none of the motors are working

hi everyone,

I just powered up my reprap, uploaded the Sprinter firmware with the instructions in readme.. I managed to connect it to my computer with USB, but when I tried moving the motors (tried replicatorg and kliment-Printrun-a4b3751) , none of them worked, except for Y- and it was making loud kicking noise and moving back and forth within 1mm or less...

Does anyone here know what is going on?? I hope I didnt blow up the stepper drivers..

BTW, when the y motor was doing that weird jumps, the stepper driver was quite hot.. I guess around 50C..

I'm using RAMPS 1.3 with Pololu A4988 drivers.

Thanks very much guys.

Adrian

Have you adjusted the current on the Pololus? It seems your Y axis is too high and the others possibly too low.

It also seems like your endstops are misconfigured or missing as an axis only moving in one direction is a sure sign.

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[www.hydraraptor.blogspot.com]

nophead:

I tried adjusting the current setting on the Polous, within the 360 degrees allowed rotation, it gave the same kicking result.. do you think I should ignore that stopper and do a few more turns on the current setting?

You should also double check your stepper motor wiring. The clicking could be the two coils fighting each other.

You may have the order of the four wires mixed up. I think its red, blue, green, black with the red nearest the power supply end of the ramps board.

One further thing is that you may be stepping the motors too rapidly and they just grind and dont move. It could be you have not set your firmware configuration up with the correct values. You can check this by entering a very slow manual G1 move, such as G1 X0 Y0 Z10 F5 in your host software. Even if scaled incorrectly such a low Feed value should allow the motor to move, confirming the wiring is ok, but the configuration.h values need looking at.

Also dont run the pololu without a stepper motor connected. I blew two up this way.

Set the pots so there is 0.4V on the test point (or the wiper).

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[www.hydraraptor.blogspot.com]

the motor wires are in this order (red, blue, green, yellow) I don't have black, so I'm guess that would be yellow.

also how do I check if the stepper driver is blown??

many thanks.

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Also dont run the pololu without a stepper motor connected. I blew two up this way.

They are fine with nothing connected, they must have been faulty already.

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[www.hydraraptor.blogspot.com]

nophead: sorry im very bad with electronics... what is pots and wiper? did you mean to measure the voltage at the 2 points connected to the adjuster (the turning thing). I've getting 1.6V at these two points no matter how far i turn the adjuster..

I think you need the endstops connected for all banks to work on the ramps board, otherwise only one axis works, I think it was the Y axis if I remember correctly. Make sure these are normally closed switches or you will have to fiddle about in the firmware.

See here for pre flight check info Pre flight check

There is also some test firmware you can upload which just moves the motors back and forth and I think works without endstops connected. This should at least tell you whether anything is blown and whether you have it wired up correctly.

Test code

I think the pin assignments are the same for ramps 1.4 as 1.3 so that should be ok for you.

I had this issue. If you can get one motor working at least a little, just swap the other drivers into that slot, You dont need to fill all the banks with drivers, just make sure you have motors connected to the ones that are inserted. Externally they don't give you any indication that they are blown, they just don't work. Concentrate on just one bank at first with one motor connected. get that sorted , wired up and adjust the pot on the board until it moves OK. Then you can swap the other boards in and check they are still functioning.

Thanks for your info.

Now I managed to get the + /- axes to work, by fiddling with the configuration.h file.

What appears to be the problem is the motor doesn't know which way to rotate.. its like trying to go CW and CCW the same time, hence making this kicking noise.

I've check the solder points and pins are not touch each other, (as far as I can tell with a multimeter). The type of stepper motors I have doesn't have black wire, but I've put them in this order (red, blue, green, yellow).

Up to this moment, the Y axis, Z axis and extruder motors are working (but neither of them knew which direction to rotate!). With the X motor, no sign of movement, although there is a 1.6V power passing through.

any help would be much appreciated.

Many thanks.
Adrian

Try swapping the center pair of wires. If that doesn't work, post the part number of the motors or a link to where you bought them.

