WHEEL QUARTERING.

[melvin]

I have a Hornby A4 Body that has the lubricator arm attached.

I have a suitable chassis to go with it, Except. the right hand rear wheel does not have the correct crankpin.

I do have a suitable spare wheel. I have a puller to get the wheel off, But how can i be sure that the quartering will be correct. Help Appreciated. Mel.

[Jeff Smith]

Before you start pulling wheels does it run ok, and what is wrong with the crank pin?

[micklner]

The Crankpin is a different longer length for the Oil Drive.

 

Remove the wheels/axle  from the chassis

Remove the driver from the axlePush the crankpin out the rear of the wheel it has a T fitting on the end .

Line the new Crankpin up with the T shape in the rear of the driver and push through fully home into  the wheel. Replace the wheels and axle back into the chassis. Refit the Coupling Rods on the nearside only.

Look through the wheel spokes after first lining up roughly 45 degrees around from the wheel on the other side. Line the wheels on the same side until all the Crankpins are in line. Leave the Coupling Rod on the front two wheels on,  it will help when lining the wheels up.

Push the wheel onto the end of the axle which  has a knurled finish , it should slide back on without any force. If it wont go back on move the wheel slightly either way  until it slides back on . Ensure the Crankpins are in line , replace the Coupling Rod and test under low power. Once running ok ,then place the Oil Drive Bracket onto the Crankpin , and test again.

Edited October 15, 2023 by micklner

[DCB]

The trick is to check the alignment of wheel spokes before you pull the wheel off and replicate the positioning with the new wheel.  Generally on 12 or 16  spoke wheels the spokes are in line, anything  a multiple of 4, but anything other spokes won't line up.      To be pedantic the A4s were not quartered they were thirded 120 degrees ( It gets worse the onside cylinder was inclined so the crank throw  were off from 120 by the angle of inclination to get 120 degrees Apparently the  120 doesn't work too well on a model,  12 or 15 spoke wheels spokes would line up ,,,,  but I  haven't tried it myself,though might be worth a try

 

[34theletterbetweenB&D]

Side note: 'Thirding' is possible but inadvisable, as it is less tolerant of error than quartering. (For any truly determined, best not attempted by spoke alignment, a wheel press is the path to repeat consistency in angular setting.)