engine balance - how to

[ronmar]

Looks like its bolted to the floor but its hopping on the first power stroke....

Prices for spares aren't bad!

If you look real close at some of the pics on the site Doug, you will see that the engine case is bolted down on 4 rubber mounts between it and the steel frame. 

Ron

[M61hops]

Well here's a good argument for simpiel.  I just tried moving one of my heavier weights on each flywheel around and just out of luck hit a very good balance!  I can now use a dial indicater to try and fine tune the balance but it must be real close.  I haven't weighed the U channel pieces yet but I think I have about 1.5 pounds on each flywheel at about 90 degrees from the cast counterweights.  It's so nice to not feel the vibration for the first time!  This has got to help things on the genset last a lot longer!  Oops... now I have to change my forum handel  maybe I could be M61sits?  In another thread someone wanted to know how much power it takes to rotate a 6/1 and I measured the 3HP golf cart motor I'm using to turn mine 650RPM for balancing as using 50A at 32V.  Thats about 1600 watts.                     Leland

[rcavictim]

  In another thread someone wanted to know how much power it takes to rotate a 6/1 and I measured the 3HP golf cart motor I'm using to turn mine 650RPM for balancing as using 50A at 32V.  Thats about 1600 watts.                     Leland

Huh? Leland,  Did you install a golf cart motor as an electric starter or are you using it as a DC gen for battery charging from the Listeroid?  I was thinking that might be a fairly good generator for a 28 volt battery bank setup.

[Doug]

Ron if thats on Rubber maybe they shoudl consider something a little firmer....
That looks like the kind of shake thatcould cause a bolt failure

[ronmar]

Ron if thats on Rubber maybe they shoudl consider something a little firmer....
That looks like the kind of shake thatcould cause a bolt failure

Yep...  That is probably why Bob mentioned it.  After I saw his post, I had to take a closer look to see what he was talking about as it is not readilly apparent unless you see that startup torque movement and look closely at the photos.

Ron

[M61hops]

Hi rcavictim.  I'm just using the golf cart motor to rotate my 6/1 so I can balance it.  I'm not sure this motor would be a good generator because it has no cooling.  There are no holes or air passages into the motor so I think it would get hot after a short time.  The cart was being thrown away because the stator windings are aluminum and got hot and melted off from where it was welded to a copper bolt, one of the terminals.  It came along on it's way to the scrap yard just as I was wondering how I could spin my 6/1 for balancing.  When I saw what was wrong with it and noticed that it has no way of cooling I was a little surprised; I wonder how long the designers expected it to last.  Hmm... I guess it made it about 20 years or so.  Short duty cycles I guess.                   Leland

[rcavictim]

Hi rcavictim.  I'm just using the golf cart motor to rotate my 6/1 so I can balance it.  I'm not sure this motor would be a good generator because it has no cooling.  There are no holes or air passages into the motor so I think it would get hot after a short time.  The cart was being thrown away because the stator windings are aluminum and got hot and melted off from where it was welded to a copper bolt, one of the terminals.  It came along on it's way to the scrap yard just as I was wondering how I could spin my 6/1 for balancing.  When I saw what was wrong with it and noticed that it has no way of cooling I was a little surprised; I wonder how long the designers expected it to last.  Hmm... I guess it made it about 20 years or so.  Short duty cycles I guess.                   Leland

I have an military surplus aircraft generator nameplate rated at 28 volts DC @ 25 amps that I am using as a DC motor to move a 650 lb. modified motorcycle (400 lbs are AGM lead acid batteries) which is being built to comply with new regulations allowing E-power assisted bicycles here in Ontario. This ball bearing motor is heavy at 40 lbs and is totally hermetically sealed.  No fan inside or way for exchange of interior air for cooling. I chose this because it was the most suitable `motor` of all the treasure I have in stock.  It is about 6-1/2 inches diameter and 10 inches long. Nameplate power (volts X amps) is 700 watts.  It was probably designed to operate at elevated temperature in an engine compartment and at high elevations where the air is thin and less effective as a cooling medium.  I am not yet on the road with this project but it does get mildly warm in wheel off the ground testing in the shop.  I mention all this because I think your gof cart motor might be able to handle continuous duty at some power level that might be high enough to be of practical use.  Only testing will tell for sure.

[M61hops]

This golf cart wiring has a thermal snap disc circut breaker (mounted on the chassis, not the motor) that is probably there to get hot and open just before something in the motor melts.  I'd seen the cart stranded on steep hills a few times over the years waiting for the overload to cool down and reset.  Since the overload doesn' touch the motor I guess maybe somebody tried too many trips up the hill on a cold day and one day the winding failed.  It was an easy fix, I just clamped a piece of wire onto the winding with a split bolt connector.  It would make a slick setup to have a starter/generator so I will play with it.  The problems would be the cooling which could maybe be fixed with a fan and lots of holes, and the fact that it is a series motor.  I don't think it would work to try and use as a generator with the field and armature in series, and if I try and run the field in parallel I'm afraid it would need a large resister to limit the current because the field has quite low resistance due to the fact it has few windings of large gauge wire.  I think I'd have to shove an inefficient amount of current through the field to generate enough voltage to recharge 36 volts of batteries.  Because of the potential value of having a starter/generator I will experiment a little after I finish balencing.  There is just not an easy way to put a starter on a Listeroid that I can see.  I think the easiest way would be to mount an automotive flywheel on the crankshaft and make a big ugly bracket to hold the starter.  That is on my to do list if this golf cart motor/generator thing doesn't work out.  The fun never stops....Leland