Playing trains with kids

Brilliant - the extra diode answers Question 1 - circuit works fine now. Actually it works without any of the diodes except the initial one from the supply to the collector. Some sites had dismissed the idea of back EMF blocking - turns out it's needed. Thank you Actually, looking around a bit more I found you could use as low as 220R (Brian Lambert's design) - I added a second 470R in parallel and it still works and gives quicker recharge.

Actually, thinking about it, it can't be the capacitor charging - because the circuit works fine to throw one motor.......

Help please! I'm using a home made CDU aiming to throw 2-3 Peco point motors at once. (old ones mounted under the point directly to the point) The circuit is: (apologies for the quality) I take the +12v/-12v from an old ATX power supply rated at 0.8A for the -12v. The 470R is 5W. This works fine for 1 point, but for 2 points the power supply cuts out when you throw the points (it does throw the points!). Same happens with only one capacitor 2200uF My understanding is that using the capacitors should reduce the load on the power supply as it only charges the capacitors, and the sudden flow of charge comes from the capacitors. I have 2 questions: 1. Why might the supply supply be cutting out? Is there something wrong with the circuit (note there probably should be lots more diodes - I have tried a reverse diode across the output, to no avail. Trying to keep construction simple as I want to build a few of these locally for different parts of the layout). Am I right in thinking this circuit shouldn't draw more than around 600mA (read this somewhere......)? How could it be modified to prevent the cutting out? 2. I'm really interested in the idea of using SPDT switches with one capacitor per point - but these require a power supply capable of 3-4Amps (briefly!). What do these power supplies actually look like - and could you use a CDU arrangement to provide the necessary power bursts from a less strong supply (i.e. an ATX!)? Does there need to be a small resistor between the emitter and the capacitors (30R by my calcs?) to limit the max charging current to 0.8A? If this is the case, is there any value to the transitor other than to stop the coils burning out if the switch shorts? What would this do to the charging time? I really like using the ATX as it provides 12v for the tracks, 5v for signals, accessories and servos, potentially 24v for the points if this works, and the whole lot is in one box, turned off by one switch and runs from one plug socket. Note - I have another older ATX which is less sensitive to current spikes and quite happy with throwing three points - but of the three ATXs I've tried two have this issue. Many thanks

I am collecting rolling stock from two periods - vaguely BR blue and vaguely BR late crest steam/diesel. However, the above photos perhaps need some explanation. The layout operators (11, 9 and 5) use the following rules to determine their train formations: 1. Which locomotive runs the fastest, and Daddy has cleaned the wheels on - Wrenn models are also liked because they are heavier and harder to derail. 2. Subsequent stock is selected based on the passengers - mineral wagons hold lego men well and Sylvanian family babies; flatbed wagons or motorail wagons can hold the lego men's cars. The Triang cement wagons are particularly desired because the roof comes off and lego men can hide inside. Occasionally passenger coaches are added to make it look a bit realistic ! Much of the stock is from my childhood, the rest from ebay. I am trying to collect wrenn wagons as the diecast chassis make them more stable and therefore better endure my poor tracklaying. The heavier the better - the layout is flat so there are few traction problems :)

A few more photos. I forgot to add this is 4mm scale. you can see in the last photo the 1 &2 radius curve board - which was constructed first, and then later the 3 &4 radius board was added on the outside. The spur led to a fiddle yard, in which the stock will (eventually) be stored in removeable cassette boxes.

The advantage of this method is that over the years, new pieces could be added as they were constructed. In time, two more tracks were added, allowing four trains to circle at once. Passing loops were constructed in the station, giving a 6-lane station. I also added a junction for sidings, and built the sidings approach As you will see, I didn't go for any scenery apart from platforms. I also chose not to ballast the tracks (yet) as I was concerned that ballast would come loose when the boards were assembled/dismantled.

