[stevenrf]

Don't trust the schematics that come with the boards. It sounds like you have the correct settings for one axis and wrong pin settings for the other 2.

[fma]

Hi there,

I recently ordered that 'nice' board, and read all the usefull informations arround; thanks for sharing! I will apply them as soon as my board arrives.

The only remaining issue I see is that power on/off sequence. As I plan to use little NEMA 17 motors (to drive a Prusa reprap), 12V will be enough.

Do you think it is OK to power the board with 12V without having the short-circuit issue during power on/off?

I plan to remove the diodes between the VDD and the motor capacitors, in order to use them to power up the board during shutdown, instead of adding diodes back, as described in a previous post. Is it OK?

I may have to remove the 12V regulator, as it has a 2V drop voltage, and need at least 14V in order to work. This will also fix the fan issue.

Thanks for any comments on this solution.

PS: I'm not sure to clearly understand what you plan to do with the additional relays for power on/off sequence; could you make some schematics? Thanks!

[bschwand]

Hi everybody,

I have the 4 channel version of the board. It was not running well at all so I did the mods described in the post #91. Now it seems much much better. I still have to find the correct parameters for EMC however. I also found that DIR pin also should be made to go through buffer or we will lose steps on direction change. Anybody has done that conversion ?

I wonder if anybody has gotten this board:
Wholesale CNC Engraving Machine TB6560 3 Axis Stepper Motor Driver Board

from the description it seems that they looked at this thread, and applied all the mods to the new design !

[ktchk]

Hi I am testing tb6560 chip single drive boards.
The first test was very noisy and lots of missing steps.
I raid the thread and notice that the rising edge problem.
I try to reverse the pulse polarity with the emc2 control software.
It works, now my controller works fine.
No need to modify the circuit.

[ToshiroTamigi]

Hello guys:
I have one of such 3 axis board.

Concerning the power sequencing problem I think that I'll use the spindle relay (that i don't need in my work-in-progress cnc).

I have to investigate further but this is my idea:
Route the positive supply to the NO relay contact, the other contact will be connected to the supply input of the board.

Cut the the supply trace to the 12v regulator and connect directly to the NO contact (connected to the positive supply rail) so that is is connected to the power supply directly.
Connect the relay coil directly to the correct voltage, so the 12V regulator if it is 12v or 5v regulator if it is 5V.
In this way as soon as the regulator settles itself to a voltage enough to trigger the relay the drivers will be powered, assuring a less harmful power sequencing.
I need to check what happen at power off.

The spindle data pin can be used as an optional Output.

[ToshiroTamigi]

Also, i think that i'll remove the optoisolator at all.
They are useless with this design: the 74hc14 connected to the parallel port pins are powered by the same supply as the rest of the board so no form of isolation exists.

[James Newton]

(snip)
1.
The 6560 requires to get the 5V first and later it will accept the motor voltage. The schemtic of this board reverses this requirement! :-( Constantly! Let me explain:
The 12V and 5 V regulator along with their capacitors perform a delayline for the 5V supply. It takes some milliseconds until the 5V is stable on the drivers.
Ignoring this the Motor supply is directed to the drivers instantly.
(snip)

Hey John, thanks for bringing this to our attention. I've opened another thread to discuss exactly this issue:
http://www.cnczone.com/forums/steppe...60_driver.html Perhaps you would like to comment there or follow that discussion.

[Mariss Freimanis]

I would like to offer some general opinions regarding monolithic motor driver integrated circuits. A monolithic motor driver IC integrates low-level control circuitry with a power stage able to drive a motor in a single, neat and ready to use package. That is the promise anyway; unfortunately the execution usually falls short for one or more of the following reasons:

1) Custom (application-specific) ICs are very expensive to design. Usually a big client approaches an IC manufacturer and says "I have motor application for a printer and I will need 10 million ICs designed for controlling this motor to these exact application specifications."

The client signs a contract that allows the IC manufacturer to sell the resulting design after the client's needs are met in exchange for monetary considerations.

The IC manufacturer then free to sell the IC in the marketplace as a generic device. Unfortunately, the device only meets one customer's requirements exactly, the one who commissioned the device in the first place. Everyone else afterward who buys it has to deal with the idiosyncrasies built into the device as specified by the original client.

2) An IC manufacturer learns from their client base and attempts to build a generic motor IC on their own which should satisfy everyone. The manufacturer may be a top-rate IC designer but that doesn't mean they are top-rated motor drive designers.

