scootz
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| posted on 12/11/11 at 05:12 PM |
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Been thinking of instrumentation and switches. As I've already mentioned a dozen times - the cockpit is tight!!!
It looks in the photo as if there is sufficient mounting space on the panel behind the steering wheel for the display / controls. Unfortunately
it's just an illusion - there is no space! 
Sooooo, was thinking of putting the switches on the steering wheel, and the display / tell-tale lights on the 'lip' at the front edge of
the cockpit...
The blue oval being the display (wired to also act as the position light tell-tale).
The green circles either side being the indicator / hazard tell-tales.
On the wheel:
The two green circles being the indicator switches.
Red oval being the hazard switch.
Yellow oval being the dip / main switch.
Blue oval being the horn switch.
It's Evolution Baby!
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scootz
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| posted on 11/2/12 at 01:00 PM |
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Still skint, so no progress
Lots of thinking going on though... mainly about the front-end (still)... and most of it nuts!
The main problem with building a front-subframe to take double wishbones (in my circumstances) is that the wishbones would need to be narrow, and they
would have to be pretty long to make the 'magic' 1:6 ratio.
The other issue is that they would have to be shaped something like the following pic so that the wheels weren't sitting right at the front end
of the vehicle (it would make the wheelbase / track insanely long and would look awful).
I'm thinking that such a long / narrow wishbone would have to be made of kryptonite or cast iron to prevent it flexing (snapping!) under load???
Can anyone offer any opinions?
I think I previously mentioned that a Formula Vauxhall Lotus uses an upper wishbone that's about the required shape, but it would need
the rocker 'section' cut-off as I couldn't go inboard with the shocks and I would need to use them for top AND bottom of the
trike...
But would 4 of these last long???
Or could I abandon the 1:6 theory altogether and fit two (very) wide wheels (F1 stylee) up front on short stubby wishbones (narrowing the track) with
LOTS of travel, so that the machine leaned lots in corners, but still retained a large rubber contact patch on the outside wheel???
All thought welcome... particularly those suggesting that I should step away from the computer and never think about designing my own build EVER
again! 
It's Evolution Baby!
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Sam_68
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| posted on 11/2/12 at 01:56 PM |
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Do a Google Images search for 'Frank Costin Protos'.
The Protos suffered big problems with judder under braking, due to the raked suspension arms flexing, and I believe they later fitted additional
radius arms to cure the problem, but to be fair that was a slick tyred racing car under racing conditions with a top-notch professional driver: Costin
himself reported that he couldn't replicate the problem when he drove the car, 'cos he couldn't drive it hard enough.
But as I've suggested previously on this thread, I think you're getting too hung up on retaining the existing 'hard points' on
your tub: it's really not that difficult to bond in additional hard points for the suspension wherever you want them, if you know what
you're doing.
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scootz
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| posted on 11/2/12 at 02:45 PM |
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That's the problem Sam... I don't know what I'm doing, and it seems it will be big bucks to get someone who knows what they're
doing to do it!!!
I spoke to a few CF tub makers about it and they recommended making a bulkhead in the region of where my knees will be in the car. (Motorsport
Industry) cost = ŁthousandsŁ.
Will check out the example you raised.
It's Evolution Baby!
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scootz
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| posted on 11/2/12 at 02:53 PM |
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Yup... that's the type of wishbone I envisage - but it would need to be top AND bottom.
Unless I could bond a simple metal strut across the ali-honeycomb floor panel at the knee area that could incorporate the left and right rear-most
lower wishbone locating points (the forward ones being clevis type mounts attached to the face of the footwell bulkhead)???
It's Evolution Baby!
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Neville Jones
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| posted on 12/2/12 at 11:07 AM |
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Stick a USA hotrod type beam axle across the front, with trailing radius rods back to the tub. Single leaf steel spring mounted to the tub front. Job
done! And you can get the thing on the road and having fun. 
99% 0f people wouldn't know or feel the difference on the road, to the fancy and complicated setup you're thinking about. And does it
really matter?
Cheers,
Nev.
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Sam_68
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| posted on 12/2/12 at 11:22 AM |
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quote:
Originally posted by Neville Jones
Stick a USA hotrod type beam axle across the front, with trailing radius rods back to the tub.
Part of the problem as I understand it, though, is that Scootz is cautious of providing additional hard-points for suspension pick-ups .... and the
radius rods would need such pick ups.
quote:
Originally posted by Neville Jones
99% 0f people wouldn't know or feel the difference on the road.
Hmmm... not sure I agree with that; I've driven a number of beam axle cars (from vintage sports cars to my workhorse Range Rover) and
there's a very distinctive feel to them: no matter how well located and damped they are, there's a distinctive 'shimmy' to the
feedback you get through the wheel when you hit bumps at speed, due to the gyroscopic forces.
But in any event, if you're satisfied with the compromises of a beam axle instead of tricksy double wishbones then well set-up trailing arms are
really no worse (just a different set of compromises), so the sensible solution would be to bolt on the suspension that the tub was designed
for in the first place.
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scootz
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| posted on 12/2/12 at 11:34 AM |
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Thanks again Nev and Sam... your input(s) are much appreciated!
Would I find the handling characteristics of a trailing-arm beam-style set-up to be a problem... probably not!
This piece explains the handling peculiarities for those who are not familiar with it...