In order to make the tracks precise standard spacing at the end of the board, I used two double track level crossings, one at either end of the piece I was constructing. The level crossings, as the track, were mounted on plywood with the softwood supports The construction method was as follows: 1. Make the softwood support. Drill holes and install furniture nuts on one side 2. Bolt the supports to the jigs (the level crossing pieces) 3. Cut the plywood for the piece constructed. Drill pilot holes (1mm) in the corners to nail the plywood to the softwood support (don’t nail in yet) 4. Place the plywood on top of the supports (which are connected to the crossings), and lay the tracks between the two level crossings -fix the track in place with rail joiners 5. Nail down the track to the plywood.(you need to slide a softwood strip under very close to where you are nailing in the track pin to stop the plywood bouncing, don’t put it directly under otherwise the pin will go into it. 6. Nail the plywood down to the softwood strips on which it sits 7. Unbolt from the level crossings. Piece is now complete. Take care – as the track pins sharply protrude out of the bottom of the plywood. You make wish to glue some thick cardboard over them, otherwise you may scratch your hands when trying to fit the bolt in during assembly The above method is for settrack. For flexitrack, I also found that the rails needed to be secured more robustly at the board ends. The was the case for curves - in order to keep the curvature (I later built 3rd and 4th radius bends, but used flexitrack for the 4th radius as I didn't have any set track and it was quite expensive to buy. It was also necessary for straights - especially short ones, as somtimes when disconnecting the board pieces, the rail joiner pulled the rail along its length (i.e. perpendicular to the sleepers, slipping through the chairs) . Initially I fixed the rails by removing one plastic sleeper, replacing it with a thin pcb sleeper and soldering the rails. However, I discovered sometimes during assembly or dissembly the copper layer came off the (cheap low quality) PCB. So I then soldered to a nail banged in just outside the track. Neither of these were right at the board edge to allow space for the rail joiner to connect between the boards. Sometimes the nail-rail solder joints failed too (actually the metal meant the solder seldom took well to the nails). In future I will use a wider pcb strip to prevent failure, or brass plated screws into the plywood, under the rails and installed before the track is laid) to solder the rail to. This method was to ensure that each end is a standard alignment for the bolts and the rails, in theory allowing any piece to connect to any other piece. Will try and add some photos later

The boards have the standard track spacing (67 mm) perpendicular to every join, so in theory pieces can be connected in different ways, and most importantly, a roundy-roundy layout could be produced quickly, then more sections added as they were built. Joining the boards needs to take into account 3 factors: 1- Physical alignment of the rails - to prevent derailments 2 -holding the baords together (they are easily knocked by children dancing around 3 - electrical connectivity between the rails on each section The segments are made of 6mm ply sat on 30*10mm softwood perpendicular to the tracks at the end. I went through a variety of ways joining them, but the system I ended up with (Mark I) was to use M6 bolts and furniture nuts (see photo). The holes are standard spacing (under the centreline of the track). I use a bolt turner, connected via an angle crank to a battery drill to quickly tighten them (see photo). I decided to keep the rail joiners to connect each section. This can be incredibly fiddley (as you not only need to get the horizontal alignment of the track right, but also the vertical alignment, and both tracks need to be joined at once. The rail joiners alone are not enough to hold the segments together, as they often got knocked apart by overexcited children dancing around, so the bolts are still necessary. You also need to be careful that when you separate the boards - the rail joiners protrude and are share and can easily cut little toes - ask me how I know! However, the rail joiners sovled the rail alignment problem and the electrical connectivity. As you can see from the photo, you need to only put the furniture nut on one side, on the other side the bolt just passes through a 6mm hole. I had a convention that on the inner track the bolts protruded in an anticlockwise direction (the direction of travel of the train...) The furniture nuts required and 8mm hole and were screwed in with an allan key. 30mm gives enough for the bolts to be attached under the track, and also clearance for a point motor or servo. The boards simply sit on the laminate floor (or the lounge carpet when my wife is away :).

I started with a simple double track loop (double track - I have two boys!). It was simply first and second radius Hornby curves, with a set track crossover. The tracks are 67mm apart, (as per the Hornby standard) and the straight section is 2*167.5 = 335mm long - enough to accomodate the crossover. On the plan below, the dotted line is the track centre. Each board is 2*67 = 134 mm wide (actually cut slightly less to allow adjacent boards to be added (see later).

