Access to drawings for G.H Thomas design sheetmeatal rollers

Myfordboy did exactly that Jason and doesn't seem to pleased with the result. That may be down to pride in his own design but he doesn't seem to be that sort of bloke.

I don't need rolls but if I ever do I will follow his design. I think I have seen a comment that one of the video's shows him rolling 1/4 steel with it. A longer handle would make that easier. Personally if I was making one specifically for thick material I would add a step and adjustable collar to a pair of the rolls to act as a guide and also make the rolls shorter. Getting the ends to match might be a bit of a fiddle but that has to be balanced against the time needed to make the other type. Once welded up they could be run through again anyway.

John

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John, Myfordboys ring roller is not a scaled up GHT. I think one of the problems is the short rollers are only supported at one end so tend to flex apart.

Andrews uses two side plates with the short rolls between. Capable of rolling 5" x 3/16" or there abouts.

These are Will Doggett's rollers that I referred to above.

Neil

Or you can always go for a poor mans roller, 3 bits of metal in a vice make an effective "pyramid" which can be used to bend metal into curves and circles.

J

Edited By JasonB on 22/07/2016 14:19:27

Jason,

You missed out the Producer's words of comfort:

"No precision vee blocks were harmed in the making of this illustration"

MichaelG.

That's OK Michael, mine are from the far east so it's OK to abuse them and I'm not sure about the precision either before or after

I assumed he had supported the rollers inside the casing on two bearings Jason so effectively he would be using overhang for the actual rolling. That would also easily enable him to re roll after welding. I have a feeling I have seen that idea used before. Not the crank linkages on his other type though.

This Schmidt coupling is mentioned as being used in the rolling industry

Not in exactly the same way going on this video though but I have wondered if there is a smoother arrangement than 2 cranks

John

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PS I aught to add that I suspect that Myfordboys crank linkage needs laying out rather than just making one and hoping. I also suspect that a bit of a rearrangement would allow it to feed onto a roller as per the other design. In other words the rollers driven by the cranks would provide the feed but I feel that's the weakness of the design over the pyramid ones - the bending provides the feed pressure on those. The cranked rollers need to adjust in an arc if I have the mechanism correct.

Edited By Ajohnw on 22/07/2016 15:46:32

Edited By Ajohnw on 22/07/2016 15:48:04

I can see how it works and the arms in the video are short enough not to interfere, but the one in the drawing would surely lock up?

Neil

There are loads of video's of them on youtube, just use coupling instead of the German word.

Interesting mechanism but I'm not sure I can think of a use for it.

John

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I think something very similar was used in the final drive of the Turbomotive (and possibly GT3), so that the gearbox was mounted on the chassis but the axle could move up and down. Otherwise the unsprung weight would have been very high.

The dimensions on the drawings of the 10" Bending Rolls in the G H Thomas book are in Imperial, as one would expect for that time.

Recently, I made a set, but expanded to 12" wide, and using metric material. Would not expect to roll anything too thick, probably 10 gauge would be the absolute limit, if not actually pushing one's luck! If in doubt, make it thicker.

For the gears, unlike GHT who apparently, and surprisingly, bought in his, I cut 20T, 20DP gears. Probably not very precise, but so far, they seem to do the job, bearing in mind that for one of the meshes the gear centres vary as the pinch roller moves up and down.

For anyone looking for details of the GT3, talk to Tim Coles when he is at one of the shows with his model. He did a LOT of research before making his superb model.

Howard

Maybe a lathe driven milling spindle ?????

John

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+1.

Wot he said.

If you just want to make the rollers, Hemingway sell the drawings and also kits of materials.

Neil