Nick Dunhill's 7mm W (A6) or Whitby Tank Workbench

[Nick Dunhill]

Yes, yes, yes, you're all right and have beaten me into submission. I'll rectify later in the week.

Mutter mutter mumblemumble

 

[Elliot 84A]

As Nick's contact at the North Eastern Railway Association I've been discussing the matter of the D section with him and have been able to provide this cross section of the wheel taken from the 1 in to 1 ft GA of a NER Class C, which uses the same driving wheels as the Class W. No doubt Nick will post his solution to the oversize hump shortly.

Tom.

View attachment 114640

This is a render of the CAD I did for the F5 wheels a couple of years ago, shows perfectly the hump in both the rim and the boss, quite a nice wheel if I'm being honest

E.

 

[Brian McKenzie]

Elliot's superb CAD render has rendered this CAD redundant. But further doodling over the plan image uploaded by Tom, suggests in the absence of full dimensioning, the "hump" is radiused at something like 1-1/8"

What seems a little odd is that the casting parting line required for the rim is offset from the fullness of the spokes by 1/2"

 

[Elliot 84A]

Nick,

This is a section through the wheels and a snip off the works drawing, hopefully this helps along with Brians sketches

 

[Nick Dunhill]

Done!

 

[Tim Watson]

Subtlety is everything in model making! Just the job.

Tim

 

[Elliot 84A]

They've come out really well Nick, must've been bloody fiddly but worth the result. This was a test machining of the F5 wheel I did a couple of years ago, I think with a coat of paint yours will look spot on

E.

 

[Nick Dunhill]

I DID NOT KNOW THAT........

So, I bought Slater's wheels for the above, and they duly arrived with their (Martin Chuzzelwit, still imperial) 3/16'' axles. Silly me assuming I'd recieve bogie wheels with five thirtytooths (really guys?) diam. axles in the Finney style and made the bogie axleboxes accordingly. What would I do, I know ring DLO Smith who has forgotten more about engineering than I'll ever know.

The result ''Just turn them down...'' So he did just that for me, as I don't have a lathe. So to summarise you can turn down a standard 3/16'' axle to 5/32'', it knocks the corners off the locating squares on the ends, but they still locate perfectly.

Thanks very much David. (I suppose after Brexit we'll have to start using chains or furlongs or something, thanks for that!)

 

[Scale7JB]

That's given me an idea...

JB.

 

[Nick Dunhill]

.....here we go fitting up the wheels and checking it'll go round a 6' rad curve. It is mahoosive......

 

[Nick Dunhill]

And with bogie.......

 

[Nick Dunhill]

Ready for the show.....

 

[Nick Dunhill]

.....brake system now fited up, and since this pic was taken the sanding pipes too.

Just the motion to fit up (it's already assembled on an axle and just needs aligning with the outside cranks and soldering up).......

 

[P A D]

Superb Nick.
I like the crankpin nuts with the cotter pins. Did you make them or are they castings?

Looks like you've got the coupling rods on upside down, but then we've all done that putting things back together for the photos.

Cheers,
Pete

 

[mickoo]

No he hasn't, they're a double boss design, nearly caught me out when doing the etch artwork lol.

 

[P A D]

Yeah, I can see that Mick, but isn't that a cork I can see on the top of the boss?

 

[mickoo]

As far as I know theres a cork on top and a plug in the base, which in 7mm basically means a blob on top and bottom.

Don't quote me but I dimly recall the plug also held in a sprung plunger that forced a felt pad against the lower side of the pin.

 

[P A D]

Okaydoky. Iam suitably chastised for my ignorance.

 

[P A D]

Either way, I've put rods on upside down before now, even if Nick hasn't.

 

[mickoo]

Every days a school day