Roller bearing drop gears

General Chat with an emphasis on BMC Minis & Other iconic cars of the 1960's. Includes information on MK1 Action days.
Rusty old S
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Re: Roller bearing drop gears

Post by Rusty old S »

Mine are Straight cut, never seen helical full roller.
Richspec
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Re: Roller bearing drop gears

Post by Richspec »

They were in development though i think, was it Minispares?
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phil82
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Re: Roller bearing drop gears

Post by phil82 »

I saw pics of one used set about a year ago but none in real. Will dig out the pics later
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Spider
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Re: Roller bearing drop gears

Post by Spider »

Rusty old S wrote: Mon May 22, 2023 4:17 pm Mine are Straight cut, never seen helical full roller.
Here :)

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phil82
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Re: Roller bearing drop gears

Post by phil82 »

Exactly. Spider do you have source where to get them?
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Spider
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Re: Roller bearing drop gears

Post by Spider »

phil82 wrote: Mon May 22, 2023 9:19 pm Exactly. Spider do you have source where to get them?
This one is an A+ type, the conversion is my own brew. I've done a few of these and so far, seem to be working well.

Years back, Jack Knight offered them for A types.
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mk1
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Re: Roller bearing drop gears

Post by mk1 »

Please excuse me if I am stating the obvious. But doesn't it make more sense having a roller bearing helical idler gear than a straight cut one. Surely it is the side loading on these gears that is always the most important thing influencing their performance.
Smiffy
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Re: Roller bearing drop gears

Post by Smiffy »

IIRC it was also someone on Turbominis who did that.........
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Spider
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Re: Roller bearing drop gears

Post by Spider »

mk1 wrote: Tue May 23, 2023 1:32 pm Please excuse me if I am stating the obvious. But doesn't it make more sense having a roller bearing helical idler gear than a straight cut one. Surely it is the side loading on these gears that is always the most important thing influencing their performance.
Yes, the side thrust is the bigger issues I've found with helical idlers. That is a pair of Tapered Rollers with a spacer between them in those that I've done. There is though a type of Cylindrical Roller, similar to those used in the Straight Cut gears, that can take side thrust, but those I looked it were marginal for thrust loading in this application.

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