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0-6-2T radial axle


Steve Sykes

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I'm considering making a model of an 0-6-2T.  In the prototype, this had a radial axle to allow movement of the trailing carrying wheels.  Lacking the skills of Nigel H who can make working radial axleboxes in 2mm scale, what do people think is the best way to arrange the necessary movement?  Is a crude but simple narrowing of the frames at the rear to allow sideplay sufficient or is it better to arrange the rear of the frames as a pivoted truck to let the wheels follow the track more effectively?

If so, what's the best way to arrange it?  Any suggestions or experiences would be welcome.

 

Steve

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Just having sideplay doesn't work, allowing the frames to pivot is much better, the split can be behind the cab steps in most cases. These radial axles were normally on a large radius, typically about 10ft, a very short radius will cause trouble on K crossings in most scales.

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Hi Steve,

 

Mick Simpson has done something similar to Michael's suggestion with his N10 loco. I've put a link to the specific post below, but there are other relevant posts on the NEAG blog.

 

http://neag.2mm.org.uk/2012/10/n10-radial-truck.html

 

The other source of info that springs to mind is Tim Watson's article in an early MRJ on his Kirtley 0-4-4t loco - which was built as an 0-4-2-2t I think.

 

Andy

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I'm considering making a model of an 0-6-2T.  In the prototype, this had a radial axle to allow movement of the trailing carrying wheels.  Lacking the skills of Nigel H who can make working radial axleboxes in 2mm scale, what do people think is the best way to arrange the necessary movement?  Is a crude but simple narrowing of the frames at the rear to allow sideplay sufficient or is it better to arrange the rear of the frames as a pivoted truck to let the wheels follow the track more effectively?

If so, what's the best way to arrange it?  Any suggestions or experiences would be welcome.

 

Steve

Hello Steve,

 

You have an etch for the L & Y 2-4 2T so you can see how the arrangement works. I can probably dig out an etch for a radial pony truck for you so all you would need to do is somehow arrange the 'legs' on the chassis for guiding/ retaining the radial truck. What loco are you planning to build?

 

Regards,

 

Nigel

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These are the best pics I can find showing the 2-4-2T arrangement. In theory, the legs, as viewed from above or below, are aligned along the circumference of a circle with its centre midway between the driving wheels, if I remember correctly. For our 2mm models I don't know how accurately this needs to be replicated, but I would have thought an approximation should suffice. The 2-4-2T I built is almost certainly made as such and appears to run satisfactorily.

 

In a scratchbuilt chassis, I wonder whether you could use brass bar with the faces against which the truck rubs filed to an angle so as to copy the legs on the etch.

 

post-12813-0-94166600-1426239302_thumb.jpg

 

post-12813-0-65429600-1426239333.jpg

 

Nig H

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From memory I think it was Geoff Balfour's armoured GER 2-4-2T that had the radial trucks completely separate from the rest of the chassis and attached by springs. When it was lifted off the track the trucks bobbed about like Zebedee in the Magic Roundabout but it ran beautifully. Perhaps someone else can better remember if it was that loco and how the trucks were arranged.

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These are the best pics I can find showing the 2-4-2T arrangement. In theory, the legs, as viewed from above or below, are aligned along the circumference of a circle with its centre midway between the driving wheels, if I remember correctly. For our 2mm models I don't know how accurately this needs to be replicated, but I would have thought an approximation should suffice. The 2-4-2T I built is almost certainly made as such and appears to run satisfactorily.

 

In a scratchbuilt chassis, I wonder whether you could use brass bar with the faces against which the truck rubs filed to an angle so as to copy the legs on the etch.

 

attachicon.gifL & Y 2-4-2 T chassis.jpg

 

attachicon.gifL & Y 2-4-2 T radial trucks.jpg

 

Nig H

 

Hi Nigel,

 

Can I ask how far the wheels on the radial axles can swing before the backs touch the main frames?

 

Chris

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Hi Nigel,

 

Can I ask how far the wheels on the radial axles can swing before the backs touch the main frames?

 

Chris

Hello Chris,

 

Width over frames is 7.1mm, so with 8.5mm back to back the swing is 0.7mm either way, less a small amount for the angle of the wheel to the frames because the radial truck moves from side to side along a curved path rather than a straight line. Ability to go round curves is also helped by building in some side play in the driving wheels, but what you might gain with this for the front end should be lost at the back end of the chassis.

 

Hope this helps.

 

Regards,

 

Nigel

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From memory I think it was Geoff Balfour's armoured GER 2-4-2T that had the radial trucks completely separate from the rest of the chassis and attached by springs. When it was lifted off the track the trucks bobbed about like Zebedee in the Magic Roundabout but it ran beautifully. Perhaps someone else can better remember if it was that loco and how the trucks were arranged.

 

I think Geoff's F4 had a Mike Bryant chassis where the frames were curved inwards somewhat towards either end, leaving the leading and trailing wheels free to move sideways a small amount.

 

Mark

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Thanks for all the responses and my apologies for the slow reply, due to being away from home for a week.  It would appear the consensus is that simple side-play is not enough.  Now I'm back I will look at the drawing to see how a split in the frames and a pivot point could be arranged.

 

 What loco are you planning to build?

 

I'm looking at a Rhymney Railway A class.  I haven't done much modelling recently due to ill-health, but did buy the Welsh Railways Research Circle's book of Rhymney drawings which inevitably led to an "ooh, shiny" moment.  I've always thought the South Wales railways were interesting but the prospect of having to build gazillions of PO wagons with elaborate liveries was too off-putting.  Mathieson Models have rather solved that problem, so I'm tinkering about with a few bits.

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I think Geoff's F4 had a Mike Bryant chassis where the frames were curved inwards somewhat towards either end, leaving the leading and trailing wheels free to move sideways a small amount.

 

Mark

In that case it was a different 2-4-2T that I am thinking of. The whole frame sections front and rear were separate from the section of the chassis with the driving wheels and attached by springs in some manner. Not just a springy wire but quite long coil springs. I remember the reaction when it was lifted off the track at an Association meeting and the front and rear wheels were bobbing around on their springs. When it was put back on the track the weight of the loco held everything in place and the loco ran beautifully. It worked well but it was an odd way to build a chassis and I have never seen another like it. I wonder if it was ever written up in the magazine.

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I have a distant memory of this. I think it was a model of an L&Y radial tank built by John Robinson? IIRC he brought it to a meeting of the Yorkshire area group back in the late 70s or early 80s.

That's the one! :D It would have been late 70s as that was when I was going to Yorkshire area group meetings.

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