Bill Bedford Models Mark 1 Coach Bogie

John Brighton

1 Introduction

With the introduction of the new Bachmann Mark 1 Coaches came the opportunity, long awaited, to provide our EM gauge model of Millhouses, Sheffield, with the coaching stock it needed. We run a four track main line with scale length trains up a 1:200 gradient, 30ft frontage at scale speeds and timings so good free running stock is essential. One additional requirement was the need to be able to run down 1:47 on 3ft radius and up 1:100 around 180 degree turns again at 3ft radius.

The first thing we found was that the clever idea of Bachmann's to use close couplings caused derailments on the downhill sections so they were changed to Kadee No 5 couplings. Over the years we have tried all makes of wheels but we have now standardised on EM RP25 coach wheelsets from Branchlines of Exeter. They have proved very good in service and gone are the days of tyres falling off, wheel wobble or out-of -gauge problems, plus the added bonus of a serious reduction in derailments. One added bonus is that these wheelsets have a one-sided live axle so future coach lighting projects are going to be that much easier. As time passed, and a lot of running, (120ft circuit for each of the 4 tracks) we noticed some wear in the bogie axle bearings and consideration was given to installing new bearings in all the bogies to improve free running and eliminate wear.

2 Development

At this time ideas bounced around the Scalefour Society on the use of sprung loco, coach and wagon wheels were coming to fruition and so I was pleased to be asked to trial build a new Mark 1 sprung bogie etch from Bill Bedford Models. After assembling the first test etch and fitting it to a coach I was astonished at just how far it free-wheeled with one push. To give you some idea, an unconverted coach was pushed free up the layout and it travelled some 20ft; the same coach with the same force of push was still going strong after 80ft and had to be stopped! The really interesting thing was that on the steeply curved downhill section normal coaches would sometimes derail, as they would on some of the diamond crossings at that speed, but these sprung bogies were rock solid all the way round. The demonstration caused quite a stir amongst those attending the area group meeting that week. So a report with a few suggestions was passed back to Bill together with potential orders of some 60 or so coaches worth of bogies. The second test etch has now been made up - it is quicker and easier than the first with equally good results. So, with just a couple of minor points needing fine tuning, the first production batch of bogies will be available by the time you read this.

3 The Kit

Bogie Fret

The kit now comes complete with everything you need to enable you to sit down the evening you purchased it, build two sprung bogies and have them fitted to your coach. Included are etched brass parts with good clear easy to cut tabs, 8 Markits waisted bearings, 4 spring wires, and instructions. Some may wish to change the wires to softer or harder ones after experimenting with the ride qualities but this will very much depend on the type of coach and its weight. The instructions are clear, with exploded diagrams plus a few words of explanation.

4 Tools and Equipment

Tools used

Whenever I read kit reviews I get quite cross when the author includes the phrase "from my scrapbox" or "using my milling machine" as part of his building. It is at this point that I stop reading because most builders do not have the part that the author has kept hidden away for the past 20 years! So it is with tools and equipment. I was once told, whilst giving a demonstration at Scaleforum "I don't have that kind of equipment at home, so what you are doing is irrelevant to me". The picture shows what I used in this project and the sources I obtained them from. There are other suppliers of course but I show and name them for those who work alone and may have difficulty in this area. Firstly there are the Xuron brass fret shears; I use nothing else for simple, untwisted cutting out of brass parts. Then a pair of square nosed pliers for holding bending, hard wire cutters for the spring wire (do not try cutting this wire with anything else as you will end up with notches in the cutting jaws!). Next a small flat smooth file for cleaning and dressing plus a half round needle file for use on cleaning up the brakes. Finally stainless steel tweezers for holding and prodding. A syringe of solder cream from C & L Finescale, hard steel wire (if required) from Eileen's Emporium (who also supply all the tools mentioned), and the wheels, available in all gauges, from Branchlines of Exeter complete the requirements. As with all soldering do ensure you use a soldering iron of sufficient wattage for the job in hand.

5 Preparation

As with all modern brass etching the trick is not to handle it with dirty or greasy fingers, so wash your hands carefully first. Cutting out is easy using the shears and you see here the result prior to any further cleaning up. Use the smooth flat file to remove any parts of tabs that may be left.

