y motor shaking back and forth after firmware update

[protom]

I just updated my firmware on my printrboard rev B and since then the Y stepper just makes the motor shake back and forth.. whatever voltage I put with the potentiometer.. any idea how to fix that ?
also I extended all axis quite substentially so it might be that too...
but all potentiometers works when I look with a multimeter and also the same behavior happens to X motor if I switch the X and Y motors so its seems its not motor related...

also if I do need to replace my board with a better one with stronger steppers what would you recommend at the moment ?

[RetireeJay]

The symptom of a motor that shakes back and forth but doesn't consistently move in the direction requested basically means that only one of the coils in the motor is receiving current. Usually that's due to a broken wire or a connector that's not making good contact.

However, you have an unusual situation. The fact that the X motor exhibits the same behavior when plugged into the Y connector on the board eliminates the possibility of a broken wire (or open-circuit coil) in the Y motor.

The correlation with a software update is almost certainly a coincidence; this failure is almost certainly a hardware failure. The firmware sends repeated commands to the motor-driver chips to move a (micro)Step in a given Direction; the motor-driver chip itself keeps track of how much current should be going to coil A and how much to coil B.

A further troubleshooting step would be to carefully pull the motor connector part way off the board so you can access the voltage on the pins while the motor is still plugged in. I'm fairly sure that you will find one pair of pins has nothing on it, while the other pair of pins has a varying voltage (which can be positive or negative, or "AC" when the motor is being told to move). The pairs are at the ends of the connector: one pair at the north end and one pair at the south end.

If, as I'm guessing, one pair of pins has no voltage under any circumstances, then it's possible you have an open circuit in one of the "sense" leads, or else it's possible that the motor driver chip itself has gone bad. This schematic is for one of the four motor controller chips; in this channel the sense resistors are R17 and R18.
PrintrboardStepperController.JPG

[protom]

Thanks for the detailed reply
it seems like the easiest if it is indeed an issue with one of the motor controller the easiest would probably be to replace the board with something more modern
would you have any recommendations its a little bit messy with all the RAMPs options as well as the new 32bit boards...

[protom]

I have been looking at these boards :
https://www.amazon.com/gp/product/B07LG1BKCB
https://www.amazon.com/gp/product/B07B2HN8ZP
https://www.amazon.com/gp/product/B076S2SDQ9
https://www.amazon.com/gp/product/B07GVFSRCK
https://www.panucatt.com/ProductDetails ... I&CartID=1

[RetireeJay]

If you go with a different board, you won't be able to use .hex files that are pre-configured for the Printrboard when used with a Printrbot. If you are comfortable hacking connectors to fit the new board, and compiling your own firmware (or figuring out how to get all the ins, outs, and settings right), then go for it!
Personally, my own choice would be to stick with a Printrboard, not because it's the best possible board but because most of the bumps in the road have already been smoothed out. But that's just me.

[protom]

I most likely don't have the tools to resolder a resistance on the printrboard...

[protom]

An di think I might have issues down the line with the Y and extruder motor sharing the same power line
and maybe getting enough power to my motors since I extended all axis...

[RetireeJay]

[protom]

I see somehow I though I read somewhere that the y axis and extruder motor channels on the printrboard where linked...
my heated bed is on a completely separate power supply with a relay to trigger it
but if your diagnostic is correct I would have to resider a resistor on the board itself right ?

[protom]

I bought a crimper and was going to recrimpe all the connectors
but if you think repairing my printrboard is faster ill give it a shot

[RetireeJay]

[protom]

yes one of the two channel has nothing on it...

[RetireeJay]

Great! Now we've nailed it down to a hardware defect on the board.

It could just be a bad solder joint rather than a defective component. If you have access to a "makerspace" or any friends with electronic troubleshooting expertise, it will be very easy to just re-heat all the solder joints involved with a fine point soldering iron. If you aren't sure which areas are involved, I could create a picture from the board layout indicating which components to re-solder - but basically it would be the square black integrated circuit chip and everything that lies between it and the connector for the Y channel motor.

If the chip is bad, or a resistor has gone open-circuit, it gets "interesting". It's more difficult to remove and replace surface-mount components than it is to just re-heat solder joints, requiring some special techniques and/or tools.

[protom]

Yes a picture would help I do have a soldering iron and can probably repair a bad connection but probably won't be able to remove a chip or replace a small component

[RetireeJay]

This picture had the adjustment pots already circled; I drew a purple line around the components most associated with the Y motor channel output.
PrintrboardRevB_YMotorCircled.jpg

[protom]

it doesn't seem like any bad soldering there could it be on the other side of the board ?

[RetireeJay]

I believe the connector uses through-hole pins that are soldered on the back of the board, so yes, you definitely should look at the back.
Even when solder joints look good (and I agree with you that the ones in your picture all do look good) it doesn't hurt to briefly melt them and let them solidify again. Just be careful not to move any of those tiny 2-terminal components in case the solder on both ends melts at the same time. Try to melt just one end at a time. You will need a soldering iron with a very fine point!

[protom]

is it mostly the resistor that could be the culprits or would you redo the whole chip below ?

