10x15 Old Style C&P Pinion Key


I’ve recently revived the letterpress studio at my university, and am fortunate to have a room of type and a both a vandercook and an old style treadle C&P. After using the C&P for a couple of weeks, it began to lock up when printing, never in trip though. With a bit of sleuthing, I realized the rod inserted in the pinion which turns the large gear cam wheel is slipping and just spinning when there is too much force on the platen.
this seems to be happening because there isn’t a pin connecting the two, currently it’s just a rod through the pinion, without a key—

so, the question is, where can I find one, or what can I use?

also, for other people with the same press, am I wrong? is there not a key there?

I’ve added a photo of the part I’m talking about—you can see the slot for the key and that it’s not aligned.

thanks so much!!!
I’m really excited to be using this press!!!

image: IMG_2669.jpg


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ok, so as soon as I posted this, I started rummaging around the studio and found a metal key that would work lined it up and inserted, and now it prints, but each time at the point of maximum contact, the press makes a loud “pop” from the general area of the pinion, which seems somehow to be slipping internally.

as an additional note, if I take out all of the packing so that there isn’t enough pressure between the platen and the type to even kiss, then everything is fine, but adding even one redboard causes this, so I don’t think I’m over packing the press…

Looks like you need a new pinion gear too - the missing tooth can’t be helping. The key you’re missing is a standard machine part, and easily available - though it would probably need to be fitted for the press.


Bill is right
missing key is a standard machine part

you need to replace broken gear
run it like this
you will break more gear teeth

yours truly

I won’t go into details here; during my apprenticeship, I saw one of the machines (not a printing press) had had teeth on the rack of a rack-and-pinion repaired; they were relatively large teeth; no other solution (spare parts) available. It’s a standard procedure here.



Are the other teeth on the pinion in good shape, or slightly, or badly, worn?


Try these guys, they have some presses they are parting out.

First off, thanks so much!
The other teeth seem to be ok, but I’m not certain what an appropriate level of wear would be, also there is a missing tooth from the large cam wheel as well.
I’ll start working on fixing that.

See what kind of a deal you could get on trading in both gears, and just replacing them - probably faster than a repair.

the noise you are hearing is most likely from the key you are using. if it is a loose fit at all,,, the pinion will load up against the key in a counterclockwise movement. then as the press goes past full impression the pinion snaps forward to clockwise. that is the noise. this will wear out or possibly fracture your crankshaft. a fitted key needs to be used. an easy way out is to go to “mc master carr. search for a “gib head key” i think yours is 3/8in x 3/8in x 3 in long