easy-cnc mechatronics board good or bad?

[pminmo]

Couple of points, the A3977 DOES NOT TOLERATE anything over 35V, and that includes back emf. So Practically don't run it at more than 27VDC power supply voltage. 2nd, you might get some thermal adhesive and glue a heatsink to the 3977. Something that has verticle height and plenty of fin area to pull some heat out of the chip.

[James Newton]

Originally Posted by HankMcSpank Old thread I know, but thought I'd give a bit of feedback - I bought this board a couple of years ago when I was clueless...Is still am, but I can report that I've fried about FIVE A3977 ICs during the time I've owned it. Two of these were probably down to my fault (bare pcb base touched something metallic etc)...but he other three...hmm. Of course swapping out the A3977 on this board is a breeze since they're socketed, but at $10 a pop (delivered) having these ICs fry so frequently is wearing a bit thin. My only other board to gauge this one against is a cheap Chinese TB6560 variant.....that chinese one is awful and makes the mechatronics one appear ooze quality by comparison!

Thanks for PMinMO for pointing out why the A3977's are frying: Heat will get them every time in that design since there is no heatsink! Controlling lots of power, especially if you are doing it in microstepping modes, will cause any controller to heat. I can't imagine why the designer didn't account for that.

And then there is the garbage TB6560... Don't even get me started.

These people selling junk really tick me off. It's driving people away from the hobby by giving them a bad experience and wasting their money and time. We need a "protect the newbies" campaign to keep people from making that mistake with their first purchase.

[pminmo]

The TB6560 itself isn't a bad chip, it's the board designs that turn it into crap...

[James Newton]

Originally Posted by pminmo The TB6560 itself isn't a bad chip, it's the board designs that turn it into crap...

Yeah, I should have been more clear. Although... I've been given to understand the TB6560 is a little light on self protection... e.g. not terribly rugged.

How do you feel about that open source TB6560 design you have on your site? Is anyone using it? Is it "hardy"? It looks like it would be a bit easier to repair than most of the junk boards from China.