I have been noticing this "ribbing" on my prints lately. I have recently switched to the newest versions of prontoface and slic3r. Not sure if that has something to do with it. Other than that I haven't changed much, and this just can into existence in the past week or so. Slic3r or SF(depending on the part) --> Marlin --> RAMPS 1.4 --> JHEAD. ABS I have played with different layer heights but to no avail. Any idea where this is coming from? I assume it isn't missed steps since the "rib" is symmetrical around the part. i.e. it isn't indented on one side and sticking out on the other; it's indented all the way around. It seems to happen for a few layers, then go away, then come back a few layers later. Need help! https://reprap.org/forum/read.php?1,126468,126468#msg-126468 Sun, 19 Jul 2026 21:15:47 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,126468,168513#msg-168513 https://reprap.org/forum/read.php?1,126468,168513#msg-168513 -------------------------------------------------------
> Just to throw this out there, I can't really see
> any way that the "wobble arrestors" could perform
> as promised.
>
> The stiction of plastic on plastic when the weight
> of the x axis and motor is resting on it must be
> higher that whatever wobble force is created. That
> means that the wobble is then transmitted. Just
> like without the wobble arrestors. If you put some
> sort of bearing / sliding interface in there then
> I could see it working better.
>
> Isn't the best answer to all of this to use
> thinner threaded rod and thicker z shafting?

You overestimate the friction between plastic pieces. For ABS anyway. The isolators I designed can be seen moving independently of the X axis assembly.

You are correct about rod sizing being the better solution, though.]]> Dale Dunn General Tue, 27 Nov 2012 14:22:49 -0500 https://reprap.org/forum/read.php?1,126468,167841#msg-167841 https://reprap.org/forum/read.php?1,126468,167841#msg-167841
I'm having the same problem with my prusa V2...my problem]]> magicald General Fri, 23 Nov 2012 21:19:32 -0500 https://reprap.org/forum/read.php?1,126468,167777#msg-167777 https://reprap.org/forum/read.php?1,126468,167777#msg-167777
The stiction of plastic on plastic when the weight of the x axis and motor is resting on it must be higher that whatever wobble force is created. That means that the wobble is then transmitted. Just like without the wobble arrestors. If you put some sort of bearing / sliding interface in there then I could see it working better.

Isn't the best answer to all of this to use thinner threaded rod and thicker z shafting?]]> tinyenormous General Fri, 23 Nov 2012 11:41:54 -0500 https://reprap.org/forum/read.php?1,126468,127769#msg-127769 https://reprap.org/forum/read.php?1,126468,127769#msg-127769 -------------------------------------------------------
> nophead Wrote:
> --------------------------------------------------
> -----
> > Do the layers bulge all the way round are are
> they
> > simply displaced laterally? The former implies a
> Z
> > / flow rate problem, whereas the latter is an X
> /Y
> > problem.
> >
> > One thing to check is that the hot end is
> solidly
> > attached. If it can wobble very slightly where
> it
> > is joined to the extruder it can give a big
> offset
> > at the nozzle.
>
> As far as I can see without better eyes or
> magnification it appears to bulge all the way
> around.
> I've tightened down the hot end mount and the
> extruder idler, next I think I will recalibrate my
> steps/mm.

I took a closer look at some of my recent prints, and I'm not sure what is going on.
In some cases it appears that a layer or two after a bulge, there will be a perimeter that appears not to be pressed down enough (hairline gap between layers). If I were skipping steps on Z I don't think this would happen (wouldn't "catch up" and cause a layer to be too high).]]> tsb4k General Sat, 07 Apr 2012 17:42:16 -0400 https://reprap.org/forum/read.php?1,126468,127350#msg-127350 https://reprap.org/forum/read.php?1,126468,127350#msg-127350 -------------------------------------------------------
........
> Since installing the isolators, I haven't printed
> any parts that don't have sections so thin they
> end up being filled 100% despite Fill being set to
> 35%. I was thinking that perhaps the bulges are a
> symptom of a slight overfill condition resulting
> in a periodic overflow. I need to try a part now
> that has room inside for properly sparse fill to
> see if that looks any metter.
>
> There are no guarantees that what I'm seeing and
> what Entropy is seeing are two instances of the
> same problem. I just don't think it's clearly a Z
> wobble problem. I'll try to remember to report
> back here what I find.

