Anyone know how the rounded angle iron frame of the outside plates at the sprockets each end of the tank are formed and made, seems to be quite a tricky task for a modeler making one of these tanks in a metal construction.
Are there any books devoted showing the constuction of these tanks at the factory, i am interested how they were constructed from the ground up.
It depends on the scale you're building, and the material of course. Brass L girder strips can be rather easily formed with the help of a vice and a (hobby) torch, and a hammer. First you have to anneal the strip. Burn it till it's coloured orange,(red when you're using iron) let it cool down. The brass is then soft enough to form it. You won't get the right shape at once, but by hammering the strip piece by piece you'll get your rounded angle iron. And after some hammering you'll might have to anneal again. If one angle is too width, file it the proper size, or mill it down.
You can make them in two pieces too, a flat strip heated and hammered the same way, a second flat 90 degrees soldered on it. A good vice with smooth 'claws' is rather essential, or put two L formed strips on them, preventing damage or scratches. It's not that difficult, but it takes some exercise and patience. Good luck,
Many thanks for that, i suspected that would have been the way to make them. Would this be the way the original ones have been made on the real tank forgin the metal work or would they have been put through a metal forming dolly.
There appears to be little information about the methods of construction used on the Briitish tanks.
A current way of forming angle iron is as shown on the attached link. I would expect it was done in a similar fashion in WWI, though the layout of the machine may well be different. http://www.ercolina-usa.com/ce70-ring-roll.htm
Some years ago I made enquires to a number of companies about rolling the angle for the front horns and I couldn't get a guarantee that a satisfactory roll could be made. The problem is the possible distortion of the material that is being compressed.
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ChrisG
The cure for boredom is curiosity. There is no cure for curiosity(Dorothy Parker)
yes, you'r right I think, there's the risk of distortion. The 'top' of the L getting overstretched and the 'down part' understretched so to speak, and causing wrinkles. If carefully clamped in a vice and bending only a few millimeters at a time the result will be fine. If distortion isn't that dramatic things can be brought back in shape with a hammer. I tried both methods, bending the complete L and make one out of two strips. It's painstaking but as you only have 8 roundings (apart from those under the belly but these are easier to form) it's doable. The latter, properly soldered, and polished after, works fine. I will try to post some pictures later.
I guess the originals were made on a forming device, though on ship yards iron was formed too on a heavy iron table, with holes. Only know the Dutch word, it was called a 'pen bank'.
-- Edited by kieffer on Monday 31st of October 2011 12:22:26 PM