Thursday, August 22, 2013

How I constructed an IP Engineering Lollypop Railcar kit

The kit had been sitting on my shelf for around two years after winning it unexpectedly on a well-known online auction website. The motivation for finally blowing off the dust and starting construction was my desire to create a new fleet of battery powered locomotives to operate the railway. While this particular model will not really contribute to day-to-day running, it did provide an opportunity to find out how well the Deltang radio control system (see An Evaluation of the Deltang control system) would operate on a vehicle powered by a lower voltage than my usual 12 volts.


To start with, the instructions and the kit were laid out and checked.

Everything required to produce a functioning model is provided in the kit and the instructions are clear and helpfully illustrated.

Following the instructions, I cleaned-up the whitemetal castings and superglued together the four main components forming the control panel and added the control levers.

I then turned my attention to the main parts for the body. Holes were drilled in the buffer beams for the couplings, in the front panel to accommodate the lights and in the base plate to allow the wiring for the lights to pass through, following the guidance on the drawing provided with the kit.

The front of the railcar was then constructed with exterior PVA adhesive, using the drawing to ensure the main components were correctly positioned. At the same time, the grille for the radiator was cut to size and glued into the radiator, using superglue.

After the buffer beams were attached, the sides were put together as a unit with the front of the covered van section, and the rear of the railcar was also glued on to the base.

The front of the railcar was then attached, as were the spacer pieces along the tops of each side.

The solebars were then attached to the underside of the base, using the correct spacing for 45mm gauge, and the axle boxes were superlgued on, making sure the wheels and axles were appropriately positioned.

The motor was temporarily inserted into its hole in the base whilst this was being done to ensure that the worm wheel would mesh with the worm gear.

The doors were then fixed into place. The left hand door was glued shut while the right hand door was allowed to slide, by fixing two battens behind it to hold it in place.

 At this point the pre-formed aluminium roof was glued into place with clear contact adhesive. This flexible adhesive allows it to be removed if necessary.

Normally, I would glue the roof on last of all but I wanted to do some test-running with the Deltang receiver/controller to find out how responsive it was with 4.5 volts of battery power.

The wiring loom for the testing comprised a battery box with three AA alkaline batteries (I prefer to use alkalines when testing as rechargeables do not like being accidentally short circuited - they have been known to explode!). The positive lead was connected to an auto-reset fuse and then to a two way switch which directs the electricity from a charge socket in one direction and to the receiver/controller in the other direction. The controller is then connected to the motor and also for the benefit of testing, a bi-colour LED.

 The trials proved to be successful and so I continued with the build. My next job was to prime the whitemetal fittings using a couple of coats of Halfords' grey primer from a rattle can.

I decided to add more detail to the plain, slab-like sides of the railcar by gluing on planking made from coffee stirrers. The sides were tackled first ........

....... followed by the front .........

...... and the rear.

An exterior framework was added to the sides using coffee-stirrers slimmed down to 4mm width (using a razor saw as a craft knife was too easily deflected along the grain).

The doors were scribed at 5mm intervals to represent planking.

The front of the railcar was detailed last of all as this was the most fiddly. On reflection, it would have been easier to to clad the front of the closed van section prior to fitting - but I had been anxious to complete the shell for test-running.

Once the planking was completed, I added some extra depth to the buffer beams (with lolly sticks) and then, when the glue had set, used filler to mask some of my inaccurate cutting and joining.

The wheel treads were masked off with masking tape and the body was given a couple of coats of red oxide primer from a Plastikote rattle-can.

While this was drying off, the wiring for the front and rear lights was prepared. The correct value for the limiting resistors for the LEDs was calculated (100 ohms) using an online calculator ( http://ledcalc.com/ ) and these were purchased from Maplin.

Three red/white bi-colour 5mm LEDs  has been purchased from the USA (UniqueLEDs.com) as that was the only source I could trace - it turned out that the owner of the company originated from Burnley! The resistors were soldered to the anode leads and a black wire soldered to the middle cathode lead.

A white wire was soldered to the anode for the white LED and a red lead for the red LED.

All the wires and resistors were then shrouded in heat-shrink sleeving (again from Maplin) to prevent short circuits (Note: once slipped on to the leads, the heatshrink was gently heated with the flame from a lighter to shrink it).

The two front lights were then wired in and the the wires fed through to the van interior using the holes in the base which had been drilled previously.

The LEDs were fed through the front panel ..........

..... and then the lamps (which had by now been painted with black acrylics) were glued on with epoxy. The radiator (now painted with Plastikote brass) was also glued on with epoxy.

The rear lamp was positioned over the rear LED and the exhaust pipe glued on.

