Plastic/Metal Bearings in Slipper Clutches

[Grastens]

Inspired by my readings on the TR-15T and given my experience with the TTC gear train setup from the Super Astute, I was curious as to the benefit of metal or plastic bearings located in slipper clutch systems as opposed to ball bearings. The specific bearing for each in question would be that inside the slipper spur gear, in contact with the spring adjustment system.

Is it a matter of economy, loading, or something else entirely? I admit I was a little surprised to find a single 850 copper bearing in the TTC gearbox when everything else was specified as ball bearings; I suspect there are distinct mechanical advantages since cost-cutting measures for a high-end hop-up would seem illogical...

[kontemax]

No mechanical advantages. Only cost cuts.

Max

[WillyChang]

just be a bit mindful if a solid bronze bushing is used in some situations as a thrust bearing,

don't replace with a ballbearing as it won't survive the side load

also in applications where the bearing doesn't do much work under normal performance

(Eg Supports slipper clutch, spins only rarely) a bushing would be less maintenance

[kontemax]

I used the ball bearing on both Tamiya vintage clutches (TTC and MDC) and they both quietly survived without problems.

At contrary the clutch axles slightly wear where the ball bearing is located due the side load. I believe I saved both axles with the ball bearings because if you add the rotational friction to the side load the material got wear more than normal.

Max

[Fruitfly01]

I use a ballrace in my TTC and haven't seen any harm come to the main shaft. I was never sure why Tamiya didn't ballrace the entire gearbox. Unless there is a mechanical reason, I can only imagine that it's because the the Super Astute was not fully ballraced upon release and the gearbox had the same 850 size bronze bushing on the main shaft, this was just carried over when the TTC was released as a hop up option for the Astute/Madcap buggies.