lucas,
thanks for your excellent explanation.
Best regards
Ah, much appreciated Lucas. I couldn't find the datasheet anywhere.
There aren't any pin numbers on the second block diagram but there is a complete diagram within one of the pdf-s documenting the PiBot drivers, which can also be found in this thread.
It turns out that pins 3 & 4 are on opposite sides of chip, next to each other from the left. I don't have enough capacity for precision in order to short them out properly.
Oh, and Lucas, have you ever experienced one of these producing a kind of rasping or grinding noise in the moving motor? I have four of them, one has this issue. I traced it, tried to find what was wrong but there isn't anything.
Last edited by Sion1138; 11-26-2013 at 08:29 AM.
lucas,
thanks for your excellent explanation.
Best regards
Do not assume that the schematic posted by Lucas matches your HY-DIV268-5A driver. There are multiple versions out there. Mine for instance has a different capacitor in the TOQ timing circuit. It is a 100 nF instead of the 1 nF in the schematic from Lucas. There are also other differences. The LED current limit resistors for the 6N137 are both labeled 560 ohms on mine, but they are actually 56 ohms. Please just note that the manufacturer has changed some of the design, and in other cases the board does not actually have what the component is labeled to be. The only way to be 100% sure is to measure it. I am a bit concerned that mine has 56 ohms, I would appreciate hearing back from others if they can measure those resistors.
Shorting out pins 3 to 4 can be detrimental for some machines. if you have the correct capacitor timing circuit that matches your machine it should be left alone. Shorting it out will lead to the drive being set at full torque at all times. For users with Linux CNC this can lead to excessive heat build up. The problem is that Linux CNC does not have a default setup for axis by axis enables. That would allow a motor to cool while not moving. In the default setting for Linux CNC all three motors will be pulling current, loading the power supply, and getting hotter until the machine is shut off killing the Amplifier Enable pin. If you have a scope you need to do exactly as Lucas did and verify the waveform across the current limit resistor. Watch for the spike indicating activation of the torque reduction. If this occurs during a step, the capacitor in that timing circuit needs to be increased. It is surface mount, but not that hard to replace. I
Good Luck.
Tommy
Beste Lucas,
ik heb mij eveneens laten vangen door de goedkope driver,er wordt gezegd 50V 5A ,maar dit blijkt wel een illusie te zijn gezien de datasheet maar 42V en max 4,5A geeft.
De driver blijft op 30% vermogen staan doordat die TQ op 0V blijft ,ze hebben gedacht onderdelen uit te sparen en dit met enkele transistors op te lossen.
Verder zijn de senseweerstanden veel te licht en de diodes over de low side van de H-brug worden ook gloeiend heet.
Ik heb de transistor die de TQ input laag houd losgesoldeerd en de TQ ingang met 4K7 aan de +5V gelegd,nu heb ik wel de volle 100% ,de diodes heb ik ook losgesoldeerd deze hebben een negatieve invloed en zijn in de datasheet ook niet gebruikt.
Zoals je al hebt aangegeven de staptabel blijkt ook niet kloppen.
Verder blijkt het wel te werken maar het is toch niet zoals een duurdere driver.
Ik ga hem toch maar gebruiken met max ca 35V en max 3A ,ook nog wat warmte pasta aanbrengen en dan maar hopen dat het blijft werken.
Heb jij ze nog in dienst of liggen ze al in de vuilbak of heb je nog verbeteringen aangebracht.
groeten,
Ludo Van Ginderen
I rechecked the schematic for those capacitor values and there's one 100 nF missing on the 5V line. There are only 2 1nF capacitors on the unit, both are in the torque reduction circuit, could you indicate wich one has another value on a picture or so?
Regarding the resistors for the 6N137: my mistake, they are 56 iso 560 ohm here also. This is to low, the led current would be 62mA and the datasheet mentions 50mA maximum. But I think that the optocouplers will survive this, a value of 270 to 680 would be best.
@ludovanginderen: I agree with most of what you are saying, some components will be hot so use a fan to cool the top of the PCB to extend their lifetime.
I only have one wich I bought to check it out, I won't use it :-)
I'm afraid that this won't work for long. The transistor just below that capacitor has to discharge the capacitor wich is charged to 5V. There are no current limiting resistors or other features to reduce the discharge current. When the transistor is active it will short that 1µF capacitor and create a very high peak current, value could be something like 10A or more depending on the type of capacitor used. The transistor has a max current specification of 200mA, it will also limit the current but there are no specifications in the datasheet for this situation.
How long did you test this change?
