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Newbie Question - DCC/Computer Control


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I have managed to drill holes in sleepers with a minimum diameter drill (1mm) in a conventional large chuck Black and Decker not a specialist item. The drill bit tends to slide so you need to make enough of a dent in the sleeper face to stop it slipping. MDF is Ok but not the easiest for pinning. With a 1mm hole my track pins can be pushed through with fingers.

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Likewise - I drill 1mm diameter holes in sleepers for the pins. I have a standard cordless Bosch drill with keyless chuck and it has no problems gripping the 1mm drill bits.

 

I have both ply and MDF in my baseboards and I've never needed to drill pilot holes to drive home the pins - I use a small & lightweight jewellers' hammer to avoid damaging the pins & hold the track pins with tweezers while hammering them in to keep them vertical.

 

Yours, Mike.

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Thanks both - I got some of the Peco track pins; they were smaller diameter than what I had. Which, with a small hand drill, enables me to get the track down neatly without splitting the sleepers. 

 

I've also found I can solder the dropper wires on neatly using crocodile clips to hold the wire in the required position on the track first  That leaves me one hand for the soldering iron and one for the solder wire. I get on better using flux-less solder and painting on the rosin flux by hand.

 

I hadn't realised how painstaking tracklaying would prove to be - it's slow motion work that requires a lot of patience. Which, in a way, makes me glad I'm building a test layout first. I can make my mistakes on that before I try and build a real layout.

 

Every day's a school day...

 

Wordsmith

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Wordsmith - I'm glad it's working out for you.

 

Regarding the soldering, for "small" jobs like soldering dropper wires, I never hold the solder wire. I leave a roll of it on my workbench with the end pointing upwards and then rub the tip of the soldering iron across it when I'm ready to do the work. The tip collects more than enough solder for a small job and that leaves me with a hand free to assist getting the wire and track positioned. I'm not against using croc clips to hold things, but I'd only hold the solder wire for jobs requiring large quantities of solder - more in the plumbing line ;-)  As for flux - I have belt & braces approach and apply flux to the work and also use flux solder - I don't get any failures of my solder joints.

 

Tracklaying is steady work and you need to take some pains with it to get smooth running. I've moved over to a system of using track layout software (xtrkcad is my current program), getting the design sorted out on there and then printing out the design on paper at 1:1 scale, which I then stick down to the baseboards and use as a guide for laying the track. The design software helps ensuring that things fit together properly and that you avoid curves being tighter than necessary - xtrkcad lets you specify a minimum radius and then gives a warning if that radius gets breached anywhere. The software also lets you play with variations like changing between different radius points.

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Another question for the experts to answer. I'm using Peco code 55 flexible track. It's not very keen to be bent into curves of 9" or 12" radius. Or in staying (prior to pinning) in something approximating the Tracksetta curve.

 

Is there a trick to making it more flexible - for example by cutting more gaps in the webbing underneath? Or is it a case of bending it to shape with a Tracksetta curve, putting some panel pins outside of the track to keep it roughly in place, and then pinning it?

 

Advice welcome....

 

Wordsmith

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You can pre-bend the track to make it follow the curve more naturally or you can cut webs to allow more flex, but in all cases you will need to pin the track in place to allow the glue to set - or if only using track pins then more pins are needed.

 

Ideally solder jointt together before bending or even better don't have joints in the curves :)

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Wordsmith,

 

I use all pinning & no glueing.

 

My approach is to use track layout software (xtrkcad in my case), print out the layout at 1:1, stick down the printouts and then lay the track, pinning it in place to match the position on the printout. For curves, I usually start at one end where there is already a piece of pinned-down track and then work my way along, pinning every 11th sleeper or so - the tighter the curve, the smaller the gap between pins. When I'm done, I trim up the rails using my Dremel, since the curve means that one side will be longer than the other.

 

Avoiding joints on the curve is a good idea but in a layout with more relaxed curve radii, they become inevitable. I usually aim for some pre-bending of the rails around a joint to avoid getting a discontinuity in the curve.

 

I much prefer using the software-and-printout approach since it makes it easy to use curves which are not circular in form (ellipse, Bezier...) and where the radius of curvature changes as you go round the curve. 

 

Once the track has been pinned down once, it is easy to lift it, remove the printouts and replace the track ready for ballasting, etc.

 

Mike.

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Yes, laying track well is a slow and painstaking business - even more so when you add in point motors and the mechanical & electrical aspects of those.

