Hello Dennis, To balance a assembly, it is best to have each unit balance separately and then again as a assembly. Some electric motor shops can do balancing for engines assemblies and electric motors.
About every 10 years, I pull my motor for maintenance and install another motor and transmission that went into maintenance 10 years ago. I got it down to where I can do this exchange in two hours. The electric motor shop I go to, first balances the motor rotor after its been recondition, assembles armature in the motor, installs the taper lock coupler and then balance again those two units together. Sometimes the taper lock bushing may have to be rotated in the taper lock housing to reduce the vibration. When they fine the best position of the bushing, then they punch mark it, so the user assembles assembles the components in the correct position. Then they balance the flywheel separately, install the flywheel on the coupler and test run the balance again. And again they may have to rotate the flywheel on the motor coupler to get the best balance point. It is also punch mark so the user installs it in the correct position. This balance method is done for all rotating components. It may that the flywheel you have is design to balance the engine that it was on. This type of flywheel is call a external balance flywheel. A internal balance flywheel is design for a balance engine or its best for a balance electric motor. Purchasing balance flywheel assembly, which includes the flywheel and pressure plate, are normally mark with a indicator so user bolts these two unit together in the correct position. It is also importance that the motor coupler has a pin hole install by the coupler manufacture. A crankshaft flange has this pin hole, so the flywheel pin press fits into the pin hole. Use only flywheel shoulder mounting bolts. Standard bolts allow the bolt threads to touch and wear the flywheel holes. Using standard bolts could allow up to 0.003 inch clearance, it is best to not to go over 0.001 inch in clearance. You will also notice, than when a flywheel is assembly on a engine crank, there is a raise center where the flywheel pressure fits over this center raise. I had the manufacture that made my taper lock coupling, machine this pressure fit center raise and also install a pin hole so the flywheel pin will also press fit into this hole. You may get by with the standard installation, with no center raise and pin up to 5000 rpm for awhile. I had my assembly balance for 10000 rpm for a increase safety factor. Roland ----- Original Message ----- From: Pestka, Dennis J via EV<mailto:ev@lists.evdl.org> To: Electric Vehicle Discussion List<mailto:ev@lists.evdl.org> Sent: Monday, July 07, 2014 5:07 AM Subject: Re: [EVDL] Vibration Wanted to give everyone an update on the vibration problem. Took it to a local mechanic and put it on a lift. He raised the rear end and had me rev the motor while he was underneath. I tried 3rd and 4th gears and both were the same. Vibration became very noticeable at ~ 1500 rpm. When I drive it I don’t really notice it until ~ 3000 rpm. Looks like the problem is somewhere in my motor assembly. Motor, flywheel, pressure plate, coupler, ?. I suspect it needs to be balanced. I’ll pull it this winter for a full inspection, and then try to find someone that can balance it. Thanks for all the responses; Dennis Elsberry, MO http://www.evalbum.com/1366<http://www.evalbum.com/1366> http://evalbum.com/3715<http://evalbum.com/3715> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140707/29bb62d0/attachment.htm<http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140707/29bb62d0/attachment.htm>> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub<http://www.evdl.org/help/index.html#usub> http://lists.evdl.org/listinfo.cgi/ev-evdl.org<http://lists.evdl.org/listinfo.cgi/ev-evdl.org> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA<http://groups.yahoo.com/group/NEDRA>) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140707/8bb32337/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)