AlienCNC 4axis board and magic smoke

[Memran]

Hi all

I've been using an AlienCNC 4 axis all in one board for a couple of years and it has been great --- until today. Today was special.

I turned it all on, and was greeted by some magic smoke and a burned-electronic smell. Now X and Y are dead, but Z and A still work. I can't see anything visibly fried on the board, so I don't even know what components to replace (is it even worth trying?)

Soooo... The aliencnc brand seems to have vanished, so I cannot replace like-for-like, unless I can find a used board. Anyone have one?

Are there any reasonable all in one boards available, or do I really need to bite the bullet and get separate drives?

All advice gratefully received!

[Memran]

I should probably add that I should probably get a better PSU, probably.

I made the one I have out of an old computer 300W PSU, at 36v. I think something with a bit more power would be good.

[Memran]

Something like this, maybe?
4 Axis TB6560 CNC Driver For NEMA17/23/34 Motor 3A | eBay
Any of you have experience with this board?
Thanks

[ger21]

Google TB6560 here and you'll find plenty of experience.

[allesg]

Highly reccomend Gecko 540 Solution. Easy to use. Easy to get support.
Easy to get good tested and well documented wiring diagrams. It will cost you
more to get started but less by the time you get it working.

Many 6560 work just fine, but many don't. If you buy a cheap one don't be surprised if you have trouble and end up with 2 or 3 cheap ones you or maybe the factory toasted. Buy a good tested one from an American company and get American support. There's a guy on EBAY with nice tutorials and tested 6560s
who does a really great job. seller tag is carolbrent.

[Memran]

I've heard nothing but good things about the gecko solution, but it costs as much as my mill!

I found this on ebay:
CNC Kit 5 Axis CNC Breakout Board +Cables+ 3 Axis M542 Stepper Driver Controller | eBay
It looks to be a "proper" driver kit.
Does that look reasonable?

Thanks

[James Newton]

Please, please search here to see what others have run into with those cheap Chinese TB6560 based controllers!

If you can't afford a gecko, and you don't need to drive more than a few amps at 35 volts, you might want to try a Linistepper kit. About $36/axis. You have to build it, but the nice thing is, if you fry it, you know how to repair it! And the parts typically cost less than $6/per axis to repair a fried one.

[Memran]

Thanks for the advice about those Chinese ones. I've searched and read a LOT of bad things, and the only positive comments are one or two people saying 'it worked for me'.

I looked briefly at the linistepper drivers, but I thought they were for unipolar motors only? My motors are all bipolar. This is probably due to my lack of knowledge, but I thought unipolar was the type of stepper where you have one common wire connecting to all other coils?

After examining my AlienCNC board, I found that the IC for the X and Y axis are somewhat melted. I have ordered a couple of replacements, and am going to have fun trying to solder these tiny surface mount chips!
I am still planning to purchase a replacement, however.

[john_100]

Hi Memran ,

running off a 36V supply , I guess you have been lucky for the board to last so long , the A3977 or later A3979 stepper driver IC's are only rated upto
35V max !

just check the two current sense resistors are OK ( I think they are 0.2 ohms)
and the wiring to your motors are not damaged

depending on the design of the PCB , the fun part is going to be soldering the metal tab under the IC to the ground plane

John

[Memran]

Hi John and thanks for your reply!

Since the chipset for the alien board was not previously mentioned in this thread, I'm going to assume you have some experience with it.
Have you performed a similar operation on an alien board?
Do you have any alien board which is not in use?

My PSU is not quite 36v (and probably drops a bit under load), so I guess that is why it was ok for 3 years.

[James Newton]

Linisteppers are unipolar only. But Unipolar isn't as bad as people think it is... Here is a nice page on all the connection options:
techref.massmind.org/techref/io/stepper/connections.htm

Basically any motor with more than 4 wires can be connected unipolar. And you will typically get a better top speed; all else being equal, which it typically isn't. For example, when you go bipolar, you have to buy a more expensive driver (8 power transistors vs 4 in the drive circuit) and if you have spent that money on a bigger motor instead, you would have a higher top speed. Also, most bipolar drive is bipolar /serial/ not parallel and bipolar serial just sucks. Anyway, I could go on about this all day. Bipolar isn't horrible, it just isn't better.

On your surface mount repair, you may want to check out the ideas and instruction on this page:
techref.massmind.org/techref/smds.htm
scroll down and look at the part on desoldering as well.

[john_100]

Hi Memran

not exactly ,

while searching for info on various allegro stepper driver IC's

I found some data on boards using the A3977 IC
including the instructions (PDF) for the 4 axis board from StepmasterNC
its made by the same company that makes the aliencnc boards

(after a quick search today , I found the instructions for your board )

with the data sheet for the A3977 you should be able to trace the
circuit for the aliencnc board

about two years ago Magenta Electronics supplied the kit of parts
for a project in EPE magazine
a stepper drive board using the SLA7062M , its a 3A driver and easier to fit a good heatsink

John