Connoisseur Models J71 Frame Spacing

[Caggers]

Hi all,

Looking for some advice, I have a Connoisseur Models J71 kit which I want to start building to run on my S7 layout (which is under construction).

Having never build a Loco before I am not sure which Frame spacing to use, or how to best work out which I should use. Any advice would be greatly received.

Thanks for reading...

 

[Scale7JB]

Hi, probably want to try and aim for around 29.5mm overall, though this does depend on what sort of curves you want to run on..

What is the width of the real thing?

JB.

 

[victorianman]

Hello. I would concur. 29mm to 29.5mm outside gives some leeway and also allows the wheels to tip if required. But as JB says, depends on your curves and length of wheelbase of the loco.

Victorianman

 

[Ian@StEnochs]

Hi,

I have built 6 0-6-0s in S7 but only two are from kits. A JLTRT 4f and a Meteor models Caley 812 class. The 4f has the frames spaced at 28.5mm, it has working crank axle and valve gear while the 812 is spaced at 28mm and has dummy gear.
On the scratchbuilt engines I have spaced the frames at 28mm with 28 thou frame plates. In all cases there is a little sideplay on all the axles, a wee bit more on the centre, all wheels live sprung and the motor drives on the rear axle. The sharpest curve on my layout is just over 6’ and all are happy on them except the 4f which needs a bit more generous 7’.

Ian.

 

[Caggers]

Thanks for you replies. I need to find the frame width on the 12" to the foot, but wanted to understand what others had done before.

 

[PaxtonP4]

Thanks for you replies. I need to find the frame width on the 12" to the foot.

Why is that relevant to the model?

You have to work out the distance over the outer faces of the frame bearings and compare that to the inside dimension of a pair of wheels and decide if the difference provides sufficient clearance for the radius of curves that YOU intend to run the locomotive on.

 

[Scale7JB]

Why is that relevant to the model?

You have to work out the distance over the outer faces of the frame bearings and compare that to the inside dimension of a pair of wheels and decide if the difference provides sufficient clearance for the radius of curves that YOU intend to run the locomotive on.

You may find that the frames were prototypically narrow...

JB.

 

[Dog Star]

Simon,

You may find this interesting reading:-

Sorting side play

which was an attempt to determine what side play is required to get a loco around a specific radius given wheelbase and width over bearimng thrust faces.

regards, Graham

 

[Eastsidepilot]

29.5mm O/A frames, if the prototype scales out narrower then build to that dimension.

Col.

 

[7mmMick]

Caggers,

I can send you a copy of the GA if that helps. I had a similar quandary with my build, and the J72. Have a nosy through my WB, see if it’s of any use. It may not be though

Mick

 

[Caggers]

Thanks all for your feedback. I am at the early stage as I have been working on othere stuff recently, I'll take a look at that URL @Dog Star

@7mmMick the GA would be useful thanks.

 

[lnerjp]

On the prototype the frames are made from 1" plate giving a inside measurement of 4'1 1/2" and therefore 4' 3 1/2" outside.

Cheers
J.P.

 

[Scale7JB]

On the prototype the frames are made from 1" plate giving a inside measurement of 4'1 1/2" and therefore 4' 3 1/2" outside.

Cheers
J.P.

29.5mm perfectly acceptable then.

Hope you're well JP!

JB.

 

[lnerjp]

Hi Johnathan and all.

Yes, I am well thanks, just very busy, my chosen builder went sick 3 weeks before I was due to start a big extension on my house, so decided to do it myself, and I've done nothing else with my spare time since June.

When you coming for a day out on the moors?

J.P.

 

[Scale7JB]

Hi Johnathan and all.

Yes, I am well thanks, just very busy, my chosen builder went sick 3 weeks before I was due to start a big extension on my house, so decided to do it myself, and I've done nothing else with my spare time since June.

When you coming for a day out on the moors?

J.P.

As soon as I can! Maybe a family trip up the moors this year with a day off for daddy? I'll sow the seed..!

JB.