Newbie Question - DCC/Computer Control

[Wordsmith]

Well you can't fault Digikeijs on service. I ordered a command station and a switching decoder from them on Sunday and they turned up at lunchtime today (Wednesday). Need to start building some temporary layouts on the baseboard I've got to start out figuring how they work now...

 

Then I guess the credit card gets dented again shortly...

 

Wordsmith 

[Wordsmith]

So, not having done any railway modelling for 50 odd years, and with a very new technology to hand (DCC), I’m trying to learn in stages – each stage building on the one before. Exercise 1 was to fire up a Digikeijs command station, connect it to a programming track and run a loco up and down it. The command station went OK, as did the running of the loco, but sorting out the programming track was an indication of the learning curve…

• For N gauge, hacksawing the track is not accurate enough – I’ve brought some track cutters.
• I need to improve my soldering skills. I got the wires soldered to the track, but it was far from neat – and not the quality of soldering that would guarantee a trouble-free layout. So, I’ve brought a glass fibre brush to rough up the rails a bit, plus I found a little book in Kindle on how to solder properly.
• Track pins are unsightly in N gauge – the track will have to be glued down when I get to build my permanent layout. The track I’m using in test layouts will have to be reused (if suitable) in the staging area.

[Wordsmith]

So, the next stage is to build a small test layout on a temporary 4 ft x 2 ft baseboard I have. I’m not intending anything fancy at this stage – just a layout I can control a couple of locos and some points on. I want to work out how to do things a bit at a time…

 

This is the basic layout:

 

 

The loop at the rear is intended the represent the staging roads of a full-sized layout; the loop at the front, head shunt and couple of sidings, an eventual station. I also intend to try magnetic decouplers in the sidings to start getting an idea about the accuracy of the intended eventual automated shunting possibilities. I have a Digikeijs DR 4018 module for the point motor control and Tortoise TT300 point motors for the points themselves. I have Peco PL-25 magnetic uncouplers to play with – but will experiment with other brands if required.

 

I will put in the rail breaks and wiring such that I can experiment with track occupancy at a later stage – using a Digikeijs DR5088RC Digidetect module. At a rough count, that will require 9 independently powered sections of track coming off a power bus; 4 in the loop areas, 2 in the semi-circles of track, 1 in the head shunt and 2 in the sidings, with the appropriate insulators to stop shorts across the points. In the short term, I can connect sections together – for example, so I have a complete circuit of track to run locos round/run them in. I know I’ll need insulating fishplates for the points to stop short circuits there when they switch from one lot of track to another.

 

This has also thrown up a few questions – if you don’t mind, I’ll pick your brains.

 

Power Supplies

 

The Digikeijs modules run off a minimum of 12 volts DC and a maximum of 18 volt DC power supply. The DR5000 manual suggests a voltage drop of 1.5 volts for that unit, so does that suggest its worth running the individual modules off their own 15-volt DC supply. The Peco uncouplers run off 16 volts AC. A small layout, like the one I’m experimenting with isn’t going to require a lot of power, but the full size I’m aiming for I will – quite a few Digikeijs modules to power. Does that suggest it’s worth investing in something like a 15-volt DV, 10-amp power supply to power the DC stuff, and the smaller equivalent to power the AC stuff; distributing the power as required via a bus under the baseboard?

 

Wiring

 

So, if I understand this correctly, I’m going to end up with two three busses under the baseboard; the DCC power bus to carry the signal from the command station to the track, a second DCC power bus to carry the signal to the auxiliary equipment such as points and signals and a third bus (or busses) to carry power (e.g. 15 volts) to the varying Digikeijs modules that control all the auxiliary stuff. I also need small dropper wires to takes the power to the different sections of the track from the main DCC power bus.

 

There’s a bewildering amount of advice on wire types and diameters to use in the internet, but does the below seem reasonable?

 

• Power buses and 15-volt supply: 24/0.2 mm cable (24 strands x 0.2 mm)
• Run from main power bus to auxiliary equipment and close to track: 12 or 16/0.2 cable
• Dropper wires from track: short lengths of 0.7 mm dia solid copper wire from track to underneath baseboard (intended to be inconspicuous).