Allegro comes to mind here; they have nicely executed ICs that make very fundamental design mistakes in understanding what's required to make a motor happy. An example is their recirculating, non-recirculating mode switching depending on what angle you are on the sine-cosine reference. It is a naive misjudgement of practical drive requirements.

I don't mean to single Allegro out, there are design criticisms for all the other monolithic ICs as well.

3) Integrated circuits are exquisitely sensitive to temperature gradients. They depend on a constant temperate across an IC silicon chip. Manufacturers constantly combat thermal gradients across an an IC to to guarantee it will work properly. To an IC designer, a motor drive is an IC from hell. There is the motor section that generates enormous heat and that heat interferes with proper operation of the control section of the IC. Motor drive ICs are not reliable devices; it's why they smoke easily.

4) Manufacturer's marketing departments over-spec the devices they sell. A good example is the L297 / L298 chipset. It was touted as a 2.5 A rated IC even though no sensible engineer would ever use it with motors over 1 Amp.

I have seen the L297 / L298 chip-set, the various Allegro offerings and the currently popular Toshiba IC come and go. In my opinion they are all doomed to failure for the reasons mentioned. Don't worry, there will be another new one next year and it will have the same fate.

Mariss

[Lake Cruiser]

My machine has worked ok without any mods until yesterday. I used the machine about a week and a half ago and when I shut it down it worked ok. When I turned it on yesterday the Z axis did not work. It shows activity on the LED, and when you first turn it on all motors lock like they have always done. I am not using the 4th axis and switched the 6560 the 74 drivers and the opto's. The motor also works when switched with the X or Y. Any ideas?

Thanks in advance

[DirtBound]

My machine has worked ok without any mods until yesterday. I used the machine about a week and a half ago and when I shut it down it worked ok. When I turned it on yesterday the Z axis did not work. It shows activity on the LED, and when you first turn it on all motors lock like they have always done. I am not using the 4th axis and switched the 6560 the 74 drivers and the opto's. The motor also works when switched with the X or Y. Any ideas?

Thanks in advance

I had this happen with my x axis today, it still moves but not normal kinda sputters at a very slow speed. Motor is good and all the other axis's work.

It was working last night, but mach3 did trigger a driver watchdog error?

I am thinking it is a G540 time?

[aarggh]

I had this happen with my x axis today, it still moves but not normal kinda sputters at a very slow speed. Motor is good and all the other axis's work.

It was working last night, but mach3 did trigger a driver watchdog error?

I am thinking it is a G540 time?

The best thing I did to fix my 6560 problems was to go to a G540, it was almost like a religous experience once I had it working! For the huge amount of completely wasted time I spent trying to chase potential earthing problems, wiring problems, etc, etc, it really made me wonder why on earth I didn't do it earlier!

cheers,
Ian

[James Newton]

My machine has worked ok without any mods until yesterday. I used the machine about a week and a half ago and when I shut it down it worked ok. When I turned it on yesterday the Z axis did not work. It shows activity on the LED, and when you first turn it on all motors lock like they have always done. I am not using the 4th axis and switched the 6560 the 74 drivers and the opto's. The motor also works when switched with the X or Y. Any ideas?

Thanks in advance

This sort of failure is exactly explained by the FACT that every single TB6560 driver I've ever seen totally violates the chips specifications for start up sequence as specified by the data sheet. For more on this see: http://www.cnczone.com/forums/steppe...60_driver.html These driver CAN NOT be reliable because they don't manage the power up sequence correctly. Everyone of them is "tossing the dice" every time you turn it on.

[Lake Cruiser]

Well...I brought the O Scope from work and compared signals from the Y to the Z. All signals were the same. No for the mystery. When checking the Z enable (pin 4) the Z starts working removed the probe and it stopped. I found that if I shorted pin 5 to pin 4 it worked. Now there is a jumper between pin 4 and 5 and I am up and running again. The down side is that I ordered yet another board before I made this discovery. Maybe when I get all of the bugs worked out I will go with Geckos.

[Lake Cruiser]

OK...latest update. I got in my other (yes I ordered another one) 4 axis driver board. My old board has been working fiine since my "Mod". I connected the new board to my machine and guess what? NO Z DRIVE! My conclusion is that my parallel outputs on my desktop pc are not enough to drive the Z axis. Also the new board drives the motors differently than the old board, (motors whine more and X axis seems weakereven though the settings on the board and Mach3 are the same).

