Stepper Driver Board is overheating

Hello There!

currently I am trying to get my techzone Stepper driver running.
There's a diversity of problems and only one of the boards works as expected.
Another one only stutters and two others overheat. It's peculiar, first it runs fine, even more quite than all the others, then it starts to blink.
I think it overheats, the 5V converter gets painfully hot and the voltage drops suddenly in a short intervall.
The Converter is a LM7805C and thats the same on all my boards. So why do only some boards overheat?
Would it help to add a heat sink or even a fan?

Also my Extruderboard won't work but thats the problem to worry about after this one.

... heat sinks will help a lot, but maybe you have to check if the motor-current settings are correct and/or you have heavy noises on the wires connecting the boards ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

If the regulators are getting hot and shutting down you have a problem on the board as normally the current taken by the stepper chip is so low that they only get slightly warm. Perhaps a decoupling cap the wrong way round ?

---

[www.hydraraptor.blogspot.com]

Where can I find the motor-current settings?
And how could I check if there's indeed too much noise on the wires? Would it suffice to try shorter ones?

... the motor current should be adjusted by a potentiometer on the board somewhere.

Shorter wires could help, but you need a scope to evaluate ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

@nophead: How could I recognize an ill placed decoupling capacitor?
Are the Techzone boards based on the same schematics as the generic gen3 boards? (http://reprap.org/mediawiki/images/1/1b/Stepper_Motor_Driver_2.3r1_schematic.png)
Good to know that it isn't in fact normal that the converters get warm. So that it isn't a problem of conducting the heat rather than avoiding it at all.

@VDX: I already very carefully adjusted the potentiometers to no avail.
Theres only a very slight chance that I could get my hands on a oscilloscope but I will try the shorter cables, right now they are about 30cm long

@VDX: I have an oscilloscope that you can borrow if you need one. You are about a 90 minute drive from where I live (Wörth am Rhein).

---

Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Hi Bob,

... i have some scopes (50MS digitally and 20/100MHz analog) ... mostley is in need

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

@VDX: NEVER MIND! I suspect he lives in the USA.

---

Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

actually I live in germany, Karlsruhe (near Wörth am Rhein) hence the bad grammar

I will try that "very slight chance" (the local university) first and if that fails I would like to take up your offer, rhmorrison. Perhaps you can even help me a bit better if I show you the misbehaving boards.

mostley Wrote:
-------------------------------------------------------
> @nophead: How could I recognize an ill placed
> decoupling capacitor?

Compare the orientation of the electrolytic capacitors with the board that works. Most caps have a black line that indicates the negative pin.

> Are the Techzone boards based on the same
> schematics as the generic gen3 boards?
I think so, but not certain.

> (http://reprap.org/mediawiki/images/1/1b/Stepper_M
> otor_Driver_2.3r1_schematic.png)
> Good to know that it isn't in fact normal that the
> converters get warm. So that it isn't a problem of
> conducting the heat rather than avoiding it at
> all.

The reg supplies 5V to the stepper chip logic and that only takes a few milliamps. I think it also drives the opto endstop so if you have one connected that could be faulty.

I could be that the driver chips are damaged. Disconnecting the motor with the power on causes them to draw lots of current from the 5v rail and shut down the regulator. A ESD strike anywhere near the board does the same thing. In my experience it has always recovered when the power is cycled but I think others have not been so lucky.

---

[www.hydraraptor.blogspot.com]

the opto endstops are connected but do not work either, the LED is always off.

@mostley: If the LED doesn't light up when you block the slot with something then you should check:

1. that your cable is correct
2. that your +5V is in fact +5 volts

---

Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

mostley Wrote:
-------------------------------------------------------
> the opto endstops are connected but do not work
> either, the LED is always off.

Check that you have the grounding correct (the ground pin on the endstop is the one closest to the LED), and make sure you have it connected to min, not max.

Also, from the wiki: "It behaves differently, the LED lights up when there is NOT an object in the sensor, rather than when there IS an object in the sensor"

Edit: Oh well, a bit too late.

Edited 1 time(s). Last edit at 07/02/2010 08:38AM by Nudel.

Directly after your quoted text from the wiki it also states:

Quote
http://reprap.org/wiki/Generation_3_Electronics/Tech_Zone_Remix#Opto_Endstop
Opto Endstop NOTE
For those of you who were early purchasers of our kit, the endstop has may have problems, please read HERE (link coming soon) to see if this affects you, and what you can do to have it fixed.

So the question is...

Were you an "early purchaser" of their kit?

---

Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

I just remembered I had to resolder the middle pin on two of my endstops, as it was loose because of a bad solder joint. So it might be an idea to check the connection there.

