Layer Consistancy The left is from my printer with a .35 nozzle( few months ago). It had very good layering, [Besides Z wobble]... But it was smooth. The one on the left is recent [last night]> My printer no has a .25 nozzle. Z wobble is not what im asking, I will fix that. But why are the layers now inconsistent? Please help. My filament is ultimachine so its good. My hobbed bolt is clean and round. -Nick https://reprap.org/forum/read.php?1,185391,185391#msg-185391 Mon, 20 Jul 2026 02:48:56 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,185391,189968#msg-189968 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189968#msg-189968 jamesdanielv General Tue, 05 Mar 2013 20:38:17 -0500 https://reprap.org/forum/read.php?1,185391,189882#msg-189882 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189882#msg-189882
But yeah, I was kinda shocked at the difference. Maybe I had chosen the exact wrong layer height. Who knows. But I've since moved to a true full-step layer height and prints are looking even better.]]> akhlut General Tue, 05 Mar 2013 14:53:32 -0500 https://reprap.org/forum/read.php?1,185391,189865#msg-189865 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189865#msg-189865
A change that small made that much difference. Interesting.]]> Dale Dunn General Tue, 05 Mar 2013 13:49:46 -0500 https://reprap.org/forum/read.php?1,185391,189819#msg-189819 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189819#msg-189819
no changes to temp. PID control of both hotend and heated bed. Also, heated bed has nylon standoffs to help decouple it from the leveling screws beneath. Typical procedure is to heat bed to 110 for 5min to allow it to stabilize in Z, then start printing.

Also, I want to thank you for your X-Z decouplers! I've gone and redesigned them to fit my machine, but they're a lifesaver!]]> akhlut General Tue, 05 Mar 2013 11:25:37 -0500 https://reprap.org/forum/read.php?1,185391,189813#msg-189813 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189813#msg-189813 -------------------------------------------------------
> OK.
>
> I changed the Z-steps in firmware from
> 2035.5809493712193 to 2035.6
>
> 2 prints
>
> Same Gcode
>
> No mechanical changes, 1/4" ACME screws
>
> Same plastic
>
> I think the image below speaks for itself.
>
> [i.imgur.com]

If you had asked me what changed between those two prints, I would have guessed that you got your temperatures under control. Any chance you tuned your extruder's PID between those two prints, or made any other changes? That doesn't look like the results of a change of 0.002%.]]> Dale Dunn General Tue, 05 Mar 2013 11:04:28 -0500 https://reprap.org/forum/read.php?1,185391,189805#msg-189805 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189805#msg-189805 jamesdanielv General Tue, 05 Mar 2013 10:25:16 -0500 https://reprap.org/forum/read.php?1,185391,189559#msg-189559 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189559#msg-189559
There are a few sub-millimeter "bumps"... theyre are like blobs, but nearly invisible... any ideas?

Will post pictures if I get a chance.


-Nick]]> N314 General Mon, 04 Mar 2013 13:20:34 -0500 https://reprap.org/forum/read.php?1,185391,189506#msg-189506 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189506#msg-189506
Seems reasonable. :)

Going to print out new X-ends when I get a chance.]]> akhlut General Mon, 04 Mar 2013 10:11:31 -0500 https://reprap.org/forum/read.php?1,185391,189369#msg-189369 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189369#msg-189369

-Nick]]> N314 General Sun, 03 Mar 2013 22:03:39 -0500 https://reprap.org/forum/read.php?1,185391,189339#msg-189339 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189339#msg-189339
I use a similar z-axis wobble elimination method on an Ord Bot Hadron. I was actually going to try changing my z steps to try to reproduce your result tomorrow.

I agree that your z axis design should virtually eliminate z wobble as long as the z threaded rods are not making contact with the x carriage at any point aside from the z nuts. If they can make contact, then you can still get z wobble. Thus, with this set-up, it's best to use a z couplers that are rigid. Those flexible couples can result in the rods making contact with the x end.

Just to add to the mix, here's how I set my steps per mm in my Prusa2 that uses 5/16" rods:

#define DEFAULT_AXIS_STEPS_PER_UNIT {80, 80, 3200/25.4*18,98.3*25/24.15*50/35.18}

The z steps per mm is being calculated by the compiler and definitely has more than 2 decimal places. With this, I get perfectly lined up walls as long as z wobble is not in effect: [www.flickr.com]

I went ahead and did a quick test at different z steps per mm. Left: 2267.72, Middle: 2267.71654, Right: 3200/25.4*18. No difference.


]]> brnrd General Sun, 03 Mar 2013 19:16:45 -0500 https://reprap.org/forum/read.php?1,185391,189318#msg-189318 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189318#msg-189318

this firmware issue is still being looked into. I would guess that debugging the output and showing difference in steps would be the absolute proof it is also happening from some sort of internal error in the hardware.]]> jamesdanielv General Sun, 03 Mar 2013 17:31:05 -0500 https://reprap.org/forum/read.php?1,185391,189311#msg-189311 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189311#msg-189311 Greg Frost General Sun, 03 Mar 2013 17:07:12 -0500 https://reprap.org/forum/read.php?1,185391,189243#msg-189243 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189243#msg-189243 akhlut General Sun, 03 Mar 2013 13:04:34 -0500 https://reprap.org/forum/read.php?1,185391,189209#msg-189209 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189209#msg-189209
Im still suffering Z wobble, ive tried many things to fix it. How havy you guys tackled it?


-Nick]]> N314 General Sun, 03 Mar 2013 11:12:48 -0500 https://reprap.org/forum/read.php?1,185391,189058#msg-189058 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189058#msg-189058
Also, I think that Z-wobble is pretty improbable. I've got 10mm chromed smooth rods on Z with sintered bronze bushings,which provides a nice, snug fit. Add to that the drive screw is as unconstrained as possible from the X-end as there is a decoupler with a pair of teflon washers between it and the X-end.

image

I've also changed out the coupling to something like this, which works very well.

