[H500]

Slow diodes are worse than nothing. The shoot through might even damage the chip. Fast diodes might reduce the heat, but the chip will work fine without them. I never use diodes on my mosfet bridge designs.

[PaulMakesThings]

I have the same 3 axis as lilmike and have applied the same fixes. I've cut the traces, moved the resistors and wired in a 74HC14. I haven't touched the optocouplers, I'm not quite sure what the consensus (or closest thing to one) is about that.

Since the true power ratings aren't quite as advertised, what would be a good stepper to use with the board as it really is? I'm using a 24V 10A power supply. I'm trying to move a home made mini mill about the size of a sherline, with 20 turns per inch. What kind of experiences are people having with various motors with this driver?

Thinking of using these
http://www.ebay.com/itm/251069118152...#ht_558wt_1344

[H500]

Choose a motor with a rating as close to 3.5 amps as possible, with as low of an inductance as you can find (2mH or less)

[109jb]

I would say keep it below 30v and 3A. I am running TB6560 drivers with Keling NEMA23 570 oz-in motors, at 24v and 3A. I am not getting their full potential, but they are running well on my mill- drill conversion. My mill is an older HF about the size of an RF25. It is beefier than aG0704, but round column. When tuning, I was able to get 100 ipm rapids without losing steps, but I slowed it down to 80 ipm to lessen the chances of losing steps. Works very well. These motors really need 5A and 50Vto reach their full potential though.

[H500]

For comparison, on my SX3 with ball screws, I can reliably use 200 ipm rapids on the x and y axes using 280 oz in motors with a 34v power supply and a discrete mosfet driver.

[109jb]

Remember that speed is approximately proportional to Voltage and torque is approximately proportional to amperage. In my case I am at 50% voltage and 60% amperage of what my motor would like to have so if I were to get it to what it wants, i could get 200 ipm easily. I chose the TB6560 as an interim driver knowing full well I would not be able to see the full potential of the motors. That was a "get the machine running at low cost" decision that I am still happy with.

[boldford]

Can you point out one that has separate power inputs? I've not seen one yet. And double points for one that mentions the need for the logic power input to be stable before applying motor power.

I'm sorry for coming in so late. However, if you prefer a separate driver for each axis these may prove to be OK. One Axis Single 3.5A TB6560AHQ Stepper Motor Driver Board f CNC Router Semi-Flow | eBay I've received one this morning and intend reporting in a week or so when I've had chance to try it. Unfortunately, perpetuating the error, it has got the logic voltage derived from the motor voltage.

[109jb]

I...James will be pleased to note it has segregated logic and motor voltage inputs.

I don't believe this is accurate. If you look at the signal wiring diagram for the inputs from the computer, that 5v terminal is just for powering the optical isolation circuits. It doesn't provide logic power to the tb6560 chip. If you look at the bottom side of the board, hidden by the heatsink, I'd bet you will find a little 5v regulator.

[boldford]

I don't believe this is accurate. If you look at the signal wiring diagram for the inputs from the computer, that 5v terminal is just for powering the optical isolation circuits. It doesn't provide logic power to the tb6560 chip. If you look at the bottom side of the board, hidden by the heatsink, I'd bet you will find a little 5v regulator.

I think you noticed my error at the same moment I also did. At least it appears to have true opto-isolation.

[qrstu]

Hello all,

I have some troubles with 4-axis TB6560 CNC Controller after upgrade like in Post#1 running with mach3

X- and Y-Axis doesn't change direction :-(
Z- and C-Axis are running fine :-)

Wiring is the same for all axis. --> Like Post#7
If I change the wiring back as before upgrade it's working fine again

Any idea ?

Thanks

[doorknob]

Hello all,

I have some troubles with 4-axis TB6560 CNC Controller after upgrade like in Post#1 running with mach3

X- and Y-Axis doesn't change direction :-(
Z- and C-Axis are running fine :-)

Wiring is the same for all axis. --> Like Post#7
If I change the wiring back as before upgrade it's working fine again

Any idea ?

Thanks

I would suggest a "signal tracing" approach using a multimeter to check the voltage on the Dir pin of the X and Y axis TB6560 chips while jogging in one direction and then in the other direction. You can use the Z axis as a reference for comparison.

If you don't see a change from a 'high' to 'low' logic level on the Dir pin right at the chip (or vice-versa), then proceed "backwards" one step at a time to see if or where in the circuit you do see such a change (for example, as a next step, put the probe on the output of the 74HC14 (?) section that connects to the TB6560 and check for logic level changes there, and if you don't see it there then put the probe on the input to that inverter section, and continue backwards if necessary to the optoisolator output, opto input, etc. The place where you lose the Dir signal is the place to look for the problem (for example, a poor solder joint, a connection to the wrong IC pin, etc.).

