Author Topic: Holy Jumping Listeroid Batman (Read 18048 times)

Montana · « **on:** February 09, 2010, 11:34:55 PM »

I have a Powerline 12/1 with counter balance weights on the crank. I bought this new last winter. I disassembled it, cleaned it, had the crank polished and put new rod bearing in it. I even painted it with Gyptal. I put everything back together and cranked it up. A little jumpy on the wood 6x6's ,not at full rpm's, but I just wanted to see if it would run. It did. I finally got the framing done and the generator mount finished. Bolted everything together and it looked good. Got around to pouring a 3x5x2 foot block of concrete to mount it on the beginning of this winter. After everything was bolted and welded down i ran it and set the rpm with a laser tach. Rpm not quite 980 on the engine and 1800 on the 7.5kw generator. I have got to run it about 5 to 6 times for about 2 to 3 hours at a time. The problem that I have noticed is vibration, a lot of vibration. It is so bad that I can see the 4500 pound block of concrete move a little. Everything is shaking on this thing, although not violently. It has even shaken the rubber of the fuel tank straps and broken welds on the frame mounts.
I had hoped to use this unit to power our off grid home this winter when the solar panels could not keep up. But I have decided not to run it until I can get the vibration under control. I'm afraid that some major will brake on the engine besides some of the welds on the frame.
Can anyone help me get the vibration under control ?

I have tried to post picts but they dont seem to come up. I have them in the listerenginegallery under mike.

http://listerenginegallery.com/main.php?g2_itemId=3782&g2_imageViewsIndex=1
http://listerenginegallery.com/main.php?g2_itemId=3772&g2_imageViewsIndex=1
http://listerenginegallery.com/main.php?g2_itemId=3779&g2_imageViewsIndex=1

Thanks
Mike

mike90045 · « **Reply #1 on:** February 09, 2010, 11:46:31 PM »

Do you have a pair of flywheels, or 2 lefthand ones - or is all that done on the crank? May be time for the chalk trick, put a couple of pipes under it for rollers, and get the chalk to kiss each flywheel to get the light (or is it heavy) spot identified.

Bummer. I hope i don't have to go thru this too with a 6/1.

billswan · « **Reply #2 on:** February 10, 2010, 12:55:53 AM »

Montana

My 10/1 jumped like a jack hammer, it was very discouraging I know. Don't give up it just needs some well placed weights on the flywheel.

Look up the MR X method in search.

Billswan

Stan · « **Reply #3 on:** February 10, 2010, 01:28:52 AM »

What's it's rated rpm, is it 980?
Stan

ronmar · « **Reply #4 on:** February 10, 2010, 03:23:07 AM »

The wheels appear symetrical as they should be for a internally balanced engine. I can't really think of an easy way to confirm this. If the inner and outer rims run true and the center plate is of a consistent thickness, they should be fairly close to balanced.

You will need to unbolt it from your block to attempt to find the balance issue. You can probably set pipe rollers between the block and the frame. I did this with 3/4" smooth rods betweenmy frame and garage floor. Start it and run it at very low rpm. Increase the rpm till it starts to show some movement. You can use chalk to get an idea where on the wheel the weight is needed, or perhaps where weight needs to be removed from the internal counterweights... you can also use a dial indicator to gauge the ammount of movement. As mentioned, search "mr x method" for more info. As you reduce the movement with weight changes, you can increase the rpm and repeate the process till you reach your op rpm.

Montana · « **Reply #5 on:** February 10, 2010, 05:27:22 AM »

The Powerline 12/1 develops it's max power at 1000 rpm. I'm lucky that every thing works a little below the max rpm. I was very careful when I took it apart to make sure I put every thing back together the way it came off. I have heard of stories of 2 left flywheels being put on and causing a problem. In looking at these they both look the same. Where could the imbalance be, flywheel, counterbalance on the crank? Should I take the flywheels off and take them to a machine shop and speed balance them? Is there a machine i could rent that would attach to the engine that would tell me what weight to put on? I'm sure that if I do nothing it wouldn't be long before something major breaks.

billswan · « **Reply #6 on:** February 10, 2010, 01:04:17 PM »

Montana

Do your flywheels have 4 or 5 holes in them?

