NEMA 23, weird velocity results.. need help

Now would be a good time to assemble the machine and test to see if your SCALE is correct.
At a slow speed (that does make any strange noises or stalls) try to make say a 1" or 2" move and measure how far the machine actually moves.
If incorrect adjust your SCALE to correct. If your SCALE is wrong your velocity results will also be incorrect.

Rick G

Tried at diffrrent velocity and uStep.

I get same speed for some reason around 6000hz.
Any higher it stalls.

Measuring the voltage while running come up somewhere around

10~14v


Attching a 15 thread per inch leadscrew for references.
Not sure if I should get a lesser tpi for use?

But still the motor stalls if I have velocity over 15mm/s or 6000hz now.

Will attach my hal and ini file in abit.

HAL & INI are here

CNC-0110.hal & .ini are the files that I use previously

CNC-3500.hal & .ini are the files that I use this morning for tests.

the values here are the max I can get to while running, and higher will stall the motor..
however, if the motor is on my hand, and not attached to the machine..
it will run almost at any given speed..


kindly advice

Have you tried reducing your acceleration to say 300 or less ?
Have you checked your SCALE?

Rick G

Yup, used 20mm/s2 as well, it would turn like a few rounds before jamming.

MAX_VELOCITY = 15.0
MAX_ACCELERATION = 750.0
STEPGEN_MAXACCEL = 937.5
SCALE = 157.480314961

these are way too high change your max acceleration to lets say 20
why are you trying to run at absolute max ?
how did you arrive at the scale value ?

also what power supply voltage and current are you using for your stepper drives ? idealy you need around 48v @10amp

if the motors are stalling whilst in your hand only then it is just a matter of reducing the accelleration and velocity settings
you are essencially trying to send pulses faster than the motor can handle

in your hal file change

stepspace to 0
dirhold 35000
dirsetup 35000

36v & 10a for power supply.
Absolute max because I cut polyfoam and for my production needs.

So gaining any speed is good progress to me

No idea regarding scale. Or how it got that number?
Will need your help here.

The motor stalls after I tightened the screw on the motor mounting plate to the machine frame.
It works and can run to 340mm/s on my hand.

Hope this helps.
Will try to run what you suggest for
Stepspace 0
Dirhold 35000
Dirsetup 35000

ok lets go back to the beginning ,
what are you cutting out of polyfoam ? , what type of cutter etc milling cutter or hotwire ?
increasing the voltage will give you more speed , up to the max input voltage of the Stepper drives ,
i think you said your using 542's which can go to 50v , i use mine at 48v and the larger drivers at 68v

i presume your using trapizodial threaded rod and delrin nuts
using steppers and a parrell port can be slow , you would be better with a mesa 5i25 which removes the parrell port speed limitations
lesser tpi will give you faster speed , or even look at gearing is another option , it all depends on the weight of your moving axis and torque requirements
if the machine is heavy ..

make the changes iv'e pointed out and attach your current files and i'll take a look further.

information on your machine or a few pictures helps too ,

ok lets go back to the beginning ,
what are you cutting out of polyfoam ? , what type of cutter etc milling cutter or hotwire ?
increasing the voltage will give you more speed , up to the max input voltage of the Stepper drives ,
i think you said your using 542's which can go to 50v , i use mine at 48v and the larger drivers at 68v

i presume your using trapizodial threaded rod and delrin nuts
using steppers and a parrell port can be slow , you would be better with a mesa 5i25 which removes the parrell port speed limitations
lesser tpi will give you faster speed , or even look at gearing is another option , it all depends on the weight of your moving axis and torque requirements
if the machine is heavy ..

make the changes iv'e pointed out and attach your current files and i'll take a look further.

information on your machine or a few pictures helps too ,

but remember the faster the speed , the less torque you have available, and again high microstepping can and does affect torque
so it's a question of trade off , to whats required

No idea regarding scale. Or how it got that number?

SCALE is the number of steps for the machine to move 1 unit of measurement.
A stepper motor on full step will turn 1 revolution with 200 steps. If directly connected to a 5 tpi threaded rod at full step it would take 1000 steps ( 5X200) to move one inch.
If your SCALE is wrong the velocity you think your machine is moving at is also wrong.
Set your velocity and acceleration extremely slow and measure how far your machine actually moves when commanded.
Stepper motors have a limited usable rpm range. I think you said you were using a 15tpi threaded rod, as Dave said if your motors have enough torque less tpi would result in faster movement.

Rick G