X-carve linux cnc upgrade tuning

andypugh wrote:

mrbishop wrote:

so the pulse is every time the count increments.

That's the stepper stepping. The only way to reduce that is in the hardware, specifically by increasing the microstep ratio.

(You need to tell LinuxCNC that you have done that, either by manually editing SCALE or changing the settings in the config wizard.

My microstep setting is at 8 what do you recommend

Going from memory I think it moves about 130 steps per inch.
i got that number from the hal that you told me about.

andypugh wrote:

Does the lurch frequency you hear correlate with the feed-rate at that number?

It appears to. This behavior is in stsrk contrast to the arduino solution I'm coming from which its why I'm so alarmed by it. And also why I'm assuming it can be fixed or solved.

i understand i'm using more amps now and this is an entirely different beast by comparison.

Did you also upgrade the motors? Are your amps settings appropriate for the motors? Have you tried reducing amps?
You could try 16 micro steps.
It is interesting that the second review of the drivers complains of jerky movement.

Rick G

Rick wrote:

i understand i'm using more amps now and this is an entirely different beast by comparison.

Did you also upgrade the motors? Are your amps settings appropriate for the motors? Have you tried reducing amps?
You could try 16 micro steps.
It is interesting that the second review of the drivers complains of jerky movement.

Rick G

perhaps i described it poorly. the movement is a start stop which causes a loud noise at ever step and makes the machine start and stop with each pulse or step.

i will try to increase the microsteps and reduce the amps tonight

also these are Nema 23's 4 wire i can't remember the weight but they are on the smaller size. my understanding is that they will hold the 3 amps but to your point the arduino never pushed anything near that powerful.

Seems to me that you don't have enough steps per inch. As it is right now if you are moving at 0.5 ipm (slow move) then linuxcnc will send a step pulse about once a second so you would definitely see start stop operation. It would move about 0.01" each second with an abrupt 0.01" step each second. This would get even worse at slower speeds.

I prefer to have my machines set up so that I get about 0.001" per step even if that means I need higher microstepping. In your case I would increase the gear ratio from the motors or the microstepping or both as required/applicable. I know that I don't actually get 0.001" resolution by increasing the microstepping but it does help with start stop jumps as you are describing.