Freelance early steel wagon

[Mike W]

John - the Gauge 3 market is very small, but most of what you mention is not scale specific and probably left from your days of selling metal sections etc? I'd gladly buy 14BA in quantity from you but somebody else may like a wider range.

Jon - A few website now have scanned RCH drawings. The LMS Society is one and here's a typical axle, though later than your period. https://www.lmssociety.org.uk/assets/RCH_1907/RCH_1907_Dwg152.png

Mike

 

[NickB]

Subtract the minimum radius of the tapered portion of the axle from the maximum radius. Divide that by the linear distance between the positions of the two radii. The angle is the inverse tangent (often labelled ATAN on calculators) of that. Or just make trial cuts on a scrap piece of material until you get it right.

Nick

 

[Ian_T]

Jon, the taper is very slight.

Using an RCH axle as an example - the axle tapers down from 5.1/2" to 4.7/8th in the centre - a 5/8th difference. Thats over 50.25" total length "between tyres", so half that in effect.

A quick calculatation gives, if a=.326 and b=25.31 then angle A = 0.74° - it's a very slight taper.

In scale terms you are reducing 6.2mm down to 5.5mm (.7mm) over 28.45mm......you could see this if you looked closely - but would anyone ever do so in practice? Of course you'd know the taper was there!

Regards,


IanT

 

[Pete_S]

From "Railway Carriages and Wagons: Their Design and Construction" - Sidney Stone M.I.Mech.E 1903:




Pete S.

 

[timbowales]

From "Railway Carriages and Wagons: Their Design and Construction" - Sidney Stone M.I.Mech.E 1903:

View attachment 236785


Pete S.

Interesting that they are all different in some way!

 

[Ian_T]

I was referencing a Standard RCH 12t wagon axle - Dwg No 1020 - April 1923.

Regards,


IanT

 

[Bigjohn]

John……I once mentioned to Alan GIbson why he did not taper his axles…….he gave me a very odd look.
My best(?) effort to make the axle in 4 mm rod, then make the tapered part separately before parting off bored to 4mm to make a B to B spacer. Then glue that 4mm rod centrally to complete the axle. Two or four was tolerable before newly invented expletives became necessary.. the spacers might be produced by the 3 D printing brigade. I know nothing of such matters
BigJ

 

[Jon Nazareth]

Thanks to all who replied to this one. I’m going to attempt putting a taper on some brass axles. I’m using brass as it’s easy to machine and, besides, it’s raining today so, no gardening.
Another question. Does anyone know why wagon axles were tapered? It’s such a small reduction that, to me at least, it hardly seems worth doing full size.

Jon

 

[Overseer]

Thanks to all who replied to this one. I’m going to attempt putting a taper on some brass axles. I’m using brass as it’s easy to machine and, besides, it’s raining today so, no gardening.
Another question. Does anyone know why wagon axles were tapered? It’s such a small reduction that, to me at least, it hardly seems worth doing full size.

Jon

At the time your wagon would have been built all axles were parallel. It was found they tended to break near the centre and the solution was found to be tapering the axle to allow some flexibility. The problem is mainly torsional forces due to wheels trying to go different speeds around curves.

 

[Jon Nazareth]

At the time your wagon would have been built all axles were parallel. It was found they tended to break near the centre and the solution was found to be tapering the axle to allow some flexibility. The problem is mainly torsional forces due to wheels trying to go different speeds around curves.

Thank you for that, Overseer.
Ah, that means that I won’t be gaining anything, aesthetically, if I taper them. Mm, more thinking to be done.

Jon

 

[Bigjohn]

I was referencing a Standard RCH 12t wagon axle - Dwg No 1020 - April 1923.

Regards,


IanT

John - the Gauge 3 market is very small, but most of what you mention is not scale specific and probably left from your days of selling metal sections etc? I'd gladly buy 14BA in quantity from you but somebody else may like a wider range.

Jon - A few website now have scanned RCH drawings. The LMS Society is one and here's a typical axle, though later than your period. https://www.lmssociety.org.uk/assets/RCH_1907/RCH_1907_Dwg152.png

Mike

Mike……..14BA, these of any use? They are probably worth £20 more than you are willing to pay. The middle brass are washers. Please don’t ask me to count them. Some more junk added, including some finished bogie wheels.
12BA also available……….john

 

[Bigjohn]

Thanks to all who replied to this one. I’m going to attempt putting a taper on some brass axles. I’m using brass as it’s easy to machine and, besides, it’s raining today so, no gardening.
Another question. Does anyone know why wagon axles were tapered? It’s such a small reduction that, to me at least, it hardly seems worth doing full size.

Jon

Jon…….to avoid wasting brass I have some finished 8mm dia axles. If you let me have your address I will pop a few in the post
to play with, you will have to work out how to mount them in the lathe!!!!!!!!
ATB….john

 

[Jon Nazareth]

Another set of machined Mark Wood’s wonderful wheels. These are for the wagon with the styrene underframe.

Jon

 

[simond]

At the time your wagon would have been built all axles were parallel. It was found they tended to break near the centre and the solution was found to be tapering the axle to allow some flexibility. The problem is mainly torsional forces due to wheels trying to go different speeds around curves.

This is curious. A torsional load would (assuming a constant section) be evenly distributed along the axle, whereas the taper would appear to concentrate the stress at the narrowest section.

From a bending perspective, and ignoring cornering forces, the axle is in four-point bending and thus has a constant bending moment between the wheels. Again, the taper would appear to concentrate stresses at the smallest diameter. I suspect cornering forces are small compared to the weight.

I'm intrigued.
Simon