Trailing Axle springs

[mott]

Hi Guys, I have now had the springs break on both sides of the trailing axle. This time I had taken the loco in its box around to a friends workshop and when we took the loco out of the box out fell the broken leaf springs. ModelWorks sent me replacements last time. It looks as though the the hole drilled through the centre of each leaf of the springs is substantially larger than the retaining bolt and the spring becomes affected by metal fatigue.
Am I the only one with this problem?
I am going to investigate using a coil spring hidden inside a casting of the leaf springs. This is common practice for example in the 5" Brit.
Any other solutions to this problem. Of course ModelWorks dont have replacement springs listed in their spare parts on their website and Steamfittings cannot supply either. Mott

[Laurie_B]

mott said:

Hi Guys, I have now had the springs break on both sides of the trailing axle. This time I had taken the loco in its box around to a friends workshop and when we took the loco out of the box out fell the broken leaf springs. ModelWorks sent me replacements last time. It looks as though the the hole drilled through the centre of each leaf of the springs is substantially larger than the retaining bolt and the spring becomes affected by metal fatigue.
Am I the only one with this problem?
I am going to investigate using a coil spring hidden inside a casting of the leaf springs. This is common practice for example in the 5" Brit.
Any other solutions to this problem. Of course ModelWorks dont have replacement springs listed in their spare parts on their website and Steamfittings cannot supply either. Mott

Sounds like you've had a spot of bother there Mott.As you mention,coil springs hidden away in a dummy casting is common enough practice.Reeves don't list such a casting in their 'Didcot' design,but they or Blackgates will have something that would do,maybe some tender spring castings?If you belong to a M.E. club,someone may have just what you're looking for lurking under their workbench.

If you did want working leaf springs,try Dave Noble and/or Doug Hewson as they both list leaf springs in their catalogues and on their websites,mainly under 'wagon bits'.Again they might be able to help.

Or you could have a go at making a pair,or asking someone to make some.Folkestone Engineering Supplies offer a heat treatment service for leaf spring assemblies.
www.metal2models.btinternet.co.uk/hard.htm

Hope you find a solution to the problem soon.

[Phil Sutton]

Jon,how are your springs set up? 2 steel leaves and the rest Tufnal?Original springs were brass top leaves and Tufnal the rest.These just sagged and led to derailments of the trailing axle,so Winsons changed the brass for steel.Perhaps sone extra leaves in steel may help.
I'll have a look at the Didcot drawings and see what it says there.

Phil

[mott]

Thanks to Phil and Laurie. My springs were as supplied by ModelWorks. No tufnel just steel. There is obviously a weakness here though I haven't heard from any other 14XX builders. If I can get a coil sring in there I will, otherwise I will have to buy in some spring steel, cut it and temper it and drill a tighter hole through each leaf to minimise the risk of fracture. Steamfittings have a slot for spring steel on their web site, so they have recognised a demand but when you go there, there is nothing available.Its a pity that ModelWorks don't make these spares available on their website. As we use our locos more there is bound to be a demand for spare parts but for the 14XX none are offered. Mott

[Phil Sutton]

Hi Jon,
Didcot spring drawings state
Top 2 leaves 4 5/8"long spring steel.3/8" thick
Each successive leaf about 7/32" shorter each end from heat treated Tufnol
Pin holes are 1/8" elongated
Pin centres are 4 5/16" in flat,4 1/4" when set (curved).
No centre pin hole,leaves held on oblong buckle 11/16" wide,3/4" high.1/2" deep
Internal dimensions3/8" x19/32",wall thickness 1/16"

If you wish for a copy of the drawing,send me your address in a PM and I'll send you a photo copy.Scanner will not work at present,so can't e mail you one yet.

Phil

[mott]

Phil, Thanks for the detail. Thats about as much as I need to know. We also have a set of Didcot plans at the club which I can access. The point is "No centre pin hole" as thats where the trouble starts. Mott

[Shawki Shlemon]

Hi mott
try this , get spring steel strips in hardened & tempered condition,cut to size and drill your hole using drill press with good quality sharp drill at lowest speed and keep the pressure on.(use cutting aid) . You may need to sharpen the drill bit after few holes .I do it all the time ,trust me it works. Good luck

[mott]

Shawki, Sure I trust you. However I have taken the soft option of using a coil spring inside the centre of a spring casting. Interestingly when doing this job, I checked the driving wheel coil springs and found 2 had broken so they have had to be replaced. I assume it is just a matter of cheap materials being used and with a locomotive getting track time these failures will occur. On the point of getting hold of spring steel, the strapping used on packing cases works very well as a substitute according to informed opinion at my club. Best Regards, Mott