Banding problem Hi, I have a problem with my Prusa that I've had since it was new. I've struggled with this problem for at least half a year since the printer became operational. In brief, prints have a "banding" problem where each layer appears to be shifted on the X and/or Y axis. That is, for each layer it prints, it looks like the layer is "shifted" in some direction. By this I mean it is as if each layer starts printing at an offset from where the other layer was printed, maybe because of some mechanical play somewhere, see the attached pictures to make your own judgement. When printing the 20 mm box calibration object, this results in uneven faces that feel rough to the touch and in general just have poor aesthetic quality. Obviously this also results in poor precision for finer prints. This is shown in the "banding_20mmbox.jpeg" attachment. [img]http://forums.reprap.org/file.php?4,file=18260,filename=banding_20mmbox.jpeg[/img] My printer is a MakerGear Mendel Prusa i2 that was bought new as a kit, with some modifications. There is a picture attached in "printer_setup.jpg". I am using 1.75 mm PLA with a 0.35 mm nozzle at 0.2 mm layer height, at 185 degrees C for the hotend, 60 degrees C for the bed. The bed is covered with Kapton tape. The filament is bought from MakerGear. Modifications: * No lower end bearings on the Z axis: Should help with reducing wobble, if there is wobble (Z axis). * No upper nut in the Z axis printed slider parts: Should help with reducing wobble, if there is wobble (Z axis). * No spring inside the Z axis printed slider parts: No function when there is no upper nut. * Acme rods: My M8 rods were slightly bent. My acme rods appear almost perfect when rolled on a glass surface. * Non-printed idle pulleys: The printed pulleys had a problem with the belt climbing slightly on the edge, new ones do not have this problem. * Printed part to hold a 40 mm fan (came with the kit, but with no printed part to mount it). * Additional 80 mm fan. * Printed filament holder with bearings inside the spool on an M8 threaded rod. Please note that I had the same problem _before_ I started to make modifications, but these modifications I'm given to understand should only improve the machine in general, not make it worse. My configuration for Slic3r is in the "config18.ini" attachment. I am using Marlin firmware. I have frequented the #reprap IRC channel and gotten some suggestions. I have checked at least the following: * Everything is tightened down on the machine. * All belts are tight with no play. * There is no binding or unwanted resistance on any axes. * There is no wobble/movement visible on the lower end of the Acme rods when using the Z axis. * The Z couplers are preloaded. By this I mean they are stretched/pulled down before the screws are tightened on them (with the threaded rod in place). This is to prevent them being able to exert a "spring effect" on the Y carriage. * I have lithium grease on the Acme threaded rods. * I have oil on the smooth rods. * I have done PID tuning for the hotend and for the bed. * I have tried two different filament spools, both from MakerGear. * I have measured the diameter of the filament with a digital caliper, it is exactly 1.75 mm and 1.74 mm in some places. * I have measured the extruded filament, it is exactly 0.35 mm. * I have done calibration, including having followed Triffid Hunter's calibration guide: http://reprap.org/wiki/Triffid_Hunter%27s_Calibration_Guide * I have tried to increase and lower esteps from 476 to 466 and increase it to 487, there are no observable differences. * I have tried to print at 210 degrees C, it made poorer results. * I have tried different layer heights, 0.15, 0.2 and higher. * I have tried printing with the bed completely turned off, it seems to give slightly improved results, but the banding problem is there, so it is not the underlying cause. * I have tried to print with no fan; with the 40 mm fan at default settings; with the 40 mm fan at 100%, with both the 40 mm fan and the 80 mm fan at 100% speed. * I have tried to reduce the travel speed from 170 to 50 mm/s for non print moves to see if there might be some play somewhere and with the intention that the effect of the play gets reduced when it does not jerk around as much. I did not observe any differences. * I have tried different printing speeds for all paramters, most prints I have done are slow, at 20 mm/s. See the attached config18.ini file. * I have checked that the z-screw on the gear on the extruder motor is tight and that there is no play. * I have tried both the Sprinter and Marlin firmware. * There is no audible, visible or tactile vibration on the machine, nor are there any unpleastant sounds from it. The following result is interesting: * I have mounted a laser on the back end of the extruder motor and observed the movements of the dot on the wall (about 6-7 meter away) when it extrudes (when it does not print, just extrude, no movement beyond extrusion): The dot moves in a horizontally oscillating pattern. The movement is minutiae. For this test I extruded 150 mm at 300 mm/min, towards the end of the 150 mm, the dot moved slightly up as well. I did the test twice, and reproduced the results. When the extrusion stops, the movement immediately stops on the laser dot on the wall. I am not sure what this overall result means, would this be normal behavior for it to move around like this, or is it an indication of something that is wrong? If so, what is wrong, how can it be corrected? Finally I have also two other pictures (but I have many more, if it would be relevant to any discussion, advice or suggestions): small_and_large.jpeg: A 20 mm box side by side with a 200% version of the 20 mm box. yoda.jpeg: A print of the http://www.thingiverse.com/thing:10752 "Yoda Lite" to demonstrate how poor quality prints I get, even after all this effort. Marlin firmware configuration: #define DEFAULT_AXIS_STEPS_PER_UNIT {52.4934,52.4934,2015.748031,476} #define DEFAULT_MAX_FEEDRATE {500, 500, 3, 45} // (mm/sec) #define DEFAULT_MAX_ACCELERATION {1000,1000,50,1000} // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for skeinforge 40+, for older versions raise them a lot. #define DEFAULT_ACCELERATION 450 // X, Y, Z and E max acceleration in mm/s^2 for printing moves #define DEFAULT_RETRACT_ACCELERATION 450 // X, Y, Z and E max acceleration in mm/s^2 for retracts // Offset of the extruders (uncomment if using more than one and relying on firmware to position when changing). // The offset has to be X=0, Y=0 for the extruder 0 hotend (default extruder). // For the other hotends it is their distance from the extruder 0 hotend. // #define EXTRUDER_OFFSET_X {0.0, 20.00} // (in mm) for each extruder, offset of the hotend on the X axis // #define EXTRUDER_OFFSET_Y {0.0, 5.00} // (in mm) for each extruder, offset of the hotend on the Y axis // The speed change that does not require acceleration (i.e. the software might assume it can be done instantaneously) #define DEFAULT_XYJERK 10.0 // (mm/sec) #define DEFAULT_ZJERK 0.2 // (mm/sec) #define DEFAULT_EJERK 2.5 // (mm/sec) Any suggestions would be appreciated, thank you. https://reprap.org/forum/read.php?4,239941,239941#msg-239941 Thu, 08 Oct 2026 21:04:34 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?4,239941,248384#msg-248384 Re: Banding problem https://reprap.org/forum/read.php?4,239941,248384#msg-248384
With the help of two friends I have gotten a new bed made of an aluminium plate, it is a 5052-H32 plate, 1/4" x 10" x 10". It has been drilled and mounted directly on top of the heated bed with a conductive compound between the two plates to provide good heat conduction. The plate itself is covered in Kapton tape and has a hole drilled into the side of it (depicted in one of the pictures below), the temperature sensor is placed inside this hole together with conductive compound.