I came across this thread because I had a similar problem a year ago on an 0-6-0 (R1?), (the bright green one with the BR logo - actually I thought mine was an HD model) which seemed odd but I thought nothing more of it, but now my Wrenn N2 (0-6-2) has begun to grind its gear. It is very surprising because the failure is 'catastrophic' (in the technical sense) - no warning and then sudden and almost immediate grinding of the worm gear to shreds. These models came from different sources (on ebay). I am not sure about the suggested failure mechanism, it seems to me like there is continuous wear, and at some point, (possibly with some fatigue mechanism), once the first slip/grind happens, the subsequent grinding is inevitable. I have two questions: - how successful has replacing the worm been? I am concerned that the worm gear and the axle gear would wear themselves into a set pattern, and therefore maybe the axel gear would not work well with the replacement worm (or may grind it again!) - Could anyone tell me if the 3-rail Hornby Dublo N2s have the same motor and worm? These are potentially a much cheaper source of a replacement motor Thanks in advance for your help. Some kids are quite eager for the resurrection of their favourite "steamies"

For me it's been helpful to set aside a small budget each month, say £20, and try and keep to it. This way you can save up for bigger items, and it stops you buying things you don't need. It seems a small amount but it works pretty well. As for point changing, second hand solenoid motors can be picked up for £2 each, switches from aliexpress 40p each if you search hard enough for the right ones...so a month's budget would enable you to motorise 8 points.

Just to complete the story: - It seems the problem was mainly lack of contact. I used some kind of hydrocarbon solvent (sold for cleaning circuit boards) and it has helped to clean both track and wheels. In some cases cleaning the contacts from the wheels (and the wheel backs) has really improved things. A quick wipe around the tracks before operation is a real help. - I also added a rumble motor - a CD-pancake style motor with an eccentric weight - sold as a spare part for an x-box controller (aliexpress) and clamped it to the bottom of the baseboard at the entrance to the fiddle yard. This is then operated with a push switch to vibrate the board if the loco stops - it works very well on 5 volts, on 3 volts the vibration was not quite enough, I have the larger (left) of the two sizes available. This allows me to run the trains very slowly over the points without fear of stall or losing contact; when this does occur a quick "rumble" gets the loco moving again. I have ordered more and will install them at other locations where trains need to be stopped or moved slowly i.e. at the station entrance (each is on a separate board). I need to work a bit more on the clamping arrangement, I'm not sure how well it would work on thicker baseboards (mine are 6mm regularly resting on floor supports); but I really like the principle (let's face it I'm lazy and the track/wheels are not always super shiny clean). - Still in the longer term perspective is to replace plastic wheels with metal ones, I think this will not only help the track stay cleaner but also improve running. Thanks again for all your advice.

I have a floor based modular system as I live in a rented flat. I use plywood raised on 10*30mm strips of softwood. The 30mm clearance allows for bolts between the sections (a hole on one side and a furniture nut in the other, M6). I use a 90 degree angle on a hex shank with a bolt turner bit (see photo, I can't find the right words to describe it.....) to connect the sections (with electric screwdriver to screw in the bolts), but I also use the fishplates to align the rails. My modules are very small, based on setrack geometry. The track endings are always perpendicular to the board at standard (67mm) spacing to the boards can be connected in different order. The 30mm also allows for mounting point motors (both solenoid and SG90 servo) If I did it again, I'd be a bit more precise with the hole location to do away with the fishplates and secure the rail ends with PCB to the board. This is a temporary/play layout with little scenery; I used 6mm ply for economy plus it's lighter and quicker to cut. Most sections are supported every 30cm, I tried longer sections but they did sag and I have had some problems with warping. PS I am in the "can't cut a straight line with a jigsaw" club, but discovered that a regular hand/garden saw works well for straight lines, I supported the board on upturned plastic boxes (being careful not to saw into them.....) The jigsaw was great for the curved sections, where wobbles are much less noticeable.

