Steps per rev for rotation axis

479 views
Skip to first unread message

cncmachineguy

unread,
Dec 23, 2019, 6:19:51 AM12/23/19
to OpenPnP
Building a new head and wondering, those that have direct drive NEMA 8 motor rotation, how many steps per rev do you have it set up for?

Jim

unread,
Dec 23, 2019, 6:48:42 AM12/23/19
to OpenPnP
On Monday, December 23, 2019 at 12:19:51 PM UTC+1, cncmachineguy wrote:
Building a new head and wondering, those that have direct drive NEMA 8 motor rotation, how many steps per rev do you have it set up for?

With smoothieware 8.88889 steps/mm at 1/16, default feed rate 30000 mm/min, 5000 mm/s² acceleration.

Jim

bert shivaan

unread,
Dec 23, 2019, 6:56:30 AM12/23/19
to OpenPnP
Thanks Jim.
So you have 3200 steps per rev correct?
And of course 1 mm ~= 1 deg?

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/openpnp/0156edc5-da0a-4f9b-b719-dc381544f71a%40googlegroups.com.

Jim

unread,
Dec 23, 2019, 7:05:48 AM12/23/19
to OpenPnP
On Monday, December 23, 2019 at 12:56:30 PM UTC+1, cncmachineguy wrote:
Thanks Jim.
So you have 3200 steps per rev correct?
And of course 1 mm ~= 1 deg?

Correct. Have it running at 24V @ 0.4A for a year now.

Mike M.

unread,
Dec 23, 2019, 7:13:10 AM12/23/19
to OpenPnP
@Jim,
I had to go With smoothieware to 17.7777 steps/mm at 1/32 - for all steppers double value - depending on driver ? Where is the magic - what I was doing wrong here?
Mike

Mike M.

unread,
Dec 23, 2019, 7:18:16 AM12/23/19
to OpenPnP
Smoothieboard v1 has been the first released Smoothieboard and has received several updates.
It has gone from an experimental project to a widely used and acclaimed system.

It features :

32-bit Cortex-M3 LPC1769 with 512kB flash and 64kB RAM
3 to 5 A5984 stepper drivers with 1/32 microstepping
.....

Jim

unread,
Dec 23, 2019, 7:24:17 AM12/23/19
to OpenPnP
Hey Mike, i have a bootleg with different drivers and a jumper for 16/32.

Jim

bert shivaan

unread,
Dec 23, 2019, 7:24:27 AM12/23/19
to OpenPnP
Mike that makes sense, 17.7777 @ 1/32 = 8.88885 @ 1/16

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Mike M.

unread,
Dec 23, 2019, 8:25:30 AM12/23/19
to OpenPnP
There is no way to change from 1/32 microstepping on Smoothiware except changing the steeper driver chip on smoothieboard- de-solder / re-solder new one, there is no Jumper to change stepping as well.
So for 1/32 is 17.7777.
Mike

bert shivaan

unread,
Dec 23, 2019, 9:02:54 AM12/23/19
to OpenPnP
makes sense Mike, never had any experience with smoothie so was un aware

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Jim Gmail

unread,
Dec 23, 2019, 10:02:22 AM12/23/19
to ope...@googlegroups.com, Mike M.
Does Smoothie have headers to connect to external drivers, like TinyG does?

--JIm

Mike M.

unread,
Dec 23, 2019, 10:43:27 AM12/23/19
to OpenPnP
Jim - Click here for large view_ http://smoothieware.org/pinout
No Header but ready for it if you wish to use external driver:

Scott Wilson

unread,
Dec 23, 2019, 10:51:41 AM12/23/19
to OpenPnP
Does it have the same microstepping limitation when used with external drivers? I'm actually putting together a new machine with external drivers- I was going to use it with the smoothieboard I bought a while back, but 1/32 microstepping definitely isn't needed, and I imagine slows things down.

Jim

unread,
Dec 23, 2019, 11:21:46 AM12/23/19
to OpenPnP
On Monday, December 23, 2019 at 4:51:41 PM UTC+1, Scott Wilson wrote:
Does it have the same microstepping limitation when used with external drivers? I'm actually putting together a new machine with external drivers- I was going to use it with the smoothieboard I bought a while back, but 1/32 microstepping definitely isn't needed, and I imagine slows things down.

Hi Scott, no there is no limitation when using external drivers, except the max. pulse rate is limited (~ 100 kHz).

Jim
 

Mike M.

unread,
Dec 23, 2019, 11:47:58 AM12/23/19
to OpenPnP
@Jim - on Smoothiware you have  "a bootleg with different drivers and a jumper for 16/32".  Can you explain a bit more - I do not understand!?
Thanks Jim
Mike

Jim Gmail

unread,
Dec 23, 2019, 2:13:06 PM12/23/19
to ope...@googlegroups.com, Mike M.

