Reply with QuoteThey are soldered to board.
Hello everybody,
I have just came across this forum while I was looking for more info about these cheap (but not bad) boards.
I am about to order 5 axis variant, but before that I would like to know how hard (easy) is to replace t8435 drivers (in case of damage)? Are they in some kind of socket or they are soldered to board? And if they are soldered how hard is to desolder them?
Thanks.
They are soldered to board.
I would suggest against buying these boards and the main reason is; No support. So unless you know how to build a PCB, you are on your own.Originally Posted by BearPaw
Hello everybody,
I have just came across this forum while I was looking for more info about these cheap (but not bad) boards.
I am about to order 5 axis variant, but before that I would like to know how hard (easy) is to replace t8435 drivers (in case of damage)? Are they in some kind of socket or they are soldered to board? And if they are soldered how hard is to desolder them?
Thanks.
Now to answer your question; looking at my board it seems easy to replace the Toshiba chip providing that you know soldering on a PCB. The chips are soldered to the board.
By the way, why would you like to replace the chip? what would you put on instead?
I hope the above it helps
Thanks kolias for info and moog for picture
I would put the same chip in case that you burn it. Exact driver can be purchased (I mean toshiba t8435). I found it on one site in Europe for about 11 euros, but it might be found cheaper. So instead of buying a new board (even they are cheap) it is cheaper to replace just damaged component.
This advice by Kolias is a very wise one. I know a lot about electronics and had the impression that the board would be very easy to use by anyone. But by reading this forum I see this is not true. A little mistake and a chip will smoke. So when you power it on, you better know what you are doing.
I like my board a lot and it works like a charm, but you must choose a matching motor and PSU and must wire it right. The power is limited also, so you must make a good mechanical design to use all available power.
In my opinion, this board is a sound choice only for people that:
1- Have a good understanding of electronics
2- Know how to choose the right stepper
3- Are sure that this power is right for the mechanical setup
4- Wouldn’t get upset if it smokes
For everyone else, get a board with good manual and failsafe features.
I have read manuals and they are more confusing than clearing up things.
So if I understood good I should use motors with rated current less than 1.6A and rated voltage (24V or more).
Power supply should be >21V and <26.4V (according to toshiba) and 6A.
Too bad that ta8435 and tb6560 have a different pin asignments tb6560 looks like a better choise (more power and more features for less money).
renatopub, is it possible to put a fuse between (Vmb together Vma) and power supply? And what would be rating for fuse? 2.5A?
My knowlidge of elecronics is not great, so excuse me if wrote something senseless
As for current, the motor should be as close to 1.5A as possible. More than that and you are wasting money on motor power you can not use, less than that and you may burn the motor. I would say the ideal range is around 1.5A - 1.8A.
For power supply I would strongly suggest 24V. Less than that and your motor will not run faster than 120RPM, more than that and you are taking a chance on burning the chip. 26.4V should still be safe, but I prefer the peace of mind 24V gives me.
Well, the current capability of the PSU will depend on how many motors you want to hook. 6A can handle 3 motors, but for using all 5 channels I don’t think it is enough.
I never tried the fuses, but I have the impression that there is some risk there. I have read several times that disconnecting a wire from a stepper while running can blow the controller chip. Not sure about that, but I would research a bit before putting those fuses there. I have never heard of fused steppers and there might be a reason for that.
I understand that. It is dangerous to disconnect motor connections while board is powered or even more dangerous while motor is running.
I attached picture with fuse location. I am not sure it is possible to put fuse there, but I am just asking does board allows it (with small modification).
Ok, now I see what you mean. You want to fuse each chip individualy. Well, some PCB tracks will have to be cutted for that... but looks possible.I understand that. It is dangerous to disconnect motor connections while board is powered or even more dangerous while motor is running.
I attached picture with fuse location. I am not sure it is possible to put fuse there, but I am just asking does board allows it (with small modification).
I just don't know how usefull that would be. These chips have automatic current control, if the chip works you wont need a fuse, if the current control is broken then what do you care if it burns, it is already useless
By reading peoples experiences, it seems to me that what can really blow those chips is over voltage caused by back EMF. What protects agains that are the big diodes in the board.
I've finally had a chance to take some photos of my TA8435H board.
Mine has a separate 5v input (plugpack supplied with the board) next to the 24v connector.
Connections are (L to R): 5v plugpack; 0v GND;+24v; blown channel 1;
Stepper outputs are: phB/phB' ; phA/phA' for each
not certain about the relay output - haven't tried it yet.
