Setting Jig

[runner42]

At the open day at SASMEE, Allan Wallace showed a simple Wheel Spring Setting Jig.

I have produced a rough sketch, it was from memory so I have not capture all the features, but there is enough to show the principle. Basically, it enables the force determined to lift each locomotive wheel and enable the spring(s) to be adjusted so that there is equal spring tension on each axle. It consists of a clamping bar that is affixed to the rails and a yoke with two pins that sit each side of the wheel, a lever that is pivotted on the clamping bar with one end attached to the yoke and the other to facilitate the anchoring of a spring balance to record the tension required to lift the wheel. It is designed to be used at the steaming bays so that the underside of the rails are available to clamp the jig and sufficient height above ground level to facilitate the spring balance and the application of the force to raise the wheel. 

I am aware that the most effective means of this adjustment is with the use of load cells and other apparatus, but this simple jig provides a convenient means of either producing an exact reading or setting each axle so tha they are balanced.

Brian


Wheel Spring Setting Jig by Brian Leach, on Flickr

[trimleytramway]

Locomotive weighing can have some variables level track can be one the weight of the locomotive at the time of weighing I.E 1/2 or full boiler. In order to get an even set up I would suggest a feeler gauge is used below the wheel as it’s lifted as is done when full size locomotives are weighed.

[runner42]

Dec 22, 2021 1:10:40 GMT trimleytramway said:

Locomotive weighing can have some variables level track can be one the weight of the locomotive at the time of weighing I.E 1/2 or full boiler. In order to get an even set up I would suggest a feeler gauge is used below the wheel as it’s lifted as is done when full size locomotives are weighed.

Agree that the force necessary to just raise the wheel is required and a feeler gauge is probable the right device to use. I suppose a very small one would be best, say only a few thou thick. But the feeler gauge would only fit between the rail and tread because the flange would prevent full insertion.

Brian

[lesstoneuk]

Would it be possible to mount a lever type dti to touch on the wheel between the spokes, set the bezel to zero and adjust the springs for... Say 5 Thou movement