4mm Wagon Suspension systems

4mm Wagon Suspension systems

Why is it desirable to have some sort of springing?  Even if your track is perfectly flat, some flexibility between the axles of a wagon, bogie or locomotive is desirable.  The wheels of an axle are coned so that if the axle tends to one side it rides up onto a larger diameter, whilst the other side rides down onto a smaller diameter.  This means that so long as the wheels are fixed to the axle (unlike the old Triang system) and rotate at the same speed, then the wheel that has ridden up will tend to run ahead of the other one and the wheelset will turn so as to bring it back to the centre of the track.  On straight track this results in simple self centering of the axle.  On curved track, the same action will occur except that the axle will stabilize off centre so that it follows a curve to match that of the track.  However to do this the axles of a wagon must be free to lift and drop relative to one another.  

As the relative movement between the axles is very small you may wonder why the natural slop of the wheel bearings won't be enough to allow this movement to take place.  Well the movement will occur, but if the vehicle is rigid, then the load will transfer from 4 wheels to 2, and as sson as that happens the two unloaded wheels will cease to steer themselves or the wagon, and theoretically the system ceases to work.

But in practical terms, most rigid models do not fall off the track even though they have a less than perfect setup as indicated above.  Well is that true?  A simple derailment is easily put right and is soon forgotten.  However if you watch a few exhibition layouts, it is surprising how some seem to have many derailments and others none...You will also notice that whenever a derailment occurs some of the audience will drift away.  But some operators become so accepting of the poor performance that the become 'blind' to it.  I have even seen a fascinating video of 'The largest Model Railway in the World (MinaturWunderland in Hamburg).  In this they devote a whole section showing how the operators reach the layout through trap doors to rectify derailments.  They appear to accept that derailments are a natural part of the trainset, and make no effort to prevent them.  But in fairness the layout is so vast that they have had to accept proprietry trains and rolling stock as part of the compromises of size.  But do you have to accept second best running?

Of course if the complication of the wagon springing is not adjusted properly, it may be worse than no springing at all.  I built an 0-6-0 locomotive about 50 years ago, in pre-P4 days, which was so badly set up, that when the power was applied, the first thing that happened was that the leading pair of wheels derailed.  The combination of one coupling rod pulling while the other pushed on a wheelset that was only located by the spring wires from the bearings of the centre axle just caused the whole axle to twist about the longitudinal axis.  I went back to rigid chasses.  So it is important to use a spring system that works properly - even on dead flat track.

Looking at the other positive gains from a good springing system, you can happily apply cant (or super-elevation) to your curves with no ill effects, even on long wheelbase vehicles.  And apart from good running, most spring systems smooth out the running, so that on less than perfect track - such as private sidings etc. you can lay your track to appalling alignment (like the real thing) and still have fun in operation.

 


4mm Wagon Suspension systems

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Product no.: 40085

Modern wagons, since the late 1930's some railway companies started to adopt a plate form of W-Iron in place of the W shape favoured by the GWR and the Railway Clearing House.  This design was perpetuated by BR.  No-ne seems to know why the 2 holes were formed on either side.  No prizes but I would like to know.!

£5.40

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can be shipped within 14 days

Product no.: 40101

In this system, a plate is fixed to the underside of the wagon floor, and a longitudinal wire carries a pair of standard W-iron etchings.  These are spaced to the correct wheelbase by means of jigs (40104) through the bearing holes.  Further wires are added between the w-irons, and the plates at the opposite ends.  Thus the two axles are sprung relative to each other, and to the body of the wagon. 

Each packet contains 8 baseplates and 4 lengths of 0.6mm dia wire. This is enough for 4 wagons. You will require rocking type W-irons (40105) or (40107), wheels and bearings. The assembly fits on the wagon floor between the solebars. Brake gear is not included.

Various etched W-irons may be used.  However I have produced standard W-irons and Inset W-irons, see below. 

£3.30
Delivery weight: 15 g

In stock
can be shipped within 3 days

Product no.: 40105

The standard GWR/RCH pattern W-iron with fold-up bridle and holes for longitudinal pivots.

£5.40
Delivery weight: 21 g

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can be shipped within 3 days

Product no.: 40107

These are for use where the model uses plastic to represent iron or steel solebars. Hence the distance between the solebars can be as much as 2mm less than is available for standard W-irons.

£5.40
Delivery weight: 21 g

Still in stock
can be shipped within 3 days

Product no.: 40104

The kit contains 2 sets of brass jigs together with 4 No. M2 nuts and bolts. The jigs may be soldered together for strength or used as they are.  They have holes in them at 3 and 4mm intervals so that they may be used to set almost any wheelbase between 6ft and 22ft. going up in 3in increments.

£2.15

In stock

Product no.: 40102

This chassis uses the unique torsion springing system which relates axle to axle and is independant of body weight. It is suitable for 00, EM and P4 standards (Wheels, cosmetic springs, and axleboxes are not included). Since body lengths vary and solebars are of different depths and detail, the chassis leaves the solebars and buffer beams to be part of the body. Originally this fret contained a set of brakegear. However I decided to thicken up the chassis from 0.25mm to 0.38mm for strength, so the brakegear has been transferred to a separate product.  Furthermore the chassis will carry either the standard RCH lever operated brakegear - independent or Moreton, or will carry the Dean Churchward design of self adjusting brakegear as used on the Great Western and some of the Welsh railways.  Note that this chassis now comes in a number of wheelbases.   Different gauges, either 00, or for P4 and EM, require different location pins so as to fix the brakegear in line with the wheels.  Location pins are provided for both settings on this fret, those which are not required may be removed.

£4.30
Delivery weight: 20 g

In stock
can be shipped within 3 days

Product no.: 40098

This chassis uses the unique torsion springing system which relates axle to axle and is independant of body weight. It is suitable for 00, EM and P4 standards (Wheels, springs, and axleboxes are not included). Since body lengths vary and solebars are of different depths and detail, the chassis leaves the solebars and buffer beams to be part of the body. Originally this fret contained a set of brakegear. However I decided to thicken up the chassis from 10 thou to 15 thou for strength. So the brakegear has been transferred to a separate product. Note that this chassis comes in a number of wheelbases.  different gauges, either 00, or for P4 and EM, require different location pins so as to fix the brakegear in line with the wheels.  Location pins are provided for both settings on this fret, those which are not required may be removed.

£4.65

In stock
can be shipped within 14 days

Product no.: 40088

RCH/GWR design W-irons for use with 3ft 6ins diameter wheels.  Used on 4-wheeled coaches where the axleheight is 3ins (1mm in 4mm scale) and passenger vans, such as some Newspaper vans, Fruit vans and Meat vans.

£5.40 / unit(s)

In stock

Product no.: 40086

These plate type W-Irons have an inward step at the top so as to give clearance between the solebars.  Thus the gap is reduced from 24mm to only 23mm.  This should be check before the W-Irons are fitted.

£5.40
Product no.: 40087

4 - wheeled coaches, baggage vans as well as mild and newespaper vans usually have 3ft 6ins wheels for fasrer running.  Thus the axle height is 3 ins higher than for a normal goods wagon.  In this case it is 1 mm higher but may also need some packing to the underside of the floor.  However the top plate of the W-Iron has gaps left in it so as to avoid .the flanges touching the plade and possibly causing short circuits.

£5.40

In stock
can be shipped within 14 days