Author Topic: AM-1 Turntable project  (Read 213 times)

faithie999

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AM-1 Turntable project
« on: January 04, 2021, 04:35:27 PM »
I don't have an AM-1 yet so must ask a question.

I'm trying to decide which 90' turntable to buy.

does the turntable program for the AM-1 provide indexing at fixed increments, or must the turntable inherently have indexing?

thanks

ken



G8B4Life

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Re: AM-1 Turntable project
« Reply #1 on: January 04, 2021, 08:06:31 PM »
The turntable project for the AM-1 does not provide indexing, it is a simple clockwise/counterclockwise fast/slow program. I imagine it might be possible to write a program using one of the inputs on the AM that will stop the table turning when it senses the rails are aligned with any track but for aligning with only the given track you want at the time would probably require external components to control which track alignment can be sensed. These components may be a part of the turntable electronics already if it has them.

- Tim

faithie999

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Re: AM-1 Turntable project
« Reply #2 on: January 05, 2021, 06:11:45 AM »
I thought that might be the case but I wanted to check.

there are a couple of companies that make turntable indexers.  I will contact them to see whether their units will accept a "remote" input. 

I found a DIY indexer project that is way over my head in terms of soldering skills and patience.  if I understand properly how it works, you position optical targets at each desired index position.  the user then presses the On button and when the table is near the desired target position presses the off button and the motor runs until the table is aligned with the optical target.  I assume that is how the commercial units work.  what I will need to find out from the mfrs is if the unit is looking for a voltage input, as I assume the AM-1 puts out, or just a dry contact.

if it will accept a dry contact from an external source, is there a way to send either a momentary contact "on" and "off" or a "press and hold" contact"?  I suppose I could connect a relay to the output of the AM-1.

thanks

ken

« Last Edit: January 05, 2021, 06:23:36 AM by faithie999 »

G8B4Life

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Re: AM-1 Turntable project
« Reply #3 on: January 05, 2021, 06:53:18 AM »
I don't have an AM-1 and the user manual isn't very good on how to use it for anything except for turnouts but I think you could do this.

The turntable would have the optical emitter at either end. They could be powered by the rail feed to the turntable bridge.

Each stall would have an optical receiver that's wired to one (as in single) of the inputs on the AM-1. Each optical receiver would need a toggle switch (or use a rotary switch) to isolate it so you pass the stalls you don't want while turning. When the optical receiver is on (triggered by the emitter) it triggers the input on the AM-1 which in it's program stops the table. Hall effect sensing would also work in place of optical emitters/receivers.

How accurate you can get the positioning is an exercise in engineering.

- Tim

faithie999

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Re: AM-1 Turntable project
« Reply #4 on: January 05, 2021, 07:52:03 AM »
Heljan makes an automated turntable (I think the Walthers turntable is a Heljan with a different control system).  the control box is simple.  there are 4 momentary contact buttons that control the direction and positioning.  is it possible to use the AM-1 or other module to simulate 4 momentary contact switches?  then it's a matter of opening the box and soldering leads to wherever the 4 control buttons are connected on the PCB.

KiloWhiskey

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Re: AM-1 Turntable project
« Reply #5 on: January 05, 2021, 11:04:26 AM »
In my humble opinion,  using RP on a newer Walthers turn Table is a waste. Walthers offers an "expansion" board that will allow for all sorts of custom controls to make an independent controller using push buttons and or a keypad to allow proper use. The instructions for said control module are attached. It explains what I am talking about better than me...

Regards,
Kevin

Kevin


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