Ride On Railways

Wheel Set Assembly

The wheel and nylon gear need to be fixed together. This can be achieved through several ways but for strength and ease of disassembly, (in case it needs to be replaced) we recommend bolting it to the wheel.
To avoid distortion when bolting the gear to the wheel, we provide a spacer piece. The spacer also acts as a template for drilling three 5mm holes through the gear. You may need to slightly file the the leading edge of the centre hole but it should fit pretty snuggly in to the recess of the gear for drilling.

4 of the 4" wheels should be supplied with centering points for the gear bolts.
Drill 3 no. holes on 4 of the wheels to take a 5mm tap (4.2mm). Drill straight through the wheel. If you are confident at tapping threads then you may not want to drill straight through the wheel but for most of us it is easier to tap a thread in an open hole. The hole in the outer face of the wheel can be filled later before painting.
Using a 5mm tap bit thread the three holes in the wheel.

Left- mould mark on the Delrin wheel. This face goes towards the wheel/spacer. If the hub has not been cut, remove this side using a hack saw. Cut to roughly the same as the edge face of the gear teeth.

Press the spacer piece on to the gear, making sure it fits flush against the gear and the holes line up. File if necessary. Now loosely bolt the gear to the wheel. Do not tighten the bolts until the axle has been inserted. This will help make sure the Delrin gear is central on the wheel.
Degrease the centre of the wheel and one end of an axle. Smear both the wheel centre and axle shoulder with Loctite 603 and press together. At this point check to make sure the axle is pushed home. Back to back of wheels should be 119mm.
Once you are sure the axle is correct, tighten up the bolts on the gear. Do up fairly tight to avoid them coming loose. If in doubt apply bearing fit to the bolts - which can be applied from the face side of the wheel.

LEFT IN FOR REFERENCE FOR PRE 2005 MODELS

Keying in the wheel

While some manufacturers don't key their wheels on we would thoroughly recommend it, especially given the amount of power going through the wheel sets. To achieve this you will need to file a flat spot in the wheel centre and a corresponding flat spot on the axle.

The flat on the axle needs to extend past the wheel so a wedge can be driven in. See picture on the right.

Using a piece of 1mm steel strip cut a 15mm long piece and file one end down. Continue to file until it fits tightly in the slot between the axle and wheel and lock the two together. Now take the wheel off the axle, clean the all the surfaces with a grease free cloth and apply thread lock to the axle and wheel.

Assemble and align the slots. Apply a small amount of thread lock to the slot then drive the wedge into the slot.

NB the threadloc may be oil tolerant, but a clean surface will give a much stronger bond.

One of the problems is how to strike the top of the wedge. For the first 3 wheels you can use the fourth wheel as a hammer. Use a pair of fine nose pliers to stop the wedge from bending (rather slow it down, as it wil bend).

For the last wheel follow the instructions below.

Drive in using a flat piece of steel or a balster chisel with a sharp flat edge. Once it has gone in, cut leaving around 2-3mm proud. If the key moves while you are cutting it then it has not been driven in hard enough.

Using a large flat bladed screwdriver (or the balster chisel) drive in the wedge the last couple of milimetres. Leave to set before filing flat.

The picture to the right shows 3mm projection of the key. Using a flat ended screw driver this was hammered in flush.

The above procedure is repeated for the other wheel once the motor assemble has been slid on to the axle.

Before fitting the other wheel make sure the bronze bushes are well oiled before applying threadloc to the wheel. This should stop any stray threadloc from sticking the motor mount bush to the axle.