F1 in schools bearings

[bhrt]

Has anyone any idea how a glass bead used like a jewel in a watch movement would compare to a good ceramic ball race.
We ran our car with pins as axles (0.6mm diameter) with some small glass beads as bearings on the public track at the NEC during the Big Bang Fair. We managed to beat 1.2 sec, but wonder if we might have performed better with ceramic bearings. We bought some cheap ball races, but these were heavy and seemed to have too much friction. The pins and beads concept leads to very light wheels, and we expected that the ability to spin the wheel up and avoid skidding friction of the wheel on the track would be an advantage.

[Richard]

I'm intrigued that you made your own bearings, could you post a pic?

[tok-tokkie]

Rex Swenson did tests and concluded that simple stainless steel ball bearings give 1/60th the friction of plain or jewelled clock bearings. Detailed here. http://bocabearings.com/dropin.aspx?f=B ... Clocks.txt

As a child I had a gyroscope similar to this:

They spun for ever it seemed to me then. Basically the friction surface is reduced to a hardly moving point. Substituting hard ceramic for the V indent would reduce the friction further. Problem is that the bearing would be on the outside of the wheel.

Jeweled clock bearings are not pointed like the gyroscope. They are plain cylindrical bearings. To control end play end stones are sometimes fitted which are plain jewel disks that the end of the shaft abuts. Clock shafts always have lateral clearance called 'shake'. I am not familiar with how watch jeweled bearings are shaped.

[giuseppespa]

Generally for applications where the cross-section space is limited the best bearing are the Needle Bearings. But my favorite ball bearing are thrust ball bearings as http://www.omniabearings.com/bearings/b ... _bearings/

[SlowSteve]

Generally for applications where the cross-section space is limited the best bearing are the Needle Bearings. But my favorite ball bearing are thrust ball bearings as http://www.omniabearings.com/bearings/b ... _bearings/

Sorry - that too much sweeping of a statement for a place like this.... this is an engineering forum

The "best" bearing is the one most suitable for the job at the lowest price with the least amount of downsides.

Is the bearing suffering radical loads? Torsional loads? high speeds? High Temperatures? Dust? Vibration? What lubrication, if any, is available? Is it EP What are the backlash tolerances? What are the requirements for conductivity? What is the heat shed requirements? etc etc etc etc etc

Cross sectional space is limited in a lathe headstock and within a cars drive train, and require very different bearings - swap the around to the other application and you would get failures.

More specifically - there are a lot of cases where two ball races next to each other, in an Angular Contact setup, have multiple beneficial properties over a single needle bearing of the same width. But... that is harder to fit and harder to maintain at setup.

Horses for courses.