2200 steps_per_mm and locking up

Controllers Smoothie
1

Acme screws /having trouble with the stepper locking up

I’m experimenting with a 3/8 20 Acme screws with steps per mm at 2200. I’m having trouble as the motors goes into lock up and the only solution so far I have found is by decreasing the acceleration down to 10 ,even with this change during the print the motor will randomly lock up.

(acceleration 10 # Acceleration in mm/second/second.)

but this affects the overall speed. Has anyone else had any experience with fine pitch Acme screws?

Imported from wikidot

2

Can you reduce junction_deviation ?

3

Arthur thanks for the help
I did lower the junction deviation ,but lowering the acceleration seem to help more. But as you can see from the settings the machine is very sluggish now. Can you suggest some settings to start off with for
acceleration set at 3
Z acceleration set at 3

junction deviation IS SET AT 0.005
Z junction deviation IS SET AT 0.0

4

3 is way too low for acceleration, try something like 20, then go up by multiplying by 10 until it stops working.

5

Still having the same problem, it must have something to do with jerk or acceleration. I can print out a circular vase with no problems, but if I put sharp corners in the vase I have the same problem again and the print will skip. It seems like if I decrease the overall speed to a snails pace it works but as soon as I pick up the overall speed the problem comes up again?

planner_queue_size 32 # DO NOT CHANGE THIS UNLESS YOU KNOW EXACTLY WHAT YOU ARE DOING

acceleration 100 # Acceleration in mm/second/second. was500

#z_acceleration 500 # Acceleration for Z only moves in mm/s^2, 0 uses acceleration which is the default. DO NOT SET ON A DELTA

acceleration_ticks_per_second 1000 # Number of times per second the speed is updated was 1000

junction_deviation 0.02 # Similar to the old “max_jerk”, in millimeters,

# Lower values mean being more careful, higher values means being

# faster and have more jerk

#z_junction_deviation 0.0 # for Z only moves, -1 uses junction_deviation, zero disables junction_deviation on z moves DO NOT SET ON A DELTA

#minimum_planner_speed 0.0 # sets the minimum planner speed in mm/sec

  1. Stepper module configuration

microseconds_per_step_pulse 1 # Duration of step pulses to stepper drivers, in microseconds

base_stepping_frequency 100000 # Base frequency for stepping, higher gives smoother movementwas 100000

  1. Cartesian axis speed limits

x_axis_max_speed 400 # mm/min

y_axis_max_speed 400 # mm/min

z_axis_max_speed 250 # mm/min

6

one more piece of information ,the problem occurs when I adjust the speed above 300.

x_axis_max_speed 300 # mm/min

y_axis_max_speed 300 # mm/min

At 250 it doesn’t happen but if I raise at the 350 it starts to skip

7

If you are using leadscrews, what you are seeing could actually be resonance, which is a very common problem on CNC mills for example.

I believe common solutions include increased acceleration ( to skip the problematic speed range ), increased weight on the rotational axis ( flywheel ), or increased acceleration ( which changes the resonnant frequency )