 

Again, OTT for a small layout, but I’m looking ahead to building something more complex.

 

Thanks in advance for the advice…

[KingEdwardII]

Wordsmith,

 

First, regarding the wire types. I use stranded wire everywhere - even for dropper wires. I find that solid core wires are much more difficult to handle, especially when soldering, so I never use them.

 

I generally use wires from mains flex (flex, not mains cables!) for larger size wires, since they are readily available and relatively cheap and are colour coded. Flex wires are available from 2.5mm2 down to 0.5mm2, with nominal current carrying capacity over distance (i.e. in terms of metres) as follows:

 

28/0.3 == 14 AWG == 2.5mm2 17A

19/0.3 == 16 AWG == 1.5mm2 13A

32/0.2 == 17 AWG == 1.0mm2 10A

24/0.2 == 18 AWG == 0.75mm2 6A

16/0.2 == 20 AWG == 0.5mm2 3A

 

I have used the 3 alternative formulations for describing the wires here - this is a very confusing topic. I prefer the cross sectional area formulation since it does not depend on the wire construction, unlike the stranding formulation.

 

I use 2.5mm2 wire for the power bus - more to keep the voltage drop low across my layout, since I doubt I'll ever be using 17A! I use 1.0mm2 wire for my accessory bus. Connections from the bus to units like the Digikeijs DR4018 for point motor control are typically done with 0.75mm2 wire while connections to my slow-action point motors (MTB MP1s) are in 3 strand 0.5mm2 flex. Dropper wires, typically no more than 200mm long, are done with black stranded wire 0.25mm2.

 

Regarding your power supplies, I was surprised to see you mention a 10A supply. You must be using some very power hungry accessories to need that, although such supplies are readily available from the world of laptops and similar equipment. I run my layout using a 3A supply for the controller and a 2A supply for the accessories.

 

Yours, Mike.

[RFS]

I would caution against using a 10A power supply especially in this gauge. A short circuit will mean 10A flowing through the short, and if the wiring to the accessory concerned is not up to carrying 10A the supply may not trip which could cause considerable damage. 

[Wordsmith]

Thanks both - the 10 amp power supply idea was me being a biff.  You've saved me from watching assorted bit of electronics send out smoke signals...

[jamespetts]

I have just come upon this thread; I notice that Wordsmith is planning something similar to what I am working on for my own home layout; the test layout is also very similar to the test layout that I put together in 2018 for the same purposes. I thought that it might be helpful to share some of the knowledge that I have acquired in that time.

 

First of all, Nigel Cliffe, who has posted in this thread, gives very good advice. In case of conflict between that and any other advice, I suggest taking Nigel's advice unless there is very strong evidence that he is mistaken in the case in question. Conflicting advice - sometimes given very stridently - is sadly common, so it is useful to be able to find reliable people.

 

Secondly, automation software: JMRI is good control panel software, but extremely limited in automation. I looked into this in some detail. JMRI lacks many of the abstractions necessary for automation to work with built-in code (e.g. there is no abstraction for a schedule), so having full automation in JMRI essentially means writing a complete, full-featured piece of software more or less from scratch in JMRI's scripting language, the only parts being done for you being the GUI and the hardware interfacing. Scripting languages are far from ideal for such a large undertaking and a big problem is that, as JMRI changes over time, the scripting language calls change such that a very large piece of software written in it becomes very fragile. I do not know how experienced that you are with coding, but you will need to understand how to write software and how to make software robust and maintainable using appropriate abstractions in order to make a workable automation system that is not very fragile (i.e., one that does not need rewriting from the ground up if you make any small changes to your layout or its operation). Some people report finding it easier to write an entirely independent piece of bespoke software than using JMRI's scripting language to achieve full automation. Be prepared, therefore, to invest the sort of time and effort necessary to write an entire computer program from the ground up if you want full automation in JMRI. For my own purposes, I chose TrainController. iTrain, which is cheaper and has a better interface and better support, is slowly catching it up, but it still lacks the ability to use variables in macros, which is important for sophisticated customisation.

