Motor issues plz help

Hi guys ,

So i have finished the physical build of my mendel90. I have been trying to get the motors to move in Pronterface but they just make noises (I’ve tried changing the potentiometers but they just increase and decrease the amount of noise produced)
I am using Sprinter - but i have also tried Marlin, in both i have changed the motherboard to 33 for ramps, and chosen my thermistors

- the heated bed and hot end work fine, along with the two thermistors and the endstops
- I found that the motor wiring was wrong and i have put the two coils next to one another ( (2B,2A) – first coil ,(1B,1A) – second coil)

When i run the Ramps test code the print head crashes into the x brackets and makes a terrible screeching noise (same with the Y-carriage) - I can change the potentiometers and make the motion of the carriages smooth but they still crash into the end brackets

Would anyone be able to help ?

Thanks so much

Jeremy

Edited 1 time(s). Last edit at 04/06/2014 08:26AM by Jerms.a320.

Update:

I can move the y-carriage with proterface back and forth fairly smoothly, but I can only use +/- 1 unit occasionally , and sometimes it will only move in one direction of not at all. I can signal all three end stops – checking them using M119 – and the come up as high when triggered but the y-carriage will sometimes try to travel further than the end stop – same with the x-carriage.

The Extruder motor responds fine to commands but the z-axis motors only make a humming noise (for length of time, depending on which command I have sent)

Any help would be great …. Getting slightly depressed 


Thanks

Jeremy

Did you invert the endstops,?
Does the home button in pronterface work? or the individual home bottons for x y z ?

did you check your wire connections. I had the humming noise and fixed it by adjusting the connectors on the board.

Edited 1 time(s). Last edit at 04/07/2014 09:26AM by DesignSmurf.

Hi DesignSmurf.,

What do you mean by invert ? Pronterface detects them with the M119 command as H when triggered and L when not

from Configuration.h in sprinter :

//// Endstop Settings
#define ENDSTOPPULLUPS // Comment this out (using // at the start of the line) to disable the endstop pullup resistors
// The pullups are needed if you directly connect a mechanical endswitch between the signal and ground pins.
//If your axes are only moving in one direction, make sure the endstops are connected properly.
//If your axes move in one direction ONLY when the endstops are triggered, set [XYZ]_ENDSTOP_INVERT to true here:
const bool X_ENDSTOP_INVERT = true;
const bool Y_ENDSTOP_INVERT = true;
const bool Z_ENDSTOP_INVERT = true;

None of the home buttons work

All the connection are plugged in tight -- the endstops don't have polarity do they ?

Thanks heaps

No polarity.

But older RAMPS need a closed signal when not triggered. the one I now use needs an closed signal when triggered.

how long are your cabels? did you twist each signal pair? it will help reduce interference in your signal.
I never had to adjust the settings in sprinter as I only use a single endstop for each axis.

can you post a pic of your printer

these are my endstop stats (pronterface) when not touching the switches

SENDING:M119
Reporting endstop status
x_min: open
x_max: open
y_min: open
y_max: open
z_min: open
z_max: open

and triggered:

SENDING:M119
Reporting endstop status
x_min: TRIGGERED
x_max: open
y_min: TRIGGERED
y_max: open
z_min: TRIGGERED
z_max: open



Yao.

Sorry that picture isn’t very useful !

I did twist the endstop pairs .... I may have mislead you, all of my endstops are working the M 119 command gets me the same results as you

- I had a look in Sprinter and I changed the homing for each endstop (for x and y) to MIN (before it was max, because my endstops are at the max end of each axis ) I then ran pronterface and the homing worked for X and Y, except it was the wrong direction -- so then I inverted the x and y axis and now they home and move fine

but I still cannot move the Z axis up or down , they are still making noises, I will change the endstop settings for the z axis now but before I change the settings i still had some movement on the x and y axis but I haven’t seen any at all from the z , any ideas ?

Thanks

Jeremy

Oh sorry I didn't upload a picture of the electronics -- It didnt show anything, too hard to see with the wires

Edited 1 time(s). Last edit at 04/08/2014 07:23AM by Jerms.a320.

Update - the z- axis motors receive the homing signal, I can tell by the noises they are making - when i trigger the endstop the motors turn backwards then approach the endstop again

I can see the turned wires

try set the revs for your z axis really slow. in the end that is what helped me figure out (another problem) with the Z

So is that in the firmware or pronterface ?

thanks

Ok so here is the next update:

- My stepper motors have 4 wires, blue, red, green and yellow (most motors I believe have black instead of yellow). I assumed that the wiring for my motors was the same as others and I used the yellow wire as the black wire in the RAMPS wiring diagram.

- A few days ago one site said to check the stepper motor pairs with an Ohm meter, I did this and found that Blue and Yellow were one coil and Red and Green the other (to check the coils you take the resistance between two of the wires if it is about 2Ohms then those two wires make up a coil if the circuit is open - as shown on the ohm meter when connected - they are part of two separate coils). I changed the wires coming into the RAMPS board so that the two coils were next to one another i.e. 1B, 1A (wires for first coil) then 2B, 2A (wires for second coil) -- I did not bother re twisting the pairs and left them as they were (today I have gone back and retwisted the pairs correctly so they cancel out the magnetic fields)

- Today i was looking over the wiring again and I realized when I found that the colours for the wires were different to the RAMPS diagram I had not re wired the z - motors ( on my printer both z- motors are wired in series not parallel ). I have just rewired the motors in series taking into account which wires are part of which coil

After doing this I changed the z mm/min speed to 20 in pronterface and now it moves (i am sure it moves much faster than 20mm/min this is probably because my settings in sprinter are all over the place)

The z- axis motors are not moving smoothly at the moment - sometimes one will move more than another - any advice ?

Also I was wondering if anyone knows how my motors should be wired (I have the two coils next to each other, as above, but i do not know how to determine which wire is 1B and 1A - one wire on each coil should have current coming into the motor and one wire current coming out) should I just use trial and error ?


Thanks heaps

Another update (ahahah, I'm just going to keep posting so that another lost soul on the reprap forums in a similar circumstance to me might solve things a bit faster ) :

I just had to change the speed of the z-axis and now the motors work fine - I just edited it in pronterface down to 16mm/min -- my extruder motor is on the same speed and working fine. now I will start calibration !

the fault was in the wiring of the stepper motor?
I was under the impression that with a wiring error the driver would burn out.
but its good to hear they are stronger then I thought.

good luck with calibrating!

y.

Thanks,

Yeah I thought I would have damaged them - first of all having the coils in the wrong place - then with the z- axis ..

With some minor changes to the speeds in pronterface and the firmware it all ran smoothly after fixing the wiring. I have just finished setting up steps/mm and it is all moving very nicely, do you know how to enable micro stepping with the A4988 stepper drivers (they are on full step at the moment so my steps per mm are 3.2 ..... ), I would like to be able to do 1/8 or 1/16 micro stepping, it would increase resolution of prints wouldn’t it ?


Jeremy