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sumterIII

complex PE bends, looking for help

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I'm having some difficulty with making the bends for railing on two kits. One is 1/350 and the other 1/700. Both kits have multiple rounded shapes to fit along the upper levels. I have the small shop bending tools but the rails seem to curl upward as I form them around the wood dowel.

Many of the bends are S shaped which are even more challenging. Anyone have a few tips that could help me?

 

Thanks

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My Small Shops bender has surfaces that are curved in various diameters just for that purpose. I also have a small supply of K&S plastic tubing in various diameters, and brass tubing in various diameters. In some cases one must combine curves and stretches of straight railing. I use some tweezers that have wide and flat jaws to help keep the straight parts straight.

 

As for 700th scale, the trained spider I hired for such things disappeared some time ago. I limit my pe bending to 350th now.

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I'm still at the beginner/experimenter stage in doing this kinda stuff, but have a technique that may help this: Roll an X-Acto knife handle (#11, typ), or a paintbrush handle, along the stretch of PE railing, simultaneously pushing it down, into one of those rubber 'hobby mat' cutting surfaces.

 

Repeated rolling imparts a gentle curve to the railing, and the radius of the curve tightens with continued rolling. Changing the angle/direction of the roller seems to give some control over the angle at which the PE piece wants to curl around it. No finished models to display for this. Best result so far is a tiny, circular railing around a 1/700 ship's superstructure platform.

 

Just my 2 cents.

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Making circular bends to an accurate fit is a challenge only mastered with practice. I have been designing and working with photo etched parts for a long time now and I have found the best tool for the job is ingenuity. I use whatever I can find around the shop like jeweler's file ends, drill bits, dowels, or mandrels for tight curves, an Xacto knife handle for larger diameters.

 

One surface that really works well for any kind of bending is Styrofoam egg carton tops. It has a lot "sponginess" allowing you add tight diameters as well as perfect bends with a #11 blade to any angle because the parts squash into the carton preventing them from being cut.

 

You really don't need to spend the bucks for a bending tool. I have never had the need for one, but that's me.

 

Your "S" curve is almost impossible to make and fit correctly in one piece. The biggest mistake most beginners with photo etch make is trying to do too much with one piece of railing. It's easier to make two smaller curved parts rather than a longer "S" shaped curve, so make your two parts intersect at the transition point where the curve direction changes. Allow a stanchion at the end of one part where the parts meet and carefully match the next part (less the stanchion) to touch. The result should be unnoticeable. If it isn't, that's where experience comes into play. Keep trying and you'll get it.

 

I produce an entire "how to" CD with tons of tips and photos for working with these parts. See my web site if you're interested. Flagship Models Inc.

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I'm still at the beginner/experimenter stage in doing this kinda stuff, but have a technique that may help this: Roll an X-Acto knife handle (#11, typ), or a paintbrush handle, along the stretch of PE railing, simultaneously pushing it down, into one of those rubber 'hobby mat' cutting surfaces.

 

Repeated rolling imparts a gentle curve to the railing, and the radius of the curve tightens with continued rolling. Changing the angle/direction of the roller seems to give some control over the angle at which the PE piece wants to curl around it. No finished models to display for this. Best result so far is a tiny, circular railing around a 1/700 ship's superstructure platform.

 

Just my 2 cents.

 

One critical point you must know about using paint brush handles. They are tapered, which will cause the railing to curve up or down like a cork screw.

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One critical point you must know about using paint brush handles. They are tapered, which will cause the railing to curve up or down like a cork screw.

 

Yup - an excellent point. Remaining conscious of this, it can be used to advantage.

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Thanks guys for all the tips. I have the Small shop set for rolled bends, Standard Rolling Set, and 2" Mini Hold and Fold workstation.

I gave up trying to make the double S bend with one rail. The rail would twist and bend upward. A double roller would have been better, like the kind I used to use in the factory for shaping large sheet metal panels. As far as I know there is no such machine made for PE. The process was similar to what Vont described.

Rusty the egg carton idea is great. I'll have to give that one a try for sure.

:smiley20:

 

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FWIW, I have a tool that looks like a set of needle nose pliers, except that one tip is a series of stepped down diameters and the other is "cupped" to fit them. You put the piece to be curved on the correct step and then close the pliers and the cupped other tip pressed in the curve. It's, of course, limited to the set diameters of the tip, but it works well. Got it from "Mr. Tool" and some model show. Also works well on brass for larger scale stuff.

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FWIW, I have a tool that looks like a set of needle nose pliers, except that one tip is a series of stepped down diameters and the other is "cupped" to fit them. You put the piece to be curved on the correct step and then close the pliers and the cupped other tip pressed in the curve. It's, of course, limited to the set diameters of the tip, but it works well. Got it from "Mr. Tool" and some model show. Also works well on brass for larger scale stuff.

 

Ron do you have a name or part number for this tool?

 

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Pliers with round jaws (available at any craft store in the jewelery section) work well. The standard jaws are tapered, but the railing you are working with is narrow enought that you should be able to flip it over and eliminate any problem from that.

Edited by JHockett

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Sorry for the delay. Just saw your question. I checked and there's no name nor number on the tool and/or its little pouch. That's a real mark of a quality tool. I did get it from "Mr. Tool" at a show at some point. Other companies must have similar tools. See what MicroMark has in their inventory.

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Model Railroaders use a tool to bend the air hoses on couplers. The tool looks like a needle nose pliers but one of the jaws has a half-pipe into which the other standard jaw retracts. The metal "air hose" is thusly bent. By applying greater or less pressure one can control the arc of the bend. On occasion I've used this tool to bend handrails but frankly speaking I've found that a set of K&S metal tubes in different diameters works just as well or better. I still use the spcial pliers to bend air hoses as it does not put strain on the metal part at the attachment point to the coupler knuckle.

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