DCC slow-action point motors and standard non-momentary microswitches

[St Enodoc]

I will be using Modratec lever frames to control the points and signals on the scenic sections of my layout. I am now considering operating the points with slow-action motors but I haven't yet identified a decoder (stand-alone or integral) that responds to non-momentary inputs such as a standard microswitch, other than the DCC Specialties Hare/Wabbit/Jack Wabbit family which are somewhat expensive.

 

Any ideas please?

[Grovenor]

Why do you need a decoder? The motors can run directly from the microswitch.

If you do use decoders you also need an encoder to put the microswitch positions into the DCC system.

All this costs a lot compared to a length of wire per lever and a few plugs and sockets.

If you are prepared for a bit of DIY MERG do a variety of kits that can be used with cheap servo motors, which can be more cost effective than Tortoise or Cobalt.

Regards

[St Enodoc]

Why do you need a decoder? The motors can run directly from the microswitch.

If you do use decoders you also need an encoder to put the microswitch positions into the DCC system.

All this costs a lot compared to a length of wire per lever and a few plugs and sockets.

If you are prepared for a bit of DIY MERG do a variety of kits that can be used with cheap servo motors, which can be more cost effective than Tortoise or Cobalt.

Regards

Thanks Keith. At the moment I'm weighing up the cost of the DCC solution against the value of my time, the cost of the wire and power supply, and the use of space under the layout for installing the wiring for the analogue solution.

 

I'm not sure that I understand your comment about the encoder and microswitch though.

 

I haven't investigated servos in detail as yet, although a friend is using a Megapoints controller with success.

[Nigelcliffe]

Thanks Keith. At the moment I'm weighing up the cost of the DCC solution against the value of my time, the cost of the wire and power supply, and the use of space under the layout for installing the wiring for the analogue solution.

 

I'm not sure that I understand your comment about the encoder and microswitch though.

 

 

The lever frame is in one place.   To get from the lever frame to the turnout motor, there are basically two methods:   Either wires per lever and motor (largish number of wires) OR some method to encode the switch at the leverframe, send the message over a data link (could be DCC, could be other data links), and a decoder at the far end to decode it all.

 

Given you (St Enodoc) said that you wanted to use DCC turnout decoders,  the matching encoder would need to be a DCC Encoder of some sort or another.    This could either be a stand-alone DCC encoder/command station (such as the MERG turnout encoder system, which gives a completely independent device), or it could be an input device to a whatever DCC system you currently own for driving the track. 

 

 

The use of the switch inputs on the Wabbit/Hare (or any other decoder) won't save any wire if going back to a lever frame.   Those inputs are really meant for a very local control button/switch, as a local over-ride control.   To use those inputs with a lever frame requires running wires back from the Wabbit/Hare to the lever frame.  At which point the Wabbit/Hare is an expensive waste - achieves nothing which cannot be done with analogue. 

 

 

 

- Nigel

[St Enodoc]

The lever frame is in one place.   To get from the lever frame to the turnout motor, there are basically two methods:   Either wires per lever and motor (largish number of wires) OR some method to encode the switch at the leverframe, send the message over a data link (could be DCC, could be other data links), and a decoder at the far end to decode it all.

 

Given you (St Enodoc) said that you wanted to use DCC turnout decoders,  the matching encoder would need to be a DCC Encoder of some sort or another.    This could either be a stand-alone DCC encoder/command station (such as the MERG turnout encoder system, which gives a completely independent device), or it could be an input device to a whatever DCC system you currently own for driving the track. 

 

 

The use of the switch inputs on the Wabbit/Hare (or any other decoder) won't save any wire if going back to a lever frame.   Those inputs are really meant for a very local control button/switch, as a local over-ride control.   To use those inputs with a lever frame requires running wires back from the Wabbit/Hare to the lever frame.  At which point the Wabbit/Hare is an expensive waste - achieves nothing which cannot be done with analogue. 

 

 

 

- Nigel

Thanks Nigel for that clarification. I use NCE Mini Panels for route setting in my storage loops but never thought of them as encoders before. I think I can see now that the choice for slow-action motors is really between:

 

DCC: Lever frame - microswitch - Mini Panel - decoder - motor (fewer/shorter wires, higher cost); or

 

Analogue: Lever frame - microswitch - motor (more/longer wires, lower cost).

