03-22-2010, 03:36 PM
As promised, some ladder construction.
The first task is to construct the stiles - I used Detail Associates .010"x.030" flat brass bar, forming it on the jig shown below using a small pair of smooth-jawed pliers.
The first task is to determine how much material is required for a single stile. I measured a partially-used length of brass bar, then formed the curve near the end of it - I started the curve farther in from the end than was probably necessary, but better to waste a little material on a single test piece than to screw-up a batch of 20 or 24 for all the cabooses that need to be built.
After the test piece was done, I cut it from the strip using an X-Acto knife (working on a hard surface, such as a piece of glass, a moderate downward pressure will "snick" it right off, nice and clean with little or no clean-up required). Holding it up to the caboose, I determined approximately how much needed to be trimmed from both the top and bottom, then trimmed accordingly, taking care to save the cut-off ends. Re-measuring the remaining strip that I started with, plus the two short cut-offs gave me the total amount of material left, and subtracting that from the original length showed that 14' HO was required for each stile. Due to the slight change in construction of the roofwalk, about 13' should be plenty for this particular caboose. 
For two ladders, four stiles are required, or, more aptly put, two pairs.
The simple jig used yields a decent approximation of the part needed, but there can be minor variations between pieces, especially in the curved section. I made four, then compared them to get two near-matching pairs, tweaking them as required until both in each pair were identical - they may or may not be identical to the pair on the opposite end, but they'll be far enough apart that comparisons will be unlikely.
After the pairs were formed and then cleaned using 400 grit wet/dry sandpaper, they were tinned (I used an 80 watt iron only because it has a chisel tip, whereas my 25 watt iron has a pencil tip), then pinned to the forming jig with the tinned surfaces facing. A quick touch of the iron joined them as one.
I used a divider to scribe one side of each pair lengthwise along its mid-point, then, after setting it to the proper rung spacing, "walked" it along the lines, pressing slightly at each point where a rung was to be located.
Using a #79 drill bit in my pin vise, the holes for the rungs were easily drilled through the soft brass. Here they are, still soldered together as pairs, with the holes all drilled:
After another quick touch of the hot iron, the pieces were separated (keep them together as pairs, though, and each pair separate from the other), then all of the solder was removed using the sandpaper. If necessary, use the drill bit to clean out any holes that may be blocked with solder, then use fine sandpaper to remove all oxidation, dirt, and fingerprints from both sides of each piece.
Next, place the stiles in the soldering jig (previously shown HERE), with the bottom ends butted against the stop block. Make sure that the stiles are tight against the spacer blocks and that they're firmly held in place by the keeper pieces and clothes pegs. I used a couple of straight pins, as shown below, to prevent bowing the stiles inward during soldering.
Clean a length of .012" brass wire by dragging it through a folded piece of fine sandpaper, then, using your X-Acto knife, snick off the required number of rungs - make them longer than required, as shown, then use tweezers to install them in the stiles.
I used an X-Acto blade to apply a small amount of resin flux on the outside of the stiles wherever a rung poked through, then, using a 25 watt pencil iron with a "wet" tip, touched each joint until the solder flowed into it.
After removing the ladders from the jig, I used a cut-off disk in my Dremel to lop-off the excess rung material outside of the stiles (don't trim too close!) then used appropriately-sized needle files to finish the clean-up. After a quick dip in some lacquer thinner to remove any flux residue, the ladders were set aside 'til later.
Wayne
The first task is to construct the stiles - I used Detail Associates .010"x.030" flat brass bar, forming it on the jig shown below using a small pair of smooth-jawed pliers.
The first task is to determine how much material is required for a single stile. I measured a partially-used length of brass bar, then formed the curve near the end of it - I started the curve farther in from the end than was probably necessary, but better to waste a little material on a single test piece than to screw-up a batch of 20 or 24 for all the cabooses that need to be built.
After the test piece was done, I cut it from the strip using an X-Acto knife (working on a hard surface, such as a piece of glass, a moderate downward pressure will "snick" it right off, nice and clean with little or no clean-up required). Holding it up to the caboose, I determined approximately how much needed to be trimmed from both the top and bottom, then trimmed accordingly, taking care to save the cut-off ends. Re-measuring the remaining strip that I started with, plus the two short cut-offs gave me the total amount of material left, and subtracting that from the original length showed that 14' HO was required for each stile. Due to the slight change in construction of the roofwalk, about 13' should be plenty for this particular caboose. For two ladders, four stiles are required, or, more aptly put, two pairs.
The simple jig used yields a decent approximation of the part needed, but there can be minor variations between pieces, especially in the curved section. I made four, then compared them to get two near-matching pairs, tweaking them as required until both in each pair were identical - they may or may not be identical to the pair on the opposite end, but they'll be far enough apart that comparisons will be unlikely.After the pairs were formed and then cleaned using 400 grit wet/dry sandpaper, they were tinned (I used an 80 watt iron only because it has a chisel tip, whereas my 25 watt iron has a pencil tip), then pinned to the forming jig with the tinned surfaces facing. A quick touch of the iron joined them as one.
I used a divider to scribe one side of each pair lengthwise along its mid-point, then, after setting it to the proper rung spacing, "walked" it along the lines, pressing slightly at each point where a rung was to be located.
Using a #79 drill bit in my pin vise, the holes for the rungs were easily drilled through the soft brass. Here they are, still soldered together as pairs, with the holes all drilled:
After another quick touch of the hot iron, the pieces were separated (keep them together as pairs, though, and each pair separate from the other), then all of the solder was removed using the sandpaper. If necessary, use the drill bit to clean out any holes that may be blocked with solder, then use fine sandpaper to remove all oxidation, dirt, and fingerprints from both sides of each piece.
Next, place the stiles in the soldering jig (previously shown HERE), with the bottom ends butted against the stop block. Make sure that the stiles are tight against the spacer blocks and that they're firmly held in place by the keeper pieces and clothes pegs. I used a couple of straight pins, as shown below, to prevent bowing the stiles inward during soldering.
Clean a length of .012" brass wire by dragging it through a folded piece of fine sandpaper, then, using your X-Acto knife, snick off the required number of rungs - make them longer than required, as shown, then use tweezers to install them in the stiles.
I used an X-Acto blade to apply a small amount of resin flux on the outside of the stiles wherever a rung poked through, then, using a 25 watt pencil iron with a "wet" tip, touched each joint until the solder flowed into it.
After removing the ladders from the jig, I used a cut-off disk in my Dremel to lop-off the excess rung material outside of the stiles (don't trim too close!) then used appropriately-sized needle files to finish the clean-up. After a quick dip in some lacquer thinner to remove any flux residue, the ladders were set aside 'til later.
Wayne