Ulster body painting

[merlinart]

The radius arm ball joint does not need to be moved.
The castor is corrected by using a flat front spring in place of the standard curved one. This takes the modified radius arms back to the correct position.
There are pictures of the lowered front end on the internet.
eg https://www.pinterest.co.uk/pin/356980707937391114/

The front spring can only affect the camber angle of the wheels, not the castor angle of the front uprights though?

Castor on uprights is the angle of the upright in relation to a 90 degree vertical, measured as +/-.

Surely on a 7, the angle of the axle through which the kingpins/uprights pass is the castor angle and if the angle differs as the radius arms are lowered, the angle goes forward, thus decreasing the castor angle?

When I build my own 3 wheelers on wishbone suspension, by altering the position of the smaller upper wishbone, backwards on its bolts it increases castor and decreases the angle by pushing them further forward and spacing accordingly, thus I have 2-6.5 degrees of castor.

The point I'm making is that if the radius arms are lowered at the front, than the angle of the front face to which the axle bolts, must have changed?

Arthur

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Hi all

I collected my "Ulster" body from Rod Yates last week, and I'm pondering the paint finish.

I've turned the body sideways and upside down whilst musing. What have others done re painting, just the outside and engine bay internals?

What about paint to the underside...this could be simply hand painted black having etched it first?

Looking down into the tail, I wonder is others have fully painted or at least fully etch primed the total interior?

Very early days yet as the chassis hasn't even been blasted, then this will need painting and all components worked on.

I took the front axle to be lowered yesterday, then the lowering of the radius arms will tax my brain.

Now, if lowering the radius arms, say by 60mm or so (what is the recommended drop please?) the arms slope downwards thus when bolting up the lowered axle, the castor angle will have changed as the bolt up flanges now point down at a different angle?

My question therefore, should the radius arm ball joint on the cross member be lowered the same amount, thus putting the bolt up positions/flanges in the same relative positions?

regards

Arthur

David Cochrane (A7 Components) sells Ulster type axle connections for the radius arms. These allow the axle to retain the correct castor angle with the usual 'lowered' axle and flattened spring. This can also be achieved with fabricated links to the standard radius arm ends, with a spacer on the big stud which originally goes through the axle eyes.

Yes, I realise both, thank you, but I'm using and bending a 1938 Ruby axle with a twin stud radius arm, the pitch between the studs is approx. 60mm, so in effect I could drop both location studs 60mm respectively and still pick up both, the smaller stud through the larger hole suitably sleeved, and the larger on drop links?

I am still confused though since dropping the arms clearly alters the angle of the face to which the axle bolts, and angles the axle forwards, thus decreasing the castor angle, surely?

To correct this anomaly, it must be the case that the ball joint needs dropping the same distance?

Arthur