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Good decision...
The chip is quite hot at currents above 2.5Amp and some other components also heat up depending on the supply voltage.
Best solution is a small breeze from a fan to keep everything cool, same applies to TB6600.
Cables can be several meters long if a decent gauge is used, I normally use shielded 0.75mm².
Thanks lucas. Now I am prepared to continue wiring.
Just for double checking: Arduino(grbl) ports need to be high in idle state? Factory init is low (measured with scope).
BTW: I just bought at eBay 3 PC coolers Pentium 478 socket for the drivers with fan (for about 10 bucks!) That might be an opportunity for others as well along superiour cooling.
I received my driver this week. I ordered it on ebay from Rattm Motor. First thing I checked is the contact of the driver chip with heat sink. There was a gap of 2mm! between them. They put some silicon pad in between. I shortened the spacers to make contact between heatsink and driver chip. Then I added a heat conducting paste an mica in between.
Attachment 264558
Next I added a base resistor of 330 Ohm to the transistor. Then I changed the 10k resistor in the RC time constant circuit for 20k. This way I gained a bit more delay before driver goes to 30% of current set by trimmer.
Attachment 264560
Measurements are done on the capacitor of RC time constant circuit. Settings on oscilloscope were 2ms/div horizontally and 0.1V/div vertical. The fed frequency was 1ms.
I also checked the output voltage on the VREG pin and measured 4.67V. This is probably because driver can not supply current for all things that require 5V on board.
Then I changed the resistor for alert (pin1) from 510 Ohm to 3k9.
As last thing a looked to the output current. I took the measurement across the resistors on the RNFA pin. There were no spikes or artifacts seen.
Attachment 264564
It's quite hard to take a good picture of this because the oscillogram is not steady. The settings on vertical were 0.2V/div so 1 division is 1A. I set it to 1.5A because I don't have larger motor at my hand. The feed frequency was 1ms. For a brief moment I set it to 4A just to see the output, but the motor went fast to hot. But the heat sink was at the end only a bit warm to the touch. Supply voltage to the board was 20V.
For now I can say that driver board is working good. Tomorrow I'll do some more tests at higher step frequencies.
I had a number of problems with the RATTM TB6600, detailed int this post: http://www.cnczone.com/forums/steppe...ml#post1233542
In particular:
1. The gap/pad, as you already corrected. It seems they put random length spacers in there.
2. Terminal block quick-connects can have intermittent contact, easily frying the chip and PS. I'd suggest gluing them in place permanently.
3. The amp pot turns opposite of how it should.
4. Motor hiss and whistle.
Have they fixed 2, 3, 4? If not, the Hayou is better for a 6600.
2. Terminal block quick-connects seem good. You can not easily disconnect them (like pull on one wire), but they are not a good choice in general for a good contact. Gluing is recommended or change them for better ones.
3. Amp trimmer still turns counter clockwise for increasing current.
4. There is no signifficant hissing/whisteling comming from the motor.
I tested the board a bit more. I increased step frequency from 10Hz to 5.8 kHz. Driver was in 1/8 stepping mode and the voltage supplied was 20V. Above this frequncy motor started to loose steps (lack of torque). My motor is size nema23, 1.5A, taken from A3 old needle printer. I was unable to stall the motor with bare hand- had to take the pliers to stop it :D. I've runn it at 1.3A/20V.
Has anyone used this version of TB6600 ebay/aliexpress board?:
Attachment 264896
Attachment 264898
Attachment 264900
Seems different (smaller PCB) than the previous posts in this thread and claim "stepless" current regulation with a pot resistor. As it does not mention idle current reduction I have to assume it has none? So for that an external circuit should be used on the enable pins of the PCB? At least from the images it seems that for this version heat-sink has been attached properly with screws. So any comments on this version?
I am planning to do my first CNC desktop machine for learning the ropes and are considering using these because of reasonably low price and should be adequate for driving some steppers (currently thinking about using just 12V for 2.55V, 1.7A rated Nema17 steppers to be dr).
The links didn't work.
For motors needing less than 2 amps, these looks interesting.
DRV8825 Stepper Motor Driver FOR Sanguinololu RAMPS1 4 Reprap Prusa Mendel Delta | eBay
Hmmm That looks indeed quite decent driver and unlike the H-Bridges I was eyeballing at first says it is taking step+direction signal. Somehow I have missed this when looking around the ebay for stepper drivers. So Thank you - this is indeed useful information. With a additional heatsink this little driver should handle the drives I was planning to use adequately (they are rated at 1.7 A max but I will not be needing to run them at that level as the first machine I want to do is only about 500x400 mm so rather modest).Quote:
Originally Posted by H500
The driver I was asking about initially was 4 5A TB6600 Axis CNC Controller Stepper Motor Driver Board CNC Controls | eBay - seems like some kind of new revision of RATTM board based on TB6600 but I have no prior experience with stepper driver so my initial impression might be not correct.
The DRV8825 is a pretty good chip -- just be cautious about the voltage as they tend to fry easily. Put a capacitor on the power inputs to absorb backdriven EMF, and get some spares. 12V should be no problem.
That RATTM is the same as the one I tested a year ago -- I'd skip it.
Quote:
Originally Posted by dmalicky
Thanx for a clarification. For some reason I had managed to get impression this one was somehow different - as it is not then I will better steer clear of it for now and will go with DRV8825 for now for the first-learning-the-ropes machine.
Hello Lucas!
Have a question....
Recently, I change the electronic of my CNC (TB6560 to a new TB1H+DIV268N-5A)
I have 4 drivers with a HY-TB268-N6 board and one with the HY-TB268-N2.
The problem was 2:
1- I can´t disable the step motors when I pressed the ESTOP.
Tested all!, configuration ACTIVE LOW/HIGH, ports, wires...I just don´t know what´s up.
2- The N2 board has more power than the other N6...why?
I been waiting for you response, and, thank you very much!
Best regards
Just an update:
My drivers from Lucas arrived , did well after assembly from the vey first moment. No noise at all. I monted the drivers on heavy PC-CPU heat sinks(cheap surplus) for dead effective cooling. I will come back soon with pics.
BTW: Glad you guys get Chineese drivers running well! :-) I was not so lucky.
Just a hint: If you get the HW running well please study in detail the polarity of signals. I observe many of you having problems with reversed signals. It is essential e.g. to have the clock signal in real inactive state while changing direction. Some drivers behave unpredictably when not operated as required.