Thanks again everyone. I am in the process of upgrading to metal wheels and adding weights. I found the issue of how best to add weight has been discussed elsewhere on this post (sorry I can't work out how to post it here, the link doesn't work it's called "Adding weight to loco's") Sadly it's not just my kids, but also my budget that stops me going for newer stock (maybe that's because of the kids....)

PS I love the expression "heritage fleet."

Thanks again everyone, some helpful tips. I haven't yet been able to rig it up with the ammeter to check, but from observation it does seem like 90% of the time it is due to electrical contact, with the occasional stall (noted either by humming, or by the loco making a small jolt then stopping). I've got hold of some lighter fluid so will get to work with cleaning. I have a question: as mentioned, the axle-chassis conduction path on the diesels, any advice as to what this should be cleaned/lubricated with? I have also ordered some components to make a "Seismic effect" so we'll see if that also helps. I do have an old relco unit which was close to being chucked because I was under the impression they are no longer considered useful. It probably won't help as I use controllers that give 12v pulses (PWM), and I'm not sure how the unit would be compatible. I will also look into adding extra weight, I had noticed this problem on the Hornby Class 43 and added extra weight to the non-powered bogie as there was intermittent pickup as it went around; sounds like I need to do this to other locos too.

and obviously, I forgot to add I need to do lots of cleaning/servicing! Thanks for the great tips everyone! Will try the ammeter test, just need to think about how to wire it in, I have a multimeter. Although by Murphy's law I probably won't have the problem for a while when I'm looking for it. I had the idea of installing something more subtle to vibrate the board, any one done this? One component I've seen available is a mobile phone vibrator, although the challenge is to fix it to the board without dampening the vibrations (my board is plywood). N.B. choose your words carefully if you do an internet search for this......

Thanks for the swift responses, I had not realised this was now an old problem! I'm sure I've seen the hand method once or twice on an exhibition, but maybe it was because like me they're still attached to their childhood rolling stock. I admit I came back to the hobby after about 20 years away, unpacked the old stuff and was surprised that so much still worked. A lot of things have passed me by and I'm still catching up. The idea of double heading sounds the most practical at the moment, but I do like the mallet idea. I haven't yet used cleaning fluid/IPA; I live abroad and I haven't yet found it where I live, and you can't transport it by air So if the problem is conductivity, then adding a second motor won't help any more than increasing the pickup. But if the problem is torque/stall, then a second motor bogie would potentially help. But doubling heading would help either way. At the moment my kids are quite young so the rolling stock has to be easily (cheaply) replaceable so I'm not about to invest in modern stock. However, at least when they're around there's plenty of hands to push the locos! Just the problem of when I'm playing trains when they're in bed!

To me this is the biggest question for my layout, but I can't find any discussion anywhere: How can you make sure a loco starts from a stop without requiring a push occasionally? I have cleaned the wheels, the track, ensured it is not stopped on the plastic bit of the points etc. It doesn't happen with every loco every time, but most locos occasionally. Technical info: I have mostly Hornby/lima OO models from 1980s, the odd Wrenn loco (which interestingly, usually start without help), it is dc not dcc. I've even replaced one diesel with a CD can motor, but this doesn't always go without a push. I usually run the locos a bit first to give them a "warm up," but still have the problem...... My theory is that it's caused by the coils of the motor stopping in an awkward position, effectively stalling. Therefore my guess is that the only real solution is to use 5 pole motors (all mine are 3) or to install 2 motors (for diesels), one on each bogie; but before I invest in this, I'd like advice...... How has anyone else solved this problem? Or could someone point me to where this has been discussed (I'm sure it must have been, but I couldn't find it)? Also, I noticed that when I send another loco down the same track to try and rescue the stopped loco, the stopped loco often comes to life well before the rescue loco comes near. I suspect this might be something to do with the back emf of the rescue loco doing something to the coils of the stopped loco? This makes me wonder if there is any way of simulating this to "boost" a stopped loco without physically putting the rescue loco on the track - although maybe here I'm moving into a more control topic than a motor topic?