 

Third of all, turnout motors: stall motors (such as Tortoise motors or Cobolt motors) have the disadvantage of having a large footprint. This can be a problem in N gauge, as it may not be possible to use them to motorise many turnouts in close proximity to each other, although there may be some scope to work around this using cranking of the rods. I ended up using servo motors in the end, which take more setting up but can be mounted in a smaller footprint and are also much cheaper. Finally, stall motors draw a significant amount of current when idle, whereas servos draw none. This can be a problem when you have a very large layout, as the idle current draw may exceed your power supply's capacity. My own layout uses a 1A 12v auxiliary supply.

 

The more amperage that your power supply puts out, the thicker the wires that you will need so as not to create a serious fire hazard in the case of overload: generally, your wires need to be rated to carry the maximum current output of your power supply unless protected by a circuit breaker, fuse or similar (e.g. District Cut-Out), or else there is a risk of overheating and fire. 10A (or even 5A) rated wires are impractically thick. Even 3A rated wires are quite thick.

 

Do be careful what sort of servo motors that you buy: digital servos are more widely available, but they cannot be turned off at the end of their travel easily, meaning that they are very prone to buzzing, creating irritating noises, and, more importantly, constantly drawing currant, which will, if enough are affected, have the same problem as with the stall motors (and possibly worse). Constantly being under power may also overheat the servos. However, analogue servos have their own problem in that they will twitch when first turned on in many cases. If you have a great many of these, you will find that them all twitching at once will draw too much current from your power supply, tripping the breaker, blowing the fuse or simply causing the power supply's voltage to drop to very low levels, which would then deactivate the servos, allow the voltage to be restored, causing the servos to twitch again and cause the whole cycle to repeat indefinitely. What I do to avoid this problem is use analogue servos with power on delay cards connected many of the servo cards to stagger the turning on of the servos and thus not draw too much current at once.

 

As to the Digikeijs unit, I have one of those. There are problems with these units in that they sometimes become unresponsive when connected via USB. They can also be connected by ethernet, but TrainController is not compatible with these units when not connected via USB (but iTrain and JMRI will work with these connected via ethernet). It is possible that a recent firmware update has corrected this, as I have not noticed this problem when I have used this recently, but I cannot be sure of this. I use a self-soldered Hans Deloof command station, albeit that has its own disadvantages, including the inability to use it for programming using the computer (and JMRI's DecoderPro, which is the best DCC programming software that I know of).

 

As to buses, you will need a LocoNet bus for your feedback units. This is because DCC is, with the exception of RailCom, which cannot be used for occupancy detection, a one way bus: it can be used to communicate commands from the command station to the locomotives or accessories, but it cannot be used to communicate data back from the locomotives or accessories to the command station. Since automation requires occupancy detection so that the computer knows where a train is at any given time and therefore how to drive it, automation requires a bus capable of feedback. The LocoNet bus is not the only bus capable of doing this: other buses, such as the MERG CBus, the new LCC and Lenz's XPress Net are all capable of feedback for occupancy detection, but the Digikeijs occupancy detection units such as the DR5088RC work with LocoNet, and, because it is a bus with an open protocol, many other devices also work with this. I have found that this is the most flexible of the buses to use. Using LocoNet with servo motors for points/semaphore signals and LocoNet servo control cards (and LocoNet IO boards for colour light signals), you can dispense entirely with the DCC accessory bus. You will then have: (1) a DCC bus for your track; (2) a LocoNet bus; and (3) an auxiliary power bus. These are easy to manage with cable colours, especially as the LocoNet cables are obviously different to plain wire and need no further distinction. For my own part, I use red/black for the DCC bus and yellow/blue for the 12v accessory bus. 

