Thanks for 3dprintersonlinestore for great support. First of all plz have a good sense of what ur doing. if u do you will not have probs. the video guide is ok. Some pieces are not the same as the video. but easy enough to figure out... Took 6hrs to assemble. and we have been printing are buts off from key chains to mario figures.
However, with some effort put into the heated print bed and calibration, it will print as well as a $2500 printer. There isn't really anything else on the market, in my opinion, that touches this printer at this price. It's pretty quick and prints with nice surface finish and is infinitely repairable and up gradable. I don't regret my purchase in the least.
The mechanics of this printer are pretty good.
1. Initial MAXTEMP error and the extruder indicated a temperature of 357 degrees at room temperature. Thermocouple set screw was too tight, shorting out the wires. Loosened and re-positioned.
2. Fans slowed down when power supply loaded down with both heaters and all motors running. Power supply read 11.75 V no-load and 9.6 V under load. Seller replaced power supply.
3. Extruder heater started fluctuating wildly and then stopped working entirely. Extruder heater voltage at the controller board was 0.5 V. Seller replaced the MKS controller board.
Z-axis uses 2 stepper motors. One of them was kinda stuck, it was very hard to move by hand (unpowered) and as a result it was often missing some steps. This was fixed by itself after some time. The other stepper motor moved in the opposite direction as it should, this resulted in 4 broken linear bearings. After swapping 2 wires on the stepper and buying new bearings all was fine.
Wires from power supply to the control board are too hot, they should be thicker.
When I start the printing, the bed and nozzle are heated first. This takes some time but you can not just leave the printer because the Z-axis positioning is not very accurate and printing sometimes begins 1-2 mm above the bed.