Mystery treadle on Challenge 15GP Proof Press

Hi everyone,

I recently acquired a Challenge 15GP Proof press that I am currently restoring and I cannot figure out what this lever does. Obviously the center treadle activates the grippers but this one on the far left of the press is a mystery to me. There is a “button” you push on the very end of the press at the top which I have shown in the pictures below. I have found one manual on the Challenge website for this press but this treadle isn’t in the parts or operations so I am assuming I have a later model…. or earlier?

Any help would be much appreciated, I am more curious than anything.

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It is the self destructing lever…
I emailed you!

Hard to tell without fiddling around with it in person. Maybe it’s a print/trip lever?

What comes in contact with that bar in the 3rd picture? These machines are pretty simple, just follow the cause & effect.

It could have also nothing to do with the essential functionality of it, maybe some type of accessory.

Any pedal on a proof press is bound to be for the grippers or trip assembly.

That bed looks like it wants some Evapo-Rust!


Logic seems to imply that there has to be a means to raise and lower the forme rollers and vice versa for the impression cylinder, could *Danielheff* have given the clue with his Picture 3, nothing attatched to the lever? presumably going down to meet A peddle or THE pedal, which might raise/lower the ink train or impression roller OR ramp bearer rails, 2x2 up and down???
The unoccupied lever looks suspiciously like such.???
Apologies for possible red herring. (or Bum Steer)???

Thanks everyone for all the help, ScottMc found a better manual that what I had found. It’s a manual trip lever to throw the cylinder off and on impression. Apparently the GP models are set to automatically go off/on impression at the beginning and end of the cycle but the treadle allows you to manually do it at any time. Kind of a nice feature. The press is well on it’s way to being finished and printing again. Excited to see what it will do!

this pedal will raise the cylinder. after you have pulled a print step on this and hold it down while returning the press bed and you won’t print on the packing.
I have access to this same machine if you ever need pictures or anything you can email me.


Quick update if anyone is interested, the press was stuck off impression probably from sitting for years and years, the lightbulb went on over my head when I realized the manual impression treadle was stuck down as far as it could go. It just needed a little elbow grease underneath the press bed where the gears are to trip the press off/on impression. A pretty nice feature this model has was an automatic off/on impression at the end/beginning of the cycle. Thanks again for all the help everyone.