This is regarding R8A robotdigg soldering machine we would like to 
know some technical datas about this machine.  
1.  Accuracy on X,Y & Z axis?
2.  Operation range of R axis?
3.  Minimum / maximum solder wire size recommended for R8A machine?
4.  Minimum / maximum solder wire feeding speed?
5.  Minimum / maximum soldering temperature range?
6.  Minimum / maximum recommended solder tip range?
7.  Solder tip cleaning frequency if any?
8.  Recommended gap between soldering pads to avoid solder short?
9.  Is this suitable for 0.2mm (gap between pads not pitch) edge to edge 
designed pcb?
10.  What is the minimum space clearance required for better soldering 
around the soldering part?
11. Is there any restriction of tall profile components around the 
soldering part?
12. What is the maximum height of component is recommended around the 
soldering part?
7. I have not found a solder  tip cleaning capability built into the software.  The Chinese manual does not explain many capabilities the the software actually has.  I may have not discovered it yet since I cannot read Chinese.

9.  I would say no.  The machine does not seem to move in less than 0.2mm movements even though in larger movements it has much more precision.  Also, the size of the solder tip is going to determine the minimum pad size.  It will be difficult to have a tip that is small enough to not touch the adjacent pad and have enough mass to heat larger pins.  And the solder tends to wander around since the solder tube is large enough to handle very large wire solder.

10.  This will be determined by the solder tip you use.  I don't think it would be advisable to have surface mount components less than 3mm away.  As for taller components, the angle of the solder tip and heater will determine the minimum distance.

11. This will be determined by the angle the solder tip /heater and the side the pin is soldered on.

12. I use 5mm, but the software allows you to set the height above the PCB that the tip uses when moving.  So you can determine the max height you want.  However, the software will always use this height between every move to a new pin or set of pins.

I hope this helps.  I am still a novice at this.