[DDMODS]

Hi all. Im building a new cnc machine and only just finished the other day.

A few weeks ago i received my 4 axis driver kit and wired it all up had it running for about 5 minutes all was well then pop i blew a driver put a new driver in its place then pop again blew that 1... checked my wiring and it turned out one of my dir or step or en wires had come out and was touching the ground so i brushed that off as my fault ordered replacement drivers and here we are today.

I wired it all up had it all running nicely even did some cuts was about to cut my new dust shoe and was just setting my y zero (jogging backward precisely so like tapping the jog down) and pop again psu was off and turns out another driver had failed.... long story short all 4 drivers out of the 5 have all failed. i checked my wiring and this time there is nothing wrong.

I know the tb6600 isnt a great driver at best but i wouldnt expect them to just fail not at this rate at least.

Specs:

Driver Settings:

46.5v (tested) (supposed to be able to go to 50v or rated at 48v)
microstepping 1/2
steps per mm 80 (inc microstepping)
current out: 2.8 amps (rated to 5a )

Stepper Motors:
NEMA23 254Oz-in
Stepper motors inductance: 3.6mh

Is there anything that i could have setup wrong etc thats causing the failure (even though it was running for around an hour fine)

I ask this because i dont want to get some good quality drivers and then blow them all because i have something setup wrong internally they are all blowing on the stepper motor output pins linked to the tb6600hg ic internally shorting across them all (tested with mulitmeter)

I can supply pics of my wiring if needed or any other details.

So if i do replace them with a better quality driver am i able to use the same bob or would i be best to upgrade that as well?

The bob is a 5 axis that came with the tb6600 bundle

Thanks

[Toinvd]

with the supply voltage you are close to the limmit. Any spike will be to much.
Check your wiring. short wiring from the powersupply to the driver. This needs to be short and good quality wires. Perhaps add a capacitor directly on the driver power connection ( 1000 uf and 100nF ) this will suppres spikes
Check your motor wiring. any bad wiring on motor or powersupply is a reason for the driver to blow. ( disconnect a motor while power on, and big chance you lost a driver )

[DDMODS]

with the supply voltage you are close to the limmit. Any spike will be to much.
Check your wiring. short wiring from the powersupply to the driver. This needs to be short and good quality wires. Perhaps add a capacitor directly on the driver power connection ( 1000 uf and 100nF ) this will suppres spikes
Check your motor wiring. any bad wiring on motor or powersupply is a reason for the driver to blow. ( disconnect a motor while power on, and big chance you lost a driver )

It happened just as i was tapping the y direction down semi fast so could that have created a spike? i was trying to line up the y to the edge of my workpiece.

Do you have a diagram showing the cap added? or any particular cap i should get?

Thanks for the reply

[KOC62]

Example. Let's say your motor suddenly disconnected in 1 usec.
L=3.8mH, i=2.8A t=1usec, then the voltage spike is e=3.6 X 2.8 / 1 usec = 10,080 volts. (>10KV)

I can't say that this is what you experienced, unless you had intermittent motor wiring problems.
Your failure is most likely is due to too high a power supply voltage.
Try your system with a 30V supply to see if the reliability improves.
A line voltage variation can also occur in your area which could exceed 48V output for a non-regulated power supply.

An electronic device should not be used at its full rating, but more like 75% -80%, for increased reliability..

[DDMODS]

Example. Let's say your motor suddenly disconnected in 1 usec.
L=3.8mH, i=2.8A t=1usec, then the voltage spike is e=3.6 X 2.8 / 1 usec = 10,080 volts. (>10KV)

I can't say that this is what you experienced, unless you had intermittent motor wiring problems.
Your failure is most likely is due to too high a power supply voltage.
Try your system with a 30V supply to see if the reliability improves.
A line voltage variation can also occur in your area which could exceed 48V output for a non-regulated power supply.

An electronic device should not be used at its full rating, but more like 75% -80%, for increased reliability..

Ill have to order replacements then and drop the voltage down. I originally had a tb6560 i think it was all in one unit with lcd and it worked fine but only accepted up to 36v and was only able to get 1500mm/min out of it before stalling. With the new drivers i am able to get 4000mm/min but its close to stalling so i run it around 2500mm/min so it wont be able to stall under operations or rapids etc.

