How to add sprung axles to JLTRT diesel bogies?

tomstaf

tomstaf

Western Thunderer
Hi,

After getting a decent drive system (Steph's), and some wheels turned down to S7 scale is seemed like I still have one link of the chain missing: Sprung axles.

So having invested in some Slaters 7960 (old sytle) sprung hornblocks I'm going to have a go using JLTRT's class 37 bogie. Before I start cutting chunks out of the bogie, I just wondered if anyone else has done this to their JLTRT bogies and could provide any advice or pointers?

Cheers

Tom
 
S

SteveO

Guest
Hello Tom, I'm going to use Steph's complete solution which provides for moving axles. Essentially it's an inner frame which you attach the JLTRT cosmetic bogie parts to.

Maybe Steph can provide more info and un update?
 
tomstaf

tomstaf

Western Thunderer
Thanks Steve,

I'm not using Steph's complete bogie replacement, just his axlesboxes and gears. I'm looking to see if anyone has done it with JLTRT's bogie.

Cheers

Tom
 
Steph Dale

Steph Dale

Western Thunderer
Tom,
I'd be concerned that any mods to take the Slater's units would weaken the bogie (a problem I have already with my class 50, and that's without any changes). Is there a way you can open out the bearing holes in to slots? If so all that you then need to do is find a way to stop the bearings turning in the slots formed and then you're more than half way there. Col (eastsidepilot) has some ideas in his thread, although relating to steam loco bogies, rather than diesels.

Steve,
The EE bogie is some way behind the 8'6" versions, which I'm working on as fast as I can. Unfortunately I'm currently working 7-days a week in the 'day job' so it's all a little delayed, although I'm still hoping to get the 8'6" bogies to a sensible position by Kettering show.

Steph
 
tomstaf

tomstaf

Western Thunderer
Hi Steph,

The centre axle is already like your suggestion so the wheel can 'float'. It'd just be a case of lengthening the holes with a mill to ensure they're perfectly aligned. It'd then be a case of thinking how to fabricate a 'hornblock' around the opening to keep the bearings in situ. Scratches head a bit more...

Cheers

Tom
 
Steph Dale

Steph Dale

Western Thunderer
Tom,
Naw, lengthen the holes as you wish, the use of a mill isn't necessary as it's not that critical, you don't have coupling rods to worry about for example.
Wrap a length of brass wire around the bearing, and feed it through a hole drilled in the top of the bogie frame. Threading a spring over the wire will give you springing and pegging it through the frame will stop the rotation.
Simples?
Steph
 
tomstaf

tomstaf

Western Thunderer
Steph Dale said:
Tom,
Naw, lengthen the holes as you wish, the use of a mill isn't necessary as it's not that critical, you don't have coupling rods to worry about for example.
Wrap a length of brass wire around the bearing, and feed it through a hole drilled in the top of the bogie frame. Threading a spring over the wire will give you springing and pegging it through the frame will stop the rotation.
Simples?
Steph
Click to expand...

Err (feels stupid) can't envisage the wire holding the bearing in part - could you sketch what you mean Steph?

Cheers

Tom
 
mickoo

mickoo

Western Thunderer
Or use CSB with thin tube soldered to the bearing to stop it rotating (tried and tested on my standard 5), you'd need a fixing for the other ends of the CBS but it'd all be floating then with elongated slots of course. Though Stephs idea of a vertical piece of wire up through the top with spring would also work very well.

Either method I'll probably apply to my class 40 when I get around to it.
 
tomstaf

tomstaf

Western Thunderer
Thanks Alcazar.

ZiderHead said:
Didn't Pugsley spring his 37? Cant find my bookmark for his build at this point.
Click to expand...
A bit more than springing on Pugsley's example. That's a whole special micro engineering project in itself and not something that'd I'd be able to do.

Cheers

Tom
 
mickoo

mickoo

Western Thunderer
alcazar said:
Continuous Springy Beam.
See here: http://www.clag.org.uk/csb-gallery.html

VERY interesting idea, and works well.

Some folk using it over on RMWeb too.
Click to expand...

Yeah I'm surprised how well it does work, the 08 and Standard 5 just glide through track work, primarily as the CSB allows the axle to move up as well as down, conventional horn blocks sit on a set screw for height and only move down to cover dips in the track, any high points then make the loco jolt up as there's no upward give.

Having said that, if you pick the correct springs then the axle does not sit on the set screw and some upward movement is possible, when it set up right it works as well as CSB, normally though the axle box just rides on the set screw. The set screw does not adjust the spring pressure in those cases, merely holds the spring in place and is a final up stop.

The only down side to CSB is setting the ride height, it's not easily done and requires the initial calculations to be pretty close +_ 3mm (example) adjusting the ride height after that involves different wire to alter the springiness.

Having seen buffer height differences in locos of up to 6" centre to centre I tend to not get too hung up if my locos sit a little high or low:thumbs:
 
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