thanks
al
finally got round to posting up my solidworks designs of my chassis! i changed a lot! can anybody see any glaring mistakes? i prefer twin rollbars so
had to change the back portion to support that, is the redesign sufficiently strong? alos added a trany tunnel similar to a westfield to accomodate
mt75 box (the westy design i used incorporated the mt75) also a diagonal rear crossbar for rear impact protection as i had to widen the ditance
between the rear vertical tubes, and i few other mod i cant remeber, what do u all think? red is added, blue is modified, yellow is modified from the
book measurements simply to fit, and green is stuff i need to change later
thanks
al
just an idea but I like a second rail the full width of the car for the roll bar mounts ect
i'm not sure if its worth some kind of triangulation under the seats? i forgot what the book chassis' like. just seems the floor of the chassis is very square
quote:
Originally posted by big_wasa
just an idea but I like a second rail the full width of the car for the roll bar mounts ect
i'd run the back braces for the roll hoops down to the back corners of the chassis onto a plate in the rounded corner.
also i'd swap the top braces in the engine bay for y braces running to the top of the fu tubes. as they are, they do very little as the top side
rail will offer no support.
yeh the second rail idea is a good one i was thinking that the chassis plate were a little flimsy! triangulationwise i dont know what is needed both the book chassis i was looking at and the westfield drawings dont have any triangulation under the seats but i agree it would seem like it needs it there... good idea about bringing the stays down to the bottom, only problem i could think of is would the angle then be a little shallow-also the bars might then encroach on the fuel tank...? what do you mean about y braces?
Not a Y brace but better than the short braces you have.
The top two braces that run from your bulk head to part way down the top rails.
front rack mounts will need more bracing aswell
If i had some pictures id post them, but ive just done my roll bar exactly as the suggestions, seems plenty strong enough. Mine bolts in, and your right it does foul the fuel tank but i just cut two scallops out of it and welded plates back in to clear it. With your welded in rollbar, can you actually get a fuel tank into position? I didnt like the idea of going back to the top rail without putting more triangulation in (looking sideways on the car) from roll bar base straight back to top rail where the rear stay mounts to stop it all collapsing backwards in an accident, but then that would serverely restrict the size of tank you could get in.
this is what i mean.
tom
Rescued attachment y brace.jpg
my mk does'nt have all that extra triangulation!
(http://www.locostbuilders.co.uk/photos.php?action=showphoto&photo=2DSC00111.JPG)
I dont think it needs it , if you keep adding bars and all that extra weight you might as well drive an off the shelf car and if weight is not an
issue and your after better crash protection drive one of these
(http://www.locostbuilders.co.uk/photos.php?action=showphoto&photo=well%20build%20will%20survive%20a%20crash.jpg)
i hear there good in an impact but heavy on fuel.
^^^ I agree - however if you are going this route I would add additional triangulation for the Roll Bar bracing as shown in yellow below.
Of course if the chassis is fully braced then you might get away with 19mm steel instead of 25mm - however you would need to get a profesional FEA
done to check
Description
thanks for the ideas, what is the average weight of a chassis, does anyone know? ive done an analysis on what ive got so far and it wil weigh around 100kg (103) is that hefty? also that diagonal bracing for the rollbar is a good idea i may well add that , the y bracing looks interesting, but ill run an fea to see what tubing i can get down to safely in places to lighten er up, and see if that will really make much of an impact (the top of the engine bay as it is, is almost exactly the same as the top of a westfield bay)
search for posts by cymtriks on fea. liam also did some fea on his chassis and both came to the asme conclusion. the R tube is very important to
torsional rigidity of the chassis.
following a manufacturer's example doesn't neccesarily mean it's correct. an MK is missing all sorts of tubes in the engine bay that
would probably help.
tom
Are there any suppliers who offer heavy guage roll hoops, or do you have to commission your own?
im going to have to get them made i think as id rather know that my head isnt going to become closely aquainted with the ground if the worst happens! so ill be getting in touch with some people and getting it done 1 off! spensiveeee
hellbent345
Well done!
It looks pretty nice in SW.
I have done a comparable design in SW and the weight [without the foot well,plates] is 66Kg.
How much is yours?
Watch out for the suspension components, that will make or kill your car.
Regards,
Cobra289
quote:
Originally posted by hellbent345
thanks for the ideas, what is the average weight of a chassis, does anyone know? ive done an analysis on what ive got so far and it wil weigh around 100kg (103) is that hefty? also that diagonal bracing for the rollbar is a good idea i may well add that , the y bracing looks interesting, but ill run an fea to see what tubing i can get down to safely in places to lighten er up, and see if that will really make much of an impact (the top of the engine bay as it is, is almost exactly the same as the top of a westfield bay)
8 guage :O! ive done a bit more on the design taking quite few cues from the caterham rs (V8) the chassis weighs a bit over 100kg cobra, i think i
shelled all the members but i cant be sure so thick members may be part of the cause! i recon if i lifted with my knees i could prob lift up 100kg
with one hand but only for a split second, does that count? ill post up the pics of the design, itll be mainly bodywork im fraid!
al
quote:
Originally posted by hellbent345
[img]
I had a go at a nosecone ages ago. See here...
http://www.locostbuilders.co.uk/viewthread.php?tid=37702
It was really just to learn a bit about using the 3D surface features with a minimal number of profile sketches. As such, it's dimensionally
reasonable but certainly not an 'elegant' use of Solidworks. I had all sorts of problems thickening to solids and it's ended up with
over 30 unmerged solid bodies etc etc. Anyway it served its purpose and you can get it at that link.