 

Note that there are two different varieties of LocoNet bus: LocoNet-B and LocoNet-T. They both use the same sort of cable, but two of the wires in the cable do different things in each case (I recommend using different coloured cables for each; I use white for Loconet-B and black for Loconet-T). LocoNet-B is the default type of LocoNet and using this type is necessary to connect boosters as it carries the railsync signal. Loconet-T is used for throttles, as the pair used for the railsync signal instead carries 12v DC. Many of the Digikeijs units are powered by the 12v on the LocoNet-T bus, so need no independent 12v bus (although the circuit cards to control servos from LocoNet do require a separate 12v bus; these take a LocoNet-B connexion (I think that they just pass through the pair that is railsync in LocoNet-B and 12v DC in LocoNet-T so it is possible that they will take either connexion, but I am wary of the current rating if these have to pass power)).

 

Do not underestimate the number of feedback sections that you need, especially if you want to do any coupling/uncoupling automatically. If you want, for example, a locomotive automatically to back onto a waiting train and stop in the right place, then the automation software needs to know that the locomotive has entered the section so that it can slow it to stop at just the right point that it couples with the carriages without pushing them back. However, if your platform is all one section, the computer will not be able to detect the locomotive entering the section, as it is already occupied by the carriages. Thus, you will need an extra, short, section in advance of the place where the carriages will stop to use as a detection section for the locomotive backing onto the carriages. (In theory, you can work around this by using the exit time from the previous section, often a turnout; but most feedback units have a delay in reporting the clearing of an occupancy sensor that they do not have in reporting an occupancy sensor becoming activated (deliberately to avoid noise caused by imperfect connexions), so this will be far less reliable).

 

Also, I recommend using District Cut-Outs. I use the MERG type (and I also recommend joining MERG). This will prevent a short circuit on one section of track disabling your whole layout. It will also allow you to use 1.5A rated droppers even if your power supply is 3A (set the DCOs to a 1.5A rating). Make sure, however, if you want RailCom functionality, to use the 1.2 version of the PIC's firmware for these, which I believe that you still need to download and flash onto the PICs yourself at present. You will probably not need these for your test layout, however.

 

As to RailCom, if using iTrain or TrainController, the software will keep track of a train's position automatically using only basic occupancy sensors. Where RailCom is useful is in seeding the information as to what locomotive is where when you first put the locomotive on the track. Thus, you do not need RailCom feedbacks for all sections: only those where you are likely to be manually placing locomotives on the track.

 

Also for occupancy detection, you will need the rear of any given train to draw current. For a multiple unit, this will not need any additional work, as most modern multiple units have rear lighting that will do this. For hauled carriages, however, intervention is needed. There are one of two things that you can do: either fit carriage lighting, which will draw current (a tail lamp for a goods wagon will suffice), or fit a resistive wheelset by putting a 10k ohm resistor across each axle of the rear carriage of a train (or both front and rear carriages if the train may run in either direction). If you later fit carriage lighting, do not forget to remove the resistors. For N gauge, you will need to use surface mount resistors; use glue and conductive paint. Avoid resistive paint: I have found this to be too unreliable to use.

 

For automation, you will need high reliability. This means following the dropper per section of track advice, using live frog points and, especially in N gauge, fitting stay-alive capacitors to all your locomotives (or alternatively, for multiple units, using little pin header plugs to communicate track power all down the train). Without these measures, there is a high chance of any given locomotive stalling after a time. For N gauge, you will need to use tantalum capacitors. I find 4x 470uF capacitors to be ample for N gauge locomotives. Using Zimo decoders, which seem to work well, and the SACC16 charging circuit, this can quite easily be achieved (although note that my N gauge layout is diesel - others will have to comment on fitting these to steam locomotives). One quirk; the capacitors that are small enough and hold enough charge to be useful in N gauge are all 16v. This means that the SACC16 unit must step down the voltage if the track voltage is >16v. They do in fact do this, but only down to ~14v on an 18v input. This is not ideal, as capacitors will age quickly run near their rated voltage. Also, any failure in the SACC16 that passes full track voltage to the capacitors could cause them to explode, damaging your locomotive, although the chance of this occurring in normal use is very small: see here for details. The Digikeijs command station and boosters determine the output voltage using the input voltage. For N gauge, I recommend selecting a low input voltage (perhaps 13-14v) to give a correspondingly low output voltage so that the voltage passed to the capacitors does not exceed their rated voltage. N gauge does not need higher voltages in any event.