 

That is one reason why I really appreciate the track layout software. You can build an accurate model of your layout quite quickly - see what works and what doesn't work in the space available. You can chop & change, try out multiple "what if?" alternatives. I like the ability to impose a minimum radius for curves, with the software giving you a warning if it gets breached by your design, allowing for some replanning. You can try out the effect of different choices for pointwork - it is especially valuable for the software to have accurate models for the pointwork you are using.

 

I think I prepared 15 versions of the track plan for the layout I'm working on at the moment and I've only made a couple of minor tweaks while laying the track itself.

 

Mike.

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As I automate layouts for myself and other people I always recommend that the track layout is created in the automation software before track is laid because operational issues can be identified in simulation and correct much more easily than the can when the track has been laid :) 

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4 hours ago, grriff said:

It's worthwhile loading your layout into 'Train Player' https://www.trainplayer.com/ to simulate real operations. This can highlight operational problems which may not be obvious from the track layout.

Was the demo version of trainplayer adequate for a decent sized loft layout? Just being lazy, wondered how capable it is without trying it myself.

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25 minutes ago, RobinofLoxley said:

Was the demo version of trainplayer adequate for a decent sized loft layout? Just being lazy, wondered how capable it is without trying it myself.

Don't know I'm afraid. I used it on  small 72 by 30 inch layout. 

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  • 2 weeks later...

So - made a little bit more progress and now have things running on my little 4 ft x 2 ft trial baseboard. Although the first thing I found was Dapol Schools locos don't like running round 9" radius curves. So I'll be building a slightly 5 ft x 2 ft 6 inch baseboard (and 12" radius curves) when I've exhausted the learning potential of this one.   :o( 

 

But now understand how to wire the track correctly. (Bit of trial and error - mainly error). A couple more questions if I may.

 

Is it worth pre-planning wiring runs and then putting in the feeder wire positions accordingly?

 

For a small test layout like mine, I might have been better to run the power bus along the inside of the timber frame with spurs to the different feeder wire locations. Plus, I ended up taking the power feed from my command station and splitting it into two feeds: one to the oval of track/passing loops and one to the head shunt/sidings (which were isolated behind a pair of insulating rail joiners  [facing points] to prevent a short circuit). Which, in turn, suggests on a larger layout, you're going to end up with 'sub-buses' going to different electrically isolated areas of the layout.

 

Chuck in another power bus for points, signals, etc., and I can foresee rather complex wiring needed for a larger layout.

 

Finally, is it worth laying think cork under the track bed to deaden the noise a little? I was slightly surprised how much of a sounding board MDF made.

 

Again, thanks in advance for the answers.

 

Wordsmith

 

(Next stage is getting a few point motors working from the command station. More head-scratching in store...)

 

 

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Having been an electronics/software guy for 40 years I do a lot of my own model railway electronics.

 

I did a small layout (Penrith & Blencow) which had 2 platforms at each station.

This meant I could run 3 trains automatically around the 4 branches.

I used PIC microcontroller, PWM and relays to switch power to various block sections.

I also had a destination board LCD display.

I added an automatic speech announcement system using a sound chip. I used my echo box to get some spacial sound and it sounded very good.

 

In more recent times I have got into DCC.

I designed and built a DCC shuttle.

I am currently working on a DCC encoder. It can control up to 127 loco's. It can also control function decoders for points etc.

It can change loco's address if required.

Great fun.

mr_dccshuttle.jpg

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Wordsmith,

 

For my layout, where the baseboards are basically 600mm (2ft) wide around a room, I simply ran a power bus around the outside of the baseboards and an accessory bus around the inside and then ran wires off those where necessary. I didn't plan too much in advance since the final positioning of droppers, point motors etc was decided as I laid the track - and taking into account the positions of supporting timbers and other obstacles.  For example, in some cases I reversed the orientation of point motors to make it easier to attach the wires.

 

If you use electrofrog points as I do, there are insulating joiners all over the place and a consequent need for a lot of droppers to the track, even where you're able to lay long sections of flexitrack. Plus, for the future I plan to have occupancy detection and for that there is a need to ensure separate droppers for each track section and for the isolation of each track section - and so yet more insulating joiners!

 

What point motors are you planning to use?

 

Mike.

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Hi Mike,

 

Yep - I'm using electrofrog points. I'm planning to model the SR in the 1930's. And as a lot of that was tank engine based, I didn't want the locos stalling on insulfrog points. And yep, insulating rail joiners over the place. One of the many lessons I've learned is to wire as you go along and then run an engine along the new section of track - that way you find problems early and avoid a lot of re-wiring/adding more insulating rail joiners.   :o(

 

I have Traintronics TT300 point motors that I'm planning to run via a  Digikeijs DR4018 module, although I've yet to figure out how to use it. That's next on the list.

