20 replies to this topic

[DeadSquare]

I was chatting with a chap on Easter Monday, trying to dissuade him from fitting Straight cut Drop Gears. 

 

At one point in the conversation, he was clearly of the opinion that the Idler Gear, shaft, is a press fit.

 

It would save a lot of machining, so just out of interest, this afternoon I set one up in a substantial Vice and squeezed, but no sign of movement.

 

Does anyone know if the shaft is integral or pressed in ?

[imack]

The straight cut roller bearing idler gear have a press fit "dead" shaft.

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Edited by imack, 01 May 2025 - 04:56 PM.

[Spider]

Yes, the shafts in the standard gear are pressed in, but good luck ever pressing one out !

[OzOAP]

Could be the angle of the pic but look at the gear mesh.
The mesh between the idler and input gear is obviously determined by the gearbox casing, so that is the distance the gear manufacturer works with.
Now look at the primary/idler mesh.
I use different thickness sump gaskets, or even non at all, to set mesh the same between primary/idler and idler/input.

Edited by OzOAP, 01 May 2025 - 07:01 PM.

[DeadSquare]

Could be the angle of the pic but look at the gear mesh.
The mesh between the idler and input gear is obviously determined by the gearbox casing, so that is the distance the gear manufacturer works with.
Now look at the primary/idler mesh.
I use different thickness sump gaskets, or even non at all, to set mesh the same between primary/idler and idler/input.

No, that's not the angle of the picture.

 

Self respect wouldn't have let that Primary Gear leave my machine shop.

[DeadSquare]

Yes, the shafts in the standard gear are pressed in, but good luck ever pressing one out !

Thank you Spider.

[DeadSquare]

 

Yes, the shafts in the standard gear are pressed in, but good luck ever pressing one out !

Thank you Spider.

 

A 30 ton hydraulic press hasn't moved it.

[Spider]

 

 

Yes, the shafts in the standard gear are pressed in, but good luck ever pressing one out !

Thank you Spider.

 

A 30 ton hydraulic press hasn't moved it.

 

 

That was where I got to !

When I machine them out for the Tapered Roller Conversion, it's clear it is a separate shaft.

[DeadSquare]

I friend says that he has a reasonable sized Fly Press, I wonder how many tons that would be at the moment of impact, and if the shock would move it a bit ?

[stoneface]

I very much doubt a fly press would do it. I have a 10 Ton flypress and without even trying I'm pretty sure it wouldn't, unless he's got one much bigger.

 

Is it just curiosity or is there an actual reason for wanting to press one out? It's not that difficult to just machine it out.

[DeadSquare]

I very much doubt a fly press would do it. I have a 10 Ton flypress and without even trying I'm pretty sure it wouldn't, unless he's got one much bigger.

 

Is it just curiosity or is there an actual reason for wanting to press one out? It's not that difficult to just machine it out.

I want to take a second Idler drive from the Diva gear, and in if I remove the shaft and replace it with a temporary bush it to take a cylindrical punch, I could mark where to put a spigot.

 

How hardened is the shaft, to machine it out ?
 

[Ethel]

Another Skool Day!

 

I'd never have thought that - Machining the shaft & hole to a high enough tolerance to press fit that tightly  surely can't be any cheaper than creating a single piece blank? Are the aftermarket straight cuts the same?

[Gaz66]

Is that primary gear in the picture "right" as in teeth? It looks the wrong tooth profile compared to the other drop gears.
Interesting someone mentioning getting the mesh correct. I've never thought of this in the past and have just presumed all is good.
How do you measure and correct the mesh?
Is it a case of facing the case or building up with thicker gaskets?

[imack]

It's a Minispares drop gear set, 22 tooth primary, 23 tooth input. The primary gear teeth are chunky compared with the 23 tooth version.
The gear mesh was checked during the build (I'd read about checking in in an old post Ian at OAP had commented in) especially as the block flange had been faced for line boring of the main caps.

Edited by imack, 28 June 2025 - 03:14 PM.

[stoneface]

I want to take a second Idler drive from the Diva gear, and in if I remove the shaft and replace it with a temporary bush it to take a cylindrical punch, I could mark where to put a spigot.

 

How hardened is the shaft, to machine it out ?
 

 

 

You can machine it with carbide tip tools.

Once you get through the case hardening it is easy. I've done a few.