Heljan BR class 02, conversion to S7

[RichardG]

I managed to acquire £20 in discount vouchers from Heljan when I bought the class 45/0, and so I have bought this as something more suitable for any S7 layout I might build for myself. Yes, £130 for an 0 gauge loco - but there will be work here.


The model has a split chassis within an outer chassis.

The wheels are of plastic with metal hubs, the hubs being insulated from the axles. These hubs run in plain bearings machined into the inner chassis. There are strips of metal across the backs of the wheels (not visible here), to connect the hubs to the tyres.


The keeper plate provides additional electrical connections from the hubs to the inner chassis.

I have never seen so much engineering achieve so little!

My first thoughts turn to making a new chassis and buying a set of Slater's wheels for it. Slater's do wheels for the 02, from the days of the DJH kit. Keep the Heljan side rods but not much else. This would be my first scratchbuilt chassis in 7mm.

Maybe there is a better way?

 

[Rob R]

Richard.
If you are half expecting to scratchbuild a chassis then you have nothing to lose in trying to modify what is already there.
Can't offer any advice as to how because I have not seen one in the flesh.
Rob

 

[RichardG]

If you are half expecting to scratchbuild a chassis then you have nothing to lose in trying to modify what is already there.

Well, I reckon the conversion can go one of two ways. Either re-profile the HJ wheels and pop them back onto their axles a bit further out; or buy Slater's wheels and put them into a completely new chassis.

If I begin with the Slater's option, I would have a chance of selling the original chassis as a going concern. This is I think all I would lose if I try to convert the factory wheelset and mess it up.

I could ponder the longevity of the factory wheels and indeed their bearings, but this isn't really dreadfully important given the kind of layouts the loco is likely to run on.

 

[RichardG]

The model has been created around a large central casting which incorporates the running boards and hanging bars, and gives the model most of its weight. There is no clear-cut division between a "superstructure" and a "chassis".


I have a feeling I could take this to pieces to let me make space to put in a completely new "under-chassis", but the process would be destructive and decidedly one-way.

I can see three approaches:

1) Reprofile the HJ wheels but leave them at their original widths.

2) Reprofile the HJ wheels, including reducing the tyre width to scale. This is a bit risky because I don't (yet) know how much spare metal there is to play with on the front and back of the tyre.

3) Strip the chassis to pieces, possibly mill out some of the large casting, and install something completely new using Slater's wheels and a commercial motor/gearbox in scratchbuilt frames. This would use the original side rods. It would let me have a rocking axle or even CSBs; and better wheels. This could triple the cost of the build if I try hard enough!


4) If I really went to town with new underpinnings and installed battery-powered r/c, the existing access cover on the bonnet could hide a power switch and a charging socket. Battery power would need a very compact motor/gearbox if I was to shoehorn a PP3 battery in as well.

Fairly clearly, I could start with 1 or 2, and I could still try 3 if I wasn't completely satisfied. 4 would probably need a stack of phone or camera batteries to fit them inside the bonnet. Whatever I do, the conversion cannot be reversible.

I do feel, buying a RTR model with a view to altering it does sort out the parts of modelling I don't enjoy very much and am not very good at - like painting and putting on little transfers.

 

[Rob R]

There is an option 5.
Put it back together and move it on.

 

[RichardG]

There is an option 5.
Put it back together and move it on.

Well, the scale width of a loco driving wheel is 3.2 mm and the HJ ones measure 3.8 mm. If there isn't enough meat to slim down the HJ tyres, it is very difficult to justify the amount of work in option 3 to lose that 0.6 mm. I could still create a model which is S7 compatible if not quite compliant.

I risk feeling weary if I "move on", because this is my fourth attempt. There was a kit, for which I entrusted the wheel turning to a person who decided they couldn't be bothered. Kit and wheels sold. A Heljan 48DS, which seemed too simplistic to try and was returned for refund. A Bachmann Brassworks class 04, which seems too beautifully original to alter. And now this.

So move on to where? Perhaps a kit. The right wheels from Slater's and some broader frame spacers would make building a kit look more predictable. This takes me back to where I was a year ago.

The 02 is back together and running, but I need to sort out the rear buffer which fell off and the front step which was crooked and I pulled off. As evidenced in the photos in my last post.

 

[Yorkshire Dave]

Could you not look at reworking the chassis to accept Slaters axles and wheels using top hat bearings. It looks possible from the photo but I don't know what the dimensions are nor the clearance available for this. It would mean losing the split frame pickup and fabricating new wiper pick-ups.

It is also possible to make Slaters axles for use in split frames (these are links to a website I was part of).
Split axle pick-up in 0-gauge, Page 1
Split axle pick-up in 0-gauge, Page 2
Split axle pick-up in 0-gauge, Page 3