(I'm doing this from memory - I haven't looked at the details of the mod for a while)

[H500]

Hello all,
X- and Y-Axis doesn't change direction :-(
Z- and C-Axis are running fine :-)

Try swapping the Z and X Dir outputs from the buffer. Does the problem follow the X Dir output?

[qrstu]

Hello,

I messured the voltage on pin21 for all axis.
Low --> 0.1V, High --> 4.8V --> Equal on all axis (X,Y,U and C)

But X and Y don't turn the direction.
I have allready changed the TB6560 from another board. No success :-(

For me it's only surprising when a undo the changes it's working fine again.
But I didn't any changes on x- ord y-dir

Regards
qrstu

[doorknob]

Just to clarify - you need to measure the voltage on pin 21 while you are jogging the corresponding axis in one direction, then measure that voltage while you are jogging the axis in the other direction. The exact voltage reading is not as important as whether or not you see a 'high' in one direction and a 'low' in the other direction.

Do the same thing on each axis and report the results.

Does the measurement of the Z-axis pin behavior differ from the behavior seen on the Y- or X-axis pin?

(Also, are you sure that you are reading the voltage on pin 21?)

[qrstu]

Hello doorknop,

Yes, I messured the voltage on Pin21 when I jogged. (TB6560)
It changes from high to low wen I changed the direction and vice-versa.
Same behavor on all axis
But the stepper motors doesn't truning direction on x- and y-axis.
On z- and a-axis they do

[qrstu]

I found the problem.
x-dir pin configuration was connected to y-TB6560 :-(
y-dir pin configuration was connected to x-TB6560 :-(
There is an error in documentation mach3 of TB6560 4-axis board

Thanks for the help
Regards
qrstu

[boldford]

I have decided to modify my single axis TB6560 board so that the power on sequence can be accomplished correctly. It really isn't that hard to do. On the board is a 5VDC voltage regulator. It supplies all of the 5V needs for the TB6560 IC and anything else on the board that needs 5V. I simply plan to leave the VR on the board, but take the VR out of the system and tie in a wire to feed the 5V from a 5V wall wart. It will reguire cutting 2 small lugs and soldering on one wire. The photo shows what will be done. The negative side of the 5V power supply will just connect to where the 24V motor supply negative feed connects as it is electrically common with the common lug of the VR.

I assume this will require you to manually control the power-up sequence. I have some similar boards and what I had in mind was to remove the 5v regulator to a piece of stripboard and use that to control a relay that switchs the (say) 24v to the main board. I think I can control the power-down sequence by sizing the smoothing capacitors appropriately.
I.e. when the 24v is first applied it is dropped to 5v but held off the TB6560 until the 5v is cleanly established IYSWIM.

[pj-callaghan]

Hi everyone, I need some help. I have a 3 axis version of this board, and carried out the necessary repairs to stop missing steps. It worked well. I was able to set up my steps per millimeter perfectly. (Mach 3 program) Now, the problem I am still getting is when the machine is cutting a circle, (only tested with MDF board) and doing multiple passes, both x and y axis are creeping backward towards the home position. When checking with a clock guage in millimeters, the machine is creeping back at + - 0.02 of a millimeter per pass. This may not sound like much, but after 30 passes, the circle is now oval. I have tried (in mach 3) setting the step and direction pulses incrementally to see if and when it would stop this creeping, but with no success. I am using Nema 23 290oz bipolar motors (set to torque not speed) with a 24v power supply.

[boldford]

Hi everyone, I need some help. I have a 3 axis version of this board, and carried out the necessary repairs to stop missing steps. It worked well. I was able to set up my steps per millimeter perfectly. (Mach 3 program) Now, the problem I am still getting is when the machine is cutting a circle, (only tested with MDF board) and doing multiple passes, both x and y axis are creeping backward towards the home position. When checking with a clock guage in millimeters, the machine is creeping back at + - 0.02 of a millimeter per pass. This may not sound like much, but after 30 passes, the circle is now oval. I have tried (in mach 3) setting the step and direction pulses incrementally to see if and when it would stop this creeping, but with no success. I am using Nema 23 290oz bipolar motors (set to torque not speed) with a 24v power supply.

Your description suggests it is loosing steps in one direction only. Could there be a timing issue between the step and direction signals?

[B-RAD]

Or step per rev is wrong, examples is mine through math would be 8000, but when I did the automated setup in mach3 it said 7994.371847 steps was needed, that's not an exact number but close.