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Driving a C&P by Friction

Hi All!

The Chandler & Price spec sheets for New Style presses note: “If Press is to be driven by friction, specially Milled Fly Wheel should be specified.”

I take it from this that it is possible to mount a motor so that some sort of attachment on the motor shaft is held in direct contact with the flywheel, eliminating the need for a belt. But I am not sure at all what that attachment on the motor shaft would look like. (Is it perhaps called a “capstan?”)

Is anyone running their C&P this way? If so, could you perhaps post a photo of the interface between motor and flywheel?

Any thoughts about the wisdom of this setup vs a belt?

I am currently using a belt drive with a large drive pulley on the lefthand side of the press, but need to slow down the press while I learn to feed it, and it occurs to me that the friction drive might be one way to accomplish that.

Thanks!

Greg

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I’ve seen a couple of presses set up this way. The motor has to be blocked up to bring the drive roller into direct contact with the flywheel surface underneath. It can be done very cleanly, but you need a decent variable speed motor to pull it off. I will try to find some photos.

Have a look at ‘drive rollers’ on McMaster Carr for something in urethane that matches the stub of your particular motor.

Daniel Morris
The Arm Letterpress
Brooklyn, NY

Thanks, Daniel!

I’m currently using an ancient Kimble Electric Motor with variable speed from 500 to 2000 RPM (at least, that’s what the plate says). It’s one of those in which the speed is controlled by altering the position of the brushes.

I’ll take a look at the drive rollers. If the speed works out, this does seem cleaner to me than a belt.

Greg

A long long time ago here in the U.K. there existed at least 2 forms of motorising pedal cycles, one was the B.S.A. winged wheel which incorporated a tiny engine within the rear wheel, the other variation was a similar tiny engine, sat on what would have been the luggage rack, and performed exactly the same operation as in this post, except that it was a hatched/serrated metal pulley driving directly on to the rear tyre, (only vice versa) in fact metal driving pulley rotating rubber driven pulley, but because of the considerable thrust in one direction only, the driver was supported with an outrigger bearing, to ease the pressure on the first inner bearing, this may be a consideration if a fairly big flywheel is to be driven by a small driving pulley.. There will be a lot of friction to overcome, if it is a direct on start system. At least with a capacitor start/capacitor run motor and pulling on the belt, it gives a little chance for the motor to hit the ground running, and it would seem almost essential to incorporate an anti surge device in the starter switch. Check me out and offer SENSIBLE/CONSTRUCTIVE comments, by all means (welcome) Might just help future queries. Mick

I think this might help you out. I have scanned the original Kimble Press-O-Matic Motor Controller documentation. You will note that the first configuration on page one is what you are looking for. I have also taken a picture of our pulley which is a friction drive.

These are original to the press which was built in 1926.

http://elationpress.com/kimble-press-o-matic/

Thanks, rontxhou! That is super helpful. And it’s apparently the same motor I have — or one very like it.

A couple of questions:

1. Do you have the motor control pedestal shown in the instructions? I’d love to see a photo of that. I’m sure there’s no chance I could find one, but it might be nice to try to manufacture a decent substitute

2. Is your motor mounted on the spring base mentioned in the instructions? A photo of that would also be helpful.

3. One problem I can see for me is that my motor has spent its entire life rotating counter-clockwise. Moving it over to the flywheel, if it is positioned outside the press, will have it rotating clockwise — and the brush do scream when I run it that way. I wonder if I can reverse the brushes?

4. I’m also probably going to need new brushes. Do you have any trouble finding replacements?

Thanks again!

Greg

If as you imply you have moved the orientation of the motor from right to left, or vice versa and positioned it outside the arc of the flywheel, instead of inside and you now require the motor to run in the opposite direction, as with virtually every motor with carbon brushes,(and even composite copper/carbon) the brushes start off as completely flat, in their approach to the armature and very quickly adopt a curvature to match, consequently they by their very operation, adopt a leading edge and a trailing edge, and as they are normally only retained by a small coil spring, (which keeps them in contact whilst running) and allows for wear, carbon is only pencil lead by another name, examine the possibility of rotating the brushes in their holders 180 degrees, so that the brushes maintain their original approach to the armature, and even possibly to the extent of rotating the armature by hand, and cleaning the commutator with the finest side of Ladies nail treatment emery boards. Your “screaming” is probably the poor little brushes trying to push against what WAS the trailing edge and is NOW the leading edge.

Greg,

Yes, we have a complete motor controller. I was able to find one for another press, so I wouldn’t give up that easy. I will see what I can come up with in terms of photos, but it is really as simple as the diagram portrays it to be.

Regarding motor direction, you will want the motor to run counter-clockwise, (if you are facing the pulley) so that the flywheel turns away from you when standing in the operator position.