Does one of the holes line up with the key way?

The key way on the crank is in line with the balance weights on the crank inside the engine? At least it is that way on my 10/1 Omega!

On my Omega the internal balance weights are to small, and light, so I added weight in line with the key way on both wheels.

Cannot remember how much but am sure it was near to a pound on each side!

Not saying that will work for you but it did for me.

Start out small and work your up but BE CAREFUL!!

Billswan

Stan · « **Reply #7 on:** February 10, 2010, 03:11:58 PM »

Mike, are you familiar with the "Mr X" method of balancing with a piece of chalk?
Stan

mike90045 · « **Reply #8 on:** February 10, 2010, 06:44:26 PM »

I think the Mr X method was :
engine on rollers
Chalk at the ready, using a rest, and just kiss the flywheels.
Shutdown, and add some weight, restart and try again.

I've forgotten if you add weight at the chalk mark, opposite, or halfway inbetween. I've searched, but never found the original posting, just hints about how it does not work if there is a lump in the flywheel. Some have pulled the head, and spun with a motor to get rid of the ignition pulse.

ronmar · « **Reply #9 on:** February 11, 2010, 12:44:47 AM »

The whole assy will move back and forth with the heavy point of the wheel. If you carefully move the chalk in till the wheel just kisses the chalk and leaves a mark, that will nearly indicate the heavy spot on the wheel. Because of inertia however, the engine/frame movement will lag behind the heaviest point of the flywheel. What this means is the actual heaviest point of the wheel will have already passed by when the engine/frame fore-aft movement pushes the whole thing forward into the chalk. Not a big deal, you just need to be aware of this phenomenon when you place test counterweight. It won't go directly opposite the chalk. Because of the ammount of mass involved, you will reach a point where the chalk marks become hard to interpret due to lack of movement. Here is where a dial indicator comes in handy to gauge ammount of movement. Once you get the correct position, you can use the dial indicator to refine the balance by varying the ammount of weight. On a running engine, you will eventually reach a point where you cannot reduce the ammount of movement. This is probably due to the energy from the massive torque pulse being added to the mix. I spun mine with head and case door off using an electric motor. This worled really well. I also tried it while running. The running tests worked best when opening the compression release and marking the chalk while the engine was coasting...

Modeling clay makes excellent test counterweights for working out the needed weight.

Stan · « **Reply #10 on:** February 11, 2010, 01:05:21 AM »

Mike if you're concerned about a lump on the flywheel, just do the chalk test while turning it very slowly by hand. or as ronmar says, use a dial indicator. Not really a huge concern though as I've never heard of an "out of round" flywheel.

That's not to say it couldn't happen. As they say, "if a man can imagine it, it just might be true somewhere".

Stan

lowspeedlife · « **Reply #11 on:** February 11, 2010, 01:27:09 AM »

Didn't CMD stop selling 12/1 units last year because of vibration issues? seems like they had a problem with their mounting system that they altered to correct the problem.

Scott R.

Montana · « **Reply #12 on:** February 12, 2010, 03:01:56 PM »

The fly wheels are 5 hole and they look perfect. I have looked at the flywheel and cant see any where on them where weights have been added or taken away. No holes drilled, nothing. What about putting these things on something like a tire balancer? Any way Im down to my last straw. If I cant figure out how to get it fixed Im going to sale it.

listerboy · « **Reply #13 on:** February 12, 2010, 05:38:18 PM »

Mike,

I doubt that you would be able to tell if any weight was added/removed from the flywheels without stripping the paint off first. If you believe the flywheels are the problem, and they very well could be, you might want to think about stripping them down and looking for body putty that has been used to fill in casting voids. There's a thread here somewhere that talked about that. Not sure if it would make that much of a difference but you never know. But before you go to the trouble of stripping, try looking for filled-in spots with a magnet.

As for balancing, contact a tire shop that caters to the trucking industry. If anyone can do it, they can. I doubt that the local Sears Tire & Auto would even try!

Dave

billswan · « **Reply #14 on:** February 12, 2010, 06:34:10 PM »

Montana

Don't give up so easy!!

These oids take some tweaking!!

I will send you a PM in a few minutes!

Billswan

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