Mechanical Type Non Electronic Rotor Balancing Machine

Amazon probably can.

Did you try using a search engine, or did you want me to do that instead?

Nope, it's google books. A Study of the Carwen Olsen Type Balancing Machine ...

May not be an easy book to find.

crabtree, thanks for your promt reply. i coud not find because i am not conversant . kindly do it for me. thanks in advance. shujauddin

Lyn has already done it. Good luck.

This is a thesis written nearly 100 years ago....it's not likely to be in print in any place other than the MIT library....

What makes you think even a good design mechanical balancing machine would ever be more reliable and less breakdown prone than a robust design electronic one, not to mention coming any close when it comes to accuracy? Well, read my lips: (sort of). It isn't. If device gives you that impression, it is because the frequent calibration cash wasn't enough for the manufacturer, so designed it in a way to get some extra cash for servicing it, plus control the time it will become useless (obsolete) by just stopping that "support" and sell the next model. This sadly is a short sighted general practice, but reverting to older technologies will not help you much. And just out of curiosity, what kind of failures are you experiencing? S.M.

What is the weight and rpm of the rotor? This might affect your approach.

Without going through a lot of research trying to figure out what you are up to, let me state the obvious, when the center of mass doesn't coincide with the center of rotation there will be unbalance.

Given the foregoing what device other than a set of precision knife edges and a visual observation that when the object is suspended between two, it either rolls or doesn't, could be possible. At best it would be a good start for a full fledged balancing program with critical speeds and such.

Sorry about that I am obviously bored.

There is a big difference between static balancing and dynamical balancing an object.

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Static balancing can be done with a set of precision knife edges and visual observation.

When the object under test can freely rotate without friction, the gravity will pull the heaviest point down. The object will rotate until the heaviest point is most downwards. So an object will be in static balance when it does not rotate anymore in any arbitrary position.

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But dynamical balancing requires to rotate (to spin, to whirl) the object under test by means of an external power source.

Suppose, you have a shaft with on both ends a extra mass, the both masses are equal in weight and at the same distance of the shaft center. But one mass is pointing to the left and the other mass is pointing to the right.

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(centrifugal force direction to the left) . . .Mass x x x x

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x x x x Mass (centrifugal force direction to the right)

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It is easy to understand that the shaft when it is not spinning, it is in any position balanced. The weight is equally distributed.

But when spinning this shaft, the centrifulag force working on the 2 extra masses will create a torque acting on the shaft. The result is that the shaft will try to revolve around the middle of the shaft and will vibrate because it's spinning.

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Dynamical balancing will require that the different torques that arise as a result of centrifugal forces working on the different concentration of weight along the shaft, are cancelling each other out.

This requires that you measure the centrifugal force against the rotation angle of the shaft. On has to add or remove weight to equilibrate the centrifugal forces.

Can you suggest a way to balance a two plane rotor on knife edge? Thanks, Shujauddin

The answer to that question requires some discussion. First you are trying to re invent the wheel, When I first got into the engineering business on my first field trip they gave me a light beam vibration indicator to measure the balance of the machine I was working on.

No description is necessary since the device is no longer used. From that point forward I was able to determine that in order to balance a machine you did not need anything except a hand full of weights and plenty of time. Of course if I walked into a nuclear plant and told them I would need to start and stop the unit numerous times I would be on a short walk out of the plant with an irate escort.

What I learned and everyone else in the business learned was;

1 You need to know the magnitude of unbalance.

2 you need to know the direction of the unbalance.

3. You need to make a base run for data, then you need to either add or subtract enough weight to make the unbalance move in direction or magnitude in order to correct it.

You can skip steps 1 and 2 and go with step 3 with a ceiling fan.

The Carwen Olsen machine wanted you to find the direction of unbalance by holding a piece of chalk next to the rotating shaft and actually mark the shaft to locate the high spot. That should in itself cause sufficient doubt as to the method. Walk up to a customers machine rotating at 3600 RPM with a piece of chalk in hand and tell him what you have in mind. Let me know how that worked out for you.

The strobe light took all the joy out of chalk marking shafts, the IRD balancing machine wasn't far behind it. Of course along came the computer and all the power of conditional statements. The basics which were developed by Jim Lindsey of GE (at the time) relating to critical speeds and such were all dumped into the all knowing computer and a veil of darkness descended over our minds.

Admittedly they are fun to play with.

I asked what shape/weight you were trying to balance? I once built a dynamic balance for a flywheel, consisting of a shaft fastened and driven on one end. The other end bearing could move back and forth between 2 plates. The shaft had a drum mounted half way on the shaft with a raised metal helix on the drum. A metal knife edge parallel to the helix formed a spark gap. By adjusting the voltage, you could get it to spark when the shaft moved horizontally to narrow the gap, the spark jumped at that point on the helix showing you where the heavy spot was on the flywheel. ( mark the point where the spark jumped, stop the shaft, manually turn the shaft with the voltage turned up and locate the matching spark jump point, mark the flywheel and remove a bit, spin up again.) One of the many ways to 'skin a cat' as the saying goes. (I apologize, Del) ( this was a 1960 personal solution)

Hi!
Modern portable balancers are not too expencive.
For example
- DYNAMIC BALANCER: Balancing System 1 & 2 Planes Erbessd Instruments - US $2,495.00
- Portable field balancer "Balanset-1" 1473 EUR
- Aerobros Ultimate 360 Dual planes Balancing machine - US $399.00
))