Thanks!

--
You received this message because you are subscribed to the Google Groups "OpenPnP" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openpnp+u...@googlegroups.com.

Jim

unread,
Dec 23, 2019, 7:46:19 PM12/23/19
to OpenPnP
On Monday, December 23, 2019 at 5:47:58 PM UTC+1, Mike M. wrote:
@Jim - on Smoothiware you have  "a bootleg with different drivers and a jumper for 16/32".  Can you explain a bit more - I do not understand!?

At the board (see schematics page 4) jumper J3 goes to M0 of onboard DRV8825 (look table on page 13) to select 16 or 32 microsteps.

Mike M.

unread,
Dec 24, 2019, 3:42:33 AM12/24/19
to OpenPnP
 Original Smoothiware is using A5984 stepper drivers and there is no such jumper ... you are on

MKS-SBASE


Mike M.

unread,
Dec 24, 2019, 3:45:31 AM12/24/19
to OpenPnP
But I see a good solution in Nanotec

Sensorless Control of Stepper Motors

Closed-loop stepper motors as an alternative to BLDC motors
Much cheaper than servos and no additional cables needed to acheeve higher speeds

Mike M.

unread,
Dec 24, 2019, 3:57:21 AM12/24/19
to OpenPnP

Jim

unread,
Dec 24, 2019, 5:56:42 AM12/24/19
to OpenPnP

On Tuesday, December 24, 2019 at 9:42:33 AM UTC+1, Mike M. wrote:
 Original Smoothiware is using A5984 stepper drivers and there is no such jumper ... you are on

Mike, thought smoothieware is firmware, smoothie or smoothieboard is hardware, i have a bootleg (do not wanna tell vendor name again).
And there are a lot of smoothieware compatible boards out there, some are excellent, some are bad - i have one of the worst.

 

Airhead Bit

unread,
Dec 24, 2019, 7:04:54 PM12/24/19
to OpenPnP
I just received my (to self) Xmas gift, the latest version of a clone that supports TMC5161 modules without wires, $19.95, the driver modules, almost as much as the board for one module!. Check  out the size next to  my pet Smoothieboard
20191224_153356.jpg

Airhead Bit

unread,
Dec 25, 2019, 3:39:21 PM12/25/19
to OpenPnP
That was a short lived thrill, they now have a SKR-1.4 Turbo with LPC1769 replacing the LPC1768 of the SKR-1.4 The Marlin 2.x code with VSCode and PlatformIO is sweet, compiled first try without errors. TMC5161 X,Y and TMC2130 Z,C SPI support. I don't know if they have optimized Marlin for TMCxxxx, removed the ramps, I do wonder if a P&P version with no curve fitting, ramps is possible.

John deGlavina

unread,
Dec 27, 2019, 10:58:20 AM12/27/19
to OpenPnP
I have the SKR 1.4 in my 3d printer running Marlin 2. Crazy that they pump these things out for $20. 

John deGlavina

unread,
Dec 27, 2019, 11:01:14 AM12/27/19
to OpenPnP
This is my config on my original Smoothieboard with 1/32 microstepping:

extruder.hotend.enable                       true             # Whether to activate the extruder module at all. All configuration is ignored if false
extruder
.hotend.steps_per_mm                 17.77           # Steps per mm for extruder stepper
extruder
.hotend.default_feed_rate            60000            # Default rate ( mm/minute ) for moves where only the extruder moves
extruder
.hotend.acceleration                 6000             # Acceleration for the stepper motor, as of 0.6, arbitrary ratio
extruder
.hotend.max_speed                    360              # mm/s
extruder
.hotend.step_pin                     2.3              # Pin for extruder step signal
extruder
.hotend.dir_pin                      0.22             # Pin for extruder dir signal
extruder
.hotend.en_pin                       0.21             # Pin for extruder enable signal
delta_current                                
0.4              # First extruder stepper motor current


extruder
.hotend2.enable                      true             # Whether to activate the extruder module at all. All configuration is ignored if false
extruder
.hotend2.steps_per_mm                17.77           # Steps per mm for extruder stepper
extruder
.hotend2.default_feed_rate           60000            # Default rate ( mm/minute ) for moves where only the extruder moves
extruder
.hotend2.acceleration                6000             # Acceleration for the stepper motor, as of 0.6, arbitrary ratio
extruder
.hotend2.max_speed                   360             # mm/s
extruder
.hotend2.step_pin                    2.8              # Pin for extruder step signal
extruder
.hotend2.dir_pin                     2.13            # Pin for extruder dir signal
extruder
.hotend2.en_pin                      4.29             # Pin for extruder enable signal
epsilon_current                              
0.4              # Second extruder stepper motor current
Reply all
Reply to author
Forward
0 new messages