 

For uncoupling, I recommend the Dapol Easifit couplings. They are much more unobtrusive than the default N gauge couplers, and can be uncoupled using magnets beneath the baseboard and thus entirely invisible to the scenic section. The magnets sold by Dapol are ceramic magnets (i.e., magnets which are not very strong) and are intended to sit between the rails. This is fine for a fiddle yard, but looks awful in the scenic section. These are also permanent magnets. If there is ever a place that you might want to uncouple sometimes but not others (e.g. a platform where locomotives change), then you will need a controllable uncoupler, and a permanent magnet will not suffice. Although the Easifit couplings are supposed not to uncouple when passing over a magnet when in tension, in reality, the slightest wobble or hesitancy of the locomotive (or even a slight judder caused by running at slow speed) can cause a train to uncouple over a permanent magnet, so I advise using permanent magnets only where you can be quite sure that you will always want uncoupling to happen, such as at the end of a terminus platform. For carriages that will remain permanently uncoupled, I recommend the Dapol NEMCoup basic knuckle couplers: they are cheaper and more unobtrusive than the Easifit couplings and cannot accidentally be uncoupled by a magnet.

 

For places in the scenic section where you want permanent uncoupling, some rare earth magnets buried in the cork beneath the track can work well. Where you want optional uncoupling, the best solution that I have found is to use more powerful permanent magnets under the baseboard raised and lowered by a servo. Dingo Servo now sell a mount for this with easy assembly instructions (you will need to buy the magnets and servo separately), based on a design that I and some others at the Model Railway Club helped to create last year. I also find that the Dingo Servo Micro 10 mounts are good for mounting servo point motors (on which, see above).

 

Plan your final layout for a good sized minimum radius. This will allow you to use shorter arm couplers, which will, in turn, make your trains look a lot better (and take less space, possibly allowing longer trains). The lowest minimum to aim for is 305mm, although an even larger minimum radius would be better, especially as it is easy for a slight error in track laying to make a part of the curve less than the desired radius.

 

In any event, automation is a joy and can add so much to a model railway. Very best wishes with your projects, and I shall be interested to be kept up to date. Do have a look at my video of how I am progressing with this so far and what one can do with it.

[jpendle]

2 hours ago, jamespetts said:

This is because DCC is, with the exception of RailCom, which cannot be used for occupancy detection, a one way bus: it can be used to communicate commands from the command station to the locomotives or accessories, but it cannot be used to communicate data back from the locomotives or accessories to the command station.

Hi James,

 

Why do you say that Railcom can't be used for occupancy detection? Both Digikeijs and Roco sell Railcom occupancy detectors.

 

Regards,

 

John P

[jamespetts]

47 minutes ago, jpendle said:

Hi James,

 

Why do you say that Railcom can't be used for occupancy detection? Both Digikeijs and Roco sell Railcom occupancy detectors.

 

Regards,

 

John P

 

I use the Digikeijs occupancy detectors (the DR5088RC); I have not used the Roco detectors, but I presume that these work in largely the same way.

 

The RailCom signal can indicate what locomotive is in a given section. (There is also RailCom channel 2, which can in theory transmit data such as speed, etc. but there is no standard protocol for this and I have not seen any application that uses it in any way; I have seen reports that it is unreliable).

 

The RailCom detectors have inputs from each section (17 in the case of the DR5088RC) and then transmit occupancy data and RailCom information down the LocoNet bus to the command station. (Other RailCom capable occupancy sensors may use another bidirectional bus such as XPress net to do this).

 

What these occupancy detectors cannot do is encode the section that the locomotive is in and send this together with the datum comprising the locomotive's DCC address back to the command station using the DCC bus: they need to use a bus specifically built for bidirectional communication, such as the LocoNet bus, to do this.