The roof, solebars, axle boxes and wheels were painted black and the control panel (now painted brown) was superglued into the cab area to cover the wiring for the lights, and a driver glued in place at the controls. Brandbright brass door handles were added to the sliding doors and the buffers screwed on to the buffer beams after having been painted red and black (with some of the paint removed to allow the silver whitemetal to show through indicating wear).

The railcar was then tested........

........ a few times.

...... until I felt satisfied it was operating successfully.

At some point, I will weather the railcar and apply some transfers to indicated that she is part of the Permanent Way roster. I also intend to add a small flat wagon on which will be some toolboxes and general paraphernalia as might be used by track gang (now completed - see How I constructed a small PW wagon). For now, she is happy to potter around the railway when I feel the need to have something running at short notice (eg see A Day in the Life of Peckforton Station).

Overall, the kit was a delight to put together. The instructions are clear and the parts are well engineered. I decided to add some additional detailing but that's largely because I like to personalise my models. My only concern is regarding the gears which, being made of plastic, seem a little delicate. However, the model will not be hauling large loads at great speed and provided I keep the gears well lubricated, so I am hopeful.



Sunday, August 18, 2013

Progress Report 48

The weather has been quite mixed since the previous Progress Report (see Progress Report 47) but I have managed to get a couple of complete operating sessions in, and also have run the railway in tail-chasing mode a few times when we've had visitors or when I just fancy seeing something running.

Battery Power

I must admit, I am becoming more and more enamoured with battery power. Today, for example, one of my friends phoned up and asked if he could bring his future son-in-law round to see the railway in half an hour's time. It's been a week or so since I last ran a train as the weather has not been conducive and normally I'd say, give me an hour and a half to make sure the track is clean enough - but not this time. A quick whiz round the track to remove fallen leaves,
........ a battery loco was placed on the track with some rolling stock and within twenty minutes we were up and running.

Normally, after cleaning the track, I'd have a test loco running around a couple of times to check whether there were any mucky bits I'd missed, but now I have the confidence to run a full train straight off.

I'm looking forward to extending the number of battery powered locos so I will eventually have a full complement for a running session (a minimum of three locos - one passenger, one goods and one for the copper ore trains).


Deltang radio control system

After hearing about this system on the G Scale Central forum, I decided to invest in a transmitter and a couple of receivers to see whether it would be up to running my slowly expanding fleet of battery operated locos. The Deltang system uses 2.4gHz with a transmitter which can control up to 12 locomotives independently. (see An evaluation of the Deltang r/c system). After some initial trials with one loco, I have now invested in another three receivers and so have no excuse not to finish adapting and building sufficient battery locos to run a full operating session.

The most reliable battery loco so far is the 0-6-2 model based on the Southwold Railway's No.4 Wenhaston (see How I constructed a battery powered 0-6-2T locomotive). I have now run this extensively with a Deltang receiver/controller which, despite its diminutive size, seems to be able to cope with the loco hauling a full train up the line's gradients. I am intending to add a heat sink to the receiver just to be on the safe side, but I'm not entirely convinced it's needed.

IP Engineering Lollypop railcar

To test out the Deltang system on a low powered loco (all my other battery models run on 12 volts), I am in the process of putting together an IP Engineering Lollypop railcar kit (no longer available) which I've had on the to-do shelf for well over a year. This is powered by 4.5 volts and responds well to the Deltang controller/receiver. Although she's sufficiently functional to enable me to engage in testing ........

... she still requires detailing, painting and weathering. I'm considering making a small flat truck to go with her so that she will form the railway's engineering train. (see How I constructed an IP Engineering Lollypop Railcar)

New gearboxes for the IP Engineering diesel and the railbus

 Diesel loco

The IP Engineering diesel was already on its second gearbox when I constructed it. I'd bought it as a half-made kit and it came with a stripped gearbox and an new one. Within a very short space of the time the plastic gears in the new gearbox became stripped as well.

I tried constructing my own using a metal worm and worm wheel from Cambrian Models but my engineering skills were not sufficient to make a gearbox which would mesh properly. A friend came to the rescue and constructed one for me using metal 00 loco gears. However, he was not convinced the gears would be up to the job for more than a short period of time.

When testing this model with the Deltang controller (see above), I found that while it was fine running in reverse, the controller sometimes struggled to turn over the motor when it ran forwards. After consulting the designer of the Deltang system, he adapted one of his ordinary receivers to work with his Tx22 transmitter enable me to use the Brian Jones Mac 5 controller with the transmitter. She now works reliably though she is more responsive in reverse than when travelling forwards which suggests the problem lies with the mechanism rather than the control system.