I just remembered. I printed a Yoda with the same SFACT settings and there is no sign of this bulging I saw on the walled part. So, I think for me at least it is a subtle flow problem. I'd fix it, but I just ran myself out of that material. Perhaps I'll get the flow under better control for this next kg of ABS.]]> Dale Dunn General Wed, 04 Apr 2012 15:32:56 -0400 https://reprap.org/forum/read.php?1,126468,127334#msg-127334 https://reprap.org/forum/read.php?1,126468,127334#msg-127334 -------------------------------------------------------
> I have been noticing this "ribbing" on my prints
> lately. I have recently switched to the newest
> versions of prontoface and slic3r. Not sure if
> that has something to do with it. Other than that
> I haven't changed much, and this just can into
> existence in the past week or so.
>
> Slic3r or SF(depending on the part) --> Marlin -->
> RAMPS 1.4 --> JHEAD. ABS
>

Do you happen to be using the Lift Z feature in slic3r?]]> brnrd General Wed, 04 Apr 2012 13:51:08 -0400 https://reprap.org/forum/read.php?1,126468,127225#msg-127225 https://reprap.org/forum/read.php?1,126468,127225#msg-127225 -------------------------------------------------------
> Do the layers bulge all the way round are are they
> simply displaced laterally? The former implies a Z
> / flow rate problem, whereas the latter is an X /Y
> problem.
>
> One thing to check is that the hot end is solidly
> attached. If it can wobble very slightly where it
> is joined to the extruder it can give a big offset
> at the nozzle.

As far as I can see without better eyes or magnification it appears to bulge all the way around.
I've tightened down the hot end mount and the extruder idler, next I think I will recalibrate my steps/mm.]]> tsb4k General Tue, 03 Apr 2012 21:57:03 -0400 https://reprap.org/forum/read.php?1,126468,127220#msg-127220 https://reprap.org/forum/read.php?1,126468,127220#msg-127220 brnrd General Tue, 03 Apr 2012 20:14:36 -0400 https://reprap.org/forum/read.php?1,126468,127202#msg-127202 https://reprap.org/forum/read.php?1,126468,127202#msg-127202
Thank you. when i searched earlier i came across others but not one like this that would work well with the mendel :)


Morrist]]> morrist General Tue, 03 Apr 2012 16:24:53 -0400 https://reprap.org/forum/read.php?1,126468,127181#msg-127181 https://reprap.org/forum/read.php?1,126468,127181#msg-127181 www.thingiverse.com]]]> Nudel General Tue, 03 Apr 2012 13:41:19 -0400 https://reprap.org/forum/read.php?1,126468,127175#msg-127175 https://reprap.org/forum/read.php?1,126468,127175#msg-127175 nophead General Tue, 03 Apr 2012 12:49:42 -0400 https://reprap.org/forum/read.php?1,126468,127172#msg-127172 https://reprap.org/forum/read.php?1,126468,127172#msg-127172 morrist General Tue, 03 Apr 2012 12:18:57 -0400 https://reprap.org/forum/read.php?1,126468,127170#msg-127170 https://reprap.org/forum/read.php?1,126468,127170#msg-127170 JohnA General Tue, 03 Apr 2012 12:00:35 -0400 https://reprap.org/forum/read.php?1,126468,127140#msg-127140 https://reprap.org/forum/read.php?1,126468,127140#msg-127140 Ollie General Tue, 03 Apr 2012 07:22:56 -0400 https://reprap.org/forum/read.php?1,126468,127125#msg-127125 https://reprap.org/forum/read.php?1,126468,127125#msg-127125 Nudel General Tue, 03 Apr 2012 05:07:30 -0400 https://reprap.org/forum/read.php?1,126468,127117#msg-127117 https://reprap.org/forum/read.php?1,126468,127117#msg-127117
One thing to check is that the hot end is solidly attached. If it can wobble very slightly where it is joined to the extruder it can give a big offset at the nozzle.]]> nophead General Tue, 03 Apr 2012 03:57:10 -0400 https://reprap.org/forum/read.php?1,126468,127092#msg-127092 https://reprap.org/forum/read.php?1,126468,127092#msg-127092
I'm reasonably happy with the quality of my prints, except I have some minor banding. I don't think it is threaded rod wobble, I've installed these to further decouple the carriage and the results are indistinguishable.

It seems to be more pronounced on layers with more detail, e.g. a simple cube appears almost flawless but anything with a region of more complicated layers has more banding on them.

I've tensioned my belts as well as possible and made sure they aren't rubbing against idlers.
Should I blame crappy chinese lm8uus? Recalibrate my extruder's steps/mm?

