got a couple of questions about designing a car...cant decide where to put them?
basically what are the best steps to take after pencil diagrams?
if you have a chassis design drawn out I'd recommend you make a model out of balsa wood and make a replica about a foot long to see if you have the bracing tubes correct, assuming it a space frame or similar. Any weakness in the stiffness of it will be very apparent in your hands and best of all you can quickly correct any faults and test them for pennies. Something that is difficult to do even on a computer. You'll also pick up the correct order in which to assemble the real thing
You could post up your designs on here and then everyone can tell you what you've done wrong
where abouts are you in scotland ?
(or does your user name give it away )
quote:
Originally posted by Mr Whippy
if you have a chassis design drawn out I'd recommend you make a model out of balsa wood
I would go for a cad model and then some CAE analysis work.
quote:
Originally posted by mcerd1
where abouts are you in scotland ?
(or does your user name give it away)
quote:
Originally posted by Mr Whippy
if you have a chassis design drawn out I'd recommend you make a model out of balsa wood
or a 3D CAD model for those of us who can
[Edited on 11/12/08 by mcerd1]
quote:
Originally posted by dubstar_04
I would go for a cad model and then some CAE analysis work.
a real model in your hand tells you far more and quicker than a computer model on a screen
quote:
Originally posted by iank
Computer model takes 100 times longer and doesn't show you how stiff/floppy it is - it's truly amazing to find how changing one or two tubes can make such an enormous difference.
Computer model is the next step especially if you want to make more than one. If it's just for you, copy of the balsa model in steel and drive it![]()
I 2nd Mr Whippy.
Anyone who has built model aircraft wings will understand the benefit of a model when determining structural stiffness.
I am quite proficient in Autocad but could build a locost model chassis faster then I could draw it and the drawing tells you nothing about torsional
or longitudinal stiffness.
Richard
im in edinburgh...nah, thats my real name believe it or not!!
cheers, ill try doing a balsa model sometime soon!
so your just up the road from me then
feel free to give me a shout if you want a hand with some cad stuff (once you've got a bit further with your design that is)
[Edited on 11/12/08 by mcerd1]
thanks very much! wherabouts are you?
Haddington
there are a few of us in and near Edinburgh, we should probably organize some sort of meet again
(I was thinking about karting next year sometime ? )
sounds good! i was thinking of trying to organize a trackday at knockhill or something...
sounds good too, but I've only got a boring car at the moment
(yes I know before anyone says it, get my finger out and build the thing.........)
Are your pencil drawings sketches or technical drawings?
I'd take some measurements of:
1) me
2) the engine and transmission
3) the wheels, suspension and steering
then draw it out to scale to make sure it all fits.
A balsa model of the chassis is a good idea. I then made a seat and pedals out of plywood and foam to check that there was enough room. Still, I
found that there wasn't space for the master cylinder below the bonnet. The more checking you do on paper, the less you have to redesign during
the build.
quote:
Originally posted by mcerd1
...
CAD (as in computer aided drafting - eg autocad) is slow and won't tell you much
but a CADD package (computer aided design & drafting - something with static, dynamic and/or FEM analysis) could tell you allot more than the wooden model and a good one will let you model it quickly
...
For a balsa model, make it at 1/8th scale.
This is convenient because 25mm square rhs can be modelled in 3mm square balsa.
I found it good for accessing torsional stiffness and for working out how joints will be made.
quote:
Originally posted by iank
My points are.......
my drawings are technical, only on a4 paper though but done to scale, one from front, back, side and top. not got any decent diags of the chassis yet,
but ive done a few rough sketches...
dont have any measurements for engine/tranny etc, but working on it...