If the present gearbox does succumb to excessive wear, I will replace this gearbox with an MFA Como gearbox motor and bevel gears, as I have done on the railbus (see below)

 The Railmotor

The railmotor also had a gearbox with plastic gears and while the gears had not become stripped they were wearing alarmingly. A major problem with the motor and gearbox on this model was that it was seriously under-powered. The gearbox provided only 16:1 reduction and as a consequence the motor didn't generate sufficient torque to power the railbus when pulling its trailer car.

I trawled the internet for suitable gears and motors and it looked as if I would have to have a special gearbox constructed for me (at considerable expense!). After consulting the opinions of fellow modellers on the G Scale Central forum, I invested in a 30:1 12-24v gearbox motor and a set of bevel gears from MFA Como. I have since seen these available in my local Maplin store - and what is more the gearbox motors cost only around £10!

After making a simple brass U-shaped bracket for the wheels I needed also to source a sleeve which would slip over the drive axle to increase its diameter to 4mm for the bevel gear. This I tracked down from MotionCo, and when it arrived, I realised I already had some 3mm brass tube which would have sufficed. This is all part of the learning process!

It's a whole lot easier to mesh bevel gears than it is to mesh worm gears and within a short space of time I had a fully functioning and powerful railbus. So far, I have only been able to test it with a few alkaline batteries, but I have just taken delivery of a 12v li-ion battery and will shortly have another couple of Deltang receivers so I will be able to wire this up properly and enable it to enter service (see How I built a railmotor and scroll down to the update).

At last figured out where the water goes

Ever since I installed the stream (see How I constructed a stream) I have been perplexed as to why it sometimes will run for several hours with only minimal topping-up and yet on other occasions it needs topping up every half an hour or so. There seemed to be no logical reason until, recently, I had need to clean out the sump hurriedly before a visitor came to call to see the railway and more specifically how I'd constructed the stream. Whereas prior to the clean-up I'd been topping it up every half hour, while he was there (for three hours) it didn't need a top-up once. Suddenly it came to me. If the holes were blocked in the cover over the sump, rather than flowing down into the sump, the water would soak away around the edge of it.

So now, from time to time, I poke a pointed stick down into the holes drilled in the lid of the sump (an inverted plastic dustbin lid) to unclog them and, at last, the stream goes on happily for hours without the need for topping-up.


Thursday, August 01, 2013

Evaluation of Deltang radio control system

I've been experimenting for some time with various options for the radio control of my battery powered locos (see How I constructed an 0-6-2T, How I constructed an IP Engineering diesel loco and How I constructed a two car rail motor). I've been trying to find the most cost effective way of controlling them which balances cost against operability.

My first venture into cheap radio control was through the use of a remote dimmer for LED lighting which uses a small keyfob (see Using an LED dimmer for radio control of a loco). Whilst this approach is very inexpensive (overall cost around £5), it does have limitations. At present, I have not found a way of reversing the loco remotely (though this could be done with another keyfob controller) and the control is not particularly smooth.

My second approach was to make use of a very inexpensive 2.4 gHz transmitter, a receiver and a controller designed for use with garden railways (see Evaluating a low cost transmitter for garden railway use). This provided a good level of control but although the transmitter was less than £5, the receivers cost around £10 and the controllers range in price from £30 to £75. A transmitter, receiver and controller is needed for each loco. A disadvantage is that the transmitters are primarily designed for aeroplanes or helicopters and hence the joysticks need to be held in position to keep the loco moving (though the transmitter can be turned off once the cruise speed has been set).

The Deltang transmitter

What attracted me to the Deltang system was firstly that up to twelve locos can be controlled from a single transmitter which has been designed specifically for use with railway locomotives. The transmitter has a control knob an inertia control knob and a loco selector switch. The second attraction was the cost. Once one transmitter has been bought (for around £60 - or as a kit for £25), there is no need to buy another. Furthermore, the combined receiver/controllers cost just under £30.

The receiver/controller

The receiver/controllers are very small in size, being intended for use in 00 or even N gauge locos as well as 16mm and G scale locos. Despite their size, they will handle up to 1.5 amps, which is fine for most of the smaller locos used on garden railways. The designer is planning a version which can handle more amps.

There are four wires attached to the receiver - black and red are for the battery supply (from 3 volts to 16 volts) and the two brown wires connect to the motor.

I use a connector block to make the removal of motor controllers easier, but if you are pushed for space, the receiver/controller could be hard-wired in.

There are several other outputs which can be used - but as yet I have not explored them. These include:
  • Servo control - eg for remote uncoupling
  • Forward lights
  • Reverse lights

Binding

Binding is extremely easy. Firstly the receiver is switched on. There is a tiny LED which indicates the state of the receiver. Initially, it flashes every two seconds as it hunts for a signal from the transmitter. If it doesn't detect a signal after 20 seconds it goes into bind mode which is indicated by a rapid flashing of the LED.