I would be happy with the parts if I couldn't produce better with my modified Cupcake.]]> tsb4k General Mon, 02 Apr 2012 23:27:13 -0400 https://reprap.org/forum/read.php?1,126468,126991#msg-126991 https://reprap.org/forum/read.php?1,126468,126991#msg-126991 -------------------------------------------------------

> Hope nobody minds the threadjacking, but I sell
> pretty cheap leadscrew sets that include nuts that
> are the same size as M8 nuts, so they're a drop-in
> replacement for your existing X-ends. The only
> printed parts that need replacing are your motor
> coupler since the leadscrews are 6.35mm in
> diameter, so you'll need to either print new
> couplers or upgrade to metal couplers.

Nice try, but as this is a techzone huxley he needs M6 for his leadscrew (and M6 sized nuts).


I also got a TZ huxley and it exhibit a similar "horizontal banding" problem - only to a really lesser extent.

Once in the past I had to do something to lessen it - it was after I dismantled and rebuilt my Z and X axis. The problem was a slight mis-alignement of the z rods.]]> DeuxVis General Mon, 02 Apr 2012 09:27:49 -0400 https://reprap.org/forum/read.php?1,126468,126877#msg-126877 https://reprap.org/forum/read.php?1,126468,126877#msg-126877 -------------------------------------------------------
> I'm not so sure. I had some Z axis wobble that
> clearly measured the same pitch as my Z rod. The
> pattern in the parts noticeably followed a helical
> pattern around the part. Now that I've added my Z
> screw isolators (Thingiverse), the wobble is gone
> and I see a pattern that looks like what Entropy
> is showing, but not as severe.

I am open to the idea that it is not just Z wobble (XY wobble caused by Z), but also a problem with the Z movement. Cheap threaded rods are made by rolling, so while the average pitch is nominal, there may be a variation in pitch thread to thread. That is one reason why I want to try more accurate machined rods or leadscrew.

I had also wondered if there is accumulated error in the Z steps, but I would guess a step error of +/- 1 step per layer is not going to cause much problem.

I further wondered if this is a property of the extrusion. As each layer pushes down on existing layers, I guess there is a tendency for the new softer layer to ooze sideways. The layers meander back and forth from the nominal position.]]> bobc General Sun, 01 Apr 2012 11:55:25 -0400 https://reprap.org/forum/read.php?1,126468,126770#msg-126770 https://reprap.org/forum/read.php?1,126468,126770#msg-126770 > I bought a cheapish leadscrew, but I am still
> looking for truly inexpensive leadscrews. I also
> haven't worked out how to replace M8 threaded rod,
> since the leadscrew won't take an M8 nut. The nuts
> and accessories for leadscrews are expensive too.

Hope nobody minds the threadjacking, but I sell pretty cheap leadscrew sets that include nuts that are the same size as M8 nuts, so they're a drop-in replacement for your existing X-ends. The only printed parts that need replacing are your motor coupler since the leadscrews are 6.35mm in diameter, so you'll need to either print new couplers or upgrade to metal couplers.]]> Pointedstick General Sat, 31 Mar 2012 15:50:36 -0400 https://reprap.org/forum/read.php?1,126468,126767#msg-126767 https://reprap.org/forum/read.php?1,126468,126767#msg-126767
Check your Z axis for binding/calibration...then lube it with something (I have been using lithium spray lately).]]> C. Cecil General Sat, 31 Mar 2012 15:10:00 -0400 https://reprap.org/forum/read.php?1,126468,126747#msg-126747 https://reprap.org/forum/read.php?1,126468,126747#msg-126747 -------------------------------------------------------
> This is clearly Z-Axis wobble. Post a picture of
> your vertical threaded rod, including the bit
> where stepper meets rod, and I can tell you where
> the problem is.

I'm not so sure. I had some Z axis wobble that clearly measured the same pitch as my Z rod. The pattern in the parts noticeably followed a helical pattern around the part. Now that I've added my Z screw isolators (Thingiverse), the wobble is gone and I see a pattern that looks like what Entropy is showing, but not as severe. The bulges on the part are uniform all the way around a part (not wrapped helically around the part), and very definitely not the same pitch as the screws. They measure close to 1.0, and the screws are 1.25. (I also checked 10.0 mm v 12.5.) The spacing stays the same for layers with both large and small total areas, so I don't think it's a filament diameter issue for me. I do see that the banding doesn't appear in the layers within about 8-10 mm of the heated bed (I'm presently using 1.75mm white ABS from MakerGear).

