micknich2003 Posted March 12, 2011 Share Posted March 12, 2011 I have just acquired an 8ins "Shear/Brake, a great aid and time saver when scratch building. The tool is ideal for accurately cutting tinplate, brass or nickel silver sheet up to 20thou/0.5mm thickness. Obviously, it will take me a few days to become acquainted with it but I can already see its potential, and if nothing else it will save me a small fortune in purchasing the various grades of Piercing Saw Blades. I obtained mine from Arc Euro Trade of Syston near Leicester. See their website www.arceurotrade.co.uk apart from the Shear plenty of other "Goodies" of use to the scratch/kit builder. Link to post Share on other sites More sharing options...
Jol Wilkinson Posted March 13, 2011 Share Posted March 13, 2011 Hi Mick to quote Moriarty "So rich!". The shearing section looks straightforward, but I would welcome your views on with the bending part when you've had a chance to try it. Would it have any use for folding etched kit parts? As it is a heavy item, what did they charge for carriage (it's not clear from their website. Jol Link to post Share on other sites More sharing options...
relaxinghobby Posted March 13, 2011 Share Posted March 13, 2011 I dream of 100% rectangular cuts and 90.00000000000000 degree right angle bends but, by hand I'm always a little bit off from perfect. Could even me manage to learn to use this device?I Link to post Share on other sites More sharing options...
micknich2003 Posted March 13, 2011 Author Share Posted March 13, 2011 The tool is not intended for bending etched kits, but no doubt with a little thought it could be made to do so. It will bend sheet metal to any angle but by its nature leaves a very small radious. I suggest marking out the sheet metal conventionaly and then cutting to the scribed line as near as possible. Any slight excess can then be romoved with a file. With practice it is possible to cut "Dead On" first time. The tool wieghs about 13K, mine came with other goods and I don't recall the carriage, a call or E Mail to Arc Euro will supply the answer, they are very helpfull. Mick. Link to post Share on other sites More sharing options...
bertiedog Posted March 13, 2011 Share Posted March 13, 2011 Shear/brakes like this are very much more used in model engineering, rather than model railway uses, where an etched kit should never need a folder to do the bends, if correctly designed. They are however great for scratchbuilding, and with heavier than etched thickness brass and steel plate. Stephen. Link to post Share on other sites More sharing options...
Jol Wilkinson Posted March 13, 2011 Share Posted March 13, 2011 Shear/brakes like this are very much more used in model engineering, rather than model railway uses, where an etched kit should never need a folder to do the bends, if correctly designed. They are however great for scratchbuilding, and with heavier than etched thickness brass and steel plate. Stephen. Stephen, you may be aware that a number of tools are sold for "bending" etched kit components, e.g. the Hold and Fold jig. As a long time builder 4mm etched kit I know what's required when folding etched components, especially long folds as on carriage sides. My question was to ask whether the tool Mick introduced would be suitable for this. I can see the benefit of a tool that, with one action, will bend an etched component along an etched fold line, simply and accurately. Any tool that makes accurate and quick forming of metal parts is an assett, especially if it has other uses as well. Jol Link to post Share on other sites More sharing options...
bertiedog Posted March 13, 2011 Share Posted March 13, 2011 Stephen, you may be aware that a number of tools are sold for "bending" etched kit components, e.g. the Hold and Fold jig. As a long time builder 4mm etched kit I know what's required when folding etched components, especially long folds as on carriage sides. My question was to ask whether the tool Mick introduced would be suitable for this. I can see the benefit of a tool that, with one action, will bend an etched component along an etched fold line, simply and accurately. Any tool that makes accurate and quick forming of metal parts is an assett, especially if it has other uses as well. Jol It is better to use a folding plate or jig, a a brake really is used with plain metal, where the fold or formed shape is forced by the chisel edge into the groove that does the fold. With the correct folding allowance the metal stretches around the bend, a curve even when it looks like right angles. Etched kits fold in a different way, the half etched surface is stretched till the inner surfaces touch, each Inner panel is the correct dimension, plus the thickness of the sheet metal. This different to a plain sheet allowance, a subtle difference, and if a brake folds an etched item it may over stretch the half etch and fold incorrectly. In practice this does not happen, but you can end up with the wrong dimensions on the folded item if the brake grips one side of the etched line more than the other as the pressure is applied... The drawing shows the variety of folds with an etched joint, even, and up and down in relation to the panel, this issue and the allowances needed plagued early etched designs, making some kits very difficult indeed to assemble, due to accumulated errors. Folding with a jig is the best way, the commercial or home made, it should end up with the "web" stretched evenly. A brake will do the same, but must be applied very gently to the etched fold, as it is easy to get the effect in the drawing of the half etch being distorted and the sheet pulled to the wrong position in relation to the designers intention.(If he even correctly dimensioned the allowances for the fold). After saying all of this a lot of etched kits are designed almost without attention to this vitally important detail and explains why folded components don't quite fit the other parts! Full length coach folding , say solebars, is best done in a plate jig, supporting the sheet both sides of the fold right up the etched fold edge, but a brake is useful for the second fold in the case of a channel section, even when a half etched line exists. Hopes this explains things, I set brakes, folders, and fly presses in scientific instrument manufacture as well as model engineering. Stephen. Link to post Share on other sites More sharing options...
ozzyo Posted March 13, 2011 Share Posted March 13, 2011 Nicely drawn and described Stephen, but in your drawing on the top line in the two at the top right where have the half etch lines gone to? You just cant lose them to describe what may happen, without showing them in place somewhere. OzzyO. Link to post Share on other sites More sharing options...
bertiedog Posted March 13, 2011 Share Posted March 13, 2011 The red line shows the outer edge, the half etch would position the plates further apart than the sketch due to the thickness which is not drawn in,... it was just a sketch to show the principles. The point I was making was that some makers, like Jidenco in the first kits, completely failed to design the folds with any allowance for the panels overall size when incorrectly folded. (which was highly likely) Link to post Share on other sites More sharing options...
micknich2003 Posted March 14, 2011 Author Share Posted March 14, 2011 I dream of 100% rectangular cuts and 90.00000000000000 degree right angle bends but, by hand I'm always a little bit off from perfect. Could even me manage to learn to use this device?I You ask about perfect 90o cuts etc. With a little care and practise they are relitivly easy, first mark out the material as you would for conventional cutting and then carefuly place same in to the shear and pull up the handle. Best Wishes, Mick. Link to post Share on other sites More sharing options...
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