The tabs have been arranged not to coincide with any mating edges, so the removal of the tab stubs is a cosmetic matter only. Most can be left in situ without detriment to the final model.

Parts removed from the fret

I show the parts all cut out here for the benefit of this article but I would advocate only removing them as you need them, you are sure to pick up a small part on a jumper sleeve and deposit it along with the contents of several boxes that disappeared the same way in the carpet over the years!

I would reinforce this. The location of parts on my frets is important in identification of the part. Removing them all from the fret all at once could result in a unbuildable kit.

6 Building

The first stage involves folding up the main body, as shown, reinforcing the folds with a little solder.

Tools used

This is where the solder cream and syringe really come into their own. By injecting a small blob of solder in the folds and running a hot soldering iron along the outside of the fold you will see the solder melt and flow along the crease. Simple, clean, tidy with no separate flux. It is wise to check that the brakes fit into the slots left to take them before soldering up and also to take care not to swamp the spring holes in the bent up corner tabs. Fit the centre stiffening cradle on the underside and the pivot mounting plate on the top. Gently lift the small square tab on the stiffening plate ready for the spring wire to be slid past. Once you are happy that everything fits and is square, run a little solder along the joints then fit the brake shoe overlays and 0.5 mm wires between them.

Brakes in place and soldered

Wash it thoroughly using a proprietary surface cleaner and an old toothbrush, rinse well and set to dry. (Avoid soap or dish washing liquid because these often contain lanolin, which may affect your paint adhesion later), I use Halfords spray Surface Cleaner as the final operation prior to painting. There has been no additional cleaning up of solder on the bogie you see here, just one advantage of this modern new solder cream.

7 Springing

The small spring/bearing retainers can now be made up, they are simplicity in itself. Just place a small blob of solder cream on the etched recess, insert the bearing, turn it over and apply the iron.

Soldering the bearings into the bearing carriers is not recommended. It is better to fit the bearings with a weak adhesive such as paint, (nail) varnish or gum. see below.

Again you will see the solder flash round the bearing and the job is done. Bend the centre tab out a little and insert the spring wire in the etched grooves, crimp up the tabs and repeat so you have two bearings on one wire.

Spring with bearing carriers in place

Insert one end of the wire into the hole in the corner tab and by springing the wire upwards in a bow insert the other in the opposite corner. When released the spring will straighten up and you can squeeze it into the gap in the centre retaining stretcher and close the small square tab that will hold it there. Twist the bearing retainers into position so the bearings are free to ride up and down in the etched slot.

Spring and bearing carriers in place

Check that everything runs freely and give it a push up the track. I used it to check whether the kitchen worktops were level. they weren't!

Completed bogie without cosmetic sides

8 Fitting & Height Adjustment

When fitting to the Bachmann coach you first have to remove the forward projection on the pivot post, use a sharp craft knife and clean up. The new bogies can then be attached using the same fixing screw and checked for ride height.

Checking the ride height

Mine were OK first time but thin spacers are included if any shimming to height is necessary.

There are no shims for the Bachmann fitting. There is however a secondary suspension system.

Do not over tighten the fixing screw as it will restrict the free movement of the bogie. Otherwise that's all there is to it. In this picture the Branchlines wheels have been chemically blackened using Birchwood Casey brass black (again available from C&L Finescale). Cosmetic side frames can now be fixed in place; the ones I shall be using are by MJT, cast in white metal and very nice they are too. Some may prefer to cut down the Bachmann frames and glue those over but it does bring the overall width out a little too much. For those who enjoy fiddly bits and pieces I understand there are also etched sides that could be added, but for me life is not that long.

9 Running & Conclusions

On test the use of this bogie has improved beyond expectations the running and road holding of an already excellent product and I can recommend this kit to the beginner or experienced modeller alike and irrespective of your chosen gauge or make of coach.

During the early production of the kits it was discovered that the bearings varied in depth considerably. Some axles worked well while others had an unacceptable amount of endfloat. Because of this the bearing carriers have been redesigned to make adjusting the endfloat easier. If you have bogies similar to the ones in the photos the endfloat can be controlled by gently squeezing the sideframes until the axle rotates freely but does not move laterally across the bogie. The later bogies use washers between the bearing and carriers to take up the endfloat