I have also redone the squaring, again. However, I have yet to print the improved i2/GregFrost X end parts. So my current setup has at least one problem, and that is that the X belt bends the smooth rods when it gets tightened. I believe printing the improved parts will solve that.

This is the setup:

New setup, picture 1
New setup, picture 2

When I print with this setup, I get the following results:

Face 1
Face 2
Face 3
Face 4
Three faces

I believe this is an improvement. However, note that some of the faces look better than others. Why is that? I have a fan both in front and in the back, as before.

Edit: Most importantly, the banding problem is still there, just less severe.]]> fractal5 Reprappers Tue, 24 Sep 2013 18:51:39 -0400 https://reprap.org/forum/read.php?4,239941,245523#msg-245523 Re: Banding problem https://reprap.org/forum/read.php?4,239941,245523#msg-245523 appdev007 Reprappers Sun, 15 Sep 2013 10:51:16 -0400 https://reprap.org/forum/read.php?4,239941,245448#msg-245448 Re: Banding problem https://reprap.org/forum/read.php?4,239941,245448#msg-245448 -------------------------------------------------------
> Hey, those look better squished together than the
> previous prints. I do notice that the layer offset
> occurs every 3rd layer. I finally dealt with the
> last of my wobble issues by printing a
> set of
> these (they hold the z smooth rods tight)
> and buying a set of
> [url=http://www.makerfarm.com/index.php/hardware/z
> -coupler.html]these[/url]. I think this took the
> play out from in-between my linear bearing and my
> x ends and dealt with the never straight z
> threaded rods.