Since installing the isolators, I haven't printed any parts that don't have sections so thin they end up being filled 100% despite Fill being set to 35%. I was thinking that perhaps the bulges are a symptom of a slight overfill condition resulting in a periodic overflow. I need to try a part now that has room inside for properly sparse fill to see if that looks any metter.

There are no guarantees that what I'm seeing and what Entropy is seeing are two instances of the same problem. I just don't think it's clearly a Z wobble problem. I'll try to remember to report back here what I find.]]> Dale Dunn General Sat, 31 Mar 2012 11:24:36 -0400 https://reprap.org/forum/read.php?1,126468,126715#msg-126715 https://reprap.org/forum/read.php?1,126468,126715#msg-126715 -------------------------------------------------------
> That definitely looks like a problem with your Z
> threaded rods, which is why I'm not a big fan of
> using them for motion. I'd suggest picking up some
> inexpensive leadscrews. Banding like that can also
> be caused by loose belts, but the regularity I see
> there really points to Z threaded rod problems.

I got the same problem banding problem with cheap threaded rod.

I bought a cheapish leadscrew, but I am still looking for truly inexpensive leadscrews. I also haven't worked out how to replace M8 threaded rod, since the leadscrew won't take an M8 nut. The nuts and accessories for leadscrews are expensive too.

I am looking for someone with a lathe to machine M8 threads onto the ends, then maybe I can fit it to my printer using standard parts.

An alternative is more expensive threaded rod (machined not rolled?) but I'm not finding that easily either.]]> bobc General Sat, 31 Mar 2012 07:28:45 -0400 https://reprap.org/forum/read.php?1,126468,126679#msg-126679 https://reprap.org/forum/read.php?1,126468,126679#msg-126679 jcabrer General Fri, 30 Mar 2012 17:36:36 -0400 https://reprap.org/forum/read.php?1,126468,126647#msg-126647 https://reprap.org/forum/read.php?1,126468,126647#msg-126647
I have changed out my Z axis pulley to a machined one so I don't imagine that would be it, but I could check again.

I will try printing two at the same time and see.

The pitch of the ribs changes based on the height of the object printed. If its a smaller part, then they seem to be closer together, if its taller, then it seems to be farther apart. I haven't measured specifically but I will.]]> Entropy General Fri, 30 Mar 2012 12:39:04 -0400 https://reprap.org/forum/read.php?1,126468,126643#msg-126643 https://reprap.org/forum/read.php?1,126468,126643#msg-126643
If it was the flow rate changing it could be due to filament diameter variation but it would have to change by about 0.2mm over quite short distances, so I think you would be able to see that on the filament. Have you tried measuring it in a few places?

What happens if you build two of the same object at the same time? If it was filament you would get ribs of twice the frequency. If it was layer height they would be the same frequency.

You haven't answered any of my questions so it is hard to make a remote diagnosis.

What is the pitch of the ribs?
It is synchronised to the layer height, or the Z leadscrew pitch, or neither?
Are the objects the correct height?

An eccentric Z motor pulley would do it.

It is hard to see how temperature fluctuations would do it as it doesn't affect flow rate unless it gets too viscous and slips. This looks too regular for anything slipping.]]> nophead General Fri, 30 Mar 2012 12:28:17 -0400 https://reprap.org/forum/read.php?1,126468,126615#msg-126615 https://reprap.org/forum/read.php?1,126468,126615#msg-126615
The machine is set up in my basement which is pretty cold. I'm thinking the differences may be to the heater in the print bed shutting off after it meets it's temp and then turning back on, or may the hot end, or a combo of both. Not too sure how to prove it.

My other idea is that my filament is not uniform in thickness. I am using an accessible wades without springs. Could the "thick" and "thin" layers be due to more filament being pushed out? I've noticed that with smaller parts that take less time, the ribbing is not as noticeable. Has anyone see anything like this before?]]> Entropy General Fri, 30 Mar 2012 09:47:09 -0400 https://reprap.org/forum/read.php?1,126468,126503#msg-126503 https://reprap.org/forum/read.php?1,126468,126503#msg-126503 Entropy General Thu, 29 Mar 2012 11:41:58 -0400 https://reprap.org/forum/read.php?1,126468,126502#msg-126502 https://reprap.org/forum/read.php?1,126468,126502#msg-126502 Entropy General Thu, 29 Mar 2012 11:41:00 -0400 https://reprap.org/forum/read.php?1,126468,126501#msg-126501 https://reprap.org/forum/read.php?1,126468,126501#msg-126501 nophead General Thu, 29 Mar 2012 11:37:27 -0400