Prusa i3 build with RAMPS1.4 and Pronterface - Motors are not turning

I am in the process of building Prusa i3 with RAMPS 1.4 running Marlin and finally got to the point where I could use Pronterface to turn the motors. I am able to connect via Pronterface and heat up the hotend. However when I try to turn any of the motors all I get is a grunting sound. Not much of the movement in the motors.

However when I use my own test program (downloaded and modified), all the motors turn perfectly.

Is there any configuration that I need to do on Pronterface or on Marlin firmware for that matter?

Thanks.

Good decision to make your own thread

However, I responded in the other thread:

Quote

This sounds like Marlin's insane default feedrate/acceleration/jerk. The speed it's asking the motors to run at is simply something the stepper drivers can't do.

Here's my feedrates, they are a little slow though:

#define HOMING_FEEDRATE {3000, 3000, 100, 0}

#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,4100,650}
#define DEFAULT_MAX_FEEDRATE {120, 120, 2.5, 50}
#define DEFAULT_MAX_ACCELERATION {120,120,5,800}

#define DEFAULT_ACCELERATION 50
#define DEFAULT_RETRACT_ACCELERATION 50

#define DEFAULT_XYJERK 20 // (mm/sec)
#define DEFAULT_ZJERK 1 // (mm/sec)
#define DEFAULT_EJERK 20 // (mm/sec)

Once you're sure that the feedrates are reasonable, if this issue still occurs you will need to adjust the trimpots on the stepper motor drivers.

Hallo,

I have an equal issue with my prusa i3:

When i trie to Home the z axis, there is only a humming noise. When i click on the Endstop the noise stops and the motors move a bit down.
So it can not be the issue, that the current is to low.

Has anyone an idea??

greatings Marco from Germany

It's the issue i presented above, your feedrate and accel.

Once you trigger the endstop, the firmware will retract and 'sneak up on home' to get a more accurate homing. This is at a reduced feedrate. That is why it works.

Marlin has very fast defaults for homing feedrate, default feedrate, acceleration, and jerk. See above. I'm not saying my settings are perfect but hey, they got my printer running good. I'll speed it up later once i'm confident in my build.

I only noticed it on low cost stepper drivers. On my Rambo boards or ramps with real Pololu driver boards the defaults work fine. On a stepstick board I need to adjust the values for proper operation. My adjusted values are similar to what was posted.

I wonder what the difference in the boards are ..aren't all the RAMPS A4988 boards all using the same chips and basic config ?

I have tested all components ( 5 x motors, 3x min stops, thermo x2 , heater bed, extruder heater , fan, ) one by one using my own diagnostic sketch.
All ok .

Then I plugged in Prontoface and had the following results

a) Y can be moved towards home and be homed but won't go the other way
b) X does the same
c) Z - seems to just turn over ..
d) Heater bed will no work
e) Extruder - WORKS
f) Fan - have not seen this come on ..

Not sure where the issue lays. I adjusted the feed rates from 100 to 1000 .and it still seems to behave the same .( but moves quicker when it does move )

I dare say it seems like a setup RAMPS issue ?

Any hints appreciated
:-)

Hi,

if motors making only some noise, there are two possible causes:

1) motor current is too low -> adjust stepper driver with respect to the rated current of the motor (check technical description)
2) feed rates are to high -> reduce feedrate

In Marlin you can limit the max. feedrates for normal moves and for homing as you can see in the config sniplet of Shootquinn.

If you didn't set the maximum limit for the normal feedrate in Marlin matching your printer, you can send feedrates with Pronterface to the printer, which are too high.
This will also result in humming sound of the motors.

So if you already testet motor movement with other tools, you may reduce the speed in pronterface.
The input field for XY is beside the "Motors off" button. I would suggest to start with a value around 1000 ~ 2000 for XY and 200 ~ 300 for Z.

BR

---

RepRap Electronics, Mechanics, NEMA 17, Filament you find here: [www.my-home-fab.de]

Check your speed settings between your custom sketch and pronterface. Pronterface uses mm/min, not mm/sec like other software such as Slic3r.

---

MakerFarm 8" Prusa i3v
RAMPS 1.4
0.4mm E3D v6 for 1.75mm