Stuck on this one..

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Kittyhawk

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The current aeroplane model under build is a Heinkel HE.115. This is a twin engined WW11 floatplane and just behind each wing it had permanently affixed ladders from the floats to the wing tops to allow crew access to the cockpit. The ladders were tubular aluminum with five rungs. In scale, they would be about half a mil in diameter and I have no idea about how to replicate them. Any thought please?
 
You might find 0.5mm copper wire in a stranded cable which would solder together easily can could be sprayed mat gray. how long will the ladder be?
 
The current aeroplane model under build is a Heinkel HE.115. This is a twin engined WW11 floatplane and just behind each wing it had permanently affixed ladders from the floats to the wing tops to allow crew access to the cockpit. The ladders were tubular aluminum with five rungs. In scale, they would be about half a mil in diameter and I have no idea about how to replicate them. Any thought please?
Wire for the rungs (guitar string?) and cocktail sticks for the rails?
 
I don't know what I am talking about but would this task be a candidate project for someone with a home 3D plastic printing machine, they can print in any colour and would take spray paint. I have seen one in action at a model game shop and was amazed at the result.
 
How about finding a jewelry maker who working with fine wire and silver solder would be a walk in park for them??
 
The ladder is 30mm long, 6mm wide. The ideal thing would be the old extra long brass dressmakers pins but I haven't seen them for decades. 0.3mm dia copper strands from electrical cable is good size wise but too floppy. Have read somewhere that you can harden copper.... what's required for a solution is this thinking outside the box thing - not my strong point.
heinkel-he-115b-1.png
 
Could you cut it out from some sort of ready made mesh. A sieve or something?
 
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The next trick will be how to solder on the rungs without the heat making the already soldered on adjoining rung fall off.
Do all the soldering in one hit? Lay everything in place, drown it in flux, place small sectionss of solder in the right areas and hit it with a big iron or hot air gun intended for rework? It's one method used to solder surface mount ICs and the like.
 
Do all the soldering in one hit? Lay everything in place, drown it in flux, place small sectionss of solder in the right areas and hit it with a big iron or hot air gun intended for rework? It's one method used to solder surface mount ICs and the like.
Good thought. I was thinking of making some sort of heat sink around the bits being soldered but what you suggest would save me from replacing my little soldering iron that recently died. The only one I have now is a Weller 80 watt which would be a bit beasty for individual joints on 0.5mm stock.
 
Brilliant!
Exactly what I need and I can afford it at 6 interest free weekly payments of 99 cents.
The next trick will be how to solder on the rungs without the heat making the already soldered on adjoining rung fall off.
You want a heat sink in-between.

Pair of plyers or something.
 
You can just put the edge of a wet kitchen towel over the joint you have done to stop it getting too hot. Tin the area of the joint first and use a very hot iron. This way you will only have to touch it to melt the solder, and the heat wont spread You can use blu tac or similar to hold the parts in place. I do this quite a lot putting new curb pins onto regulators on watches, they are often much smaller, .2 or so. You can even roll out a piece of blu tac and, having tinned all the relevant areas, lay your ladder out on the blu tac with all the joints butted up tight, then just apply the iron very briefly to each joint. Any blu tac that sticks to it because of the heat can be easily removed with a scotchbrite pad. As an aside if you ever need stronger very thin wire have a look at pivot steel for watches, comes in sizes from about 0.1 upwards in steel.
 
As to your iron, the trick is you just grind a tip down to a suitable sized point. You dont need to apply it directly to the joint. If you have tinned the parts and butted them up tight then applying the iron on the rung, or stile of your ladder close to the join should melt the tinning together, and by not applying the iron directly on the joint you can see what is going on. I often use a trigger type gun for this sort of thing. Position the tip, then a quick squeeze of the trigger, job done.
 
I'd 2nd use of copper wire, lots of gauges available from hefty 2.5mm domestic T&E down to fine or smaller 0.3mm for fine work. In a former existence I worked at Marconi's and guys would knock up incredibly intricate wire spaceframe models of cars and the like, in part to demonstrate their artistic bents but also their soldering skills!
I still tinker with IoT type projects and so still solder this stuff regularly with an ancient Weller TCP style 45W iron and if you keep everything scrupulously clean it's relatively easy to solder small stuff quite close without disturbing prior nearby joints and this is best done on a sacrificial scrap of Formica covered kitchen worktop, sure the bakelite or whatever surface will get marked, however it will withstand hours of use without catching fire and it's low thermal conductivity means you can with practice dip in and out swiftly with iron and flux cored solder and achieve surprisingly robust joints, it just takes some practice!
One of the challenges with modern components is the fact that most come in surface mount cases where the lead pitches are 1mm or less, and for than I have some reels of angel-hair 0.1mm polyurethane covered copper wire which is very tricky to work with and requires steady hands and very strong task lighting to achieve good results.
For a model ladder I am sure you can fabricate a very realistic ladder for your model, for sure it will be delicate but way easier to work with than for example piano wire, which because of the trace elements added to give it high tensile strength, they also tend to make it difficult to tin and hence solder.
Top tip if you are salvaging same domestic T&E is usually after stripping off the insulation you can easily straighten a length by clamping one end in a vice and the other with a single wrap coiled over some pliers is to pull it taught, and then marginally stretch it. because the wire is ductile it will 'give' a mm or two before reaching the snapping stage, and once the tension is relaxed the wire will remain straight even after the tension is removed,
Ed
 
Do all the soldering in one hit? Lay everything in place, drown it in flux, place small sectionss of solder in the right areas and hit it with a big iron or hot air gun intended for rework? It's one method used to solder surface mount ICs and the like.
Deffo this route. The low heat solder is very easy to use and doesn't require touching with a soldering iron. As said, lay it out carefully, place small dots of solder over the joints and apply heat to the (fluxed) parts.
Let us know how you get on. With pics!
 
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