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Post by springcrocus on Feb 23, 2015 9:41:00 GMT
I need to start thinking about bending the tender sides for my 5" Britannia but I do not own a bender / folder and nor have I ever used one. I could take the easy option and pop along to the factory where I had the components guilotined but I would really prefer to do it myself.
John (Simplyloco) had a similar problem the other day and achieved a result of some kind but didn't expand on his experience. Rather than clutter up his build thread, I thought I'd start one here and give us all a chance for an in-depth discussion about the various ways to put accurate bends in sheet metal without messing up the bit you want left flat. In my own case, I am looking at a pair of 1/2" radius bends in 16swg half-hard brass sheet over a length of 23" approx.
I have been toying with the idea of making a former out of some 25mm MDF using a router cutter as my starting point. I also have about twenty feet of 3" x 2" x 1/8" rectangular box section so I could have a go at making something. What I don't want to do is spend money on a two-foot bender / folder because it will probably never see enough work to make it viable.
Over to you, Gentlemen, all your thoughts on the matter will be greatly appreciated. As a last resort, I might have to hop on a Red Jet and go chat up John for assistance.
Steve
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Post by Deleted on Feb 23, 2015 9:47:53 GMT
John (Simplyloco) had a similar problem the other day and achieved a result of some kind but didn't expand on his experience. Rather than clutter up his build thread, I thought I'd start one here and give us all a chance for an in-depth discussion about the various ways to put accurate bends in sheet metal without messing up the bit you want left flat. In my own case, I am looking at a pair of 1/2" radius bends in 16swg half-hard brass sheet over a length of 23" approx. SNIP Over to you, Gentlemen, all your thoughts on the matter will be greatly appreciated. As a last resort, I might have to hop on a Red Jet and go chat up John for assistance. Steve Hi Steve, and thanks for the vote of confidence. Our Eddie showed me the way and it's easy. You don't have to make anything and your box section will do just fine. I'll take a photo of the setup Eddie specified. I only tried out the apparatus: I haven't bent the thing yet as I only cut the copper sheet yesterday. John BTW you are welcome anytime! |
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Post by Deleted on Feb 23, 2015 9:58:17 GMT
Hi Steve
If you take a look at my Doncaster build thread I detailed how I did this without rollers on page 5.
Regards
Pete
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Post by Deleted on Feb 23, 2015 10:07:04 GMT
Just took this pic to show the principle. I'll do a couple of dummy runs to ensure the the bend starts in the right place! I'll also position the G-clamps closer to the work. John PS. Thanks for NOT cluttering up the Brit thread: some things are sacred you know   |
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Midland
Elder Statesman
Posts: 1,875
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Post by Midland on Feb 23, 2015 10:11:15 GMT
You could try this!  Fig 4 by brigandchief, on Flickr or  Fig 3 by brigandchief, on Flickr Credit goes to Steve Gosling, not me!!! He was doing a 7 1/4" Compound cab. Cheers David |
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Post by ejparrott on Feb 23, 2015 10:42:21 GMT
Agree with David and John.
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Post by RGR 60130 on Feb 23, 2015 11:20:51 GMT
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Post by springcrocus on Feb 23, 2015 19:31:15 GMT
Thank you, Gentlemen, for your replies and suggestions.
John - it appears that you are able to put a bend in the sheet first and then cut to size. Unfortunately, I don't have that option as they are already guilotined to finish size (with a bend allowance, of course).
Pete - I had seen your former before and thats what promted thinking about an MDF former. However, I don't really fancy having to clout the material, too easy to get it wrong and make a mess of things. I've used most types of machine tools in my time but have done practically no tin bashing.
David - I think clamping down into a piece of angle will only work over a relatively short distance as the 1" dia bar will tend to bend in the middle over the two foot distance that I need.
Reg - I was also aware of Geoff's thread and have followed it with interest. His home-made folder looks to be just the thing but it's not so easy for me to make something similar. For a start, my stick welding ability is about apprentice-standard. Could do with a few extra pictures of it, as well. Any chance, Geoff?
Steve
N.B. John, I will send you a PM later tonight if that's OK?
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Post by ejparrott on Feb 23, 2015 20:05:25 GMT
You can strengthen the 1" bar by welding a flat bar along its back
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Post by Deleted on Feb 23, 2015 20:17:38 GMT
Thank you, Gentlemen, for your replies and suggestions. John - it appears that you are able to put a bend in the sheet first and then cut to size. Unfortunately, I don't have that option as they are already guilotined to finish size (with a bend allowance, of course). Pete - I had seen your former before and thats what promted thinking about an MDF former. However, I don't really fancy having to clout the material, too easy to get it wrong and make a mess of things. I've used most types of machine tools in my time but have done practically no tin bashing. David - I think clamping down into a piece of angle will only work over a relatively short distance as the 1" dia bar will tend to bend in the middle over the two foot distance that I need. Reg - I was also aware of Geoff's thread and have followed it with interest. His home-made folder looks to be just the thing but it's not so easy for me to make something similar. For a start, my stick welding ability is about apprentice-standard. Could do with a few extra pictures of it, as well. Any chance, Geoff? Steve N.B. John, I will send you a PM later tonight if that's OK? That's ok Steve....there's many ways to skin a cat as they say...I would just add that panel beating if using proper dollies is pretty basic stuff...a little practice on some scrap and you'd soon get the hang of it. In my particular case rollers weren't an option as like you the sheets where already cut to shape but needed a flattened curve after the main radius along the top edge and thus couldn't be rolled, well I guess they could but they would need panel beating again after to flatten the curve...horses for courses I guess... Pete |
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jma1009
Elder Statesman
Posts: 5,926
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Post by jma1009 on Feb 23, 2015 20:31:31 GMT
steve,
just a 'tip', it is easier to bend the material overlength, then cut off the excess. to bend the sheet cut to size is rather difficult and problematic, but not impossible.
cheers,
julian
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Post by Deleted on Feb 24, 2015 20:58:25 GMT
Hi Steve---------- yes,I'd agree with Julian there..Having spent some time working in the Royal Mail MT Workshops on their commercial vehicles one gets a fair bit of practice with materials such as Aluminium and sheet steel for instance....
Wherever possible it's wise to cut over-length then trim back to size ie}-- making it a bespoke-fit so to speak..Ed's suggestion is practical and sensible I would say...If it helps you any, I've slightly miscalculated on the Bear's mainframe lengths due to them having a slight recess at the front ends...I'll be adding a 1/4" extender after bending, and that will be by welding on a 1/2" piece then cutting back...
Whatever clamping arrangement you eventually decide to use, remember to make space and access ways for re-annealing if that needs to be done...Best wishes for the job---
Alan.
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