If a stepper starts loosing steps in the middle of a print with nothing

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(Jeremy Wasserstrass) #1

If a stepper starts loosing steps in the middle of a print with nothing to catch on is it more likely the stepper driver or the ramps board? And yes I checked to make sure nothing is binding.

(Whosawhatsis) #2

If it really isn’t binding or catching on something, it could be that the stepper driver is overheating.

(Duncan Gunn) #3

When the stepper driver overheats it shuts down to protect itself. OTOH, I had a problem a little while ago where I’d made a poor choice of connector and kept loosing steps and killing drivers too.

Check your current settings.

(Greg Copeland) #4

Under voltage can also be an issue. Should confirm the voltage setting for the drivers.

(Eduardo Schoenknecht) #5

If wen’t through all traditional causes (low current, driver overheating, mechanical drag(misalignment, broken bearings, bushings, no lube)). Than, consider some boards have layout problems, like the RUMBA, which have a problematic Y axis. You can solve that by remapping, fiscally and in firmware the problematic axis to another available driver, like E1, or E2.
-Edit. didn’t see it was a RAMPS, so probably is one of the traditional causes

(Duncan Gunn) #6

Another point of note: Cheaper RAMPS board kits with can have issues with all those excess connections not making very well. Nobody would build a sword out of lego because it’d fall apart on the first swing so why do we stack so many boards?

(Jeremy Wasserstrass) #7

Thanks guys. That drive has been in service for about a year. Since I had a drive I swapped it out, and of course like an idiot I didn’t look up the best way to set the v-ref(with the meter leads clamped to ground and the screwdriver) so I now have a ramps and arduino that have a problem. Any thoughts on what let go of it’s smoke?

(Duncan Gunn) #8

It’s possible to damage these little drivers by adjusting them with the motor energized. I learnt this the hard way. :boom:

(Jeremy Wasserstrass) #9

Ok this is frustrating. I have literally changed everything out, Ramps board drivers, and even went to a Re-arm instead of the Arduino. And my problem still shows up. And what is really frustrating is that when the axis is not buzzing and missing steps I can put my finger against the carriage am the whole printer will move without missing a step.

(Jeremy Wasserstrass) #10

So does anyone have any ideas as to what the issue could be?

(Duncan Gunn) #11

Now we’re in the weeds on this one, any more clues?

(Eduardo Schoenknecht) #12

Printing speed and acceleration?

(Jeremy Wasserstrass) #13

#define DEFAULT_MAX_FEEDRATE { 200, 200, 50, 25 }

/**

  • Default Max Acceleration (change/s) change = mm/s
  • (Maximum start speed for accelerated moves)
  • Override with M201
  •                                  X, Y, Z, E0 [, E1[, E2[, E3[, E4[, E5]]]]]
    

/
#define DEFAULT_MAX_ACCELERATION { 1200, 1200, 100, 10000 }

/*

  • Default Acceleration (change/s) change = mm/s
  • Override with M204

* M204 P Acceleration
* M204 R Retract Acceleration
* M204 T Travel Acceleration
*/
#define DEFAULT_ACCELERATION 3000 // X, Y, Z and E acceleration for printing moves
#define DEFAULT_RETRACT_ACCELERATION 3000 // E acceleration for retracts
#define DEFAULT_TRAVEL_ACCELERATION 3000 // X, Y, Z acceleration for travel (non printing) moves

/*

  • Default Jerk (mm/s)
  • Override with M205 X Y Z E

* “Jerk” specifies the minimum speed change that requires acceleration.
* When changing speed and direction, if the difference is less than the
* value set here, it may happen instantaneously.
*/
#define DEFAULT_XJERK 20.0
#define DEFAULT_YJERK 20.0
#define DEFAULT_ZJERK 1
#define DEFAULT_EJERK 1

/*

(Jeremy Wasserstrass) #14

I usually print at 70-75mm/s minus whatever the slicers settings do

(Eduardo Schoenknecht) #15

I would try to slow things down, starting with Jerk, going from 20 down to something like 5. I would also cut speed in half and reduce acceleration, down to 500. I would NOT use S curve acceleration in a 8bit board. I didn’t like it even in 32bit. If loosing steps stop with lower acceleration, it will confirm you are demanding too much from your mechanics. This means to get the speed and acceleration you want you will have to imrpoove your mechanics, with less weight, more power and precision.

(Jeremy Wasserstrass) #16

Thanks everyone for your suggestions. What fixed the problem was changing out the motor cable.