Datasheet:
http://www.fairchildsemi.com/ds/2N/2N3904.pdf
Open source CNC electronics and accessories:
http://home.scarlet.be/ldt006/THB6064AH.html
Just a quick observation about post #63: as we all know, a resistor labelled 560 IS a 56 ohm resistor:
The final digit is the number of zeros after the first two digits; 0 means no zeros, so the value is 56 ohms...
A 560 ohm resistor would be labelled 561...
By the way, I also ordered one of these accursed drives on dec/2, before finding this thread... my bad...
I hope the info provided here by all the brilliant and dedicated people posting on this thread will
enable me to fix some of the design errors in this drive and recover a part of my (modest) investment...
Thanks a lot to you all, particularly the OP: Lucas.
Nelson
I just wanted to thank Lucas for sharing his knowledge, both in this forum and with his open source designs. I have attached pictures of a DQ542MA drive from Ebay. It looks the same as the TB6600 drive on the outside, but totally different on the inside. I have not used anything but geckodrives, so I have no idea how it performs. After reading this forum, I am glad that I didn't purchase the TB6600 drive. It was just luck that I ended up with this one, although I don't know if it is any better.
I cut a track and inserted a 100 ohm current limiting resistor before the 1uf cap and it seems to be OK. On that note I haven't got around to adding this resistor to my other machine and the modules are still working (haven't blown up yet)
Last edited by tt-boy; 01-03-2014 at 05:03 PM. Reason: mistake
Hi,
I am new here and hope to find some help with some timing issues for the HY-DIV268N-5A TB6600 board. Is there any information about the timing of the direction signal in relation to the clock (pulse). As far i found out, the positive edge of the pulse input is triggering the step. The signal needs to stay "high" at least 2200ns before switched back to "low" state, -according to the toshiba specifications.
Is there any information around when the Dir-Signal should be stable prior the positive edge of the clock (Step-Pulse) and how long it should stay stable (in relation to the positive or negative edge of the clock (Step-Pulse)?
Best regards
Robert
Was just pointed to this thread by another member, and all I can say as a newbe to CNC is THANK YOU LUCAS. Been searching for a CNC controller system for a CNC PCB router I want to build and its like digging in the dark. Finally I have some info that will steer me clear of crap out there and to something I can afford but will still work.
I assume that if I want a kit (the one you designed) I go to MassMind and order it there. One question maybe you can help with, Can a kit be purchased (controllers and BOB) for 4 Axis, as Im thinking of driving the y axis with 2 motors (it runs the gantry, will be using linear rail system and ACME lead screws direct drive via motor). The machine will be about 24" x 24" max and used for PCB milling only, so I think smaller motors may work for me (once I figure that part out).
Didn't have much time lately but didn't forget this thread.
How long that it will work depends on your machine settings. The transistor has some work to do only at low speed.
If your start speed and acceleration is high enough then it has to work for a few pulses at the beginning of a move, after these initial pulses the transistor has an easy job doing almost nothing. If you want a "will always work" solution: test it with the machine running at 1-5 step pulses per second.
I did some measurements and it takes approx. 70msec for a stepper motor to stabilise after a single step.
The step pulse width is only 1µsec for some 3D printer firmware.
The entire torque circuit must respond within 1µsec and remain active for 70msec (preferable longer for safety reasons).
This is quite difficult to get right with simple circuits, even a retriggerable one shot has difficulties to operate within these margins.
24" x 24" for PCB's only? That are large pcb's :-)
I would suggest to visit the "PCB milling" forum here, you will probably find very usefull info there.
Your setup is no problem, you can slave the 2 Y axis in software (Mach3 etc..) or connect the 2 drives to the same BOB output.
There are some differences between my BOB-drive setup compared with the Massmind one. Take a look and decide wich one suits you best.
I had a quick look at the latest datasheet and can't find it neither.
There are more spec's missing, like the max. output current that can be drawn from the internal 5V regulator.
On top of this they have changed some other parameters wich required some component changes in my design.
I have a design ready and it's in use on a Mach3 mill and 2 3D printers, all 3 are working fine. It will be released when I find some time to compile the documentation and update the website.
Open source CNC electronics and accessories:
http://home.scarlet.be/ldt006/THB6064AH.html
24" x 24" for PCB's only? That are large pcb's :-)
I would suggest to visit the "PCB milling" forum here, you will probably find very usefull info there.
Your setup is no problem, you can slave the 2 Y axis in software (Mach3 etc..) or connect the 2 drives to the same BOB output.
There are some differences between my BOB-drive setup compared with the Massmind one. Take a look and decide which one suits you best.
