There has been various talk within the forum regarding the cost of buying a dynamic balancer. I managed to build my own for about £62. Basically what i have done is mounted a small single phase motor to a block of walnut. Then I purchased some aluminium bar, i manufactured the motor pulley, top assembly and pulley. The bearings were cheap cast iron style plumber block bearings, they were subsequently machined flat and square. The bottom supports were then drilled and support holes reamed creating an interference fit for the brass rod - linking the rotating assembly to the base. The belt is a standard 6mm O-ring cut and glued to length. The balancer sits fine on a desk, underneath it is supported by four soft foam isolator pads.
The top assembly can be balanced single and two plane. I am in the process of manufacturing a broader balancing disc so I can sufficiently balance 2 plane overhung.
I have machined a few pulleys to mess about with speeds etc. I have managed to balance the top assembly down to 5 microns Pk-Pk – then i started to loose my phase. I am balancing using my trusty old IRD 880 and 2 IRD 970 accelerometers.
Motor - £15
Aluminium - £20
Brass rod - £5
Bearings - £6 each
O-ring - £2 per meter
White plastic end hubs - £1.50 each
Nuts and bolts - £2.50
Wooden base - £8
Foam pads - £2
Sorry the photographs are not the best (taken from phone). If there are any queries, drop me a line.
Some balancers are purpose built, slick but very expensive £1500 - £2500. I could build a slick model too for that money!