If you have any trouble with the TB6560 board there is a thread on it over on the zone. Some people are getting good results with it and some not. I am pretty sure 878 oz/in is overkill as they probably would run the 45 just fine. Alot of good information on the x2 retro here

http://www.hossmachine.info/cnc_conversion.html
He used 381 oz.in steppers and he has basically posted a step by step walk thru of the whole process. Lots of drawings with measurements as well. Might be worth a look.

I went with 381's from Keling for my router and the numbers look alot different on the Inductance. Apparently Inductance along with Voltage gives a motor power output formula. From the Gecko site:

The motor power output (speed times torque) is determined by the power supply voltage and

the motor’s inductance. The motor’s output power is proportional to the power supply voltage divided

by the square root of the motor inductance.

The 878 math is Motor inductance (15 square root is 3.872) Going to use Stepper rated voltage of 6.4 first = 1.653 Using the 24 Volt PS = 6.198

On the Keling 381 inductance is 2.8( Square root is 1.673) Stepper Rated Voltage is 2.55 first = 1.524 Using the 48 Volt PS = 28.69

Gecko says this is a Power output number and alot of guys say that Voltage is speed, from the math it looks like it is power too. I think the high inductance number is why some of the import steppers get a bad rap.

The resistance numbers are alot different as well and I bet that will be shown as heat.

I placed my order last week for Keling equipment and it came up to $506 shipped, Ordered Monday and had it Thursday. I spent an extra $100 on a breakout board upgrade, C11 , the c10 is less than $30 so you could take $100 off the total. 48 Volt PS 7.3 amps, KL6050 drivers for the 48 Volt PS, 381 3.5 amp steppers, C11 board.

From Gecko's numbers the motor power output should be 4 almost 5 times higher, but this is just for a router.

Please don't take this the wrong way as I have always wondered why some of the import steppers get bashed on some of the forums. I had chalked it up to pros, the support locals, and people in general not wanting to buy overseas. I buy from China on a weekly basis. Proximity switches are on the boat, I hope I hope. I took a look at your post, followed the link and wanted to see where the difference was. I think I learned alot from doing some reading and some googling. I hope I have read things right, maybe the more experienced guys can chime in if my logic is flawed.

I had almost ordered a kit much like yours Friday or Saturday night and decided I wanted to start adding things to the cart and see what the cost difference was. It was close enough to buy on this side of the pond and be able to call and ***** if something didn't work. We all like to be able to do that right???

I fell into, and I really mean FELL into a hell of a deal on a CNC router needing new electronics. 4X5+ table with router for less than $350. DAMN craigslist!! Figured I wanted to retro and had the money and time to run with it.

I will be making a thread about it as well as this is my first project under cnc control. I know I will have LOTS of questions.

Chris