Thanks for the advice. However I already am using similar Z couplers on my setup:



As for the improved X ends, that is a suggestion I have gotten on IRC as well. The i2 has an improved design over the i1 and I have planned to print those. Are these better than the original i2 parts? Or are they inferior, but require a lot less work to install on an i1 machine?
]]> fractal5 Reprappers Sun, 15 Sep 2013 03:06:28 -0400 https://reprap.org/forum/read.php?4,239941,245429#msg-245429 Re: Banding problem https://reprap.org/forum/read.php?4,239941,245429#msg-245429 set of these (they hold the z smooth rods tight) and buying a set of these. I think this took the play out from in-between my linear bearing and my x ends and dealt with the never straight z threaded rods.]]> appdev007 Reprappers Sat, 14 Sep 2013 23:23:55 -0400 https://reprap.org/forum/read.php?4,239941,245404#msg-245404 Re: Banding problem https://reprap.org/forum/read.php?4,239941,245404#msg-245404
I printed a new endstop by clicking the endstop manually.

I removed the longest threaded rod on the X axis at the bottom of the machine. Inserted it again and redid all the squaring of the machine. I used a caliper and a weight on a string to do this squaring.

I got some suggestions on IRC to print with 0.37 mm extrusion width and 0.2 mm layer height and 174 degress C for PLA.

This is the result:


]]> fractal5 Reprappers Sat, 14 Sep 2013 18:49:28 -0400 https://reprap.org/forum/read.php?4,239941,244596#msg-244596 Re: Banding problem https://reprap.org/forum/read.php?4,239941,244596#msg-244596 fractal5 Reprappers Wed, 11 Sep 2013 18:21:28 -0400 https://reprap.org/forum/read.php?4,239941,244582#msg-244582 Re: Banding problem https://reprap.org/forum/read.php?4,239941,244582#msg-244582 -------------------------------------------------------
> That sucks... crazy glue?

It was a complicated fracture. I printed a new one by just manually clicking the endstop, to my surprise that actually worked on the first attempt.

I'm printing a new 20 mm box now, to see if there are any improvements.]]> fractal5 Reprappers Wed, 11 Sep 2013 17:44:33 -0400 https://reprap.org/forum/read.php?4,239941,244336#msg-244336 Re: Banding problem https://reprap.org/forum/read.php?4,239941,244336#msg-244336 Bruce Reprappers Tue, 10 Sep 2013 19:37:13 -0400 https://reprap.org/forum/read.php?4,239941,244332#msg-244332 Re: Banding problem https://reprap.org/forum/read.php?4,239941,244332#msg-244332 -------------------------------------------------------
> The stuttering and scraping noise is because
> something is binding in the X end. Does that thing
> use tensioning springs for the threaded rods?

I just managed to correct it. Now the bad sound is gone and everything looks very good. I undid the M8 nuts holding the left hand side together at the bottom and moved it around while it was jogging up and down.

Edit: It does not have tensioning springs for the threaded rods. I had that before, but removed them.

However, just as I was about to adjust my Z endstop to print a new 20 mm test box, the printed part for the Z stop broke.]]> fractal5 Reprappers Tue, 10 Sep 2013 19:18:05 -0400 https://reprap.org/forum/read.php?4,239941,244326#msg-244326 Re: Banding problem https://reprap.org/forum/read.php?4,239941,244326#msg-244326 Bruce Reprappers Tue, 10 Sep 2013 18:57:24 -0400 https://reprap.org/forum/read.php?4,239941,244325#msg-244325 Re: Banding problem https://reprap.org/forum/read.php?4,239941,244325#msg-244325 -------------------------------------------------------
>
Quote
I also made another observation. When the
> X carriage assembly is at the top on the Z axis,
> the left hand Z threaded rod points to the left in
> the lower end Z part (where there would usually be
> a bearing). As I lower the X carriage assembly on
> the Z axis, the rod slowly centers
> itself
>
> The Z motor is out of line with the carriage.
>
>
Quote
Is there any guide or tutorial paper that
> would be helpful for me in this current
> situation?
>
> This is for a different machine but it's basically
> the same design, you are welcome to use it if you
> like. Near the bottom of the page it shows how to
> align the threaded rods.
>
> [url=http://forum.eckertech.com/viewtopic.php?f=7&
> t=117]http://forum.eckertech.com/viewtopic.php?f=7
> &t=117[/url]

Okay, that was just a slip on my part. I forgot to level the X carriage. That solved the problem quoted above.