[randyjb]

Hi i am new to the site and this my first post i order this with out reading to much about but any way here is pic of the board but frist when i got it i hooked it using mach 3 i had Z & X no Y so i open kcam the i had y but no z or x so the i hooked it up to the other computer when i plug in the LPT all three led came on did not work at all so move it back check all setting then i had a 3 axis work i hope this help

can some one please post a pic on a 3axis with the current limiting circuit bypassed i want to make sure before i cut one more thing when i jog the stepper start turning fast then stop

[arnederoest]

Hi all, I'm new to this forum, although I have been reading some threads for quite a long time.

My problem:
I have the 4 axis driverboard.
I made all changes as described in #91, but still no improvement in performance. Noise seems to be reduced though. I'm pretty sure I did all the mods correct.
If I try to run an axis at more than 2 mm/s (640 Hz steps) the motor starts missing steps and sometimes even stops turning.
It even seems to be worse than before the "fix". The X and Y axis were performing quite okay compared to the current situation, only the Z axis was problematic. But I decided to do the mods for all axis.

Configuration:
Using EMC2. Steptime and stepspace tested 5000 up to 20.000 ns each.
Dipswitches all ON. No microstepping.
Power supply 31 volts (I bought 36 volt power supplies but limited them as much as possible after reading this thread, they won't go lower than 31 volts)

Anyone any idea what to test next?

I'm getting quite tired of this and I'm considering to buy an expensive driver. Some people are advising the Gecko G540. Is it really that good? My experience with American Made stuff is really bad so far and the text "Quality American Made Motor Control Products" doesn't reassure me at all..
Is there any other driver you can advise?

[James Newton]

Hi arnederoest, I can tell you with absolute certainty: The Gecko drives are really that good. They just are. If you need more than 70 watts (2 amps at 35 volts) of drive for your motors, up to about 175 watts, nothing beats a Geckodrive in that range. If you can get by with less than 70, the Linistepper kit will do as good a job and cost about half as much. But the first step is figuring out how much drive power you actually need:

CoAMarcus^ says:

"Pick the weight of the heaviest item you are pushing around. If it weighs 40lbs, use 40lbs. multiply it by the IPM [Inches Per Miniute] you want. Say that's 1,000 IPM. Divide the result by the magic number "531". The answer is 75.3 Watts".
Watts = IPM * Lbs / 531

or^

Watts = torque (in in-oz) * RPM / 1351

This torque based calculation is generally going to be a more accurate estimate of the motor required for a mill or other system where a lead screw is pulling a load because the additional friction and mass of the system that moves the load is also included when you measure the torque required to turn the screw.

Once you know how many watts you need, buy a /quality/ driver that can deliver it reliably, not as a peak load, but as the standard operating power. Buying a cheap 6560 is a false economy. Eventually, it's going to fry, and even if you can repair it, when you consider your time, a better quality unit will cost less in the long run. Up to 70 watts, Linistepper. More than 70, Geckodrive.

[doorknob]

Anyone any idea what to test next?

What are the specs of your motors?

For example, how many wires do they have, what is the current rating, and what is the rated winding inductance?

[arnederoest]

Thank you James Newton and doorknob,
First of all, I don't understand why the Imperial system still exists when we have the Metric system. It is so much easier. There are no "Magic Numbers" at all in the Metric system!
If I would like to lift a mass of say m=10 kg with a velocity of v=1 m/s against the gravitational acceleration of (keep it easy) g=10 m/s^2, the power I need is:
P = m*g*v = 100 Watts
The numbers I filled in are estimates.
My X,Y table is quite heavy, but has less friction than the Z axis. And X and Y are not pushed up against gravity. I think my Z axis is only a few kilograms, but moving it by hand is more difficult. This is mainly because the lead of the Z axis is only 1 mm/rotation while X and Y have 2.5 mm/rotation.
I think I'll stick to the estimate of around 100 watts per axis.
If I can deliver 3 amps at 36 volts that is probably sufficient.

I'm using Japan Servo steppermotors I had lying around. The type is: kh56lm2b006a. Unfortunately I can't find a datasheet or specs of these motors. What I know: 6 wires of which I connected 4 and 1.8 degree per step.
I think they are strong enough to deliver the required torque since the performance before my "fix" was really a lot better for the X and Y axis. (not Z) It was moving and accelerating quite fast in X and Y. Only the driver was making a lot of noise and the Z performance really sucks. That's why I decided to do the fix for all axis.

[texaspyro]

Try reversing the polarity of the step pulse in you configuration. That may give you the proper setup/hold time in relation to the direction signal. Depending on how you did the mod, that may have changed.

BTW, when I did the mods to my board, it made no difference in performance. I can still only push my MAXNC mill around at around 12 IPM.

BBTW, the english measurement system still exists and will still exist long after we're dead and burried... get over it... embrace the ancient... femtofortnights rule!