Boonman

[mrman99]

I just took the cover off the flywheel and notice that they had some spots drilled to balance the flywheel. When you lighten it, how do you check for balance?

[ngelati]

I was asking myself the same question...... If you remove material (and that balance spots in the flywheel) I think you will lose balance....

 

Same doubt for me

 

 

[boonman]

Nope, you don't lose balance. The material is being taken off the outside diameter. Being that it is already balanced, you don't have to balance it again. It's hard to explain, but it isn't a problem. Many many flywheels have gone through my lathe, and not a one has been complained about. I am sure BD will have the same thing to say.

[sandman121383]

cmon guys u think he's actually gonna give up his secret. haha. he's right tho. it is already balanced. he's removing equal amount of weaight from the outside and by doing that he isn't throwing the balance off.

[Justintoxicated]

yea a lathe would definately keep it balanced when done properly...

[mrman99]

That does not make sense to me. you are removing the holes that are balancing it, just because you spin it up in a lathe doesn't automaticly balances it. Maybe someone with a bit more knowledge can explain it to me..Boonman you care to elaborate, or PM me if you don't want it to be public.

[Justintoxicated]

That does not make sense to me.  you are removing the holes that are balancing it, just because you spin it up in a lathe doesn't automaticly balances it.  Maybe someone with a bit more knowledge can explain it to me..Boonman you care to elaborate, or PM me if you don't want it to be public.

yea but he is removing the material equaly around the flywheel on a lathe so it should be balanced. So if done right and On a lathe it shoudl nto be an issue! I don't think he is removing the balancing holes...

Edited May 27, 2004 by Justintoxicated

[boonman]

The wheel is already balanced. Which means the material has already been removed where it needed to be removed from. When spinning something in a lathe, you aren't removing unequal amounts from areas of the flywheel. You remove it off the circumference of the wheel. It doesn't change a damn thing balance wise. I have had numerous flywheels come in that don't have balance holes. Depends on the wheel. Some are balanced good enough right off the assembly line. Some aren't..... Do you rebalance your tires on your car every 5 thousand miles when some rubber gets taken off??? Same type of thing....

[JKJK]

very interesting question,i was wondering the same thing.if the flywheel is netural ballanced to itself+the mass of it is consistant+equal all around then removeing equal material or mass from the circumferece should make no diff. why i was pondering this theory was because i took my flywheel off to send it to ya+noticed it was drilled out around the circumference.at least 6 ,1/4 plunges.so i dove into banshee#2 +found that the flywheel on that one .it's drilled out on the vertical surface or the face.so thats the one that will get shaved.

[BdBanshee]

Nope, you don't lose balance. The material is being taken off the outside diameter. Being that it is already balanced, you don't have to balance it again. It's hard to explain, but it isn't a problem. Many many flywheels have gone through my lathe, and not a one has been complained about. I am sure BD will have the same thing to say.

 

The flywheels come from the factory with the balance holes, because they are molded and not machined on the outside. When I machine a flywheel the tool always seems to touch in the same spot as the balance holes are drilled. This is because the flywheel has more material in that spot which is the reason for the holes. After I machine a flywheel it is dead on true with the crankshaft and any high spots are machined off. Like Boonman said, many of the flywheels don't have any balance holes at all. I have had both kinds on my Banshee when testing and there is no more vibration after I lighten them than there was before.

 

I hope this helps............

[Cotton eyed Joe]

Nope, you don't lose balance.  The material is being taken off the outside diameter.  Being that it is already balanced, you don't have to balance it again.  It's hard to explain, but it isn't a problem.  Many many flywheels have gone through my lathe, and not a one has been complained about.  I am sure BD will have the same thing to say.

 

The flywheels come from the factory with the balance holes, because they are molded and not machined on the outside. When I machine a flywheel the tool always seems to touch in the same spot as the balance holes are drilled. This is because the flywheel has more material in that spot which is the reason for the holes. After I machine a flywheel it is dead on true with the crankshaft and any high spots are machined off. Like Boonman said, many of the flywheels don't have any balance holes at all. I have had both kinds on my Banshee when testing and there is no more vibration after I lighten them than there was before.

 

I hope this helps............

You mean that outside "skin" is a forging??? Probably stamp that thing out in 2 seconds.

[Mr.Giggles]

I watched the guy when he lightened mine and when it was in the chuck he brought the cutter up against the flywheel ,made about 4 or 5 revolutions before the cutter started to take the same amount off all around the flywheel,that was when I understood why they had so many of the drill holes for balancing.

The jap machinist must of had a bad day

[Justintoxicated]

The wheel is already balanced. Which means the material has already been removed where it needed to be removed from. When spinning something in a lathe, you aren't removing unequal amounts from areas of the flywheel. You remove it off the circumference of the wheel. It doesn't change a damn thing balance wise. I have had numerous flywheels come in that don't have balance holes. Depends on the wheel. Some are balanced good enough right off the assembly line. Some aren't..... Do you rebalance your tires on your car every 5 thousand miles when some rubber gets taken off??? Same type of thing....

I do it every 10,000 because its free hehe

[ngelati]

BdBanshee Posted on Jun 15 2004, 04:39 PM

The flywheels come from the factory with the balance holes, because they are molded and not machined on the outside. When I machine a flywheel the tool always seems to touch in the same spot as the balance holes are drilled. This is because the flywheel has more material in that spot which is the reason for the holes.

 

Now it makes sense to me. Thanks Ron..

[mrman99]

there is no way that removing material concentricly from center of the shaft will remove equal amounts. The reason is the holes are only from one side. I can see if the series of holes are 180 degs from each other. But my flywheel is not the case. The flywheel i have only has a series of holes on one side. Spining the dia down to a point where the holes are removed, will put the wheel out of balance again. It would be like having the stock flywheel without the balancing holes.

 

 

 

The flywheels come from the factory with the balance holes, because they are molded and not machined on the outside. When I machine a flywheel the tool always seems to touch in the same spot as the balance holes are drilled. This is because the flywheel has more material in that spot which is the reason for the holes. 

 

FYI....The flywheels are stamped (not casted from a mold). And holes are drilled afterwards.