However now the left side of the Z rods is stuttering as it moves down. Is this also related to squaring, or something else? I also have that unwanted sound of "scraping" that seems to come from the Z threaded rod (still left side) scraping against the inside of the X end printed part.]]> fractal5 Reprappers Tue, 10 Sep 2013 18:39:16 -0400 https://reprap.org/forum/read.php?4,239941,244303#msg-244303 Re: Banding problem https://reprap.org/forum/read.php?4,239941,244303#msg-244303
Quote
I also made another observation. When the X carriage assembly is at the top on the Z axis, the left hand Z threaded rod points to the left in the lower end Z part (where there would usually be a bearing). As I lower the X carriage assembly on the Z axis, the rod slowly centers itself

The Z motor is out of line with the carriage.

Quote
Is there any guide or tutorial paper that would be helpful for me in this current situation?

This is for a different machine but it's basically the same design, you are welcome to use it if you like. Near the bottom of the page it shows how to align the threaded rods.

http://forum.eckertech.com/viewtopic.php?f=7&t=117]]> Bruce Reprappers Tue, 10 Sep 2013 17:11:09 -0400 https://reprap.org/forum/read.php?4,239941,244289#msg-244289 Re: Banding problem https://reprap.org/forum/read.php?4,239941,244289#msg-244289
After some more mechanical adjustments (removing rods, inserting them again, trying to square the machine more properly) I noticed that when I lower the X carriage assembly on the Z axis (home) that the right hand side nut pulls itself free from the X end.

I also made another observation. When the X carriage assembly is at the top on the Z axis, the left hand Z threaded rod points to the left in the lower end Z part (where there would usually be a bearing). As I lower the X carriage assembly on the Z axis, the rod slowly centers itself.

What does this indicate mechanically? That the nut and/or the X end printed part are askew? Or that the rod is bent? That the machine is not square? It also makes a slight circle at the bottom.

Is there any guide or tutorial paper that would be helpful for me in this current situation?]]> fractal5 Reprappers Tue, 10 Sep 2013 16:32:58 -0400 https://reprap.org/forum/read.php?4,239941,243997#msg-243997 Re: Banding problem https://reprap.org/forum/read.php?4,239941,243997#msg-243997
Feed rate or e-steps: I have measured this before and got a good measurement, it is accurate. However I have also tried to increase and decrease e_steps while printing, including having printed several boxes with higher and lower e_steps just to see if this makes any noteworthy difference. It doesn't appear to do so.

Bed temperature issues: Printing with the bed on makes it worse. Kapton tape is enough to make it stick, but I get a little warping. I assume this will sort itself out when I get a glass plate or metal plate so there is not so much heat fluctuations.

Hot-end temperature issues: I don't think I agree that this is the way to go, I have tried other temperatures before, it doesn't appear to really affect the underlying problem (the banding) as much as cause other issues.

If I should tweak the temperature any more, what should I do, e.g. what should the expected results be if I increase or lower the temperature? What should I look for specifically?

I feel like I'm fumbling around blindly, doing experiments without knowing what to look for, what to expect; while constantly having a feeling that tweaking just one thing at a time will never on its own solve the problem.

However, it seems to me this is a mechanical problem. Keep in mind that after I retightened the Z couplers, I got that unwanted sound from the X end and the Z threaded rod and my prints looked different. Doesn't this imply some sort of mechanical problem? I'm just having a hard time figuring out what the mechanical problem is. Everything is straight, everything is tightened down properly. There is no play, slack or anything. But still I get this unwanted sound from the left-hand side.

appdev007 Wrote:
-------------------------------------------------------
> Just saying the calculated z step value for my
> machine had to be tweeked. It might be actually
> moving 0.212 mm when you tell it to move 0.200.
>
> Based on newest pics I would look into
> feed/temperature issues.
>
> Good luck.]]> fractal5 Reprappers Mon, 09 Sep 2013 15:28:29 -0400 https://reprap.org/forum/read.php?4,239941,243829#msg-243829 Re: Banding problem https://reprap.org/forum/read.php?4,239941,243829#msg-243829
Based on newest pics I would look into feed/temperature issues.