To bind the transmitter, firstly the loco selector switch is clicked to the desired position (eg loco no. 2), the bind button is held down and then the transmitter is switched on - then the bind button can be released. The light on the transmitter flashes to show it is in bind mode and if all is well the LED on the receiver flashes in unison with it. 

After a few seconds the lights on both the transmitter and receiver stop flashing and show a steady light indicating the binding has been successful. The instructions suggest that it may take more than one attempt to bind successfully, but my experience so far has been that binding was OK first time.

Operation

Once each loco has been bound to a particular channel on the selector switch it will only respond when the switch is in that position. Speed and direction are controlled with the large knob at the lower end of the transmitter. I have found that very fine control is possible, though this is dependent on the responsiveness of the loco mechanism. Once a cruise speed has been set for a particular loco, the selector switch can be turned to control a different loco. The first loco will continue on its speed setting until the selector switch is turned back to select that loco again.

The default is for the receiver/controllers to bring the  loco to a controlled stop if the transmitter signal is lost (eg if the transmitter goes out of range or is switched off). However, this default setting can be reprogrammed to enable 'cruise control', whereby the motor will continue running on its setting if the signal is lost.

The inertia control is quite handy. I tend to set it to just under the half way mark. This provides a smooth start and stop and so is much more gentle on the loco's mechanism. The smoothness of the start and stop is dependent on the particular mechanism of the loco. One of my locos (with an LGB motor block) responds very well while another (with an adapted IP Engineering motor and gearbox) is less smooth. However, this mechanism is quite stiff and so may improve once it is run-in.

Programming the receiver

Several settings on the receiver/controller can be reset from the defaults by the user with a standard DSM2 transmitter or with Deltang's own programmer module. I have not explored the settings fully as yet but the following are just some of the settings which can be adjusted:
  • Whether the motor will respond to the single speed/direction knob or a combination of the speed knob and the reverse switch
  • The start and maximum speed setting for each loco
  • The PWM frequency. The default is 60Hz but it can be set to 250Hz. There are also options to set for 2kHz and 16kHz but only for low power, low voltage motors.
  • The time before the receiver goes to sleep if no signal is received
  • Failsafe or cruise (ie whether the loco stops or continues when the transmitter is switch off or the signal is lost)
  • Servo settings (eg for remote uncoupling)
  • Output settings (eg for flashing lights or the momentary or latched switching of accessories

Evaluation

 I have so far tested the system on three locos and a bare LGB motor block. The smoothest and most responsive control is with the LGB motor blocks. The railbus, which has now been equipped with an MFA Como planetary gearbox motor and bevel gears is also very responsive. An IP Engineering diesel loco which has had its gearbox replaced with a homebuilt gearbox is somewhat unreliable. Mostly it responds reasonably well but occasionally it has difficulties starting off in reverse. This may have something to do with the mechanism or may be a feature of that particular motor or may have something to do with the metal body of the loco (my others have plastic bodies). I need to do more extensive testing to determine where the problem lies.

All my locos are powered with 12 volt battery packs. I did find, when trying to power the bare LGB motor block with a 6 volt battery pack that it experienced problems at the lower speeds - sometimes the motor would hum and struggle to get started, even when the speed knob was turned up. This may have something to do with the motor originally being designed to run off 24 volts, though.

I have also tested the system with a small loco designed to run off 3-6 volts. At 3v the system was unreliable, However, at 4.5v there was a marked difference. The motor was very responsive and controllable. The limitation of using the low voltage was that the range seem to be considerably more restricted and the signal more prone to interference from foliage etc. This video gives a brief overview of the system in 4.5 volts (please forgive the crudity of the loco - it was hurriedly built for this test).

On 12 volts or more, the maximum range of the system is said to be around 40 metres in ideal conditions. I have tested the system (with 12 volts) in my garden and found it responds without difficulty from one end of my garden to the other - approx 25m distant. I have not experienced any difficulty with interference from foliage or buildings - at one point my railway runs behind two sheds which are full of metal objects (mower, garden tools, trailer tent, etc.) and so far there have been no drop-outs in the signal. The receivers do not seem to draw too much current. I have accidentally left them on for several hours without any subsequent appreciable loss of battery power.

Overall, I have been very impressed with the system so far. I need to do more extensive and intensive testing, but the units seem robust despite their size. I think the plan to introduce a receiver with a higher amperage rating is a good move. Although most of my locos draw around 1 amp, I would imagine there will be occasions when it would be useful to have a higher ceiling. Price-wise, there seems little to beat this tailor-made system for the radio control of trains at present

 Video Evaluation


Update - May 2016

Since writing this blog entry, I have started producing my own versions of Deltang transmitters. See  http://rctrains.co.uk for more information.