 

Cheers,

 

Wordsmith

 

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19 minutes ago, WIMorrison said:

Why do you want to use a DR4018? These motors are meant to have a decode built into them already.

 

My ignorance is showing - thanks for the info. So now I need to figure out how to get my DR5000 command station to talk to the point motors - which looks fairly simple.

 

The other thing I wanted to use the DR4018 for was to turn sections of track on/off as an experiment. I figured if a loco was moving extremely slowly when it hit a dead section of track, it would stop in a fairly precise location - a step towards computer controlled shunting. One of the many things I want to try out - at first by using a manual on/off switch and seeing how reproducible the stopping point is.

 

Wordsmith

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You could use the DR4018 to switch a relay that switched the track off an on but when you moved into automation you would not use that method as the computer would simply issue a command to the decoder to get the train to stop in the correct place.

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14 minutes ago, Wordsmith said:

....The other thing I wanted to use the DR4018 for was to turn sections of track on/off as an experiment. I figured if a loco was moving extremely slowly when it hit a dead section of track, it would stop in a fairly precise location - a step towards computer controlled shunting. One of the many things I want to try out - at first by using a manual on/off switch and seeing how reproducible the stopping point is.

 

 

This seems a rather bizarre approach, if you don't mind me saying.

Turning track power on and off to control or effect the movement of trains is completely against the whole point of DCC, which is to allow you to directly drive each individual train or loco. Not to drive the track.

If it's for automation purposes, I really think the answer lies elsewhere.

.

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Rather than turn the track off, use a detector to feed back the train position to your control system, and let the control system send an emergency stop command. That way all the lights and sound will stay on!

 

Even that method is a bit crude. Use decoders like Zimo (and Lenz) with a fixed braking distance and when you send a stop command you know how far the train will go before it stops, and it will slow nicely to a stop.

 

You can also use asymmetric braking too. There are a few ways to do this in DCC.

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1 hour ago, Wordsmith said:

 

My ignorance is showing - thanks for the info. So now I need to figure out how to get my DR5000 command station to talk to the point motors - which looks fairly simple.

 

The other thing I wanted to use the DR4018 for was to turn sections of track on/off as an experiment. I figured if a loco was moving extremely slowly when it hit a dead section of track, it would stop in a fairly precise location - a step towards computer controlled shunting. One of the many things I want to try out - at first by using a manual on/off switch and seeing how reproducible the stopping point is.

 

Wordsmith

 

Hi,

 

Glad to see you're getting to grips with all this DCC malarkey.  I just thought I'd pipe up and say that there's no need at all to do what you mention above to see how reproducible a stopping point is under computer control.   Automatic control software does this exceptionally well and this is one of its great features.  I've been building automated layouts for years now and can say that stopping distances can be down to a couple of millimetres - BUT - a lot will depend on other factors such as perfectly clean track and wheel pickups on the loco, loco maintenance and the running capabilities of the motor and drive mechanisms is also a factor and load on the train.  Basically if all running is perfect then there's no reason the computer program won't stop your train at exactly the same spot each time.

 

In the software I use - Train Controller - you can additionally specify simulated train weight which affects deceleration which can be a factor in stopping point - however the program takes care of all that, decelerating the train over a distance to stop at the correct spot regardless of load.  

 

Below is a link to a short video I did a while back showing a loco which has been decelerated and is being brought to a stop by Train Controller.  I have set it to stop with the loco's mid point at the tip of the old paintbrush I've placed across the platform surface.  You can also specify in the the software that the train will stop at the front, at the rear, at it's mid point or at any given distance from the front or rear of a train.  This is useful where, for example, you want to stop under automatic control and detach (or attach) a brake van or split a train at a certain point. 

 

So, rest assured friend, automated control software will take of these things for you.

 

If you're ever up North Yorkshire way and it's safe to do so - pop in and see all this for yourself.

 

Video link:

Cheers .. Alan

 

              

Edited by Alan Kettlewell
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Thanks all for the above comments - I wanted this to be a future retirement hobby that made me think. And it's certainly going to make me do that.

 

I'm beginning to experience the gulf between what you can pick up from books/the Internet and what practical experience can teach you.

 

As to stopping distances, etc., I've found out that you can program acceleration and deceleration rates, etc, into a loco, so that's also on my list of things to play with in the near future.

 

The hobby has come on a long way since I built DC layouts as a teenager....

 

Wordsmith

 

 

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