I think under calculations i need around 60v ideally to get max performance out of steppers.

I was looking at the gecko 540 boards today and am considering getting one if they would be recommended.

Is there anyway to stop a voltage spike from happening? like regulator or caps like toinvd suggested? Id like to try with these drivers first and if all else fails then i will upgrade

[DDMODS]

Attachment 328822
Attachment 328824

is that distance too far do you think?

[KOC62]

... I think under calculations i need around 60v ideally to get max performance out of steppers.

I was looking at the gecko 540 boards today and am considering getting one if they would be recommended.

Is there anyway to stop a voltage spike from happening? like regulator or caps like toinvd suggested? Id like to try with these drivers first and if all else fails then i will upgrade

There is a rule-of-thumb that Gecko uses for maximum stepper voltage. The usual problem is that the driver can't handle the higher voltage, unless you buy the more expensive units.
I have a Gecko 540 and it's maximum recommended power supply voltage is 48V. I don't what reserve voltage is built into it. My power supply is a linear plain 48VDC and I haven't experienced any issue with it. I haven't used it for over a year, though.

The transient response is the driver's design responsibility. If you're within the manufactere's spec then you shouldn't need to worry about it. However, if a wire breaks from the motor while drawing the full current then its possible the driver will blow. Some say not to disconnect the motor while running, else it may cause damage. There are fast acting transient suppressors but that is getting fancy and will take some time to research for a specific application. Some solutions, like capacitor-resistor networks can cause ringing which may also cause damage. It needs to be properly engineered for your case if the driver doesn't include the solution.

I still think that your issue wasn't a transient spike but rather exceeding the ratings of the driver.

[James Newton]

As KOC62 points out, the quality of the driver matters. If you can't afford a Gecko, and you can solder, my THB6064AH driver kit might be a good choice. At the very least, it costs $10 to repair if you fry it.

[DDMODS]

I got replacement drivers sent from the seller and installed them last week. Made up a new dust shoe with it and all everything fine.

Today i started surfacing my table top and that was fine too had over 1 hour of run time on the machine all axis were fine.

I smelt something a little off and i could tell it was coming from the drivers. I turned the psu to drivers off and then the 5v to the bob off.

they were off for about half hour to cool down (werent too hot or anything but i thought id leave it off for a bit while i was doing other things. Turned them back on (i think the order of turning them on was psu on then 5v on for bob)

it ran for abotu 10 seconds of me manually jogging the machine and the y axis blew again....


Second time the y axis has blown the driver.

Ive checked my wiring and all pins etc are linked to the right pin numbers (wouldnt work right with them being wrong anyway id assume)

The wires between driver and motor seem to be fine they are soldered and then screwed down in the green 4 pin clamp connectors so i dont think it is disconnecting the steppers while in motion...

I have now replaced the BOB with a new one they supplied me when they replaced the driver but im not sure if that could be the problem? Could a faulty BOB cause stepper drivers to Blow?

I was running the PSU at 39V this time

I have brand new 100v 5amp drivers ready to go on but i dont want to put them on if its going to blow them as well so im too scared to do so at this stage...


Previously i ran the steppers on my old BOB and driver combo (all in one unit) only can take 24v and it ran everything fine with no sign of troubles so i dont think its the stepper motor disconnecting (although not 100% sure)


just dont know what to do from here

Any help appreciated

[James Newton]

First I'm amazed the seller replaced the drivers. People who sell those crap 6600 drivers don't usually bother to support them. If this was an eBay seller, you must have gotten to them before the purchase was closed to feedback... usually they have the listing set so you get them about the time the feedback locks down or very shortly after that. If you got them locally, tell the seller to contact me about a much better driver chip.

I would be amazed if the BOB was the issue. Some BOB's provide regulated +5 to the drivers, but that is really rare with the TB6600 as it's only good feature is that it supplies it's only logic power.