 

Also, as a secondary point, actual occupancy sensing is generally kept separate from RailCom; the DR5088RC uses a standard current draw sensor in addition to RailCom sensing. This is for two reasons:

(1) if RailCom were used as an occupancy sensor, the occupancy detection would not work with vehicles with decoders not equipped with RailCom decoders; and

(2) RailCom is very fragile because it is trying to be bidirectional on a bus (the DCC bus) not designed for this, so it is much less reliable than standard occupancy sensing.

 

It would be theoretically possible to build occupancy sensing that uses RailCom instead of current sensors to determine occupancy of individual sections of track (albeit it would have the disadvantages set out above), but it would still need an additional properly bidirectional bus, such as LocoNet, to send the occupancy information back to the command station.

[WIMorrison]

Railcom has an added advantage in that you can also have multiple locos in the same block and the program should recognise that there is more than one loco in the block and display them (certainly iTrain can do this). The added advantage of having RailCom on all blocks is that you can track locos and train around the layout with positive identification of which train is in the block. Without Railcom the software assumes that the train which is in the block is the one that the software thinks is there. This is extremely useful if you move trains manually, especially if you move them externally to the software - with Railcom present and enabled when you switch on the layout the software will identify what train is where automatically. Additionally the software can be provided with the loco direction by Railcom which saves needing to synchronise direction.

 

The most difficult choice is not whether to use Railcom or not, it is the choice of software as once you make that choice you will be effectively locked into that software as very few people are willing to change and face the learning curve of a new program.

[KingEdwardII]

James,

 

I can't agree with your comments about turnout motors, at least as it applies to my experience using MTB MP1 motors.

 

First, the MP1 footprint is quite small, 28 x 40 x 13mm, with the longest dimension along the direction of the track, so that the motor sits underneath the turnout it is operating. I have had no problems installing MP1s in "crowded" situations including 3-way points, double junctions, double slips, etc. The MP1s have a further virtue in allowing for a good deal of adjustment, particularly perpendicular to the track direction.

 

Second, MP1s don't draw any current when they are idle - they cut out when they reach their end position. Indeed, if they don't cut out, this indicates a problem such as an obstruction preventing them reaching their end position, which I find a useful characteristic since the small buzz they emit brings my attention to the issue. And yet, despite having the cut-out, the MP1 design still means that the turnout blades are fimly held in place at the end position.

 

A further advantage of MP1s is that they have a built-in micro-switch that can be used for controlling power to the frog of the turnout.

 

Regarding wiring, I use 17A / 2.5mm2 stranded wiring for my main bus and 10A / 1.0mm2 stranded wiring for my accessory bus and I don't find them "impractically thick" - they are very easy to work with. I use 0.75mm2 and 0.5mm2 stranded wires for connections from the bus to accessories and track and they too are easy and practical - for example, connecting straightforwardly to the screw clamps on both MP1s and the Digikeijs DR4018 units. I think that protection against short circuits is advisable whatever the wiring used - but larger wiring itself is actually a protection against fire once the wire can handle more current than the power supply can deliver - it is undersized wires that can overheat and burn.

[jamespetts]

I have heard of these MTB MP1 motors; they use, I think, an ordinary rotary motor rather than a stall or servo motor. They are a little louder than servo motors, I think, but that may be of more importance to some than others. They cost £15.50 each, which is a little more than an inexpensive servo plus a good servo mount. They probably take less work to set up than a servo, which requires the construction and installation of a mount.

 

That they take no current when idle appears to be an advantage over stall motors, although, looking at the specification, they appear to have only one output switch, which would make it difficult (without added electronics) to switch both frog and feedback simultaneously.

 

Also, I have not fully parsed the control wiring, but it looks as though it needs 12v applied on one of two terminals to determine which way to go; this would appear to be the same wiring scheme as traditional stall motors such as the Tortoise or Cobolt IP Analogue. There are, I believe, circuit cards that can switch analogue stall motors from a LocoNet input (RR Cirkits, I think, from memory), although I have no experience with these.

 

I am not sure how the footprint compares to a servo motor, nor whether the output pin can be cranked to allow fitting in especially tight places (this can be done successfully with servos and also, I believe, with stall motors), but I can believe that these have a smaller footprint than a stall motor.

