JULY 1970

By R. A. Ganderton

Part Two

IN THE FIRST ARTICLE in this series we took a general look at starting in Protofour and carried out a rapid conversion on a Tri-ang coach. In this article we will look at wagons, covering most popular makes.

But first, in response to some queries, a few words on electrical connections for those using the Protofour system of track building. This uses a special punched strip of brass riveted under the sleeper so as to make electrical connection to the rail via the soldered joint. This brass strip is then bent downwards at right-angles to pass through a large hole drilled through the baseboard immediately under the rivet. This system has the advantage of being invisible when completed but is rather difficult to carry out in pracice as the large number of holes required must be accurately drilled prior to laying the track. A better method, which I developed for my own permanent layout and later used when wiring our portable layout, Ashhurton (which incidentally does not belong to the Protofour Society with whom I now have no connection), is to bring the strips out sideways, lay and ballast the track as normal and then cut away a small piece of the cork underlay to receive the strip. Drill a No. 60 hole through the base board to coincide with one of the holes in the brass strip. A 20 s.w.g. tinned copper wire "dropper" is pushed through the two holes and soldered to the strip. You are then left with a piece of wire beneath the base board to connect to. The slot left in the ballast is easily made good.  To improve the reliability of the electrical connections do not use Fryolux solder paint on the rivets which are used as electrical connections. Use only a resin-cored electrical solder.  Also solder all the connecting strips where they are riveted to the sleepers. Once the track is laid, any trouble here cannot be corrected without lifting track and ballast.

To simplify matters we will deal with each make individually. 

White Metal Kits. (e.g. K’s, Kenline, etc.) With these kits the conversion procedure is simple. The axlebox holes are the correct size to accept a Protofour pin- point bearing and need clearing out, using a 2 mm.  (or No, 47) drill held in the hand and counterbored, until the bearing goes fully home (see drawing for dimensions). The bearing can be held in place with a drop of adhesive if necessary. Either before assembly or before removing the existing wheels if assembled,   determine the distance between the inside faces of the axleguards. This must be not less than 22.5 mm.  If it is, then the inside faces must be scraped (not scrapped) or filed. If the wagon is already assembled and cannot be dismantled, gently ease apart the axle- guards until the existing wheels can be removed. The axleguards will now be at an angle and can be cleaned out with the 2 mm. drill to accept the bearings. Then gently close the axieguards in again with the Protofour wheels in position. If you are using scale three-link couplings ensure that the buffers are of scale length (6 mm. face to buffer beam), otherwise you will find it impossible to couple to other vehicles. Don’t forget to put the brakes in line with the wheels. When assembling these vehicles, as with all rigid vehicles to any standards, care must be taken to ensure that the axles are parallel to each other. This is easily ensured by assembling on a plate-glass surface. We have not found any need for springing 4-wheel vehicles when working with Protofour standards. What is essential is that all vehicles have a similar axle loading. We have settled on about 2 oz. for a 4-wheel wagon but this is arbitrary and depends largely on the heaviest vehicle in general use.

Airfix. Like the white metal kits these can either he converted before construction or when built, and the method is similar. The raised boss on the back of the axleguard must be removed (sharp knife) and the slot opened out with the 2 mm. drill to accept the bearing. This needs more care than with a white metal kit to ensure that the axles are parallel. Again the dimension between the inside faces of the axleguards must be correct and if less than required scraped with a knife or filed. It is easier with these axleguards to cut a shallow channel vertically behind the axleguard instead of counterboring.  Brake gear should be repositioned in line with the wheels. These vehicles are very light and some lead is needed to bring them up to the minimum weight.

Tri-ang.  With the closed axlebox ends the Tri-ang wheels can be simply replaced with Protofour wheels, as with the coach in the first article. No other work is needed to the axleguards—wherever a pair of Tri-ang (or B.R.M.S.B. EM) wheels will fit so will Protofour wheels, generally, with extra clearance.

Peco Wonderful Wagons.  The Peco brass bearing cups have a larger diameter than Protofour bearings, and so a means of reducing the diameter of the axlebox hole is required. This can be achieved by filing the Peco cup down in length until the bearing touches the end. The bearing is then Araldited into the Peco cup. Before the cup can be re-inserted into the axlebox, the boss on the box will need to be cut away and counter- bored. Some experiment here will determine just how much requires to be removed so as to allow the axle- boxes to be re-assembled into the W-irons with the new axles and wheels. If you have already fitted wagons with Peco cups, then use this system to convert them to true pin-point bearings.

Ratio.  The problem with Ratio wagons is that the axleguards are too far apart as well as in some cases being completely incorrect. This is particularly true of the G.W.R. “Open C" which has MR. grease and MR. oil axleboxes! Here the best way is to fit Ken- line or similar asleboxes and proceed as for white metal kits. The Ratio plastic axleboxes can be fitted with Protofour bearings. but will need to be moved closer together. Like Airfix wagons these are very light and need some weight.

Hornbv Dublo.  These are the awkward ones. I must confess that as yet I have not found a method of converting them to pin-point axles without recourse to sawing off the old axleguards and fitting Kenline ones. If one is going this far it would probably pay to make a completely new underframe for the vehicle. In the next instalment we will take a look at trackwork and start covering some vital motive power.

dwg-1s.gif (2241 bytes)

dwg-2s.gif (1982 bytes)

dwg-3s.gif (1386 bytes)

dwg-4s.gif (1851 bytes)

dwg-5s.gif (883 bytes)

Copyright - R A Ganderton, reproduced with permission.

Back to Magazine Index,  Back to Site Index.

K Norgrove 25/04/03