Author Topic: Simple servo mount for turnout control  (Read 1960 times)

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CRL

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Simple servo mount for turnout control
« on: February 05, 2019, 08:17:55 PM »
+1
I’ve seen a lot of fairly expensive brackets being marketed to mount servos to control turnouts, but this shows the most simple and cheap method I’ve seen.


Cajonpassfan

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Re: Simple servo mount for turnout control
« Reply #1 on: February 05, 2019, 09:08:44 PM »
0
Well, the 15mm "aluminium" channel idea is clever, but the install seems backwards; I prefer to lay track and turnouts the way I like them, before installing switch machines or servo motors. And of course it's easier on a workbench then under the layout😜
Still, interesting...
Otto K.

CRL

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Re: Simple servo mount for turnout control
« Reply #2 on: February 05, 2019, 10:47:42 PM »
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Well, the 15mm "aluminium" channel idea is clever, but the install seems backwards; I prefer to lay track and turnouts the way I like them, before installing switch machines or servo motors. And of course it's easier on a workbench then under the layout😜
Still, interesting...
Otto K.

I’ve thought about this, and what I’ve decided to use is a piece of Midwest plywood the thickness of cork roadbed and cut to the shape of the turnout to mount the turnout and servo. I’ll then cut a hole in the foam layout large enough for the servo to clear. This will allow the turnout and servo unit to be adjusted, installed and serviced if necessary without crawling under the layout. I’ll only have servos on mainline turnouts with all yard and off mainline turnouts being manually thrown.

peteski

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Re: Simple servo mount for turnout control
« Reply #3 on: February 06, 2019, 01:06:06 AM »
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That seems like a good idea, but if you ballast the track and scenic the surroundings, then servicing (from the top) will not be easy (without redoing the ballast and scenery).
. . . 42 . . .

CRL

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Re: Simple servo mount for turnout control
« Reply #4 on: February 06, 2019, 01:22:53 AM »
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If the plywood, which is only as thick as the cork roadbed, is trimmed and contoured carefully, it can be secured to the foam base with a small bead of latex construction adhesive (liquid nails for projects). Then you scenic & ballast as normal. It would be only be minor surgery to remove the turnout assembly. If I do it right, all it would take is a hobby knife cut around the outline of the plywood and it should pop off. If not, it’s just foam, plus the opportunity to model a switch replacement.

C855B

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Re: Simple servo mount for turnout control
« Reply #5 on: February 06, 2019, 01:30:07 AM »
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That seems like a good idea, but if you ballast the track and scenic the surroundings, then servicing (from the top) will not be easy (without redoing the ballast and scenery).

I've installed dozens of switch machines with nano servos CA-glued to the underside of the turnout which are in a "well" in the roadbed and pink foam base, and am facing the same issues. Which doesn't bother me. From my experience, the most likely failure point is not the servo (or switch machine), it is the turnout itself. So you're more likely to have to peel-up the turnout anyway. Also, servos, at least the way I've implemented them, have no adjustable or spring linkage - all the adjustment is in the servo controller.

Thread here: https://www.therailwire.net/forum/index.php?topic=40197.0
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CRL

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Re: Simple servo mount for turnout control
« Reply #6 on: February 06, 2019, 11:36:47 AM »
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I've installed dozens of switch machines with nano servos CA-glued to the underside of the turnout which are in a "well" in the roadbed and pink foam base, and am facing the same issues. Which doesn't bother me. From my experience, the most likely failure point is not the servo (or switch machine), it is the turnout itself. So you're more likely to have to peel-up the turnout anyway. Also, servos, at least the way I've implemented them, have no adjustable or spring linkage - all the adjustment is in the servo controller.

Thread here: https://www.therailwire.net/forum/index.php?topic=40197.0

Just curious if you considered using the larger micro servo mounted with the narrow side and the drive axis away from the turnout? That would enable using a standard single arm crank driving a longer pushrod to the end hole of the turnout throw rod. It would seem the narrow side of the larger servo would still provide enough glue surface for a secure bond. The micro servos are also cheaper than the nanos.

Thanks.

C855B

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Re: Simple servo mount for turnout control
« Reply #7 on: February 06, 2019, 11:54:27 AM »
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Just curious if you considered using the larger micro servo mounted with the narrow side and the drive axis away from the turnout? ...

Yes. Well was too deep for my tastes, and would be a problem in areas where the foam veneer was 1" material. Cheaper? How cheap do we need to be? The nanos are $3.65/ea.
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CRL

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Re: Simple servo mount for turnout control
« Reply #8 on: February 06, 2019, 01:18:28 PM »
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Yes. Well was too deep for my tastes, and would be a problem in areas where the foam veneer was 1" material. Cheaper? How cheap do we need to be? The nanos are $3.65/ea.
That’s pretty cheap. The nanos I’ve seen are typically twice the price of the micros.

Good to know.

basementcalling

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Re: Simple servo mount for turnout control
« Reply #9 on: February 06, 2019, 01:20:02 PM »
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Yes. Well was too deep for my tastes, and would be a problem in areas where the foam veneer was 1" material. Cheaper? How cheap do we need to be? The nanos are $3.65/ea.

That's a deal. I can send you a whole bunch of my Atlas turnouts and you can do the installing of the servos. :) :)

Seriously, I have been unable to make much progress on my layout because dealing with under the table turnout control has just kicked my butt. 12 inches between levels turns out not to be enough room for hands, drill, and my head to make accurate holes. Tracklaying can continue, but I am contemplating a change to Peco for the point lock feature.
Peter Pfotenhauer

Cajonpassfan

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Re: Simple servo mount for turnout control
« Reply #10 on: February 07, 2019, 02:28:57 AM »
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Yea, feel your pain. I have a couple of places where the upper deck is so thin it requires the servos to be mounted flat (horizontally) and the separation between decks is too tight to use a screwdriver. I ended up using hot glue to mount the servos, supplemented by balsa wood blocks to prevent lateral movement. So far, it seems to work, although I am challenged trying to program the point movement precisely.
Otto K.