Has anyone worked out how to balance a Lister. I have a 3/1 which I have finished building. It still thumps and slowly moves around when there is no load on the lister. It will possibly shake the building apart if I fix it down to the floor.
The fly wheels have not been swapped over. Is there an easy way of trial and error to balance the forces such as wrapping lead around spokes etc and if so any idea what amount would make a difference. (As a temp Measure).
I have done a search but can only seem to find this tread. Surly there must be more than this thread???
Thanks in advance. 
Dynamic balancing is fairly easy, you just need to think about the forces involved and try and isolate them as much as possible to get to the force you wish to address. With these engines, there is the vertical component of the piston and rod moving up and down, the accelerating torque applied to the crankshaft during the power stroke, the decelerating torque applied to the crankshaft during the compression stroke and the force applied to the out of balance crankshaft/flywheel/rod big end applied radially as the shaft rotates. There can also be some other forces and vectors applied based on different states of balance between flywheels, ect. The more you can take out of the equation the easier it is.
For my 6/1, I lifted my whole frame with engine and generator head up onto 3/4" rollers on my smooth garage floor. The rollers were placed parallel to the crankshaft to allow the whole assembly to move easilly in the for-aft direction. I removed the cylinder head and crankcase cover to remove any compression forces that might apply torque pulses to the crankshaft. I then powered the crankshaft with an electric motor via a "V" belt and was able to spin it up to better than 400RPM(normally 600+ RPM). The only forces remaining when the engine was spun up this way were the vertical of the piston and rod(very small compared to the overall weight) and the motion caused by the out of balance crank/rod/flywheel. That out of balance can be seen as a for-aft movement of the frame on the rollers. Now one trick that will get you mostly balanced fairly quickly is what I have heard refered to as the "Mr-X" method. Using a piece of chalk held in close proximity to the flywheel either on the forward side or the aft side level with the crankshaft, the for-aft motion of the assembly will bring the spining wheel into contact with the chalk and leave a mark on the flywheel. Without taking any other forces into account, This mark should be near the heaviest point on the flywheels, but due to the inertia involved with the frame accelerating and decellerating, the heavist point will have rotated past the chalk mark before the whole assembly moves far enough forward to touch the chalk. If you do this with a running engine, the +/- torque effects of the power and compression strokes may alter your chalkmarks, even further confusing the position of the actual heavy spot. Best to have an assistant to trip the compression release and fuel rack. If you make the chalk marks while the engine is coasting down with decompression this will remove most of the torque effects. This method will get you in the ballpark though and with a little trial and error and accounting for the delay in the chalk touching the wheel/marking, you can get the balance pretty close. For fine tuneing, I set up a 1" dial indicator clamped to a heavy steel beam setting on the floor and measured the actual movement of the whole assembly. It was well over 1/4" when I started. As I added weight in the correct position, the for-aft movement got smaller and smaller untill I had it under .005". I re-assembled the engine and with the engine running and generator attached, mine is now under .010" setting on pipe rollers powering a 1.5-2KW load.
There is an online balancing tool at the virtual machine shop that has you place equal weights at different position around the wheel and measure the movement results(the dial indicator is handy for that) and should be able to walk you into a balanced state in less than 10 cycles. You need 10 equal weights of a sufficient size to perform the process correctly.
Modeling clay is good for a test weight. If the flywheel is clean and dry, the clay will stick around the inside of the rim pretty well. I have also heard of some using the magnetic or stick on lead wheel weights, but clay is cheaper. You also want to avoide concentrating any weight once the final balance is determined. You want the weight spread out along the rim to avoid overstressing a particular spot on the wheel. My final lead weights(1/4" lead wire) are 17" long and layed along the inside of the rim and bonded to the wheel. Whatever weight you use for test or otherwise, make sure it is affixed to the wheel securely as a flying test weight could ruin your day in short order.
Good Luck