 

Thanks to you and Keith for helping me get to this understanding. Next I will discuss servos with my friend before making my final choice.

[Ray H]

If you are open to the idea of analogue DIY so to speak, MERG have developed the CBUS system that would allow you to have ordinary micro-switches on the frame and minimal wiring between frame and pointwork.

 

You would need to make a few kits using the good documentation that is supplied with them and connect the kits together using no more than four wires - or several twisted together to carry the power - around the layout.

 

I've done this on my layout where I have three control areas spread over four baseboards. The fiddle yard uses push button route control - push the relevant button to set the route to the siding of choice which may involve several points. Elsewhere I use or will use conventional levers operating micro switches that send the appropriate data command along the "bus" to the equivalent of a decoder to which (in my case) the servos that operate points and signals in the immediate area are connected.

 

My understanding is that the MERG DCC encoder has to operate on a completely stand-alone DCC circuit. It cannot be connected to anything that is electrically linked to the same circuit as the throttles. This prevents the use of the "Select Accessory" option from the throttle handset.

[St Enodoc]

If you are open to the idea of analogue DIY so to speak, MERG have developed the CBUS system that would allow you to have ordinary micro-switches on the frame and minimal wiring between frame and pointwork.

 

You would need to make a few kits using the good documentation that is supplied with them and connect the kits together using no more than four wires - or several twisted together to carry the power - around the layout.

 

I've done this on my layout where I have three control areas spread over four baseboards. The fiddle yard uses push button route control - push the relevant button to set the route to the siding of choice which may involve several points. Elsewhere I use or will use conventional levers operating micro switches that send the appropriate data command along the "bus" to the equivalent of a decoder to which (in my case) the servos that operate points and signals in the immediate area are connected.

 

My understanding is that the MERG DCC encoder has to operate on a completely stand-alone DCC circuit. It cannot be connected to anything that is electrically linked to the same circuit as the throttles. This prevents the use of the "Select Accessory" option from the throttle handset.

Thanks Ray, I'll look into that. I'm not a member of MERG but I know some folk who are. At face value it appears to be an alternative to the Mini Panel but cheaper due to the DIY aspect.

[Nigelcliffe]

Thanks Nigel for that clarification. I use NCE Mini Panels for route setting in my storage loops but never thought of them as encoders before. I think I can see now that the choice for slow-action motors is really between:

 

DCC: Lever frame - microswitch - Mini Panel - decoder - motor (fewer/shorter wires, higher cost); or

 

Analogue: Lever frame - microswitch - motor (more/longer wires, lower cost).

 

Thanks to you and Keith for helping me get to this understanding. Next I will discuss servos with my friend before making my final choice.

 

 

The problem with your DCC line is that the MiniPanel only accepts momentary input, not a change-over microswitch.   So, a single event (aka momentary input) triggers an action.   So, you can't just use a Microswitch linked to a lever position on a lever-frame, though a fairly simple circuit (handful of cheap components) could deliver a pulse to the MiniPanel.  And you'll need two inputs for each turnout, one for "thrown" and another for "closed".  

 

There will be NCE-compatible ways of doing this.  I don't know enough about using the NCE AIU device to know if it can work for this situation (or if you need a computer hooked up behind it all to take the AIU inputs and generate turnout outputs).   Another possible is the DCC Concepts "Alpha" encoder, but I would ask DCC Concepts if its OK with change-over inputs (which your lever frame will deliver) rather than momentary - their manual is ambiguous saying that you should try to make inputs momentary, but not saying that change-over won't work !   Either it works or it doesn't !!!!

 

 

 

 

 

The MERG stuff is in three different areas of kits, don't get them muddled up or a mess occurs:

 

a)  The old DCC Accessory Encoder.  This is the device Keith referred to, and yes, its sort of "mini panel alternative".   Though it differs in being a completely stand-alone DCC system for controlling accessories (turnouts), so don't try to connect it to your NCE system!, and thus you need two wires from it out to the decoders around the layout at each turnout/signal.  Critically, it takes change-over switches or push buttons as input.  (The NCE MiniPanel only takes momentary inputs (aka push buttons) ).   Advantage - cheap, simple, does the stated job with minimal hassle.   Disadvantages; only does what's said. 

