Just managed to get the axle bracket off after welding it upside down on the axle 
I distorted the bracket a bit when getting it off, so was looking to replace it.
When i measured the hole centres on the chassis it was 95mm and the ones on the brackets (that were previously fitted the axle) there are 115mm.
This would mean that the trailing arms were not parallel, and the angle the diff flange would change with suspension travel.
Or am I wrong ?
Should they be parallel or not ?
Well known error in the book --- should be parallel.
Depends whether you want to incorporate anti-squat geometry on your car, as I have with mine.
I might be wrong but I think non parallel trailing arms (With each other that is) will cause your axle to twist when you hit a bump with one wheel -
not a good idea as it will eventually rip the brackets off the axle.
i thought if they're different gaps on each side you severely limited what distance the axle could move through.
If you have them positioned so they are the same distance apart but nearer or further to the front of the chassis to the chassis in the vertical plane
you introduced other (potentially) beneficial geometry effects - but too much and you rip the axle / brackets apart.
My thought were that if the distances were different and the arms were not parallel, then (if the rear ones wee closer together) as the arms rise, the
bracket would move away from the horizontal and point upwards slightly.
If one side of the car was higher than the other due to loading in corners or due to bumpy ground, that would mean that the axle would try and
twist.
This can not be good, can it ?
Also to keep vibration to a minimum the output from the gearbox and the input to the diff need to parallel with each other, so that the oscillations
from the uj's cancel each other out.
If load load or cornering cause the angle of the diff to change, then these will not be aligned.
The Locost axle is over located ---- ie it has one more link than pure engineering location theory says is correct.
You can get away with this either by making sure the geometry is spot on or doing what they do in road cars use compliant rubber bushes.
Unless all the links are parallel with the standard Locost 5 bar linkage layout the axle movement will bind up.
Some anti-squat can be achieved with parallel linkages by raising all 4 mounting points at the chassis end.
Hi without going into all the pros and cons of it all. Keep the arms parallel to each other. But if your are looking to incorporate anti-squat or
pro-squat then you move the height of the chassis location from parallel too the ground but keep the arms parallel too each other.
Doing anything else will just get complicated although there can be benifits to be had. But requires a lot of experimenting with and understading.
Cheers Matt
sounds like a plan
See what I done Jaffa??
See how my rubbish hole saw munches?
Ta-daaaaa
And a pile of bits ready to weld on.....
Oh, and I have a length just for you!!!!!!
Just started to make the brackets (only took 8 months, well I've been busy)
The thing is, the chassis points have 96mm centres, so I decided to make my brackets the same.
So i drilled all the 8mm holes in all the right places, but I have just spent the last ten minutes cutting the 65mm hole and realised that by the time
the bracket is welded onto the axle, the mounting holes will be too near the axle to fit the holes.
Well actually, they might just fit, but would be extremely close and tight as a tight thing.
tight is good if owelly has a length for you 
5 link (4 trailing arms plus panhard) must be parallel and equal length or there will be bind. If you bushings are soft enough, you will be able to
hide it but I would suggest as close as possible.
I went with 3 trailing arms plus panhard.
Cheers.
Just got reply from Autotune, and they said that the chassis mounting points are closer together than the axle points to give anti squat.
And also Dave Beddows, who also building a Gemini measured his for me and said they were further apart on the axle.
quote:
Originally posted by Trev Borg
Just got reply from Autotune, and they said that the chassis mounting points are closer together than the axle points to give anti squat.
only by about 12mm
http://locostbuilders.co.uk/viewthread.php?tid=51734
This thread may be a worthwhile read for you regarding antisquat.
Cheers.