Hi 3v0,
the Tanbo kit is indeed comparatively cheap. €990for the basic version with one drill arm (can be fitted for a total of three). Compared to the BUNGARD CNC drilling machine in the basic version (manual tool change) it was really cheap. For the BUNGARD you must calculate 12.000€
I was thinking about the design of a hobby machine as well. Getting precision spindles for X-Y and Z movement is no problem in Thailand. You can purchase any length and diameter second hand spindles at Chinatown/Bangkok for a few hundred Thai Baht (1 €=56 THBT). Also all kinds of stepper motors are offered cheap and it shouldn't be a problem to make an own CNC-drilling machine.
There is just one small problem arising when it comes to mechanical design. You can't get strong alumimum profiles in Thailand.
Thinking about automatic tool change, which would be desirable, lets the overall costs explode. Using a KAVO-drive with pneumatically initiated tool change takes already almost 1.000€. (impressive data though: 3 phase regulated motor ranging from idle to 100.000 rpm, motor controller included in price)
It isn't the problem to do manual tool change, but with every tool change you will risk misalignment in at least one drive axis. (During tool change the drive motors are disenergized and small movements jerking with a wrench won't be recognized by the system.)
Next month I will however take a ride to Bangkok to purchase the basic stuff for such a machine.
There is a big disadvantage to all hobby machines on the market: Their basic accuracy is not better than 0.025mm. Imagining a board with fine trace technology the vias would be drilled "miles" away from their original position.
It is just a matter of sufficient reduction gears to achieve a basic accuracy of 0.005mm (even better than industry standard).
Take a sharp look at a professionally manufactured PCB. No drill is exactly centered within a pad. My adjustable eye ball system works far better.
Regards
Hans