 

b)  The MERG CBUS system.  This is a collection of modules which combine to form inputs and output devices (ie. decoders for accessories).  Optionally there are also computer interfaces (recommended for setup of modules, even if not needed for day-to-day use) and also optionally a DCC Command Station with throttles, etc..   Much more complex than (option a).  The output devices (equivalent to accessory decoders in this context) are CBUS specific devices, they are not DCC accessory devices (Wabbit/Hare).  It is a much more powerful control method than using a DCC output bus as CBUS is bi-directional, so information can come back from the layout to the centre for things such as "has the turnout thrown" and "is the track occupied".    But with that power comes cost/complexity - its probably cheaper than buying DCC accessory devices, but its not "dead simple".  There are good kits and good support for it.

 

c)  PTP-Lite system.   This is a simple/cheaper method of encoding a few inputs and sending them over a small number of wires to output devices.  Cheaper than CBUS, but less powerful.   Sort-of half way between options (a or b).   

[Grovenor]

How many frames and how many points are we actually talking about here? It makes a big diffeence to the complexity and relative merits of one or other system. Also how many boards are the points related to each frame spread over?

For Servos a megapoints controller is only really sensible if there are a lot of points in a small area, and even then will be more costly than a kit solution such as from MERG.

A servo plus kit control board and some screws and stuff to make servo brackets will be about half the price of a tortoise or cobalt machine. It doesn't take many turnouts for the savings to exceed the cost of a MERG membership. But you do need to be prepared for a bit of simple DIY.

Regards

[newbryford]

   Another possible is the DCC Concepts "Alpha" encoder, but I would ask DCC Concepts if its OK with change-over inputs (which your lever frame will deliver) rather than momentary - their manual is ambiguous saying that you should try to make inputs momentary, but not saying that change-over won't work !   Either it works or it doesn't !!!!

 

 

 

 

If I remember, I'll check on Tuesday if the Alpha encoder accepts a maintained changeover than a passing contact. I think the on-board processor looks for an input going high - what it struggles with is two inputs fed from the same switch (for example, a diode matrix) I'll also check if a Cobalt Digital IP will accept maintained contacts.

 

Cheers,

Mick

[St Enodoc]

The problem with your DCC line is that the MiniPanel only accepts momentary input, not a change-over microswitch.   So, a single event (aka momentary input) triggers an action.   So, you can't just use a Microswitch linked to a lever position on a lever-frame, though a fairly simple circuit (handful of cheap components) could deliver a pulse to the MiniPanel.  And you'll need two inputs for each turnout, one for "thrown" and another for "closed".  

 

There will be NCE-compatible ways of doing this.  I don't know enough about using the NCE AIU device to know if it can work for this situation (or if you need a computer hooked up behind it all to take the AIU inputs and generate turnout outputs).   Another possible is the DCC Concepts "Alpha" encoder, but I would ask DCC Concepts if its OK with change-over inputs (which your lever frame will deliver) rather than momentary - their manual is ambiguous saying that you should try to make inputs momentary, but not saying that change-over won't work !   Either it works or it doesn't !!!!

 

 

 

 

 

The MERG stuff is in three different areas of kits, don't get them muddled up or a mess occurs:

 

a)  The old DCC Accessory Encoder.  This is the device Keith referred to, and yes, its sort of "mini panel alternative".   Though it differs in being a completely stand-alone DCC system for controlling accessories (turnouts), so don't try to connect it to your NCE system!, and thus you need two wires from it out to the decoders around the layout at each turnout/signal.  Critically, it takes change-over switches or push buttons as input.  (The NCE MiniPanel only takes momentary inputs (aka push buttons) ).   Advantage - cheap, simple, does the stated job with minimal hassle.   Disadvantages; only does what's said. 

 

b)  The MERG CBUS system.  This is a collection of modules which combine to form inputs and output devices (ie. decoders for accessories).  Optionally there are also computer interfaces (recommended for setup of modules, even if not needed for day-to-day use) and also optionally a DCC Command Station with throttles, etc..   Much more complex than (option a).  The output devices (equivalent to accessory decoders in this context) are CBUS specific devices, they are not DCC accessory devices (Wabbit/Hare).  It is a much more powerful control method than using a DCC output bus as CBUS is bi-directional, so information can come back from the layout to the centre for things such as "has the turnout thrown" and "is the track occupied".    But with that power comes cost/complexity - its probably cheaper than buying DCC accessory devices, but its not "dead simple".  There are good kits and good support for it.