Edited 1 time(s). Last edit at 07/02/2010 11:07AM by Nudel.

So I did some of the things you told me to and got the other 2 steppers running smoothly. Thank you for that!

Only one still troubles me because despite running it still heats up and makes more noise than the others. I think the problem with this one is, that it uses the longes wires to the stepper, also the thinnest. Probably a really bad combination. What cable thickness would you guys recommend? I would love to use a ribbon cable because it can be laid handsomely along the frame. Thats why currently I am using the same type of ribon cable I use for the data connections.

For the Endstop problematic: the solder joints of the pins are all fine. Only one of my Endstops work and I got it around may. The connections should all be correct so far as I can tell, but I will do further testing.

Well, take the working part of your setup and change one part at a time. If two motors work on this connection, but not the third, there's something wrong with the motor. If all motors work on this connection but none on another connection, there's something wrong with the board. Obviously :-)

Similarly with stepper drivers and opto endstops. You can exchange them freely, all stepper driver boards are identical, all stepper motors are of the same type, all endstops are identical. If that still doesn't help, RepRap electronics build instructions come with test procedures for each part: [reprap.org] .

Long wires are very unlikely a reason for an overheating motor. The opposite should be true, long wires prevent some current to reach the motor.

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY

... especially when driving steppers with long wires you can receive big problems with noise, so use shielded cables and/or try with twisted pairs, where you twist GND-wires with the motor-phase-wires (so 8 wires instead of 4) ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I am using ribbon cable for the x-axis motor with no problems, and no heating.
I am also using a 10 conductor ribbon cable for my extruder connection as Adrian showed in his wiring video.
Neither the motor nor the chip get especially warm (but then they are 14V MakerBot stepper motors).
For my Wade geared extruder I am using a 3V stepper motor and it gets very warm but not excessively so.

---

Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Why i thought long cables could be a problem:
i need to Set the Motor current on the Stepper board with long cables very high or else the Stepper won't move a tick. It gets loud and produces this high pitched sound. I already tried this board with shorter wires and it did Not Need such an high current.

So, now I got almost everything working, the steppers do step, the endstops react and with them the motors, the extruder board communicates with ReplicatorG and controlls heater and fan.

The stepper driver heat Problem is still to be fixed.

And what I would need some help with: the extruder controller getting its motor to turn.
All it does is let the motor hum in different sounds dependung on the PWM settings. Btw. what should I use there?
Sounds like the Problem that guy [forums.reprap.org] had but I am fairly sure the D9/D10 - SCL/SDA connection is correct.
The poti on board doesn't change anything at all.

if everything else fails I'm willing to use an fourth stepper board like this guy: [forums.reprap.org]
But I wanted to ask you guys first whether you had a last idea before I submit to not using the pulsing to drive the stepper.

I am looking at trying to get the extruder controller to get its motor to run. First thing to understand though is that it is not a stepper driver, but a firmware solution to make the stepper motor turn. The Pot on the bot sets a value which the firmware then used to set the PWM drivers to the correct value to get the motor to turn.

I have managed to confirm that the board can drive the motor using the test firmware provided by Adrian.

Extruder board with steppers

One this have been uploaded to the extruder board, and then you power on the extruder, it will turn the stepper motor, it the motor does not turn, turn the pot clockwise until it turns smoothly. If you turn it too far the stepper motor stops turning smoothly, so turn it back to just before it stops turning nicely (You will understand when you see it happening).

I am now at a stage where I am trying to get the stepper to response to extrude G-codes from the motherboard, but this does not seem to be working (SLA/SDC connections I think). However I don't trust the cables any more so I am going to make up a new batch of cables with some slightly higher end connectors (if the local shop can supply them), in order to remove cable quality from the equation.

Hoep that helps

David

@davmj: I think the ReplicatorG Firmware already does something similar. Also it does not use the poti on board, instead there is a textbox to type in the PWM value.

With the 5D software it turns out the the Pot is optional, you can either control it from through G-Codes (M113) or through the on board Pot.

If you just send M113 as the G-CODE it takes the value from the Pot. If you send M113 S0 it turns off the current. the value for S can range from 0 to 1 (Off to Full) and is a float value.

My problem with respect to getting the pot to turn was a combination of things. First I used Adrians test program as I said above to get the Pot to the value where the Stepper motor would turn.

Then the other task was that fact the the SLA--D10 connection was not correct. Infact I was connected to the wrong pins completely. Once I resolved that it turned fine. (The Motor still makes a quite himming noise, but I though that was due to the PWM drivers not being real stepper motor drivers)

David