 

On balance, these appear to be potentially viable for use in a computer controlled layout, albeit with some disadvantages (albeit also some advantages) as compared with servo motors.

[WIMorrison]

The MP1 are excellent on a computer controlled layout with the motor is stopped buy an internal micro switch riding on a cam. There is an additional microswitch which provide a SPDT switch driven by the same cam which you can use for the frog - if you also want to do tie bar feedback then you can use the MP5. These are really microswitches, not open or sliding contacts that you get in many alternatives.

 

as far as controlling then the DR4018 provides I excellent cost effective control.

 

when mounted correctly the are all but silent, unlike the alternatives and the range of adjustment for alignment makes them significantly better than the alternatives.

[jamespetts]

Interesting indeed - although the problem with using the DR4018 is that this is DCC control. This either requires using the track supply DCC bus, which can introduce unreliability on all but small layouts, or having a separate DCC accessory bus on top of the LocoNet bus, which adds unnecessary work and complexity.

 

One would probably be better off using a LocoNet circuit card designed for stall motors to power these.

[KingEdwardII]

For controlling my MP1 motors, I use the Digikeijs DR4018, as mention above by Iain Morrison - that is indeed a cost effective solution if you're using DCC. The DR4018 has 8 channels for turnout motor control and a single channel can drive multiple turnout motors in situations where 2 (or more) turnouts need switching at the same time, such as crossovers, since the MP1s only take 150mA.

 

I've not used the MP1s in an analog setting, so I can't comment on that, although the feed to the MP1 motors is an analog 12V, as you mention. I think that the following video shows an analog arrangement using DPDT switches, if I have understood it correctly:

 

 

Meanwhile, it is also possible to control mimic LEDs (for feedback) for the MP1 using the arrangement demonstrated in the following video:

 

 

Yours,  Mike.

 

[jamespetts]

Interesting. Those are quieter than I had imagined. The footprint seems similar to - perhaps slightly greater than - a servo motor with the Dingo mount.

[Tallpaul69]

As an interested observer, and not being in a position to offer technical guidance, it does seem to me that the last few postings have taken this thread up a particular technical alley away from the original question!

 

So maybe its time to get back to the original question?

 

But, Wordsmith, its your thread, so tell us what you want?

 

Cheers

Paul

[Wordsmith]

Firstly thanks to @jamespetts for the detailed reply. Very helpful....

 

This will be a bit of a slow motion reply as I'm not planning to build much until I retire, to it's really learn the techniques and gradually stock-up with the rolling stock, track and points.

 

Having not tried this for over 40 years, the initial impression is how much the technology has changed.  In terms of the logic of wiring, it was relatively easy to wire up an old DC type layout. Lots of wires,  but conceptually fairly straightforward to do. DCC is rather different. I downloaded some books from Kindle to refresh my memory, gradually accumulated enough rolling stock, track and points to build the test layout and am now starting to learn how to so do.

 

The first thing I've learned is that the manufacturer's instructions (locos, command stations, etc) are pretty basic - so rummaging around on the web, reading the Kindle books etc., let me find out some more. So, for instance, I've found you can program some of the running characteristics of the locos; speed with which they'll accelerate and brake, maximum speed and so on. So, when time permits in a day or so, I'll have a play on my programming track and find out how to do that.

 

I've also found out that the Digikeijs DR4018 is actually quite a complicated little beast and can be programmed to do quite a lot. So I need to get it to pre-set 6 (slow motion point motors), and get it operating my point motors via the command station and my PC. (Theoretically  I can get it to run a combination of point motors, signals and whatever, but I'll learn to do that further down the road). 

 

[The Digikeijs DR4024 is on my metal roadmap for the future - I'm assuming the programming logic for servos will be broadly similar  to the 4018]

 

When I've sussed out how to control the point motors, it's then a case of  getting some track and points down onto my baseboard to construct a test layout. Objective one is just to get manually controlled trains running round the track with manually controlled point motors. And with track that doesn't cause a derailment every 5 minutes; which means I have to find out how to lay N gauge track neatly - and wire it correctly.