Typically failures like this come from:
1. Loose wire to the motor
2. Loose wire from the motor power supply
3. Poorly regulated motor power supply
4. Very long, or too thin, wires from the motor power supply and too small a cap on the driver to filter out the power supply spikes.

But based on the heating issue you reported, I would guess the major problem is poor thermal connection between the TB6600 chip and it's heatsink. You shouldn't smell anything, and if the heatsink wasn't horribly hot and you were smelling something, then the chip was overheating without being cooled by the heatsink. On the other hand... that's pretty rare. Usually the chip is well mounted because they supply a heatsink that isn't big enough anyway and are over rating the driver so people run them hotter than hell.

Last note: If you build your drivers from the kit, then when you fry one, you can easily and cheaply repair it. And if it's MY THB6064AH based kit... you won't fry it.

[DDMODS]

First I'm amazed the seller replaced the drivers. People who sell those crap 6600 drivers don't usually bother to support them. If this was an eBay seller, you must have gotten to them before the purchase was closed to feedback... usually they have the listing set so you get them about the time the feedback locks down or very shortly after that. If you got them locally, tell the seller to contact me about a much better driver chip.

I would be amazed if the BOB was the issue. Some BOB's provide regulated +5 to the drivers, but that is really rare with the TB6600 as it's only good feature is that it supplies it's only logic power.

Typically failures like this come from:
1. Loose wire to the motor
2. Loose wire from the motor power supply
3. Poorly regulated motor power supply
4. Very long, or too thin, wires from the motor power supply and too small a cap on the driver to filter out the power supply spikes.

But based on the heating issue you reported, I would guess the major problem is poor thermal connection between the TB6600 chip and it's heatsink. You shouldn't smell anything, and if the heatsink wasn't horribly hot and you were smelling something, then the chip was overheating without being cooled by the heatsink. On the other hand... that's pretty rare. Usually the chip is well mounted because they supply a heatsink that isn't big enough anyway and are over rating the driver so people run them hotter than hell.

Last note: If you build your drivers from the kit, then when you fry one, you can easily and cheaply repair it. And if it's MY THB6064AH based kit... you won't fry it.

It was an aus seller so took about 3 days to get here ( i live in aus) and feedback now is extended for a much longer time than it used to be on ebay i think its like 60 days or something now.

I switched over the drivers from the z axis to the y axis last night and ran it back and forth for about 156 minutes while i wriggled all the wires on the y axis around pulled them and wiggled them at the motor etc and nothing seemed to do anything.

The power supply wire to the driver is about 30cm in length and approx 3mm diam (core not inc insulation)
I ran it last night with the multimeter on it and it stayed constant at 39.8v while using motors turning spindle on or off and dust extractor on and off didnt change from that once

i touched the heatsink and i could feel it was warm on all 4 drivers and the steppers were also warm on all 4 but they were by no means hot at all and i could smell something that wasnt good and that was before it blew.

I guess my next step would be to pit my new drivers on ( about twice the size and a built in fan on each) and try those and if something goes with one of them then ill just have to replace the stepper motor and wiring to the stepper even though i never had a single problem with my old tb6560 all in one driver and BOB with the same wiring and motor so its got me stumped only difference is instead of 24v its now 48v psu well running it at 39v but yeah. Ill switch over to the new drivers and see what happens

I may replace all wiring on the y axis just to be sure but my y axis is on the left hand side of my machine and so is my control circuitry so its the smallest distance from stepper to control compared to myz or even x or even a which have to go to the other side of the machine and using the same wire (trailer 7 core wire) to link the stepper motor existing wire to the stepper drivers.

Its just boggling me why it works for ages and then doesnt and its only the y axis thats doing it

[Genuinecopies]

It might be your software, just an off chance. I blew lots of stepper controllers when resetting a board connected to them. As it sent one of the pins high for a while. I connected a power supply showing the current drawn and it went to max for a short while before it blew them.

[DDMODS]

I replaced the drivers today with the new beastly drivers and so far no heat and no problems so see how it all goes i guess time will tell haha also went through the software and some output/ input pins were still enabled and assignesd from the last driver so maybe something was enabled on the y axis causing a constant power problem or something or a sudden surge not sure anyway hopefully all good now heres a pic from today