slip rolls

[andpartington]

i am planing to make a set of slip rolls but do not have any plans

does anyone out there have and plans of a set of slip rolls?
or if not can you take some pics of each end of a set so i have something to work to

thanks for your help

andy

[GWRdriver]

Andy,
There have been a couple of other designs published in ME over the years, but my favorite is the Geo. Thomas bending rolls. These are a 3-roll design and therefore a bit more involved than some other designs, especially when the geared roll drive option is added, but they do quite a good job. I am building a set which are part-finished, which I enlarged to make full use of the steel material I had available. This has ended up wider and more meaty than the orginal design.

[andpartington]

GWRdriver.
any chance of some more detail on the picks i just need one of the geared end i will be away
thanks andy

[GWRdriver]

Andy,
I will be glad to oblige. Unfortunately I've misplaced my project file and can't point you toward the MEs where the original articles and drawings can be found.

As I mentioned above, I enlarged the design and one increase was in roll diameter, from 1" to 1.5"OD. This in turn required a revision to the gear size and gear cluster relationship, which I layed out on Cad. Unfortunately I couldn't find stock commercial gears of the size needed in the US so I was forced to get my gear-cutting feet wet, so to speak. With the exception of purchasing the involute cutter, the exercise was essentially painless and very satisfying. You can of course build the gearless version.

In this photo things are still very much under construction but you get the general idea.

There is a gear on the upper and lower main roll shaft extensions, and two stationary idler gears (shown) fixed to the end plate. The driven gear is on the lower main roll which in turn transfers reverse rotation through the two idler gears to the upper main roll. In order to accommodate varying sheet thickness the upper main roll obviously must move through a short path requiring the upper pair of gears to drive in less than optimal alignment. Those two gears are so arranged that they are in optimal alignment when the sheet thickeness is 16ga IIRC and are in less than optimal alignment when the sheet is thicker or thinner than 16ga, yet still retain tolerable tooth engagement.

This is one of the several unfinished projects I have going at the same time. Why I do this, I don't know. (See "Why" thread below.) Why it should matter to anyone else I don't know. ;D

[teakfreak]

I built a set of rthe ungeared rolls to the original Geo Thomas design, and whilst they work well I do wish I had gone for the geared version as they can slip a lot. I'd also recommend going for up to 15-18" length - its surprising how many jobs turn out to be juast over 12"!

[GWRdriver]

For just that reason I made these rolls 12.5".

Of course Sod's Law dictates that the first job to come along after they're finished will be 13".

[baggo]

Andy,

you can download a PDF of the original ME articles here:

fostertool.com/projects/BendingRolls.pdf

Hemingway do a complete kit including gears for the Geo Thomas rolls at about £100.
I bought one last year but unfortunately it's on the 'not got around to it yet' list! (along with the Kennet tool and cutter grinder!)

The advantage I think with the Thomas design is that you can bend the plate right to the very edge. I believe with the ordinary sort of rolls they tend to leave a bit at each end which is still flat and has to be trimmed off.

John

[GWRdriver]

John,
I've seen this called a "pinch-roll" type and that was one of the attractions of this design. However, as I understand it, the "flat" is only removed (in theory) from the trailing edge of the work and one must reverse the sheet and run it through again in order to remove the flat from what was the leading edge.

[baggo]

I think you're right there Harry, I seem to recall mention of turning the strip around and feeding from the other end. That's obviously the reason why.

[steamjohn248]

Andy,

We've got a nice little set of slip rolls, (geared )and I've taken some detail pics of the ends. if you give me your E mail I will send them over. They are very simple and would be easy to fabricate using a suitable pair of gears

Regards

Steamjohn

[andpartington]

ok john send away
my email is [e-mail]

thanks all for your replies

andy