Good luck.]]> appdev007 Reprappers Mon, 09 Sep 2013 00:52:28 -0400 https://reprap.org/forum/read.php?4,239941,243700#msg-243700 Re: Banding problem https://reprap.org/forum/read.php?4,239941,243700#msg-243700 -------------------------------------------------------
> You might try taking a look at this post about
> z-ribbing on another forum.
>
> [www.printrbottalk.com]
> =20&t=4596
>
> Hope it helps.

Thanks, I am using a layer height that should deal with the Z ribbing problem though, as explained here: [www.evernote.com] See my earlier post for how I arrived at 0.254 mm which I'm using for my current prints.]]> fractal5 Reprappers Sun, 08 Sep 2013 14:05:17 -0400 https://reprap.org/forum/read.php?4,239941,243699#msg-243699 Re: Banding problem https://reprap.org/forum/read.php?4,239941,243699#msg-243699
I have since retightened the Z couplers to the Z rods. I still have the same problem with the sound of the Z threaded rod scraping against the inside of the X end. I have no idea why this suddenly started happening. The rods are not bent.

I removed the Z isolators and adjusted my Z endstop. I now get prints that look like this:

[img834.imageshack.us]
[img541.imageshack.us]

Layer height: 0.254 mm
Extrusion width: 0.4 mm
Extruder temp: 185 degrees C
Bed: 0

So it appears I'm back to my original results now, except that now my Z threaded rod is scraping against the inside of the X end part, even though the rod and the coupler are both straight!

I was given the suggestion I should move to M5 rods instead of 1/4 inch acme. However, this suggestion makes no sense to me. As I understand M5 and M8 rods are manufactured with a lower specification than acme rods, you will almost never get a perfectly straight M5 or M8 rod. So if I bought M5 rods, I would likely end up with even more imperfections in my rods.

appdev007, why do you think I should adjust my z steps?

My z steps:

2015.748031

Which I have arrived at doing the following:

z_steps = (200 * 16) / (25.4 / 16)
z_steps = 2015.748031

In what way should I adjust my z steps?


appdev007 Wrote:
-------------------------------------------------------
> I asked about layer height because it looked like
> your layers weren't smashed together enough. I
> think your Zs being loose could have been causing
> some of this. It might be squashed on the bottom
> now because the tip of the hot end is making
> better contact with the print and now that 190 deg
> is just too much down there for it. Notice how the
> widening shrinks as you go up? That's probably
> your hot end shedding that extra 5 deg.
>
> If you need 190 to get plastic to stick to bare
> glass or something, then consider using some hair
> spray and bring the temp back down to 185 for the
> first layer. I haven't ever needed to set my first
> layer temp higher, but of course, this doesn't
> mean you won't have to.
>
> Still think you might look at adjusting those Z
> steps.
>
> fractal5 Wrote:
> --------------------------------------------------
> -----
> > 0.254 mm layer height.
> > 0.4 mm extrusion width.
> > Same black PLA as before, from MakerGear.
> > 185 degrees C except for 190 degrees C for the
> > first layer.
> > Bed turned completely off.
> > Two fans for cooling.
> >
> > I have printed quite a few boxes with this
> exact
> > same configuration before. The difference is:
> >
> > Retightening the Z couplers. This appears to
> have
> > fixed something, but caused a new
> problem
> > as I mentioned in my above post: The Z threaded
> > rod scrapes along the inside of the X end
> plastic
> > part on the left side now.
> >
> > Also: I'm using Z screw isolators now.
> >
> > I got the suggestion my Z couplers may be bent.
> So
> > I'm going to remove them and see if I can
> figure
> > that out.
> >]]> fractal5 Reprappers Sun, 08 Sep 2013 14:02:51 -0400 https://reprap.org/forum/read.php?4,239941,243643#msg-243643 Re: Banding problem https://reprap.org/forum/read.php?4,239941,243643#msg-243643
If you need 190 to get plastic to stick to bare glass or something, then consider using some hair spray and bring the temp back down to 185 for the first layer. I haven't ever needed to set my first layer temp higher, but of course, this doesn't mean you won't have to.

