optimal layer vs steps/mm? I'm sorry if this is a duplicate post, but I've been wondering about this thing for quite a while now. Prusa mk2 uses tr8*8 acme, while one of my printer uses the same acme screws; has 8mm lead per revolution. The setting of steps/mm in the firmware config should be at 400 steps. I checked the prusa calculator for optimal z layer height it only requires 25 steps to have a full mm travel. the optimal layer height for 8mm lead acme screw is a multiplication of 40 microns. However, prusa mk2 able to go with a multiplication of about 25 or 50 microns. If I were to take the number of steps from the config which is 400 steps/mm, to get 0.1mm should be at 40 steps while at 0.05 at 20 steps and lastly 0.025 at 10 steps. Currently I'm using a 1/16th stepper driver. I'm thinking that something is odd here especially on the firmware configuration or was it that the steps/mm in the configuration is only required to generate a full steps which is 1.8 degree turn? Now I'm confused My question was, if my optimal layer height should be a multiplication of 40microns, can I go to a multiplication of 25microns? https://reprap.org/forum/read.php?1,741639,741639#msg-741639 Sat, 13 Jun 2026 10:45:15 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,741639,741969#msg-741969 Re: optimal layer vs steps/mm? https://reprap.org/forum/read.php?1,741639,741969#msg-741969 DjDemonD General Wed, 25 Jan 2017 03:42:53 -0500 https://reprap.org/forum/read.php?1,741639,741944#msg-741944 Re: optimal layer vs steps/mm? https://reprap.org/forum/read.php?1,741639,741944#msg-741944 A degree of freedom, we don't want to see. I helped myself with a 4.5mm steel ball inserted in the coupler. Now the stepper shaft and the lead screw have no vertical play, but the coupler can still do it's job.]]> o_lampe General Wed, 25 Jan 2017 02:03:27 -0500 https://reprap.org/forum/read.php?1,741639,741940#msg-741940 Re: optimal layer vs steps/mm? https://reprap.org/forum/read.php?1,741639,741940#msg-741940
Quote
JamesK
I wonder how much the full steps wisdom applies if you use a single stepper and don't let it turn off during the print.

I think it depends on the pitch of the leadscrew. Usually switching off z steppers will not drop the X-carrier and the driver knows, what was the last microstep position and counts on from there. ( I hope :S ) The steppers will follow and jump to the position they had have before.]]> o_lampe General Wed, 25 Jan 2017 01:54:19 -0500 https://reprap.org/forum/read.php?1,741639,741841#msg-741841 Re: optimal layer vs steps/mm? https://reprap.org/forum/read.php?1,741639,741841#msg-741841 DjDemonD General Tue, 24 Jan 2017 14:34:07 -0500 https://reprap.org/forum/read.php?1,741639,741823#msg-741823 Re: optimal layer vs steps/mm? https://reprap.org/forum/read.php?1,741639,741823#msg-741823 JamesK General Tue, 24 Jan 2017 13:52:44 -0500 https://reprap.org/forum/read.php?1,741639,741822#msg-741822 Re: optimal layer vs steps/mm? https://reprap.org/forum/read.php?1,741639,741822#msg-741822
Say, you home the printer and unfortunately the Z steppers zero at the worst point between full steps. Now you print with a layer height that is a multiple of the 40 microns. Does it mean, the stepper will stay at this worst position , or will it vary layer height up/down randomly?
In other words: does it make sense to chose layer height, based on the 40 microns when you don't know the starting point?

It would probably make sense to home the printer in full step config, then you'd know your starting point and use microstepping later to make it run quiet.]]> o_lampe General Tue, 24 Jan 2017 13:49:57 -0500 https://reprap.org/forum/read.php?1,741639,741711#msg-741711 Re: optimal layer vs steps/mm? https://reprap.org/forum/read.php?1,741639,741711#msg-741711
However the two motors still come to a stop when powered off on full steps and one motor can go in one direction and the other motor the other direction, hence they can become 1 step out of balance at each power off. Before I decommissioned my i3 I was in the process of using a closed loop belt and pulleys at the top of the two leadscrews to tie them together and see if I could run them both from one motor at the bottom. I was going to use a pillow bearing at the base of the non-motor side.]]> DjDemonD General Tue, 24 Jan 2017 05:47:51 -0500 https://reprap.org/forum/read.php?1,741639,741709#msg-741709 Re: optimal layer vs steps/mm? https://reprap.org/forum/read.php?1,741639,741709#msg-741709
The first rule of steppers is they can really only do 1/4 steps, when you select something higher it wont actually move every step. But it does result in quieter moves
(Some steppers will attempt 1/8 positions, but the positions will not be uniformly distributed)

Eg In general if you have 1/8th micro stepping

position, action
1 doesnt move
2 moves to 2/8 position
3 doesnt move
4 moves to 4/8 position
5 doesnt move
6 moves to 6/8 position
7 doesn’t move
8 moves to 8/8 position.]]> Dust General Tue, 24 Jan 2017 05:42:10 -0500 https://reprap.org/forum/read.php?1,741639,741697#msg-741697 Re: optimal layer vs steps/mm? https://reprap.org/forum/read.php?1,741639,741697#msg-741697 sarf2k4 General Tue, 24 Jan 2017 04:56:45 -0500 https://reprap.org/forum/read.php?1,741639,741693#msg-741693 Re: optimal layer vs steps/mm? https://reprap.org/forum/read.php?1,741639,741693#msg-741693
So you can use 0.04, 0.08, 0.12, 0.16, 0.20, 0.24, 0.28, 0.32, 0.36mm layer heights with a 0.4mm nozzle. That's a fair range of options. Can you use 25micron multiples, yes but you might get less than ideal prints if you have twin screws and twin motors which might go out of sync when they stop between full steps.

Why not try 0.9 deg motors then you get 20 micron multiples which gives you a wider range of optimal layer heights.

I used to have an i3 rework with tr8 leadscrews and I was quite surprised at the 8mm/rev pitch, surely designed more with a CNC axis in mind for slightly faster travel, a 2mm pitch leadscrew must make more sense for a z axis, gear it down increase resolution. Increase accuracy, not unless those leadscrews are very well made.]]> DjDemonD General Tue, 24 Jan 2017 04:45:32 -0500 https://reprap.org/forum/read.php?1,741639,741639#msg-741639 optimal layer vs steps/mm? https://reprap.org/forum/read.php?1,741639,741639#msg-741639
The setting of steps/mm in the firmware config should be at 400 steps.

I checked the prusa calculator for optimal z layer height it only requires 25 steps to have a full mm travel.

the optimal layer height for 8mm lead acme screw is a multiplication of 40 microns. However, prusa mk2 able to go with a multiplication of about 25 or 50 microns.

If I were to take the number of steps from the config which is 400 steps/mm, to get 0.1mm should be at 40 steps while at 0.05 at 20 steps and lastly 0.025 at 10 steps.

Currently I'm using a 1/16th stepper driver.

I'm thinking that something is odd here especially on the firmware configuration or was it that the steps/mm in the configuration is only required to generate a full steps which is 1.8 degree turn?

Now I'm confused

My question was, if my optimal layer height should be a multiplication of 40microns, can I go to a multiplication of 25microns?]]> sarf2k4 General Tue, 24 Jan 2017 00:40:04 -0500