Mark Allanson
|
| posted on 7/2/08 at 07:35 PM |
|
|
You can buy some king of inert goo to go in motorcycle tyres to prevent punctures and self balance the tyres - or at least thats what it says on the
tin.
I am guessing thats how the wet newspaper idea was born
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
|
|
|
|
|
rusty nuts
|
| posted on 7/2/08 at 07:47 PM |
|
|
Having seen some of the damage caused by out of balance props I would say it's cheaper to get them done properly as well as safer!
|
|
|
The Doc
|
| posted on 7/2/08 at 08:30 PM |
|
|
Will you necessarily know if your prop is out of balance through feeling vibration.
I modified my own prop and gave it a whirl. So far absolutely no vibration that I can tell.
Is this luck or is the imbalance something that might not show?
|
|
|
02GF74
|
| posted on 8/2/08 at 10:51 AM |
|
|
well I must still stand in the front of the queue of disbelievers.
ok so we put in a weighted bag in a tyre.
Due to gravity it falls to the lowest point of the tyre. The wheel starts to turn as the lorry pulls away so bag will rise then drop, much like your
clothing in the tumble drier.
At some point the tyre is turning fast enough so that centrifugal force holds the bag against the tyre.
I cannot see how the bag can mysteriously locate itself to lie opposite the heaviest side of the tyre although it has a 50% change of being on the
opposite half of the tyre that is the heaviest.
With the motrocycle goo. This stuff is liquid (to begin with at least) so one would imagine it spreads itelf more or less evenly on the inside of the
tyre.
Adding this additional mass to the tyre will reduce the ratio between the heaviest spot and its opposite side so that may improve the balancing so
some extent.
This is a good one for Mythbusters - anyone have their address?
[Edited on 8/2/08 by 02GF74]
|
|
|
02GF74
|
| posted on 8/2/08 at 10:51 AM |
|
|
.... so I thought I'd ask the question to those that manufacture propshafts/ repsonses as below.
quote:
I must admit that this is a new one to me !
i have heard of the propshaft been filled with oil to balance it & several other theories, non of which work very well.
the only way to balance a propshaft is to have it done properly on a dynamic balancer, which we can do.
the cost to balance a propshaft depends on what it is from.
and
quote:
think you are right it is an urban myth. we have been manufacturing propshafts for 31 years and not seen or heard of this.
If they have the capability to weld a shaft it would be just as easy to weld weights on the tube to overcome imbalance.
The wet paper would eventually dry. If they believe the rotation of the shaft will cause the wet paper to slide to the imbalance point this would be
highly improbable.
and another
quote:
You are correct not to believe it!
Some shafts are filled with cardboard to stop sound resonance/pinging of drivelines but it is not used for balancing.
The only way to balance a propshaft is by adding or removing weight on a dynamic balancing machine.
[Edited on 8/2/08 by 02GF74]
|
|
|
liam.mccaffrey
|
| posted on 8/2/08 at 09:22 PM |
|
|
oohh! mythbusters my favourite show!
Build Blog
Build Photo Album
|
|
|
.jpg)