Still think you might look at adjusting those Z steps.

fractal5 Wrote:
-------------------------------------------------------
> 0.254 mm layer height.
> 0.4 mm extrusion width.
> Same black PLA as before, from MakerGear.
> 185 degrees C except for 190 degrees C for the
> first layer.
> Bed turned completely off.
> Two fans for cooling.
>
> I have printed quite a few boxes with this exact
> same configuration before. The difference is:
>
> Retightening the Z couplers. This appears to have
> fixed something, but caused a new problem
> as I mentioned in my above post: The Z threaded
> rod scrapes along the inside of the X end plastic
> part on the left side now.
>
> Also: I'm using Z screw isolators now.
>
> I got the suggestion my Z couplers may be bent. So
> I'm going to remove them and see if I can figure
> that out.
>]]> appdev007 Reprappers Sun, 08 Sep 2013 10:07:28 -0400 https://reprap.org/forum/read.php?4,239941,243550#msg-243550 Re: Banding problem https://reprap.org/forum/read.php?4,239941,243550#msg-243550
[www.printrbottalk.com]

Hope it helps.]]> KDog Reprappers Sun, 08 Sep 2013 03:24:00 -0400 https://reprap.org/forum/read.php?4,239941,243401#msg-243401 Re: Banding problem https://reprap.org/forum/read.php?4,239941,243401#msg-243401 0.4 mm extrusion width.
Same black PLA as before, from MakerGear.
185 degrees C except for 190 degrees C for the first layer.
Bed turned completely off.
Two fans for cooling.

I have printed quite a few boxes with this exact same configuration before. The difference is:

Retightening the Z couplers. This appears to have fixed something, but caused a new problem as I mentioned in my above post: The Z threaded rod scrapes along the inside of the X end plastic part on the left side now.

Also: I'm using Z screw isolators now.

I got the suggestion my Z couplers may be bent. So I'm going to remove them and see if I can figure that out.

appdev007 Wrote:
-------------------------------------------------------
> Hey, that is a ton better than what you had
> before!
>
> 1. What type of plastic is that?
> 2. What was the hot end temp?
> 3. What was the heat bed temp?
> 4. What layer height was set for that print?
>
> (I'm strongly expecting temperature issues for the
> bottom of the print.)
>
>
> fractal5 Wrote:
> --------------------------------------------------
> -----
> > This is the result:
> >
> >
> [img829.imageshack.us]
> >
> > Notice the thick bottom. I don't know why that
> > happens. There appears to be less banding, but
> is
> > it really gone? Is that what it is supposed to
> > look like?
> >
> > I also haven't gotten rid of that scraping
> sound
> > that started after I retightened my Z couplers
> > (sound from the acme Z threaded rod rubbing
> > against the inside of the hole in the X end
> part,
> > see my post above this one).
> >
> > It would be great if someone could post a
> picture
> > of what a 20 mm calibration box is supposed to
> > look like, for reference.]]> fractal5 Reprappers Sat, 07 Sep 2013 11:57:05 -0400 https://reprap.org/forum/read.php?4,239941,243279#msg-243279 Re: Banding problem https://reprap.org/forum/read.php?4,239941,243279#msg-243279 0.4 mm j-head (hotends.com)
0.2 mm layer height
0.5 mm layer width
Ultimachine blue ABS
230 deg hot end
110 deg heat bed



[www.flickr.com]

Sorry, only PLA I have on hand is clear and it wouldn't have been very good for this purpose.
]]> appdev007 Reprappers Sat, 07 Sep 2013 00:58:04 -0400 https://reprap.org/forum/read.php?4,239941,243274#msg-243274 Re: Banding problem https://reprap.org/forum/read.php?4,239941,243274#msg-243274
1. What type of plastic is that?
2. What was the hot end temp?
3. What was the heat bed temp?
4. What layer height was set for that print?