Lucas, I have been kicking this around for a long time and decided that it would be nice to not only mill PCB's but also aluminum (understand it will req light cuts). I read through a build on this forum and really love it, as its exactly what I envisioned. Cant remember the member, but it was a 24" x 24" one. As for the drivers etc, are you ones available from you ? Wasnt sure if I had to get them from MassMind, as the page kind of eludes to them being made by you FOR them.
Open source CNC electronics and accessories:
http://home.scarlet.be/ldt006/THB6064AH.html
Ah, ok, didnt realize that. Well not knowing much about CNC (still learning) chances are I would go with your units, as you know your stuff and what it will do, and that makes me feel a lot more comfortable
Thanks Lucas and every one for the great suggestions
I have 3 of these drivers from China and I noticed the same behavior of weak torque (running nema 23 with power supply of 36 volts), then I checked the board and the TQ (pin 3 was always LOW - 0 volts)
I connected the pin 3 and 4 to make TQ HIGH as you can see in the picture below
This mod made the motor stronger but I noticed that the 2 blue resistors (I measured them to be 1 ohm connected to pin 11 and 15 each) heat up a lot (I can't even touch them) so they will blow up if I run like this for long time.
I made sure that my Vref is below 1.95 volts (by lowering down current limiting switches) but they still heat up (I think even while the drive is not running the stepper motor)
My question is that are these blue resistors not powerful enough to handle this? should I replace them with something like 5W 1 ohm resistors? I guess I need to measure the voltage drop over them and calculate the power requirement for them since I don't know their current power rating.
What else can I replace on the board to make this board survive? Lucas you mentioned something about replacing the capacitor that will blow up the voltage regulator, which one is it?
When did you buy these? I can't understand that this isn't solved yet, hundreds of buyers must have complained...
Suggestion: Complain to your buyer and you might get a partial refund :-)
The resistors are 0.22 ohm, you can't measure these low values with a regular multimeter, a milliohm meter is needed for this.
The drive is always at 100% torque with the change you applied, this indeed results in heat even when the drives are not spinning the motor.
You should also notice heat from the chip or do you have active cooling (fan) on the heatsink?
I don't know if the resistors will fail: I would need the datasheet but don't know the type or manufacturer.
Changing the decay mode has an effect on the resistors heat but the TB6600 doesn't have this feature.
I think they will survive if cooled, you could change them to a higher wattage type, it's recommended to use low inductance resistors and these are expensive.
There are 2 electrolytic capacitors on this drive which are questionable:
- The biggest one (1000µF, 50V) marked on the PCB as 3300µF ... MUST be a low ESR type and it isn't, it will heat up and die.
- There's a 470µF 25V on the 5V output from the chip, the datasheet says that this should be a decoupling capacitor, this is usually in the area of 100nF and a 10µF electrolytic in parallel.
A capacitor with such a high value could destroy the chip due to the high inrush current on power up.
Open source CNC electronics and accessories:
http://home.scarlet.be/ldt006/THB6064AH.html
Does anybody know anything about this driver? and how well it works?
Sold here
TB6600 Stepper Motor Driver Board 4.5A CNC engraving driver board
and on ebay
TB6600 Stepper Motor Driver Board 4 5A CNC Engraving Driver Board | eBay
Thanks Daniel
The heatsink is small and also on the bottom, so it will likely need a fan. But the other side of the chip is exposed, so a heatsink could be applied there, too.
The connectors look identical to the Rattm version: http://i00.i.aliimg.com/img/pb/587/5...594587_317.jpg
I tested one of those and found the connectors were loose enough to break the motor current, blowing the drive: http://www.cnczone.com/forums/steppe...l#post1233542S
So, superglue them so they can't separate.
I'm sure the cap is not a low-ESR, as Lucas has pointed out. That may be ok for low usage, but eventually it will die.
It's currently the lowest priced version on the US ebay, and quality evidently reflects that. Which is not to say it won't work with some fixes. The design is unknown. Let us know if you test one.
David Malicky
Looks like the chip is glued to the heatsink (no screws) and I don't see any screws or other fixations between the heatsink and PCB.
Would they really dare to sell a drive with the heatsink glued to the chip and this whole assembly hanging only on the tiny pins of the chip?
Anyone who has handled a TB6600 chip will know that the pins are flimsy, no strenght at all.
Am I missing something or is this really the case?
I wouldn't even dare to use a construction like this for a prototype.
Open source CNC electronics and accessories:
http://home.scarlet.be/ldt006/THB6064AH.html