Original or modified Chubb drive cam?

Cepasaccus

Bought this combination lock for an Isolator. Besides the missing ring the drive cam gate doesn’t really look like the other Chubb combination locks. Is this a genuine version of the drive cam? If not, then I will probably smooth the edges, or maybe replace it by a standard drive cam.

Thanks

Alan Morgan

Looks original. Quite a few are like yours.

Cepasaccus

Thanks, Alan! I will keep it as it is.

Gary Stephenson

never seen one like that before.

Cepasaccus

A few more photos of that lock.

I was told it was used as a display lock. It really doesn’t look much used. The modification doesn’t look like the usual case where someone just files away something when doing service work, but this shape doesn’t make any sense to me and this edge is nasty. It is catching the nose of the lever in both directions.

Btw. what threading has the bolt hole? 3/16″-24?

Alan Morgan

Bet you have changed combo and all working so not inspected closely Mr S

Cepasaccus

Looked at my two other Chubbs. One has the old style drive cam and the other the same style drive cam. Both are rather edgy, but my other new style doesn’t have a cut out that large and looks not as triangular, more “normal”.

Cepasaccus

Cepasaccus wrote
Btw. what threading has the bolt hole? 3/16″-24?

I think it is 10-32.

[unknown]

Gary Stephenson

Agreed Al, I may have come across them without realizing, but of the hundreds I have seen and worked on I have not noticed one like that before.

Cepasaccus

This one is my most similar drive cam. It is more rounded, but that can be at least also due to wear.

Doug MacQueen

Since it snags in both directions, I think a little filing is in order to allow for a smoother ramping up of the lever nose onto the perimeter of the drive cam. Wouldn’t think it would take much. The lever nose shape itself it a bit weird. And that may be why the ramp on the cam was flattened more than usual. Very strange but I wont be losing any sleep over it.