Mijovil
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 posted on 4/10/05 at 06:15 PM |
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new chassis
What do you think about this chassis ?
 
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Avoneer
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| posted on 4/10/05 at 07:09 PM |
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What's new about it?
Look like Cymtrics / Aussie mods to a book chassis.
Pat...
No trees were killed in the sending of this message.
However a large number of electrons were terribly inconvenienced.
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JonBowden
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| posted on 4/10/05 at 07:45 PM |
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the red bits
Looks good
Jon
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JoelP
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| posted on 4/10/05 at 08:26 PM |
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still room for improvement. You interested in constructive criticism?
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JoelP
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| posted on 4/10/05 at 08:31 PM |
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heres some anyway. New lines in black
 
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Rorty
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| posted on 5/10/05 at 04:20 AM |
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Mijovil, are those Penguin lines, or what's happened to your drawing?
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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JonBowden
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| posted on 5/10/05 at 07:12 AM |
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do any of the locost manufacturers manke Cymtrics style chassis ?
Jon
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Peteff
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| posted on 5/10/05 at 10:02 AM |
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It looks familiar, any proof it works.
 
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yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Volvorsport
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| posted on 5/10/05 at 10:51 AM |
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the diagonals which go to fu1/2 will make it difficult for anybody with inboard supension .
www.dbsmotorsport.co.uk
getting dirty under a bus
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MikeR
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| posted on 5/10/05 at 11:21 AM |
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I was talking about this sort of thing with NS DEV last night.
What are you trying to achieve? The stiffest locost for the race track or for the road?
The engine bay is a weak point on the locost so in a crash it will crumple and hopefully keep you in one piece. Make it too strong and ..... well you
might find the crumple zone is your body.
If you claim you're not going to crash then you probably aren't going to be driving quickly so do you need the 'best' chassis?
(and are you sure of everyone else around you isn't going to hit you?)
Also Peteff - i agree about that line you highlighted.
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JonBowden
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| posted on 5/10/05 at 03:05 PM |
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quote:
What are you trying to achieve? The stiffest locost for the race track or for the road
Mike,
I did a quick back of envelope calculation a while ago. I estimated that with the specified spring stiffness and the normal estimates for chassis
tosional rigidity, that roughly half the wheel movement over a bump would be due to chassis flex rather than spring compression. This seems too
flexible to me.
If I need to I can re check the calculations and post them
One answer might be to use softer springs ?
[Edited on 5/10/05 by JonBowden]
Jon
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MikeR
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| posted on 5/10/05 at 05:24 PM |
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ok, i'd be interested in your figures (although doubt i could understand them).
this is the sort of thing i go hot and cold on.
First response is .... oooh, must improve my chassis then. Then i think, hold on, lots of people love driving these cars and think they handle really
well....... at which point i'm back to the - do you need it?
One addition i'd try and do is complete the tube at the bottom of the trans tunel enterence.
I'm also assuming you mean front wheel.....
well why use 'Y' braces around the engine? Use the standard single brace - thats stronger. Make the sides of the engine into a sheet -
lots of rivets to two sheets of ali either side of the tubes - should help and still give hte engine bay a chance to crumple.
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JonBowden
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| posted on 5/10/05 at 05:36 PM |
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Mike,
I'll redo the calculations to see if I was right later on tonight - hope I don't end up with a red face.
I tend to agree that I'd prefer strengthening around the driver / passenger compartment
Jon
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cymtriks
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| posted on 5/10/05 at 06:31 PM |
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A single Y brace is slightly less strong and less stiff than a single diagonal brace. The order goes like this..
single Y brace
single diagonal (book chassis R tube)
double Y brace
double diagonal (as on the Caterham chassis)
The reason I suggest a double Y brace is that it gives a very good improvement if strength and stiffness over the book design while at the same time
giving the best possible engine bay size. Many builders report that the single R tube snags on engine ancilliaries, the Y brace is less likely to do
this.
If you are using a normal size engine, less than 1.6/1.8 then I'd suggest my double Y brace mods. For a bigger engine the front of the chassis is
getting marginal and some builders report that tubes TR1/2 flex.
I suggest something like this design which is in the "bigger engines" section of kitcaranalysisv2.doc for 2.0 and over...
edited to change the first sentence which didn't make sense before! Damn kids distracting me!
[Edited on 6/10/05 by cymtriks]
 
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MikeR
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| posted on 5/10/05 at 06:37 PM |
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my only concern wit this approch is the red triangle in the middle. You're introducing loads into the middle of a chassis rail - i'm not
an expert and i've learnt most of my fag packet space frame theory off this site, but i thought that was a bad idea!
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Rorty
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| posted on 5/10/05 at 09:22 PM |
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quote:
Originally posted by MikeR
my only concern wit this approch is the red triangle in the middle. You're introducing loads into the middle of a chassis rail - i'm not
an expert and i've learnt most of my fag packet space frame theory off this site, but i thought that was a bad idea!
Generally speaking, any branch tube ending in a T junction on a trunk tube, midway or otherwise, is not a good idea, however, if the branch
tube forms one side of a contained triangle (as is the scenario above), then it doesn't matter to the same extent, because it can't really
exert any great amount of force on the trunk tube. The trunk tube is really just holding the triangle up.
Does that make sense?
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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Messenjah
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| posted on 5/10/05 at 09:22 PM |
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quote:
A single Y brace is slightly less strong and less stiff than a single Y brace
hm thats like saying a bacon sandwich is more like a sausage sandwich then a bacon sandwich ...
mmmmmmmmmmmmmmmmmmmmmmm bacon sandwich
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