Thanks andrew! now I've got the Z axis and Y axis moving in a specific direction. you're right, just swapping around the motor wires!

Now I have them in this order:

(Red, Green, Yellow, Blue) now
(Red, Blue, Green, Yellow) before

I'm unable to get the X axis working in this order.. so maybe I'll try different combination later.

With one of the stepper driver.. it's been dead silence.. not sure if I've blown it. Do you think I can test if it's still working or if I've just poorly soldered the connectors??

many thanks.
Adrian

This shows the location of the pot and the test point: [picasaweb.google.com]

If you have 1.6V on the test point it is far too high unless you are using stepsticks rather than Pololus. When it is too high the motor will click and twitch when stationary.

To test the suspect one swap it into an axis that is working.

To get the motor connections correct use the multimeter to find which wires are pairs, i.e. have some resistance between them. Connect one pair to pins 1&2 and the second to 3&4. If it goes the wrong way swap pins 1&2.

@martinprice2004

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You dont need to fill all the banks with drivers, just make sure you have motors connected to the ones that are inserted.

Please stop repeating this misinformation in these forums. A Pololu with no motor attached simply does nothing. It does not do any damage. I have done it often. Connecting or disconnecting with the power on may damage them.

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[www.hydraraptor.blogspot.com]

nophead Wrote:
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> Please stop repeating this misinformation in these forums

Are you one of those Cyber Bullies everyone is talking about? Come on its Christmas.....good will to all men!

I'm off to tell my mommy about you now.

Your mommy will probably also tell you inserting Pololus without connecting motors is just fine.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I realised there could be something wrong with my stepper motors..

Its clearly they are all working as they could drive the motors.. however, when I was using kliment's printrun to move the axes, 2 of the 4 drivers could not rotate the motor at a slow speed.. Hence I established that 2 of the stepper drivers are working fine, and 2 were something wrong.

I tried turning down or up the wiper, the only result I got with high current was the kicking sound which couldnt drive the motor to move. When I turned them down, there wasnt enough power to drive the motors (because they worked fine when I tried to assist the motors with my fingers twisting the shafts).

In some cases, 1 of the driver could drive a motor at high speed, and it sounded only slightly louder than the other 2 "normal" drivers. But when I turned the rpm down, it started making loud kicking noise.

I've checked and made sure that none of the pins on the steeper drivers were short circuited, and so was the pins on RAMPS board. I've got all 3 jumpers in place, can anyone make suggestions what I can do??

Many thanks and happy Christmas!

If a motor will run quickly or not at all it usually means only one coil is being driven. Then instead of being a stepper motor it acts like a synchronous AC motor and is only happy to run at certain speeds and in a random direction.

Have you tried swapping a motor that works with one that doesn't to see if it is the motor or the driver. It is far more likely to be the driver, especially if it is a stepstick rather than a genuine Pololu.

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[www.hydraraptor.blogspot.com]

nophead:

what do you mean "stepstick rather than a genuine Pololu"? I thought I bought a genuine A4988 pololu driver...??

The Polulu drivers are all made by Pololu. The stepstick is an opensource replacement that has current limited to 1A. Anybody can make them and judging by the comments in this forum the build quality can vary.

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[www.hydraraptor.blogspot.com]

i think i've blown one of the driver... I accidentally inserted it the wrong way, and now most of the adjacent pins on the driver has a resistance of 2000k+ ohms...

have I really blown it??

I think so because other people have done that and it has taken out the drivers.

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[www.hydraraptor.blogspot.com]

apart from the blown driver.. all other motors are working fine now! at fast or slow speed.. yay!

I've found out that one or two of the driver pins were pushed upwards when inserted into the board, making the pins not connected to the driver.. must be due to my poor soldering skills...

anyway.. I guess I'll have to wait until new year, or later, to get a new driver...

but thanks very much for your support!

Happy Christmas.
Adrian