Model C vs Model M

Differences between Kelsey Excelsior 3×5 Models C and M

This post is the result of my search for replacement ink disk for the Model M. Even though they are all supposed to be the same, they have slight manufacturing differences such that not all of the ink disk stems fit into a particular press’s holder. (I still haven’t found one that fits the M.) Then I got curious about other differences between the new-style 3×5 models, and there is, AFAICT, not much recorded on that topic. So here are some of the differences I found between the new-style Models C and M. The Model N that is not yet covered here.

If you go by what was published by Kelsey, you’d be forgiven for thinking that all of the new-style 3x5s are exactly the same. Not much was recorded about the manufacturing design history of the newer little ones. Thankfully there is some historical coverage, especially the excellent work by Alan Runfeldt at Excelsior Press and Stephen O. Saxe, David M. MacMillan, and others at Circuitous Root – Find Your Kelsey. Plus, various topics are discussed at Elizabeth Nevin’s community site BriarPress.

The obvious difference I find between the two is the branding on the press body. The newer model M says “Mercury Model” on the base, and adds “send for catalog of supplies” along its gooseneck arm.

The older Model C does not have a serial number, whereas later models have a serial number that identifies the size of the chase bed and the month and year it was manufactured. The M is from February 1958.

The biggest functional differences between the two are the location of the ink table operating dog, and the sturdiness of the arm. The older model C’s operating dog arm is much thicker and sits on the left of the disk. 

Alan Runfeldt explains:

Note: the 3×5’s use the same ink disk. On the early series 3×5, (square handle), they are struck upward from the left. On the newer  series (round handle), the striker comes down on the right. The striker dogs look different and one goes up, while the other goes down, but they both go clockwise, so the disks are interchangeable.

(Observation: Alan says the handles are different, but the ones I have are both rounded. It’s possible one or both were put together from different parts than the original parts, as I have no idea about their individual histories.)

Another difference is the shape and thickness of the roller carriage. The C is wider at the mid-point and has a U shape, whereas the M is thinner at the center and has a concave curve upward.

Next there is the platen back. The C has 3 screws and the M has 2, with a squarer shape.

Those are the main differences. Given that the C looks sturdier, I was surprised that when I weighed them they each came in at 21 lbs, without the chase and ink disk.

I may find more tidbits as I continue the quest for an ink table that fits the M, and for an affordable Model N.


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