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.


Unknown said...

Hi i use dvd motors for my 1/24 trains with a beltbdrive to a reduction gearbox made from heavy duty nylon gears from technobots. I use hard foamex for the gearbox and pressed ball races in. 100 percent reliable.quick and easy to make. My deltic has done over 10k scale miles! An no noticeable wear on gears or belts. Thats with a heavy load and mostly flat out running up and down 1/40 gradients . Its always best to over engineer when it comes to gearboxes. Plus not having a worm drive means you can tow the loco with another if its dead.

GE Rik said...

I've always been a bit wary of belt drive - concerned about the belts slipping when hauling heavy loads and how to get a decent reduction ratio in the space available. The advantages seem to be that there is more leeway in aligning the pulleys than there is with gears, where even a fraction of a millimetre can make a difference. Given your experiences, I may explore belt drive on my next build - any tips would be welcome.