Buying a C&P

I am currently looking to buy a floor press with a limited budget to do stationary/art letterpress printing. I have been in contact with someone and wanted to know how I should proceed. Here’s his message:

“It’s a 11 x 17 C&P Letterpress. I’ve had it for about 25 years. We used it to print on compressed sponges for a while but mainly used it to slit compressed sponges for Weller Corp. makers of soldering irons. We haven’t used it since last August. I have the cores and trucks for the ink rollers. I also have the chase and some furniture. I believe that’s what they’re called. Attached is a video showing it running. If you have more questions let me know. Be specific and I’ll answer the best I can.” (Here is the link to the video https://youtu.be/38G5zQXlOk4)

What questions should I ask and what advice does anyone have?

Thank you.

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The 11x17 is a fairly large (read: heavy) press, so moving it may be a challenge if you’re not accustomed to moving top-heavy cast iron machinery. Find someone who is, this should be a good press to grow into. Then find someone who can teach you how to run one - books are nice, but hands-on training can’t be beat.

Also, you will want a speed control on that motor - the video shows it running way to fast to hand-feed.

(Edit - posted twice)

The press is either a 10x15 or a 12x18. The owner may have measured the platen or the full bed and not the inside dimensions of the chase.

The motor is driving directly from a wheel attached to the motor shaft (no belt) so the speed might possibly be changed by changing the diameter of that wheel that drives against the flywheel. That motor might also be a variable speed motor. You should certainly ask the owner. Search this site for options you might use to change out the motor or control to get variable speed (variable frequency drive or jackshaft).

I don’t hear any “clanking” or other troublesome sounds in the video, do the press might be a good choice to expand your business.

John Henry
Cedar Creek Press

Bill that looks like a Kimble style speed controled motor, not a perfect solution but I’m guessing it has a lever that slows it down. I have a motor in my shop that has a nearly identical body, where the speed control lever should be is just out of frame.

7mjake

How do you plan to move this thing, they are quite heavy as said above.

doesnt look big enough for a 12x18, maybe 10x15. Check the motor, may be variable speed, look for a brush moving mechanism on the non pulley end. Speed there is much too fast for you. Look for any extra parts- rollers, trucks, chases, maybe fountain. Sounds ok on the video. You can do a lot of work with such a press.

rmiller021 He says he moved it there in the back of a full size pickup truck, and that he’d get it loaded for me, but I’m a bit worried about unloading it. I’m also worried about the shop I will be putting it in. It has a wood floor but I was planning on reinforcing under it with as much as I can.

I would go with a smaller press if it is a 12x18.

That is one crazy fast platen. From the video it looks like the roller spring mechanism is all in place so once you got recast rollers and the right trucks it would probably be ok. It looks like my 10x15 but it’s hard to tell the scale.

The outfeed tray appears to be missing, but no great worries about that.

The only caveats I would think of are the bearings and the casting. Running the press that fast would be ok if someone’s on top of the lubrication, but if not there could
be some wear issues. And if it’s been running fast and there’d been a mechanical stall there’s a possibility that there might be a crack in part of the frame somewhere so just look for that.

He confirmed that it’s a 10x15

I don’t recommend loading this press on a pick-up. I tried that once. A forklift and a heavy duty trailer. Also to slow the motor down I use a industrial strength Rheostat from Grainger on my 10x15 C&P. Cost about a hundred bucks. The down side to a rheostat is “sparks” on the commutator. I use a commutator stone on my motor. Any comments on this from Briar Press members?

Speed control is really dependent on the motor itself. A true rheostat is a high-power potentiometer and will dissipate energy not going into the motor in itself as heat. Possibly one of the worst ways of doing speed control (OK, I guess a dragging brake would be worse than that…). If the motor CAN be varied (not all can, or only can within a narrow range), then a variable autotransformer may come into play. They go by such trade names as “Variac” or ”Powerstat”. Some other speed controllers have fixed taps on a transformer and are functionally the same thing, only they are not infinitely variable as the Variacs are and have discrete speed settings, maybe 8 or 10 or so (the variacs have a graphite brush much like a commutator brush that acts as a wiper along one edge of the coil).

A low tech but very effective way of doing it is simply changing the size of the drive pulley so that the motor can run at full speed. Smaller driving pulley will result in more speed reduction. Unfortunately most AC motors only will go down to 1800 RPM (slightly less, such as 1750 when you account for slip), and 2 pole motors zip along at 3600 (-ish) RPM. You can only go so small (a couple inches in diameter) before you have problems with the belt slipping (not enough contact area to transfer adequate power) or too tight of a curvature radius for the belt material. In such cases, you’ll have to do a jack shaft which essentially breaks the speed reduction down into two stages by adding another intermediary shaft. This is perhaps the best low-tech solution since it will work with any motor, since the motor will be running at full speed.

In today’s day and age a 3-phase motor with a VFD (Variable Frequency Drive) is really the Cadillac solution. You can cover a WIDE range of speeds (from 150% (or as fast as you dare-lol!) down to almost stopped- I think I got one to move with reasonable torque at only 10 Hertz, or 1/6th normal speed (300 RPM), though they will turn a motor less than 1Hz, just very little torque). I’ve been using the Teco L510 model which you can get on eBay for $139.99. The exact model you’d want would be an L510-101-H1-U, which takes 110/120 volts single phase (regular wall outlet) in and puts out 220/240 volt three phase (it has a built-in voltage inverter). You can power a 1HP or less motor with this which should cover a wide range of presses. 3phase motors are often scrapped so if you have a local scrap dealer they might sell you an old motor for cheap, maybe $20-30 for a 1HP? Doesn’t hurt to ask.. 3 phase motors are very reliable, have smooth torque and dead simple (no fancy starters, capacitors, commutators, centrifugal switches, etc- just three coils and three wires- the only thing to wear out possibly is the bearings).

Anyway, hope that helps. Lots of ways to skin the speed cat, but definitely don’t hand feed a press that’s running too fast for your comfort/skill-level as that’s probably the best way to lose a finger…