Trojan Construction Tips

Disclaimer What follows are a few things I discovered whilst building my Ride on Railways Trojan. Please note that these are my personal observations and tips and are in no way sanctioned by Ride On Railways. If you wish, use these alongside the official Trojan instructions. However, if you do not follow RoR's instructions do not go back to them if something goes wrong.
Since I started this list of tips, Paul Middleton of Ride On Railways has modified the instructions to clarify some of the areas I had trouble with, the revised instructions are much clearer.

Sourcing materials & tools:

If you are having trouble finding Loctite 603 and taps etc., try Compass House, they supplied me and are quick, friendly and reasonably priced.

Want potentiometers and switches for modifying the hand-controller? Try Maplin Electronics.

Cutting bolts to length:

If you use a hacksaw to cut a bolt to length you will damage the thread. Here are a few tips that might help:

  1. Put a nut on the bolt, screwing it down the bolt past where you need to cut it. (It can be useful to use the edge of the nut as a stop to put the saw blade against to get started)
  2. Measure and cut the bolt.
  3. File the cut end smooth.
  4. Undo the nut. As you wind the nut over the cut end of the bolt it will restore the thread.

Soldering axle bushes:

When using a gas torch to heat up the bushes for soldering, you'll need to know when it is at the right temperature for the solder to melt properly. This is actually easier than you might think. When the temperature is right, the flame around the bronze bush will change to a green colour.

Fixing gears on to motor shafts:

Wear safety glasses when doing this

Paul Middleton at Ride on Railways openly admits that this is one of the most difficult jobs in building a Trojan - he's right, it is a real pig. Paul has since updated his instructions, but I'll still include the following tips.

The construction information for Trojan on RoR's web site recommends 1mm drills with a note that 1.5mm might be better. I tend to agree, and I used 1.5mm. You are going to need several 1.5mm drills as I assure you you will break some.

 Hold the motor in a vice at the end where the casting is as it is stronger there. Only tighten the vice enough to hold it firmly. Over-tighten the vice and you risk crushing the motor.

The main problem is that  when you try to drill between the gear and the shaft the rotation of the drill bit will try and turn the motor shaft inside the gear. To try and get over this, run the drill faster than you might normally. High Speed Steel drills of this size can safely be run at pretty high speeds - in fact they should be.

Once you have cut the motor shaft to length file a small V groove in the end of the shaft (as in the first picture) to centre the drill so that it doesn't tend to wander.

There is no way of locking the motor shaft from turning, but a pair of pliers is sufficient to stop the gear from moving.

It is important to keep the drill parallel to the shaft of the motor. This is not easy and it might help if you can have someone standing alongside you to keep an eye on your progress.

If the drill snags it will break without warning. You can pretty much guarantee that you will break several drills whilst doing this, but you will need the shanks for the pins anyway, so don't let it bother you.

Once you have drilled the hole, take the gear and the spacer off the shaft. Rest the edge of the spacer on the shaft, put a drop of Loctite 603 on the shaft and slide the gear back on (the spacer is there to stop the gear going on too far, but can easily be removed later). Insert the shank (i.e. blunt) end of a broken drill in the hole and tap it in with a hammer (no need to thump it hard). Tap the drill at right-angles with the hammer and the remainder of the drill will break off clean - or it should. Remove the spacer and leave the motor on its side for the Loctite to harden.

Assembling wheelsets:

Be very careful when fixing wheels on to axles.

It turns out, though I didn't notice it at the time, that when I put one wheel on it was not completely seated on the axle shoulder (goodness knows how, I was careful). Net result that the wheel is wide to gauge and to top things off, wobbling too. Now this is not much, but it is enough for the rear face of the wheel to stick on the motor mounting stud - even though it is trimmed off level.

I have tried moving the wheel and it won't budge - Loctite sure does its job. Paul has suggested that I heat up the wheel/axle joint with a blow lamp or gas torch as this should loosen the Loctite. If not, I will have to cut the axle out and remove the wheels some how. I originally thought I'd have to build a complete new wheelset, but Paul thinks that worst case I'll have to buy a new axle.

Assembling the axleboxes:

The instructions are not too clear on how to assemble the axleboxes, springs, etc.

Fit the axleboxes on the axles with the wide portion towards the wheels. You will need some 10mm washers between the wheel and the axlebox to prevent too much side-play.

Place the axle guide over the axlebox. Note: In this picture the axle guide is the wrong way up. The rounded-hole end goes at the top (bottom if the chassis is upside-down as it is here).

Insert the spring support with the tab on the outside over the spigot on the chassis.

Place the bottom of a spring on the spigot and force the top in under the axlebox (these can tend to "bite" back).

In this shot I still need to fit the bolts.

 


Wiring up the motors:

The Trojan instructions recommend putting in one wheelset with the gears to the left, the other to the right. That is fine, but because one wheelset is the other way round if you wire all of the reds together and all of the blacks together one wheelset will run in the opposite direction to the other!

What you need to do is to keep both reds and both blacks for each wheelset together but then wire red from the front wheels to black from the rear and vice-versa. The easiest way to do this to avoid confusion is to swap red and black over on the terminal block for the leads to the front motor.

[ author: John Oxlade | last updated 26th Oct 2002 ] [ HOME ]