I didn't worry about polarity of the stepper outputs, just inverted the output in the software (EMC2) if it ran backwards....seems to be ok to do that.
I bought mine from CNC-IN in China/HK & it has a heatsink installed. I run a fan as well to keep it cool. I chose this one because it was just about the cheapest 4 channel driver at the time & I needed to see if the mill would even work to start with. Running at 30v seemed enough to blow the x-channel & the four diodes but it had more torque until then. It took some patience but it is possible to desolder the TA8435h from both sides of the board. Now I use ch 2, 3 & 4 to run my x/y/z axes. My steppers are 6v 1.2A and the board pulls about 0.8A at idle.
Even with all 3 axes in motion (or 2 cutting) it only ever pulls about 2A max.
It seems there are better (more expensive) TA8435H-based boards on the market and when this finally dies I willl invest (throw away?) more money.
The supplied manual is really not very good and from what you guys have found support is rubbish - I guess it's much the same for most of these generic Chinese variations. Autohec (ebay) has 3 & 4 ch boards with socketed drivers & current adjust by trimpot, (and a much better manual/info) might consider this as an upgrade later but at much higher cost. Hopefully do my first test project this weekend.
Cheers, ...John
Thank you renatopub,
I was not sure how current control works, but now is more clear.
So, from what you said this board is well protected except that we have to take a good care when selecting PSU rated voltage.
It really looks like a good board and the only drawbacks are lack of documentation and power.
But, you said that you made it work and that you are satisfied. Aren't you?
Well BearPaw, to say that this board is well protected would be a bold statment
- The diodes they use seem to be the right kind for reducing back EMF and as long as 24V is used it should hold.
- The control chip has a current controller, the datasheet of the chip explains it very well.
That said, the board is not protected for anything else:
- Wrong wiring will blow it
- Wrong voltage will blow it
- too low motor inductance will probably blow it too
Hi,
i use the 5 Port Board from iwannebuy.
Have the board a auto power down function ?
What´s going on with the current when the motor get no pulse ?
The current goes down ?
I hope for an answer.
Bye an thanks
Not really power down, but reduced current. Check the TA8435H datasheet (post #26 of this thread) you will find the explanation in page 21.
I definitely advice anyone with questions on the Chinese TA8435H board to read the datasheet posted at #26. It is understandable that not everyone will be able to make perfect sense out of it, but at least, we will have a common ground to start with.
Trying to read that data sheet is also a good gauge. If you get too bored or confused with the text, this board is not for you. The Chinese board just adds basic glue logics around the TA8435H chip. One that can’t figure the datasheet, won’t figure the board.
Hi
i know the datasheet.
Use the board the REF in ? so the current go down from 100 % (1,5 A) to 60 % ?
Thats what i am looking for.
Thanks
i have the 4 axis version from iwannebuy.i have managed to make it drive three axis if i turn every thing off it forgets two of them if i swop pin 9 for pin6 it will gain movement in one extra plain one way when i swop it back it works in three again i am not that good with electronics i just systematically tried combinations of pins . if any any nows how to make it remember its pins it would help
Ian.
Hi all,
I just bought from iwannabuy 4 axis stepper controller and having some difficulties to get it work. I connected it to the paralel port and to the 16V 5A DC-powersupply and the fan and leds turn on. Here are the settings what I have currently do you know whats wrong ? I have only 4 wires going to the stepper is that a problem ? I am using this stepper motor... http://www.bebek.fi/kauppa/lisatiedot.php?&tuote_id=43
Hodgie, could you chare your setup ?
Last edited by Jur1; 07-04-2009 at 06:45 AM.
hello,since my cnc project is comming to the end I am planing to buy one of this boards(I guess they beat my L297-8 DIY vesion) ,can you recommend one ebay seller?
univeloptech?
Iwannabuy?
easysupply?
yourschoices?
Just too many of them
If i got this right the boards can only give 1,5A and not 2.5A as they say?
And to all of you who have this board working can you share your expirience with them?
@Jur1
In your manual is a working example how to set up mach3.
First it's a bit difficult to find the right motor ports, but if you do it like in manual the motors will run.
If it's not run and you are shure all is right, try to to set "active low" pin 16 in mach3 - that was my solution.
I heared about notebooks that they can't drive a cnc-card (my can), so perhabs try it on a desktop system.
Hope this help.
Laptops can do. The problem is the energy saver function on a laptop. U don't want to power down the hardware during ur machine is running.
