Servo control

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forest446
Posts: 169
Joined: Mon May 31, 2010 9:58 am
Location: yorkshire

Servo control

Postby forest446 » Fri May 04, 2018 4:39 pm

Hi all
I am looking for a way to control points
With servos.
I have looked at the mega point controller an other specific boards
But there must me a cheap simple way to do it as I need about 45 servos over 2 boards
Any ideas
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Paul-H
Posts: 145
Joined: Fri Jun 05, 2009 3:00 pm

Re: Servo control

Postby Paul-H » Fri May 04, 2018 6:42 pm

Hi

Have a look at the kit sold by MERG, about £5 each and will control 4 servos via 4 toggle switches and they sell a low cost servo mount for use with turnouts as well, it works perfectly with the £1.99 SG90 type servo from the likes of HobbyKing and ebay

so controlling 40 turnouts would cost around £150 all in, comparing that to using something like a DCC Concepts motor would cost around £900 so quite a nice saving.

Paul

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TimberSurf
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Location: N.Wales
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Re: Servo control

Postby TimberSurf » Fri May 04, 2018 6:43 pm

I too need 40 points. My research lead me to Megapoints as well, see my THREAD, probably still is the cheapest option off the shelf. I have since discovered and programmed Arduinos, one can control up to 6 servos for just a few pounds, but would need to be developed as a shield (PCB) for inputs and adjustment. The other issue with servo's is that they have no contacts for signals and frogs.
I have made a bracket to solve that problem. There are alternatives that have brackets with space for microswitches, see POINTS, or you could use frog juicers, but it all starts mounting up in cost.
The other option is to build your own with MERG
The other angle is what you control them with, switches locally or some sort of coms, DCC would need a pad or PC, Megapoints has a built in canbus system (and they sell the hardware), Arduino has about 6 options but you would have to "build" it yourself else you will have lots of wires to run to a mimic.
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abenn
Posts: 195
Joined: Thu Jun 05, 2008 11:03 am

Re: Servo control

Postby abenn » Fri May 04, 2018 8:21 pm

I built a whole bunch of servo controllers using PICAXE 08M microprocessors. They have switched outputs via transistors for LED route indicators, plus solid-state relays for frog-switching. Cost was about £9 each, plus cheap Hobbyking servos as mentioned above.

Tom@Crewe
Posts: 170
Joined: Sat Aug 18, 2012 11:05 am
Location: Crewe

Re: Servo control

Postby Tom@Crewe » Sat May 05, 2018 7:39 am


timbologist
Posts: 362
Joined: Wed Sep 18, 2013 6:39 am
Location: Hazeldene Victoria Australia ( in the bush )

Re: Servo control

Postby timbologist » Mon May 07, 2018 9:08 am

TimberSurf wrote:The other issue with servo's is that they have no contacts for signals and frogs.


The away around this problem is using an extra wire connected to the feedback pot in the servo and feeding it back to an Arduino so you have positive feedback of position, and from the Arduino drive your signals directly or a relay for the frogs.
And with this set-up you can invoke slow motion points.


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