Short linkages for Tortoise point motors

[47137]

I have eight Tortoise point motors for my new layout and four of these need some kind of remote mounting. I've bought two of the Circuitron remote adaptor kits but these are bulky and the 40-step instructions are putting me off too. With the motor on its side a few inches away from the point, I can think of two possible DIY mechanisms and I wonder if anyone could suggest which one would be the best to try:

 

(1) The motor has a spring wire (like its usual mechanism), probably a bit thicker than the original, which operates a short push rod to the tie bar.

 

(2) There is a short push rod directly from the motor throw-arm to the tie bar. The rod might have an omega loop in it to absorb the slack, or perhaps the motor can be allowed to stall short of its end stops.

 

The topic on Creative mounting of Tortoise point motors is helpful but after some more searching around I cannot find anyone discussing method (2), although it looks the simpler approach to me because it has fewer moving parts.

 

Any advice especially photos from someone who has built something like this would be great.

 

- Richard.

 

Edit after Gile's reply post #2 below: I suspect the Tortoise mechanism must be allowed to travel through its whole distance, to make sure the changeover switches work properly - Richard.

[Giles]

This is what I do for all those awkward situations! I make a 'pivot plate' to slide in the runners, and bend the piano wire (or substitute) fully round it and back through 90 degrees. You can of course alter the distances/length ratio to alter the throw.....

 

[47137]

Thank you Giles this looks ideal, I am sure I can use this kind of mechanism in one of my four awkward locations, where I can actually get the motor under the point.

 

- -

 

For the other locations (like my photos in the first post) the motor has got to be offset to one side of the track. I'm thinking of a springy linkage instead of a push rod. I have made a mock-up using some soft copper wire, to show what I am thinking of. The depth of the Z shape would depend on the springiness of the piano wire. The Z would have enough 'give' to let the motor throw arm move through its whole travel.

 

- Richard.

 

[ExPatBrit]

Here's a link to a .pdf I've found very useful. It's specifically about Cobalt point motors, but 99.99% is applicable to Tortoise as well. Covers installation in difficult locations, improving the appearance of Peco points, frog wiring, ballasting and weathering etc, etc.

 

http://www.gaugemaster.com/instructions/dcc_concepts/cobalt_manual.pdf

[brightspark]

I (or rather our model group) ignore the wire and screw a plate to the black actuator arm. Then use linkage off that to operate the turnouts.
 
Picture one shows a plate mounted onto a Tortoise under Swaynton.
 
 
Picture two shows a quarter crank.
 
Picture 3 shows the arrangement for the turnout operation. This is a bit of old curtain rail with a strip of PCB in it. The two vertical rods run up the point blades. (This is for EM Gauge hand built track) you would only require a single upright.
 
We also only use one Tortoise for each pair of slips.

 

I hope this helps

[47137]

Thank you to everyone for these suggestions. I especially like the idea of the tie bar being under the baseboard. I'll post something here when I have made my own mechanism.

 

- Richard.

[47137]

Thank you everyone for your patience! My solution for this point is a push rod below the tiebar. The push rod is a length of brass tube sliding in two short lengths of a larger tube as bearings. The Tortoise motor uses its original steel wire, and the link from the push rod to the tie bar is a steel dressmaking pin. The motor is glued into position with Evostik impact (contact) glue.

 

The mechanism works nicely with the motor fulcrum at its mid-way position, so I have slid the fulcrum along towards the motor throwarm a little (to get more throw) to be on the safe side. A nice thing about Tortoise motors is you do not need an omega loop.

 

There are two other points on the layout needing remote linkages, so I can move on to these with some confidence now.

 

- Richard.

 

The orange lines in this third photo are the bus bars for the layout power distribution

[AndrewC]

Some excellent solutions. I too picked up about a dozen of the adapters for tight areas. Sadly none of the solutions given would have worked for me as I was putting points too close to the module leg brackets so only have about 1" below board to play with. The remotes worked great for me.

 

Don't be frightened of the number of steps. It really only took around 40 mins to do the first one and by the end I could Install from the package to tested in less than 25 mins. The only downside is the somewhat limited length of the wire-in-tube provided. (18", iirc)

[47137]

My second remote linkage has been difficult to get working. I am trying to use up some stock and not buy any more bits and pieces(!) so I went for a length of flat bottom rail as a push rod, running between some steel screws as guides. However hard I tried, I could not get the point tie bar to move far enough using the original steel wire supplied with the Tortoise motor. In the end I sleeved the wire with a length of small-bore brass tube - and now the linkage works perfectly. The brass tube covers the steel wire from the 10 degree bend (as per the Circuitron instructions) through the fulcrum to the push rod. The fulcrum is drilled out to suit. Details in the photos. The tube is 1/16 inch outside diameter, secured onto the steel wire with super glue.

 

- Richard.

 

[47137]

This is my third and final remote 'Tortoise' linkage, and it to my mind this is the best of my three. Easy to make, easy to set up and plenty of throw at the tiebar. The push rod is a length of piano wire about 0.028 in diameter, running in guides formed by brass panel pins. The connection from the motor wire to the push rod is a piece of 1/16 inch OD brass tube, flattened at one end and drilled through at 0.9 mm for the push rod. The brass tube is soldered onto the motor wire.

 

- Richard.

 

 

 

[Les le Breton]

Absolutely brilliant thread, thank you for the detail and clear photographs. You have made an old man very happy!!

[John ks]

Another variation on the similar theme

this motor is in a unseen part of my layout

 

 

 

this one has the motor under the baseboard

 

 

 

John

[47137]

The last two posts have reminded me, my linkages have now been running for 9 months or so without needing adjustments, but I have just put some tiny droplets of oil onto them.

 

I think the "trick", if there is one, is to keep the linkage short and straight, and give it a little free play but not enough to let it want to twist or bind.

 

I do like the idea of using the insert from a terminal block.

 

- Richard.