Access to drawings for G.H Thomas design sheetmeatal rollers

[Michael GilliganParticipant @michaelgilligan61133]

Jason,

You missed out the Producer's words of comfort:

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

MichaelG.

[JasonBModerator @jasonb]

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

[AjohnwParticipant @ajohnw51620]

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

[Neil WyattModerator @neilwyatt]

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

[AjohnwParticipant @ajohnw51620]

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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[duncan webster 1Participant @duncanwebster1]

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.

[Howard LewisParticipant @howardlewis46836]

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

[AjohnwParticipant @ajohnw51620]

Posted by Ajohnw on 22/07/2016 17:22:09:

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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Maybe a lathe driven milling spindle ?????

John

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[thaiguzziParticipant @thaiguzzi]

Posted by Hopper on 22/07/2016 13:06:32:

Posted by rodger kallu on 17/07/2016 11:15:27:

Hi, thanks for those 3 replies. I have since googled the GHT Model Engineers Workshop and the cost is a bit steep for me (I have quite a few of the workshop series already).

At 27 quid from Tee Publishing it is not a cheap book, but it is great value for money. One of THE definitive books of the golden era of model engineering and great reading. And a different thing altogether from the Workshop Practice series, as good as they are in their own right.

Edited By Hopper on 22/07/2016 13:07:01

+1.

Wot he said.

[Neil WyattModerator @neilwyatt]

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

Neil

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