(I'm strongly expecting temperature issues for the bottom of the print.)


fractal5 Wrote:
-------------------------------------------------------
> This is the result:
>
> [img829.imageshack.us]
>
> Notice the thick bottom. I don't know why that
> happens. There appears to be less banding, but is
> it really gone? Is that what it is supposed to
> look like?
>
> I also haven't gotten rid of that scraping sound
> that started after I retightened my Z couplers
> (sound from the acme Z threaded rod rubbing
> against the inside of the hole in the X end part,
> see my post above this one).
>
> It would be great if someone could post a picture
> of what a 20 mm calibration box is supposed to
> look like, for reference.]]> appdev007 Reprappers Fri, 06 Sep 2013 23:47:29 -0400 https://reprap.org/forum/read.php?4,239941,243272#msg-243272 Re: Banding problem https://reprap.org/forum/read.php?4,239941,243272#msg-243272 appdev007 Reprappers Fri, 06 Sep 2013 23:29:25 -0400 https://reprap.org/forum/read.php?4,239941,243249#msg-243249 Re: Banding problem https://reprap.org/forum/read.php?4,239941,243249#msg-243249 -------------------------------------------------------
> Your box turns out to be significantly taller than
> the standard 20 mm box, and it confirms the same
> problem as before when I print it. Same banding
> problem.
>
> It was pointed out to me that on the last picture,
> the spacing is every 6 layers or so, which is
> 1.524 mm, which is pretty close to my thread
> pitch, which is 1.5875 mm. Hence this may indeed
> be simply traditional Z wobble and nothing more
> fancy than that.
>
> I have tried something new now:
>
> I was given a suggestion that the Z couplers might
> be tightened at an offset, that is at an askew
> angle. So I opened them up, and retightened them
> properly.
>
> Doing this has caused the left side threaded rod
> to scrape against something on the inside of the
> end X printed part. There is a space inside that
> printed part where it is more narrow than the
> rest, I'm assuming that is where it is scraping.
> This suggests the Z couplers was indeed tightened
> at an angle, and this was masking some other
> problem, which I was given the suggestion that
> might be bent Z couplers. As a side note I can
> make the metal-against-plastic scraping sound go
> away by grabbing the left Z motor with my hand
> physically and turning/tilting it slightly to the
> left (my motors are no longer fixed to the plastic
> mounts).
>
> However I simply tried to print with this
> configuration, even though is is scraping.
>
> Same problem. I still get the same banding problem
> with no real difference.
>
> I then added printed Prusa Z isolators:
> [www.thingiverse.com]
> to both sides. I tried to print again. and I got a
> new type of result which is maybe not better, but
> certainly different. I will post a picture when I
> have more time to work on this.
>

This is the result:

[img829.imageshack.us]

Notice the thick bottom. I don't know why that happens. There appears to be less banding, but is it really gone? Is that what it is supposed to look like?

I also haven't gotten rid of that scraping sound that started after I retightened my Z couplers (sound from the acme Z threaded rod rubbing against the inside of the hole in the X end part, see my post above this one).

It would be great if someone could post a picture of what a 20 mm calibration box is supposed to look like, for reference.]]> fractal5 Reprappers Fri, 06 Sep 2013 19:53:38 -0400 https://reprap.org/forum/read.php?4,239941,242997#msg-242997 Re: Banding problem https://reprap.org/forum/read.php?4,239941,242997#msg-242997
It was pointed out to me that on the last picture, the spacing is every 6 layers or so, which is 1.524 mm, which is pretty close to my thread pitch, which is 1.5875 mm. Hence this may indeed be simply traditional Z wobble and nothing more fancy than that.

I have tried something new now:

I was given a suggestion that the Z couplers might be tightened at an offset, that is at an askew angle. So I opened them up, and retightened them properly.

Doing this has caused the left side threaded rod to scrape against something on the inside of the end X printed part. There is a space inside that printed part where it is more narrow than the rest, I'm assuming that is where it is scraping. This suggests the Z couplers was indeed tightened at an angle, and this was masking some other problem, which I was given the suggestion that might be bent Z couplers. As a side note I can make the metal-against-plastic scraping sound go away by grabbing the left Z motor with my hand physically and turning/tilting it slightly to the left (my motors are no longer fixed to the plastic mounts).

However I simply tried to print with this configuration, even though is is scraping.

Same problem. I still get the same banding problem with no real difference.

