assessing and optimizing rails

I am concerned about the quality of the rails on a C&P New Style 10x15 press that I might purchase.

Can anyone here touch upon what the best approaches are for analyzing and optimizing rails? These rails have high and low spots throughout and when laying a straight edge over the length of the rails, the halfway point (along the length) is a bit higher than the ends. Should I be concerned about this “warping” or is this considered typical and something that can be resolved with rail tape, etc?

Not sure if I should have the rails machined. If so, I’d like to learn more about this process and also learn if there are experienced machinists in Colorado that can do this. What would one expect as far as cost for this?

Are there any other approaches beyond tape and machining to ensure that the rails are consistent throughout their length?

Would rails with these characteristics be considered “unfixable” and reason enough to not purchase this press?

Any assistance with this would be greatly appreciated.

Thanks so much.

Josh

Log in to reply   5 replies so far

If you would characterize the rails as “bumpy” I would encourage you to look for another press. Heidelberg Windmills and C&P Craftsman presses have rails that can be adjusted and, if needed, removed for machining. The New Style C&Ps do not have this feature and it would be quite a process to machine the rails. Not sure about the cost, but the hassle alone would probably cause for finding another press.

The true test would be to print a few different pieces on the press with good rollers and solid trucks. It may be that the rails are well within the range of usability. If you notice persistent inking issues (after reasonable taping and adjusting) then I would hold off.

Hope this helps.

Brad.

You can level the tracks yourself using a carborundum stone. You need to make a wooden jig that will hold the stone square to the track, and at the height of the low spots, relative to the bed. Then slowly and carefully take down the high spots (within the limit of the chase interior). A depth micrometer will help you understand the amount of wear, and the progress of your work.
I’ve seen metal strips used to bring up rails, as well as tape.

I’d agree with both answers above.

Having a press with removable rails myself, I’ve pulled them off, machined them true & set them right back at type high. I cant say I would have contemplated machining them (or been able to) if if they were part of the bed like they are on a standard C&P - That’s an awful big piece of steel & a fairly awkward shape to boot.

If unable to see the machine in action, you might take some measurements of the rail height to the bed & get a good solid read on just exactly how much wear there is.

I mainly have the same thought as parallel_imp. If the wear isn’t outrageous, you could lap the high spots in & get the rail heights consistent - then build them up with steel shim or poly tape. I recently did this (lapping & shimming) while repairing the back gauge on my paper cutter - It takes some patience & finesse, but good results can be achieved.

I don’t know exactly where my threshold would be for the amount of wear I’d consider fixing like this, but I personally might start to have second thoughts if I was seeing more than 0.020”. As mentioned a depth mic would be a good tool to use for measurement, if unavailable most calipers have a depth gage on the back end that could be used (a little less accurately) to get a decent measurement for evaluation purposes (calipers can be relatively inexpensive & versatile for future use). However if it came down to actually performing the work on the rails, I’d go with the mic or might prefer a dial test indicator (on a small toolmakers base) for a precise read of what the rails are doing.

-Jason

Thank you for all of your insight into this question. This will really help me to make my final decision about this press. I’m not sure the actual amount of the low and high points but now at least have a better idea of what my options are.

Your knowledge, time and experience is greatly appreciated.

Joshua

Joshua:

My rails look like washboards and are up to 3 points under type high in spots. I tried taping to correct the problem but nothing lasted very long. I purchased new rubber rollers from NA Graphics when I got my press running maybe 10 years ago, so I knew the rollers themselves weren’t the problem. Nor the trucks. But I could hear the trucks clattering over the type and hitting the rails on the other side. I print almost exclusively with metal type and cuts and since starting to use the roller bearers I have very few inking problems (other than a tendency to put too much ink on the press). Don’t let worn or low rails stop your from acquiring an otherwise good press.