But I find it incredibly un-likely since the "wobble" has disappeared since the change to firmware...not to say that it won't re-appear, it just hasn't yet.]]> akhlut General Sun, 03 Mar 2013 01:29:43 -0500 https://reprap.org/forum/read.php?1,185391,189032#msg-189032 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189032#msg-189032 -------------------------------------------------------
> OK.
>
> I changed the Z-steps in firmware from
> 2035.5809493712193 to 2035.6
>
> 2 prints
>
> Same Gcode
>
> No mechanical changes, 1/4" ACME screws
>
> Same plastic
>
> I think the image below speaks for itself.
>
> [i.imgur.com]

Z wobble. The problem with this test is that z wobble comes and go. So, the difference probably has nothing to do with the change in z steps per mm.]]> brnrd General Sat, 02 Mar 2013 20:26:22 -0500 https://reprap.org/forum/read.php?1,185391,189029#msg-189029 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189029#msg-189029 akhlut General Sat, 02 Mar 2013 19:58:43 -0500 https://reprap.org/forum/read.php?1,185391,189014#msg-189014 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189014#msg-189014 miso General Sat, 02 Mar 2013 17:42:52 -0500 https://reprap.org/forum/read.php?1,185391,189002#msg-189002 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,189002#msg-189002 jamesdanielv General Sat, 02 Mar 2013 16:28:52 -0500 https://reprap.org/forum/read.php?1,185391,188928#msg-188928 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,188928#msg-188928
Silver part printed @ 927.19
Red part printed @ 927.1899669966999

Personally I think the silver part looks worse.]]> akhlut General Sat, 02 Mar 2013 10:37:33 -0500 https://reprap.org/forum/read.php?1,185391,188849#msg-188849 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,188849#msg-188849
I would have guessed the same thing ~ 2016 steps/mm, but I guess they're not perfect. After all, they're cheap screws from mcmaster. And I haven't done a teardown of the machine to justify upgrading to 10mm trapezoidal screws - after all that would mean new x-ends, etc. Just have other stuff going on that I can't justify it.

As far as layer heights are concerned I'm using 0.1905mm - I realize that is outside the bounds that slic3r is capable of (1000ths), but it was either accept that level of imprecision or step up to 0.254mm layers. I'm trying to hit full-step layer heights.

Also, 400 step motors @ 1/8th, not that this should matter.

I attached the calculator spreadsheet I made/used.]]> akhlut General Sat, 02 Mar 2013 01:37:05 -0500 https://reprap.org/forum/read.php?1,185391,188835#msg-188835 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,188835#msg-188835
I'll post a photo of the difference when complete - tomorrow morning. :)]]> akhlut General Fri, 01 Mar 2013 23:56:23 -0500 https://reprap.org/forum/read.php?1,185391,188834#msg-188834 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,188834#msg-188834
I'd have guessed that 1/4-16 threads would need 2015.748 microsteps/mm, (or maybe 2016.0 steps/mm for 1/4-16.002 threads)

What layer height are your using?

2035.6 microsteps/mm * 0.1mm = 203.56 microsteps/layer
2035.5809493712193 microsteps/mm * 0.1mm = 203.55809 microsteps/layer

Seems like it would take 25 layers or so to stack up a rounding difference worth a microstep.]]> DaveX General Fri, 01 Mar 2013 23:52:25 -0500 https://reprap.org/forum/read.php?1,185391,188828#msg-188828 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,188828#msg-188828
I think the issue may be with how iround is used to convert number in the firmware, and the way it is done exponentially increases the error before rounding. Investigation continues.]]> jamesdanielv General Fri, 01 Mar 2013 23:24:42 -0500 https://reprap.org/forum/read.php?1,185391,188826#msg-188826 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,188826#msg-188826 akhlut General Fri, 01 Mar 2013 23:07:07 -0500 https://reprap.org/forum/read.php?1,185391,188823#msg-188823 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,188823#msg-188823 -------------------------------------------------------
> OK.
>
> I changed the Z-steps in firmware from
> 2035.5809493712193 to 2035.6
>
> 2 prints
>
> Same Gcode
>
> No mechanical changes, 1/4" ACME screws
>
> Same plastic
>
> I think the image below speaks for itself.
>
> [i.imgur.com]

no shit? wow.. So one or two decimal places for z-steps. What about x,y, same thing?]]> xclusive585 General Fri, 01 Mar 2013 23:01:12 -0500 https://reprap.org/forum/read.php?1,185391,188820#msg-188820 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,188820#msg-188820
I changed the Z-steps in firmware from 2035.5809493712193 to 2035.6

2 prints

Same Gcode

No mechanical changes, 1/4" ACME screws

Same plastic

I think the image below speaks for itself.

[i.imgur.com]]]> akhlut General Fri, 01 Mar 2013 22:19:32 -0500 https://reprap.org/forum/read.php?1,185391,188812#msg-188812 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,188812#msg-188812 brnrd General Fri, 01 Mar 2013 20:38:20 -0500 https://reprap.org/forum/read.php?1,185391,188691#msg-188691 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,188691#msg-188691
0.000390625 becomes
3.90625005820766091346740722656E-4 float

[www.binaryconvert.com]?]]> jamesdanielv General Fri, 01 Mar 2013 10:01:32 -0500 https://reprap.org/forum/read.php?1,185391,188683#msg-188683 Re: Layer Consistancy https://reprap.org/forum/read.php?1,185391,188683#msg-188683 brnrd General Fri, 01 Mar 2013 09:35:28 -0500