 

c)  PTP-Lite system.   This is a simple/cheaper method of encoding a few inputs and sending them over a small number of wires to output devices.  Cheaper than CBUS, but less powerful.   Sort-of half way between options (a or b).   

Thanks Nigel. I found out from a separate topic on RMweb (and other sources) how to convert a continuous input to a pulse for a Mini Panel, using a simple RC circuit, so I now understand that part.

 

For the rest, I don't feel up to building a lot of electronic stuff, so I am moving towards the slow-action analogue solution - subject to a discussion on servos with my friend as I mentioned before.

[St Enodoc]

How many frames and how many points are we actually talking about here? It makes a big diffeence to the complexity and relative merits of one or other system. Also how many boards are the points related to each frame spread over?

For Servos a megapoints controller is only really sensible if there are a lot of points in a small area, and even then will be more costly than a kit solution such as from MERG.

A servo plus kit control board and some screws and stuff to make servo brackets will be about half the price of a tortoise or cobalt machine. It doesn't take many turnouts for the savings to exceed the cost of a MERG membership. But you do need to be prepared for a bit of simple DIY.

Regards

Keith, initially I will have a 54-lever frame. There will be about 20 switched ends altogether although many of these are arranged as crossovers. The rest of the levers are for signals (30 or so, memory wire actuation) and dummy FPLs. Thereafter I will probably move forward with three further frames, all smaller, for the other stations and junctions as they get built.

 

The layout is permanent so the number of boards is not an issue (essentially there is only one).

[St Enodoc]

If I remember, I'll check on Tuesday if the Alpha encoder accepts a maintained changeover than a passing contact. I think the on-board processor looks for an input going high - what it struggles with is two inputs fed from the same switch (for example, a diode matrix) I'll also check if a Cobalt Digital IP will accept maintained contacts.

 

Cheers,

Mick

Thanks Mick, that will be interesting.

[Grovenor]

Keith, initially I will have a 54-lever frame. There will be about 20 switched ends altogether although many of these are arranged as crossovers. The rest of the levers are for signals (30 or so, memory wire actuation) and dummy FPLs. Thereafter I will probably move forward with three further frames, all smaller, for the other stations and junctions as they get built.

 

The layout is permanent so the number of boards is not an issue (essentially there is only one).

Given that I would just go with direct wiring from frames to point motors, why interpose a load of complex electronics to save a bit of wire, either tortoise or servo would just need 1 wire per point lever plus a power supply.

Regards

[newbryford]

If I remember, I'll check on Tuesday if the Alpha encoder accepts a maintained changeover than a passing contact. I think the on-board processor looks for an input going high - what it struggles with is two inputs fed from the same switch (for example, a diode matrix) I'll also check if a Cobalt Digital IP will accept maintained contacts.

 

Cheers,

Mick

 

 

Thanks Mick, that will be interesting.

 

Hi,

Powered up an Alpha encoder.

No apparent problems with maintained inputs. I kept one or two channels permanently connected whilst switching another.

Like wise a Cobalt Digital IP,  the DCC signal will over-ride the maintained manual input.

 

 

Cheers,

Mick

[Junctionmad]

Given that I would just go with direct wiring from frames to point motors, why interpose a load of complex electronics to save a bit of wire, either tortoise or servo would just need 1 wire per point lever plus a power supply.

Regards

Several reasons , reduction in wiring complexity , easier to debug , easier to expand or modify , allows extensions such as interlocking , mimic panel to be easily added etc.

 

Layout busses are far better imho. Personally I would separate accessory busses from track DCC , but that's just me.

[Grovenor]

 

reduction in wiring complexity , easier to debug

So you can have wire from switch to point motor, 2 connections.

or wire from switch to encoder, bus wires from encoder to decoder, wire from decoder to motor, 6 connections plus two complex electronic gadgets,

far and away easier to debug the first one, far less that can be wrong, far less to check.

Layout busses are better for some circumstances, not in this case IMHO.

Regards

[St Enodoc]

Given that I would just go with direct wiring from frames to point motors, why interpose a load of complex electronics to save a bit of wire, either tortoise or servo would just need 1 wire per point lever plus a power supply.

Regards

Thanks Keith. That is indeed the way my thinking is leading me at the moment.