Hi to all my name is Tony, I am new to the forum, love you guys there is ton of useful information here. I am moderately experienced DIY CNC user, I use mostly small CNC mills to produce prototype PCB-s and electronic's housings, front plates...
Recently my Dremmel broke down and I decided to upgrade to silent Chinese 400w 48V spindle. It is a beautiful and useful tool much better than my old dremel 300 but with mount it was to heavy for my Z axis to properly work. I have belt direct drive on Z axis with nema 23 2.5A stepper motor. Stepper driver I used with my machine was this:
http://s23.postimg.org/wzr02yum3/driver.png
http://s30.postimg.org/nv5ki1kr5/WP_20141116_003.jpg
TA8435H driver just didn't have enough power to lift new spindle, so I decided to order new driver, and this time I wanted each axis driver to be separated. To save the cost I bought 2 of the cheap chinese TB6560 for X and Y axis (about $8 each -Ebay) and the 4.5A THB6064AH for the Z axis ($27 -ebay)
TB6560: http://img.dxcdn.com/productimages/sku_217142_1.jpg
THB6064AH:
http://s28.postimg.org/bm46zq9d9/File002.jpg
http://s30.postimg.org/c3hp78q4x/WP_20141116_001.jpg
http://s30.postimg.org/pyfzppkk1/WP_20141116_002.jpg
The THB6064AH is the first Chinese driver that I can speak positively about the build quality, and performance. It is pretty clean and simple design (mostly because the chip does all the hard work and not peripheral components). The heatsink is nice and big, chip is well supported with 2 screws, the board is also screwed with 4 screws with spacers and everything is solid, and there is actualy a thermal paste on the chip! I could not take heatsink apart to take look at the other side of pcb because of special triangle shaped screws which is my only bad thing I can say about this board. From the side i can see 2 drivers that are well placed on heatsink with some kind of thermal sponge thing see the picture:
http://s28.postimg.org/pbyq8iwh9/File003.jpg
The connection to the board is preety simple and all conections are on removable screw terminals. All inputs are opto-insulated and common +5V. The marking on the top of PCB provide information for setting the microstep, decay and drive current which is set by a trimmer. The trimmer is much better and precise method of setting current than switches IMHO. The board came with no manual and as far as I know it is non existent as I was unable to find it anywhere. The seller of the item doesn't have one either. The reason I find manual important is that there is one DIP switch on the board that is not marked in english and I don't know what it does? I was unable to trace PCB signal to the chip because it is on bottom layer that i cannot access? see the picture:
http://s28.postimg.org/fh7l2asj1/File004_2.jpg
I connected the driver on 24V supply and breakout board, set 1/32 microstep and about 45% on current pot and Z axis moved like never before. The action is silky smooth and holding power is excellent. there is not a single sound of motor noise when motor is holding (decay 60%). The motors are almost cold and driver is mild warm to the touch during the operation. Its the best driver I had so far. Then I connected other 2 TB6560 chinese drivers and I soon realized I will have to order 2 more of THB6064AH's. The TB6560's are set on full power with 1/16 microstep, 50% decay, 50% hold current. If I set anything lower then max current I can move machine by hand during hold in operation, only on max current they hold somewhat. I don't know what to do? The motors get quite hot and while moving they sound like floppy drive starting (not smooth at all, they sound like full step on 1/16 microstep). Also during hold there are all king of noises coming from motors depending on where motor stops but mostly harsh hissing sounds.I have only option to set 20% and 50% holding current. If I am unable to tweak these 2 drivers I'm afraid I will have to order 2 more 6064's.