 

(It'll be wired in such a way that I can try occupancy detection next - nothing fancy - just see what's where).

 

As to jamespetts' comments about the difficulties of python programming for JMRI; I work with a load of computer nerds. Providing Covid 19 lets me get back into the office, I can probably  get them to critique my scripting - they write a lot of stuff in python and other scripting languages. My laptop is Linux (Ubuntu) anyway. One of the reasons I'd like to play with JMRI is it'll make me learn Python - I find just following exercises in a textbook boring. Working out how to do things for a real world purpose gives purpose to the learning.

 

To be honest, it's the problem solving that interests me most - I like puzzling things out. And there's a lot to work out. You can obviously do a lot with DCC/computer control - but at the moment, I'm at the very bottom of the learning curve.

 

Wordsmith

 

Edited November 5, 2020 by Wordsmith

[grriff]

Wordsmith, if you haven't read Davy Dick's book 'Electronics for model railways' it's worth reading. It's available free from the MERG website http://www.merg.org.uk

[Wordsmith]

1 hour ago, grriff said:

Wordsmith, if you haven't read Davy Dick's book 'Electronics for model railways' it's worth reading. It's available free from the MERG website http://www.merg.org.uk

 

Got it thanks, plus one or two books on railway electrics downloaded onto my Kindle. 

 

To learn, I really need to start playing with stuff...

 

Wordsmith

 

 

[Wordsmith]

So, another question I hope someone  can give some help on. Is there any practical alternative to gluing Peco code 55 down? I've tried pinning it with track pins, but that doesn't look to be a roaring success. 

 

I was hoping not to have to glue it down, because I wanted to experiment a bit with with different types of points, introducing gradients, etc, as time goes by. But pinning is not particularly successful, particularly on the 9" radius curves I'm trying to put in just to get something running on my 4 ft x 2 ft baseboard.

 

Thanks....

 

Wordsmith

[grriff]

I've not tried it, but would double sided sticky tape work? Not so easy around curves of course.

 

What's the problem with track pins? What is your baseboard material? Are you laying straight onto this?

 

[RobinofLoxley]

13 hours ago, Wordsmith said:

So, another question I hope someone  can give some help on. Is there any practical alternative to gluing Peco code 55 down? I've tried pinning it with track pins, but that doesn't look to be a roaring success. 

 

I was hoping not to have to glue it down, because I wanted to experiment a bit with with different types of points, introducing gradients, etc, as time goes by. But pinning is not particularly successful, particularly on the 9" radius curves I'm trying to put in just to get something running on my 4 ft x 2 ft baseboard.

 

Thanks....

 

Wordsmith

I have not seen it advocated here, but could glue dots be a solution?

 

I tink a few people would be curous as to why track pins didnt work for you. Are you using OSB for baseboards or something?

[Wordsmith]

Hi both - the problem is that the width of a sleeper is not enough to accept a track pin. The baseboard isn't a problem - it's MDF.

 

Having thought about it, I think I'll try drilling a tiny pilot hole in the sleeper first. It'll split when I hammer the pin in, but hopefully the pin will still fix the track in place.

 

I'm planning to glue track down on any permanent layout I construct,  but the current baseboard is just for experiments. 

 

Cheers,

 

Wordsmith

[john new]

18 minutes ago, Wordsmith said:

Hi both - the problem is that the width of a sleeper is not enough to accept a track pin. The baseboard isn't a problem - it's MDF.

 

Having thought about it, I think I'll try drilling a tiny pilot hole in the sleeper first. It'll split when I hammer the pin in, but hopefully the pin will still fix the track in place.

 

I'm planning to glue track down on any permanent layout I construct,  but the current baseboard is just for experiments. 

 

Cheers,

 

Wordsmith

 

From experience with chipboard and MDF I would definitely recommend pilot holes. The PECO trackpins are very thin so will also probably bend rather than go in, the Hornby one's are much thicker but then the thickness becomes problematic with N & 009 track.