I then added printed Prusa Z isolators: [www.thingiverse.com] to both sides. I tried to print again. and I got a new type of result which is maybe not better, but certainly different. I will post a picture when I have more time to work on this.

appdev007 Wrote:
-------------------------------------------------------
> No, set in fill to like 25% and let it rip. I made
> that box to have side walls in multiples of 0.4
> and asked you to set that just for the reason you
> were talking about above.
>
> fractal5 Wrote:
> --------------------------------------------------
> -----
> > appdev007 Wrote:
> >
> --------------------------------------------------
>
> > -----
> > > Set your layer height to 0.2 and width over
> > > thickness to 2. I'm going for an extrusion
> > width
> > > of 0.4. Then print this cube. It's in-filled
> on
> > > bottom and hollow on top. If the in-fill is
> > really
> > > the issue, then the bottom should print bad
> and
> > > the top print good right?
> >
> > It appears the object in that file does have
> > infill at half of the height, then the rest
> half
> > is hollow. Did you want me to set the infill to
> 0
> > for this print? Anyway, see my above post.]]> fractal5 Reprappers Thu, 05 Sep 2013 19:40:28 -0400 https://reprap.org/forum/read.php?4,239941,242951#msg-242951 Re: Banding problem https://reprap.org/forum/read.php?4,239941,242951#msg-242951
fractal5 Wrote:
-------------------------------------------------------
> I am printing this cube now.]]> appdev007 Reprappers Thu, 05 Sep 2013 17:12:10 -0400 https://reprap.org/forum/read.php?4,239941,242947#msg-242947 Re: Banding problem https://reprap.org/forum/read.php?4,239941,242947#msg-242947
fractal5 Wrote:
-------------------------------------------------------
> appdev007 Wrote:
> --------------------------------------------------
> -----
> > Set your layer height to 0.2 and width over
> > thickness to 2. I'm going for an extrusion
> width
> > of 0.4. Then print this cube. It's in-filled on
> > bottom and hollow on top. If the in-fill is
> really
> > the issue, then the bottom should print bad and
> > the top print good right?
>
> It appears the object in that file does have
> infill at half of the height, then the rest half
> is hollow. Did you want me to set the infill to 0
> for this print? Anyway, see my above post.]]> appdev007 Reprappers Thu, 05 Sep 2013 16:44:54 -0400 https://reprap.org/forum/read.php?4,239941,242944#msg-242944 Re: Banding problem https://reprap.org/forum/read.php?4,239941,242944#msg-242944 -------------------------------------------------------
> Set your layer height to 0.2 and width over
> thickness to 2. I'm going for an extrusion width
> of 0.4. Then print this cube. It's in-filled on
> bottom and hollow on top. If the in-fill is really
> the issue, then the bottom should print bad and
> the top print good right?

It appears the object in that file does have infill at half of the height, then the rest half is hollow. Did you want me to set the infill to 0 for this print? Anyway, see my above post.]]> fractal5 Reprappers Thu, 05 Sep 2013 16:33:26 -0400 https://reprap.org/forum/read.php?4,239941,242941#msg-242941 Re: Banding problem https://reprap.org/forum/read.php?4,239941,242941#msg-242941 -------------------------------------------------------
> Set your layer height to 0.2 and width over
> thickness to 2. I'm going for an extrusion width
> of 0.4. Then print this cube. It's in-filled on
> bottom and hollow on top. If the in-fill is really
> the issue, then the bottom should print bad and
> the top print good right?

I am printing this cube now.

However, I printed the standard 20 mm calibration box with no infill at all, just to see if it would get as good results as the spiral vase one, which would determine if the infill alone was a major factor.

The infill is not the factor, it appears that the "double" walls on the 20 mm calibration box is a problem though, observe this result:

[img829.imageshack.us]

This is of a hollow 20 mm box, no infill, but the walls are as thick as they should be (the spiral vase walls are only one extrusion width thick).]]> fractal5 Reprappers Thu, 05 Sep 2013 16:23:34 -0400 https://reprap.org/forum/read.php?4,239941,242573#msg-242573 Re: Banding problem https://reprap.org/forum/read.php?4,239941,242573#msg-242573 appdev007 Reprappers Wed, 04 Sep 2013 09:35:29 -0400