Extending tortoise throw wire with tubing

[Bill H]

Group:
I use a usual size pcb tie for the throw-bar on fast tracks turnouts. The stock tortoise wire is 0.025, which is too big for the pcb tie - drilling a hole that big would damage the integrity of the pcb tie. I have seen several guys use the 0.025 wire up from the tortoise to a point, then slip a brass tube over the 0.025 and then use a smaller wire inserted into the tube for the last inch or so with the whole unit soldered together into one piece - so that the smaller wire will be appropriate for the n scale pcb tie. My question is, what is the correct size brass tubing to just fit over the 0.025 wire? I have not seen any tables with the inner diameter of most available brass tubing such as K&S etc.

Thanks,
Bill

[peteski]

Group:
I use a usual size pcb tie for the throw-bar on fast tracks turnouts. The stock tortoise wire is 0.025, which is too big for the pcb tie - drilling a hole that big would damage the integrity of the pcb tie. I have seen several guys use the 0.025 wire up from the tortoise to a point, then slip a brass tube over the 0.025 and then use a smaller wire inserted into the tube for the last inch or so with the whole unit soldered together into one piece - so that the smaller wire will be appropriate for the n scale pcb tie. My question is, what is the correct size brass tubing to just fit over the 0.025 wire? I have not seen any tables with the inner diameter of most available brass tubing such as K&S etc.

Thanks,
Bill

Standard K&S brass tubing has the wall thickness of 0.014" and thin-wall tubing 0.007.  Knowing  that you can calculate the ID from the OD.

[Bill H]

Thanks, will do the math...

[dem34]

Also remember that the piano wire used is not a fan of solder, you may also want to wind a strand of copper wire around the top and bottom of the tube joint to act as a wick.

[Maletrain]

Epoxy instead of solder?

[Ed Kapuscinski]

Why not just bend a new wire entirely?

[nickelplate759]

Why not just bend a new wire entirely?

Because the finer wire might be too flexible if the entire actuator is made from it.  At least that was the problem I had.  So, like @Bill H , I used a piece of tubing as a sleeve to attach a short piece of finer wire on the end of heavier wire.  I didn't worry about solder nor about a precise fit - I used glue.

[mmagliaro]

I've done this sort of thing myself.  JB Weld is your friend.  It is an excellent epoxy, but on metals is where it really shines.
All you need it a piece of brass tubing with an ID that close to .025".  It can be little bigger.  Once you get it on that Tortoise wire
with a little JB Weld and wait the presecribed 24 hrs, it ain't coming off.
.025" is a bad size for K&S tubing ID.  I think you'll have to go with 1/16" regular wall (.014" thick wall), which gets you .062 - .028 = .034",
about .009" too big for the wire.  But if you just stick it on there with some JB and then give the brass tube a squeeze with some needlenose pliers over the wire, it will work.

[Bill H]

Because the finer wire might be too flexible if the entire actuator is made from it.

Exactly...

[Bill H]

I think you'll have to go with 1/16" regular wall (.014" thick wall), which gets you .062 - .028 = .034",
about .009" too big for the wire.  But if you just stick it on there with some JB and then give the brass tube a squeeze with some needlenose pliers over the wire, it will work.

Max:
I ordered the 1/16 tubing yesterday from K&S, and will be using JB as you suggested. Thanks.
Kind regards,
Bill

[GramCentralRR]

Somewhat related to this, I had issues with my Bluepoint mechanisms driving No.6 handlaid turnouts through 2" of styrofoam and an underlay of 1/4" particleboard.  The rod from the Bluepoint was not stiff enough to drive my unhinged turnouts, so I swapped it with 1/16" K&S tubing for the whole length of rod, save for the last 3/4" just under the PCB tie, where I had music wire that fit the exact ID of the 1/16" tubing.  The music wire I used (not the one from the bluepoint which from what I recall was too thick) was just big enough not to compromise the PCB tie integrity.  It fit right snug in the tubing ID, so it must have been just shy of the  .0345" in ID of the tube, give or take. If you flux the wire before sliding it in by say, 1/2", and soldering it in place, the wire will not go anywhere  .

Cheers!
Pascal

[peteski]

  The music wire I used (not the one from the bluepoint which from what I recall was too thick) was just big enough not to compromise the PCB tie integrity.  It fit right snug in the tubing ID, so it must have been just shy of the  .0345" in ID of the tube, give or take. If you flux the wire before sliding it in by say, 1/2", and soldering it in place, the wire will not go anywhere  .

Cheers!
Pascal

The music wire is probably 0.03125" (1/32") diameter.