I use a high-point balancer for checking & correcting main & tail rotor balance.
The dial indicator, will help determine run-out on shafts-etc.
Before installing the fan set it up on a hi-point balancer. According to the balance of the fan you can determine were the fan needs area taken away to allow proper balancing. You can take a drill and drill the opposite points (reverse sides) were needed to bring the fan into correct balance. Never drill through a part, only slightly to make the part lighter opposite from the heavy side.
Install the fan hub on the motor and make sure its as close to center as possible. Put the engine in a stationary non movable position, I use a vise with a insulator pad of some kind to make sure nothings damaged. Take the carb off, and put a piece of old rag into the carb hole to keep out debris. Then set-up the dial indicator and place it to were it contacts the upper edge and check it for alignment (run-out). According to the manufacturer, it should be roughly .004-.005 or less. If not in specs, break the nut loose and rotate about 90 degrees. then re-torque the nut and check until you're happy with your results.
Them install your clutch and check the bell to clutch tolerances. I have see people use tape to try and center it as close as possible at first. According to the brand loosen & position it(rotate it) until you get tolerances from .009-.012 thousandths clearance. "Distance can be figured by comparison of the Outside Diameter of the clutch in relation to the inside diameter of the you bell housing. Then dividing these by two"/ Too much could cause clutch breakage and to little will cause the clutch to engage to soon. I usually install a new clutch liner when checking with CA, some use JB weld. A machine shop turned down the liner to within the clearance specs for a small fee for their time invested.
Doing so at your own risk, but when correct you should have a silky smooth heli after balancing TR blades-Mains..correctly. It takes time..be patient.
I use a magnetic dial indicator holder for $20.00 it is worth the extra cost.
https://www.jlindustrial.com/search/result.asp
I just saw you're in Australia so try here:
http://www.mahrfederal.com/digital_e...indicators.htm
See if they have a analog type & not digital is very $$