, 2010, 9:19:23 AM12/6/10
to MakerBot Operators
Hi,
I just built my third cupcake so I could put my MK5 extruder on it and
not have to switch out the MK4. This new bot binds quite a lot. I am
pretty sure it is the acrylic expanding as it just happens after the
HPB and MK5 heat up and the Z motor gets hot. I shaved the acrylic
where it touches the nuts by using a razor blade back and forth. This
made it slightly better. I may replace the Z motor with a more
powerful one as I noticed it just needs a bit more torque. Does anyone
have the site and part number for a more powerful compatible one in
the US with a 5mm diameter shaft? The z motor pulley and the small
idler pulley are very similiar except that the small idler pulley has
a 5mm bore vs 4.8mm for the z pulley so I could pick up another idler
pulley and use that on a 5mm motor without lathing it. Sdpi-si.com has
all this in stock at the moment (also the bearings should you need
some)
A 6Z51M036DF0605 GT2 (2mm) Pitch, 36 Teeth, Polycarbonate timing
pulley
A 6Z51-036DF0606 GT2 (2mm) Pitch, 36 Teeth, Polycarbonate Timing
Pulley With Brass Insert
A 7P 6-F0816E 0.253Inch I.D. By 0.377Inch O.D., 0.5Inch Long Ertalyte
Polyester Sleeve Bearing
One other thing I might do is just put the MK5 on an older cupcake
that has been worn it. It was not binding on that one and I can put
the MK4 on the new one to see if that is the issue.
Regards,
Mark
> > For more options, visit this group athttp://groups.google.com/group/makerbot?hl=en.- Hide quoted text -
>
> - Show quoted text -
I just built my third cupcake so I could put my MK5 extruder on it and
not have to switch out the MK4. This new bot binds quite a lot. I am
pretty sure it is the acrylic expanding as it just happens after the
HPB and MK5 heat up and the Z motor gets hot. I shaved the acrylic
where it touches the nuts by using a razor blade back and forth. This
made it slightly better. I may replace the Z motor with a more
powerful one as I noticed it just needs a bit more torque. Does anyone
have the site and part number for a more powerful compatible one in
the US with a 5mm diameter shaft? The z motor pulley and the small
idler pulley are very similiar except that the small idler pulley has
a 5mm bore vs 4.8mm for the z pulley so I could pick up another idler
pulley and use that on a 5mm motor without lathing it. Sdpi-si.com has
all this in stock at the moment (also the bearings should you need
some)
A 6Z51M036DF0605 GT2 (2mm) Pitch, 36 Teeth, Polycarbonate timing
pulley
A 6Z51-036DF0606 GT2 (2mm) Pitch, 36 Teeth, Polycarbonate Timing
Pulley With Brass Insert
A 7P 6-F0816E 0.253Inch I.D. By 0.377Inch O.D., 0.5Inch Long Ertalyte
Polyester Sleeve Bearing
One other thing I might do is just put the MK5 on an older cupcake
that has been worn it. It was not binding on that one and I can put
the MK4 on the new one to see if that is the issue.
Regards,
Mark
>
> - Show quoted text -
Andrew Plumb
Dec 6, 2010, 10:16:14 AM12/6/10
to make...@googlegroups.com
The Z stepper should not be getting hot as it's mostly-off while printing and doesn't need power to maintain its position.
I've had problems when I let my 'bot warm up, using the control panel to send the z platform to Z=+20, then forgotten to disable steppers while chatting with folks for "too long". Once that stepper is too hot, there's no stopping the skipping until it's had a chance to cool down.
Related RepG issue requesting enabled/disabled status indicator on the Control Panel: https://github.com/makerbot/ReplicatorG/issues#issue/88
Andrew.
--
"The future is already here. It's just not very evenly distributed" -- William Gibson
Mark Cohen
Dec 6, 2010, 10:41:06 AM12/6/10
to make...@googlegroups.com
I agree it should not be getting hot.
I do not have this issue on my other two bots.
I do not have this issue on my other two bots.
Andrew Plumb
Dec 6, 2010, 10:54:48 AM12/6/10
to make...@googlegroups.com
Yeah, sounds more like a bad motor or stepper driver then. When I've had trouble the stepper has been *way* too hot to touch; definitely not extruder+HBP ambient heat induced.
You could try heat sinking or fanning the stepper to help it dissipate the heat, but that would just be a stop-gap measure.
Andrew.
Koen Kooi
Dec 6, 2010, 11:19:04 AM12/6/10
to make...@googlegroups.com
Op 6 dec 2010, om 16:16 heeft Andrew Plumb het volgende geschreven:
> The Z stepper should not be getting hot as it's mostly-off while printing and doesn't need power to maintain its position.
I've use the lampshade script to do some lampshades and that keeps the Z stepper continiously moving, so it is possible to tweak the trimpot enough to stop it from overheating.
regards,
Koen
Luis E. Rodriguez
Dec 6, 2010, 11:34:42 AM12/6/10
to make...@googlegroups.com
I would use a wobble arrestor (check), float one of the threaded rods (check), and maybe see if you've got a saggy z stage (need to do). You might have seen this talked about during the last Ustream of roboto hospital by Makerbot. The acrylic and weight start to sag and bidn the rods causing stress on the z stepper. Otherwise I think yes adjust the trim pot down until you can use it and then up until you can't force it to move by hand. I hope to z-rider the whole damn thing and say goodbye to 4 rods anywho. I know how you feel though. THis whole hobby/movement can be defalted with the sound of one little skip during and epic build. Ok even during a fun item like a whistle or bottle opener. Definetly disable steppers in control panel when warming up too.
Luis E. Rodriguez
Mark Cohen
Dec 6, 2010, 12:02:57 PM12/6/10
to make...@googlegroups.com
The trim pot does not help.
I do not think the acrylic is sagging. It’s brand new and level.
The rods look good.
I am going to exchange the motor tomorrow as they are only 15 minutes from my house.
Thanks!
From: make...@googlegroups.com [mailto:make...@googlegroups.com] On Behalf Of Luis E. Rodriguez
Sent: Monday, December 06, 2010 11:35 AM
To: make...@googlegroups.com
Luis E. Rodriguez
Dec 6, 2010, 12:04:36 PM12/6/10
to make...@googlegroups.com
Oh sweet! Good luck!
Luis E. Rodriguez
Mark Cohen
Dec 6, 2010, 12:06:33 PM12/6/10
to make...@googlegroups.com
Oh by the way I always have left the stepper enabled on my older bots and never had an issue ever. Although I see the logic in this. I have printed over 1000 hours so far. The only failure I had was my dc motor in the extruder and that was just two days ago, it was 8 months old.
From: make...@googlegroups.com [mailto:make...@googlegroups.com] On Behalf Of Luis E. Rodriguez
Sent: Monday, December 06, 2010 11:35 AM
To: make...@googlegroups.com
Mark Cohen
Dec 8, 2010, 11:45:37 AM12/8/10
to make...@googlegroups.com
Hi,
I replaced the stepper and it is relatively cool now and things are working much better.
Thanks.
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