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Trimming actuator wires on servos Track and electrical/DCC
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Frequent poster 691 posts Ron Ventura Notace Frequent poster 691 posts
Ron Ventura Notace

Hi.

I’ve installed servos to move my turnouts, with piano wire up through the table going through the holes in the (Peco N scale) throw bars. On the N scale turnouts, the holes are on the outside of the track, rather than between the rails, like on HO. While fitting the servos, I left the piano wire an inch or two long, and now it’s time to cut them down to their final length.
My initial thought was to put a slight bend in the piano wires so they don’t slip out of the throw bar, and then cut the wire. I abandoned that idea pretty quick as I could see no way to do it without putting all sorts of strain on the turnout and (probably) wrecking it.

My second thought was to use a Dremel to cut the wire off just above the throw bar. I did one or two and found that the heat generated (even trying to use pliers as a heat sink) deformed the throw bar. One even melted the throw bar so that the hole opened up completely, releasing the wire. I used a soldering iron to more or less repair the throw bar, but I can see myself replacing that turnout down the track.

In the end I just used a pair of side cutters (after destroying a pair of normal wire cutters which weren’t hard enough) to trim the wire as close to the throw bar as possible. In a number of cases this took a couple of attempts, as I found while testing that some of my locos would snag on the wire, which was too high. I’m wondering now whether I shouldn’t have measured the wire and trimmed them before fitting them to the layout. That way I could have put the little bend in them to secure them.

How do you guys go about trimming the actuator wires on your turnouts? What’s the best tool for cutting this stuff?

Thanks

Ron Ventura

Melbourne, Australia
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rocdoc Regular poster 190 posts
rocdoc

Trimming wires

I've made 3 N scale layouts over the last 15 years and have always used Peco points - lots of them.

First, It's far better to leave the wires overlength - if you don't you'll have a very hard time getting the wire in the hole without it popping out every time you adjust the position of the servo. Also it would be exceedingly difficult to work out exactly how long to make the wire (to the nearest 0.5 mm).

Second, you can use either one of the existing holes near the ends of the throwbar if you want, but I drill a 1 mm hole in the centre before installing it, and cut off the protruding ends - looks better.

To trim the wire, I first cut off all but about 5 mm with a pair of steel nippers, then use the dremel. The secret is to use it at a high speed so that it cuts quicker, and not to keep the dremel in contact with the wire for more than 1 - 2 seconds at a time. Cut - rest - cut - rest. Rest your arms on the layout so you get exactly the right spot each time. I have a diamond impregnated cutting disc on my dremel - best thing since sliced bread. (It also goes through nickel silver rail before you realise it, so be aware of what else is nearby.)

I leave no more than 1 mm sticking above the throwbar and the wires never pop out.

Tony in Gisborne, Australia
Tony in Gisborne, Australia
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pierre52 MRH Author 1,502 posts
pierre52

This is what I use

Hi Ron

Go to Bunnings and get yourself a good pair of  side cutters.   Suitable brands would be Bahco, Irwin or Wiha.  Check on the packaging that they are suitable for cutting hard wire up to at least 1mm in diameter.  They aren't particularly cheap but this is case where you need quality if you want them to last longer than the first cut.

If it were me I would be buying these:

Wiha%20P.jpg 

 

Peter

The Redwood Sub
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AzBaja Prolific poster 2,086 posts
AzBaja

What I have, in my tool box and could work for you

I have had this tool for years,  It is used for cutting cables etc. when making throttle cables for off road race cars, Dirt Bike Cables,  Model airplane push/pull servos and yes, piano wire on switch machines.  I also have an end cutter.  I would think the end cutter would be the best option for you.

Steel Wire Cutter for both soft and hard steel cable or wire rope or spring wire

_SL1500_.jpg 

End Cutter

52L__AC_.jpg 

AzBaja
---------------------------------------------------------------
I enjoy the smell of melting plastic in the morning.  The Fake Model Railroader, subpar at best.
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John P Regular poster 241 posts
John P

Sharpie marker, then cut

I admit it's a little tedious, but I install the switch machine, use a felt tip marker to show the location on the wire where it ought to be cut, take the machine out, make the cut with an abrasive disk in a Dremel tool, then reinstall the switch machine.
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joef MRH Founder 17,535 posts
joef

Discussed this in Sep 2020 MRH Running Extra ...

Some good options shown here, and not too expensive either ... https://model-railroad-hobbyist.com/magazine/running-extra/2020-09/ah-hah-moment

Joe Fugate​
Publisher, Model Railroad Hobbyist magazine

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Read my blog
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Ron Ventura Notace Frequent poster 691 posts
Ron Ventura Notace

Thanks Guys

Thanks for all the great advice, everyone. I’ll have to mull it over.

Ron Ventura

Melbourne, Australia
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