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Wagon axles, and wheels with a bit more finesse.

Started by MikeWilliams, Feb 01 2022 20:09

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MikeWilliams

I have a bee in my bonnet about Slaters axles and how nice they would be if correctly tapered.  By a chance encounter I've just received a price for a batch of replacement axles.  In brief, tooling and set up (the CNC programming) is about £200 and the axles then £2 each.  For 100 axles that means £4 each, or £8 per wagon.

Personally I think that is too much just to get the taper which it would be possible (though tedious) to do to the existing Slaters axles.  What do others think?

Several people have commented how chunky Slaters wheels look and I'd love to find something more finescale in appearance.  Tapered axles may be feasible as part of that but at present I've not found a nice way to make wagon wheels for less than three times the cost of Slaters.  Cast iron is one option but Mark Wood castings cost £42 per wagon set, plus machining (which is beyond most G3 modellers) and plus axles so probably £60-70 total, when Slaters cost about £14.

I suspect a cast brass centre with turned tyre and then bore for the axle after assembly would be cheaper, but is it worthwhile?  I know most people will always be very happy with Slaters wheels, but David White isn't getting any younger and it would be nice to have an alternative.

What do others think about the axles (and the wheels), please?

Mike

Nick

I agree with what Mike says about the appearance of Slaters wheels and axles. I personaly would pay the extra for tapered axles, which doesn't seem much in the context of a decent wagon, and very little in the context of one of Mike's 6-wheel coach kits.

The wheels themselves are a more difficult problem, but it might be worth investigating 3D printing for the centres using a hard plastic such as PA11 or PA12, which are basically Nylon. I'm told, but can't verify, that Slaters wheel centres are glass-filled PA12, but injection molded (with much higher set-up costs) rather than 3D printed. These materials can't be printed on machines sold for amateur use, but there are a number of companies online offering their services, and who will give an instant quote based on an uploaded STL file.

I've used these services and materials several times for loco fittings and have been impressed with the results. I am currently investigating this as a route to loco wheels for my own use, and I will report back in due course (but it won't be very quick!).

Nick

753

Mike
Regarding tapered axles, it would not be difficult to turn the tapper in a lathe.
Turn a female cup to take the axle for the tail stock, set up the axle one end in the three-jaw chuck and the other end supported in the tailstock cup.
Set over the top slide to the required angle cut one side of the taper, swap ends and turn the other taper. Once set up it would not take long to machine 50 axles.
Whilst I and many others go to extraordinary lengths to create models to emulate the prototype, I am of the school of if you can't see it why worry!

Mike

John Branch

You live and learn!  It had never occurred to me, nor have I ever seen reference before to "Tapered axles".  The tread cone angle, yes, and from a quick look at a pair waiting installation, Slaters  reproduce this.  But what use is a tapered axle?  Years of haunting railway preservation society yards littered with wheel sets of all descriptions have not revealed this design feature to me. What is the angle, and over what length of the axle, I presume it varied from company to company, and century to century, with Brunel's being hyperbolic rather than linear?

I agree that Slater's wheels can appear a bit clunky, but this can be minimised by painting the tyre sides to match the centres.

I personally find that £15 a set just about bearable, any more and I'm back to G1!

John

MikeWilliams

Thank you for the response so far.  Confirms what I suspected.

753Mike.  You are absolutely right, but when you start saying "topslide" that's me out.  My late is a small instrument lathe with tool holder.  Maybe I'll explore the possibility of somebody altering a batch of Slaters axles by hand rather than a new CNC batch.

John.  Almost all axles were tapered and both railway company and RCH drawings I've seen so far show a very similar taper - about 1.25in smaller in the centre.  But I agree they are not for most people.

Nick.  One concern is the strength of any plastic when the spokes have maybe 1/3 or 1/2 the cross section of those on Slaters.  I have done a few loco wheels (too expensive for a wagon) the old fashioned way - 3D CAD, solid print, lost wax - send the waxes for casting in iron.  Works well, but then I'm a luddite!  Mike above makes a superb job of milling in aluminium.  Attached is a wax for a 5ft 2in wheel.

Mike

cabbage

I was always told that the conical tapering of the axle between the wheels was to do with lightness and resonance.

Regards

Ralph

richardgreen

Evening everyone . my first post on here, Re the view on Slaters wheels , firstly , id like to thank Slaters for supporting Gauge 3 and producing quite the range that they do for this scale and gauge and also i cant think of another manufacturer that id rather have producing wheels, yes it would be lovely if Mark Wood could produce wheels to those beautiful standards he does as cheaply as Slaters do but you cant have everything can we!
To answer your question Mike i think one of the visual problems is the massive flange depth necessary to keep them on the rails . When you look at how shallow the depth of a flange is in real terms ie 12" to the foot , this obviously cant be used but certainly helps the look of the wheels even if its a static model.
Some of the really ancient wagon wheels ive seen look like the actual tyre is the thickness if a stiletto heel , again it would make it look better but not as durable maybe???

Rich.

Nick

Oh dear. Having lived through the "scale war" in 7mm when ScaleSeven started up, and 4mm before thatn I hope that G3 can be spared, not the discussion which is good, but the rancour that accompanied it. Yes, the G3 flange depth is overscale. Instead of 2mm it should be more like 1.4mm for most 20th and 21st century prototypes, and in some cases less than that.

One good reason for keeping it overscale is that many G3 railways are outdoor which almost inevitably means that the trackwork isn't ideally flat and a scale flange increases the chance of derailment. Turning my own wheels, I can make the flange dimension anything I like, but I decided to keep it at the G3 standard because I have no plans to build my own layout, indoor or outdoor (life's too short). Therefore I have to rely on what I find elsewhere in the way of trackwork, and I'm grateful to those who share their layouts.

Nick

cabbage

Ok this is where I get the screwed up crisp packets and beer mats thrown at me!!!

I cut my owm wheels, preferably from mild steel bar. I always cut them with a 2.3mm flange depth and 8mm thick. I never lnow when I spin a batch of wheels wether the axle will be sprung or not.

Here I depart radically from the G3 spec.

I prefer independently rotating wheels.

This means that a pair of rollar races sit  inside the wheel hub and the axle stays still. I also gauge widen my curves on the inside. This allows a lower draw load.

It has been independently tested by TGO and proven!

The question of wether to use 2mm or 2.3mm is not really a viable one. I will continue to use 2.3mm. I would far rather be accused of having fat flanges than a derailing loco injuring a child...

Regards

Ralph



MikeWilliams

Oh dear.  I really didn't want to suggest a variation from standards. Like Nick, I remember the squabbles in the smaller scales, some of which continue to this day.  I also count the late Ray Hammond (S4) and Ken Cottle (P4 & S7) among my friends.  One problem with G3 standards is that the gap at crossings is so wide that wheels can drop, especially at the more acute angles you get with large radius curves - the very curves associated with high speed where derailments are more serious.   It is common to fill the gap on these crossings so that stock rides on the flanges.  Dreadful though that is as an engineering solution, I would rather live with that than start a scale/gauge/standards war!  But it does mean that all flanges should be the same depth to prevent a kick.

Mike

cabbage

Mike,
My alterations to the std are more for my garden curves than anything else. This allows the wheels to take far smaller curves than simple "coning" would allow.

Regards

Ralph