7mm Scale Radial Axle Supplier

[Doncaster]

G'day folks.  I'm working on a GNR Small Atlantic starting from some etches I obtained a few years back.  The chassis is designed to be compensated and I can make that work.  However I'm struggling to get it to go round corners in OMF.  I'm not keen on sloppy axles so I'm going for a radial axle for the rear carrying axle.  Is there a supplier for such a thing in 7mm scale?  Any help gratefully received. 

 

Vernon

[Simond]

I don't know, but I know a guy who has built a couple of radial tanks, so he might be able to help.  I think his radial boxes were etched.

 

I'm not sure there's too much (reliable) science in defining the radius anyway, and you might be able to get away with machining angled faces on conventional axleboxes, and making the guides to fit.  I would expect the running clearances would be sufficient to allow for the boxes not being segments of a ring.  How much throw do you actually need?

 

atb

Simon

[Doncaster]

4 hours ago, Simond said:

I don't know, but I know a guy who has built a couple of radial tanks, so he might be able to help.  I think his radial boxes were etched.

 

I'm not sure there's too much (reliable) science in defining the radius anyway, and you might be able to get away with machining angled faces on conventional axleboxes, and making the guides to fit.  I would expect the running clearances would be sufficient to allow for the boxes not being segments of a ring.  How much throw do you actually need?

 

atb

Simon

Hi Simon,

Thanks for that.  I'm planning to get the cylinders underway tomorrow.  Then I'll know how much side play I can allow the bogie.  That will define how much I need for the trailing axle.  But I'm guessing at 2 or 3mm.

 

Cheers,

 

Vernon

[Giles]

The radius should really be defined by Baldry's Rule to get the best geometry, however, having made one for a 10 1/4" loco, I had a bit if a problem with it being too nice a fit, so that every time only one wheel cocked up, the axle (It was a Canon axle) stuck at an angle. The cure was to get a grinder out and make the axle a sloppy fit in the curved frame, and that still works with no problems twenty years on....

Edited October 26, 2020 by Giles

[MarcD]

Warren Shepherd sells etched GWR versions. I have one somewhere. They look good but I've never fitted one yet.

Marc

[Doncaster]

17 hours ago, Furness Wagon said:

Warren Shepherd sells etched GWR versions. I have one somewhere. They look good but I've never fitted one yet.

Marc

Hi Marc,

Thanks for the heads -up.  I spoke with Warren today and I'm expecting an etch in the next couple of days.  I'd drawn up my own version to be milled from solid and had asked a big favour from a pal with a jig-borer with a nice rotary table.  Not now required! 

Thanks again.

Vernon

[Lochgorm]

Vernon, If you can get your hands on a copy of MRJ 135 Laurie Griffin described how he scratch built  the radial boxes for a L&Y 2-4-2 tank.  I don't think he was heavily dependent on an armoury of machine tools.  Cheers Charlie

[Doncaster]

9 minutes ago, Lochgorm said:

Vernon, If you can get your hands on a copy of MRJ 135 Laurie Griffin described how he scratch built  the radial boxes for a L&Y 2-4-2 tank.  I don't think he was heavily dependent on an armoury of machine tools.  Cheers Charlie

Hi Charlie,

Thanks for that.  I'll keep it in reserve pending getting my etch from Warren.

I guess that covid stopped us from meeting up at shows.  I hope you're well and getting plenty of modelling done.   We've gone into Tier 3 so there's plenty more modelling time for me!

Cheers,

Vernon

[Simond]

Vernon,

 

I talked to my pal, and he happily admitted cheating - he used a sort of "camouflaged pony truck" approach.

 

I'm sure Warren's etch will sort you out, do post up some photos when you can

 

atb

Simon

[Doncaster]

Thanks Simon.

 

Great service from Warren Shephall,  the etch arrived today!  Looks just the ticket.

 

Thanks for your advice guys.

 

Vernon