The dune-buggy guys have some pretty neat beams with top and bottom thru-rods instead of torsion leafs, and control the arms movement through coil
over shocks. I guess I could arrange for a MUCH more discreet and MSVA friendly shock tower to be fabricated and welded to the beam as I only need a
fraction of the travel they require.
It's Evolution Baby!
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Sam_68
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| posted on 12/2/12 at 11:45 AM |
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quote:
Originally posted by scootzUnless I could bond a simple metal strut across the ali-honeycomb floor panel at the knee area that could
incorporate the left and right rear-most lower wishbone locating points (the forward ones being clevis type mounts attached to the face of the
footwell bulkhead)???
As with the roll bar mounts, ideally you want to arrange the way the loads are fed into the monocoque by wrapping them round the corner at the lower
edge of the tub, so that you have stiffness in two planes.
Honestly, it's nothing to be scared of - if you don't have access to the necessary software for the FEA, just make sure it's
over-engineered, same as most 'Locost' spaceframe projects!
If I get chance, I'll sketch something up tomorrow when I have access to a scanner to post the results, but if I forget, give me a prod though
u2u.
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Sam_68
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| posted on 12/2/12 at 11:48 AM |
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quote:
Originally posted by scootzThis piece explains the handling peculiarities for those who are not familiar with it...
At risk of stating the obvious, having a system where the front-end grip falls off as roll builds up is not necessarily a problem for a reverse
trike.... better that than the other way around!
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scootz
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| posted on 12/2/12 at 12:18 PM |
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Good point!
Would mighty obliged if you could scribble something down - I find it hard to visualise sometimes.
Thanks again.
It's Evolution Baby!
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Sam_68
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| posted on 13/2/12 at 07:51 PM |
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Fag-packet sketch of a section through the lower corner of your tub (eg. to mount a lower wishbone pick-up) as an example:
The 'top hat' section inserts theaded into each other from either side of the panel and bonded into place with epoxy are the key: you can
use these to bolt through/into to mount pretty much whatever bracketry you want to, with a bit of ingenuity (bolts not shown on this sketch 'cos
I was too lazy to draw them, but you get the idea?).
Refer back to my earlier photo of the FW400's damper and wishbone mounting brackets to see the sort of thing that can be achieved in practice.
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scootz
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| posted on 13/2/12 at 08:01 PM |
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Thanks for that Sam. I'm building a better picture in my head of what's possible.
It's Evolution Baby!
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scootz
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| posted on 22/2/12 at 09:59 AM |
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Did some measuring and the wheelbase is going to be 293cm. So, I'm looking at a track width around 183cm.
It's Evolution Baby!
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ceebmoj
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| posted on 22/2/12 at 10:39 AM |
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I know its not the Scootz way but in the first post you have a picture that shows the set up that others use on this car what's wrong with that?
I thought it looked neat and far more compact than I expected it to be.
[Edited on 22/2/12 by ceebmoj]
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scootz
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| posted on 22/2/12 at 12:43 PM |
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quote:
Originally posted by ceebmoj
I know its not the Scootz way but in the first post you have a picture that shows the set up that others use on this car what's wrong with that?
I thought it looked neat and far more compact than I expected it to be.
It is fairly neat, but the VW beam is considered a little antiquated.
It's Evolution Baby!
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ceebmoj
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| posted on 22/2/12 at 03:53 PM |
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quote:
Originally posted by scootz
quote:
Originally posted by ceebmoj
I know its not the Scootz way but in the first post you have a picture that shows the set up that others use on this car what's wrong with that?
I thought it looked neat and far more compact than I expected it to be.
It is fairly neat, but the VW beam is considered a little antiquated.
I agree, but the tub was designed to take it.
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maccmike
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| posted on 29/2/12 at 05:40 PM |
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thats awesome and stunning, would love to see it in flesh when its built
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maccmike
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| posted on 3/6/12 at 03:50 AM |
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any updates?
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scootz
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| posted on 3/6/12 at 09:03 AM |
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Not really... I've gone full circle a couple of times on the front suspension design, and I'm currently back working on a Beetle style
beam for it.
The beam I'm building is 6-inches longer than a standard VW one to give me an increased track-width for stability. I won't be using
torsion leafs springs... instead I'm running a 0.750" 4130 anti-roll bar through the bottom axle tube to eliminate as much body-roll as is
comfortable (body roll is particularly unwelcome on a beam style front axle as it promotes positive camber).
I'll use coilover shocks mounted between the lower trailing arm and upper beam tube and put a tie rod through the top tube to hold the arms in
place.
I'll hopefully have the beam tack-welded together later in the week, so will fire up a few pics when it's ready.
It's Evolution Baby!
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maccmike
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| posted on 3/6/12 at 11:50 AM |
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luck forward to it
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JC
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| posted on 30/12/12 at 09:04 AM |
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Scootz, have you seen this? Links not cheap, but would be a simple bolt on?
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scootz
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| posted on 30/12/12 at 11:39 AM |
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Cheers JC.
I've been meaning to have a look at the Red Design unit in the flesh for sometime.
It's Evolution Baby!
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scootz
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| posted on 12/2/13 at 02:33 AM |
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Bad news... Decided that the VW front end is too much of a compromise, so I'm abandoning the Formula Vee tub.
Good news... I have the whole front end from a Dallara F396 arriving next weekend! Still full of carbon tub goodness and comes complete with
roll-bar, steering, pedals, tank and (insert fanfare)... double wishbone suspension!
It's Evolution Baby!
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T66
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| posted on 12/2/13 at 03:26 AM |
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Go to bed....
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