[RetireeJay]

Actually, given the schematic and the board layout, you could probe around with an ohmmeter to find where the open circuit is; that would minimize the amount of solder joint reheating you have to do. I'd be most suspicious of the connector, then the resistors, then the chip.

[protom]

I ended up recrimping all the cable to connect to a SKR v1.1 with marlin 2.0 just to realize the problem was a cable heat shrink extension on two of the cable motors got used by friction and was creating a bad connection...
stupid me
anyway I now have a Skr v1.1 with marling 2.0 and TMC2208 x and y are working fine but z is shaking and not moving the motors if I set it to step per unit 2500 if I go around 500 it works but logically moves 1?10th of what it should ( for 100mm command it will move 10mm..)
also have some issues with extruder skipping..
I Suspect it has to do with my axis step per unit default max federate and max acceleration...
these are my current settings :


#define DEFAULT_AXIS_STEPS_PER_UNIT { 80, 80, 2500, 96 }

/**
* Default Max Feed Rate (mm/s)
* Override with M203
* X, Y, Z, E0 [, E1[, E2[, E3[, E4[, E5]]]]]
*/
#define DEFAULT_MAX_FEEDRATE { 200, 200, 3, 14 }

/**
* 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 { 2000, 2000,50 , 2500 }



I am using m8 threaded rod with the original dual nema17 for Z
and the V1 aluminium direct drive extruder for E...

any idea

[RetireeJay]

Actually, the ideal steps/mm for your Z axis setup is 2650 ()

You have two possibilities here: either the board can't keep up with the required pulse rate, or the motor drive current is too low.

At a max feed rate of 3mm/s, your board should be able to keep up with that because it's actually less than the pulse rate needed for X or Y.
On X: 80 steps/mm X 200 mm/s = 16000 steps/s
On Z: 2650 steps/mm X 3 mm/s = 7950 steps/x

But you are driving two Z motors, presumably wired in parallel, so you need twice as much current. I don't see any physical pots on the picture of the SKR 1.1, so the motor drive adjustment must be done with software commands (probably G-code commands).

[protom]

Thanks for your very insightful replies
with the settings I sent it actually seems to work fine now I did up the current on the individual potentiometer of the 2208 z driver.
now I have a 15x15 inch heated bed with a separate power supply and a relay and for some reason it show 0 degree so I suppose there is an issue in my marlin 2.0 config file
must be something in there...

#define TEMP_SENSOR_0 1
#define TEMP_SENSOR_1 0
#define TEMP_SENSOR_2 0
#define TEMP_SENSOR_3 0
#define TEMP_SENSOR_4 0
#define TEMP_SENSOR_5 0
#define TEMP_SENSOR_BED 0
#define TEMP_SENSOR_CHAMBER 0
#define CHAMBER_HEATER_PIN -1 // On/off pin for enclosure heating system

// Dummy thermistor constant temperature readings, for use with 998 and 999
#define DUMMY_THERMISTOR_998_VALUE 25
#define DUMMY_THERMISTOR_999_VALUE 100

// Use temp sensor 1 as a redundant sensor with sensor 0. If the readings
// from the two sensors differ too much the print will be aborted.
//#define TEMP_SENSOR_1_AS_REDUNDANT
#define MAX_REDUNDANT_TEMP_SENSOR_DIFF 10

#define TEMP_RESIDENCY_TIME 10 // (seconds) Time to wait for hotend to "settle" in M109
#define TEMP_WINDOW 1 // (°C) Temperature proximity for the "temperature reached" timer
#define TEMP_HYSTERESIS 3 // (°C) Temperature proximity considered "close enough" to the target

#define TEMP_BED_RESIDENCY_TIME 10 // (seconds) Time to wait for bed to "settle" in M190
#define TEMP_BED_WINDOW 1 // (°C) Temperature proximity for the "temperature reached" timer
#define TEMP_BED_HYSTERESIS 3 // (°C) Temperature proximity considered "close enough" to the target

#define TEMP_CHAMBER_HYSTERESIS 3 // (°C) Temperature proximity considered "close enough" to the target

[RetireeJay]

Look at the whole "Thermal Settings" section in Configuration.h and you will see that Temperature Table 0 is not used.
If your bed has the same kind of thermistor as your hot end, use Temperature Table 1.
i.e.
#define TEMP_SENSOR_BED 1

[protom]

Thanks the heat bed temp is now correctly reported !
But now I still get issues on my z axis with mostly the right motor gridding
could it be bad soldering of the motor wires in parrallel ? should I try to wire them in serie ?

[RetireeJay]

Glad to hear about the thermistor working now.

I think that the motor wires are normally crimped, not soldered. But whether crimped or soldered, yes it's possible you have an open or weak connection to one of the motors.

The motors will work in series (I've done it) but there's no advantage in doing so. In fact, the disadvantage is that now you have half the voltage "headroom" per motor for driving the requested amount of current through each motor.

The motor control circuit is a "current source" not a "voltage source" meaning that for any given microstep it is trying to send specific currents through coils A and B, regardless of the voltage it takes to achieve that current. Voltages naturally vary with the rate of change of current and the mechanical load on the motor.

[protom]

I just ordered new motors since I was unable to pin point where the bad loose connection was and I tried A/B Testing with the other drivers ( switched x and z an dy and z ) but still had the issue..