I guess the 'proper' accurate way to do it would be painstakingly measuring up the real thing and building up cross section profiles, say
every inch, the lofting between them, shelling, trimming etc - i.e. the computer version of building a wooden mould for replica bodywork. Or using a
package more geared for abstract 3D shapes.
Liam
yup that would be the way to do it, i lofted in rathr larger stages with guide curves and it didnt give me exactly what i wanted, but near enough to
look alright, that linky was good when im next on my cad computer ill download them iles, i have my nosecone file cobra if u want it? its rather rough
but ur welcome if u want it (2008 file, or parasolid) im still at the stage of not knowing how front uprights work so i cant design them, i know about
the cortina upright part, but i dont know how the wheel then bolts onto the shaft, plus people say shaft through bearing is beter than some other
method but i dunno whats up! anyone got an exploded drawing of a fully assembled front upright, bearing hubs and all? thanks for kind words!
alan
quote:
Originally posted by hellbent345
yup that would be the way to do it, i lofted in rathr larger stages with guide curves and it didnt give me exactly what i wanted, but near enough to look alright, that linky was good when im next on my cad computer ill download them iles, i have my nosecone file cobra if u want it? its rather rough but ur welcome if u want it (2008 file, or parasolid) im still at the stage of not knowing how front uprights work so i cant design them, i know about the cortina upright part, but i dont know how the wheel then bolts onto the shaft, plus people say shaft through bearing is beter than some other method but i dunno whats up! anyone got an exploded drawing of a fully assembled front upright, bearing hubs and all? thanks for kind words!
alan
Why do people always want to do this?
wouldn't it be easier just to remake the tie road the right length?
Rescued attachment Untitled-1.jpg
quote:
Originally posted by Doug68
Why do people always want to do this?
wouldn't it be easier just to remake the tie road the right length?
quote:
Originally posted by Doug68
Why do people always want to do this?
wouldn't it be easier just to remake the tie road the right length?
i would say that mine is the same as yours chap, and i just did mine to fit a bonnet that i just did so that it all looked right! im fiberglassing it
all myself anyway, but i need the sw drg to get dims for laser cutting mdf for the buck! you are still welcome to it if you desire! also what would be
reqd to make a tie bar rather than an extension out of interest 
alan
just an update on the build, ive now finished my build table and put on all the wooden blocks! and got my steel 
welding next woop!
the chassis bench
the steel!
quote:
Originally posted by hellbent345
i would say that mine is the same as yours chap, and i just did mine to fit a bonnet that i just did so that it all looked right! im fiberglassing it all myself anyway, but i need the sw drg to get dims for laser cutting mdf for the buck! you are still welcome to it if you desire! also what would be reqd to make a tie bar rather than an extension out of interest
alan
oh and i gave one of the calipers a lick of paint (poor quality paint, dont buy from waxacar off ebay people, it takes about a year to dry fully!)
what thinks you?
alan
quote:
Originally posted by hellbent345
oh and i gave one of the calipers a lick of paint (poor quality paint, dont buy from waxacar off ebay people, it takes about a year to dry fully!) what thinks you?
alan
Thanks cobra!
theres no way to make it (the steering extensions) from one piece?
i still havent done the fea on the chassis so i cant go much further until im absolutely sure that it will be stiff enough for my purposes and more
importantly survive a rollover situation!
Nice surface work on your nosecone, it looks a lot better than mine now, i think i should give surfaces a fair try now, as ive been using loft and
shell up to now, and its been giving..... mixed results lol
about the paint, its hard now, but i can still pick it off with a fingernail dunno if thats my fault or the paints! maybe i should have put it in
an oven? its supposedly heat resistant as well, i dont know if its therefore designed to be applied on the car, then the heat of the brakes working
cures it...? anyway i wasnt happy with thier communication so i still wouldnt recommend
[Edited on 19/8/08 by hellbent345]
quote:
Originally posted by Cobra289
quote:
Originally posted by hellbent345
oh and i gave one of the calipers a lick of paint (poor quality paint, dont buy from waxacar off ebay people, it takes about a year to dry fully!) what thinks you?
alan
Hi,
I have had the same problem with a good brand aerosol.
It was red and it was for the brake caliper of my Cobra, I can say that after waiting for a week I could install it without picking the paint. But till today [3 years] that paint remains in very good condition.
It was a heat resistant paint.
Regards,
Cobra289
quote:
Originally posted by hellbent345
Thanks cobra!
theres no way to make it (the steering extensions) from one piece?
i still havent done the fea on the chassis so i cant go much further until im absolutely sure that it will be stiff enough for my purposes and more importantly survive a rollover situation!
Nice surface work on your nosecone, it looks a lot better than mine now, i think i should give surfaces a fair try now, as ive been using loft and shell up to now, and its been giving..... mixed results lol
about the paint, its hard now, but i can still pick it off with a fingernail
[Edited on 19/8/08 by hellbent345]
if i was to change the plates for that second rail, would i have to keep the plates to attach the rollbar to? i want to add it anyway i think its a good idea, but i dont know if there would be any reduction in weight, only an addition..?
quote:
Originally posted by hellbent345
if i was to change the plates for that second rail, would i have to keep the plates to attach the rollbar to? i want to add it anyway i think its a good idea, but i dont know if there would be any reduction in weight, only an addition..?
update on progress, ive made a good start of getting the chassis welded up, got a few piccies here
quality of some of the tack welds (co2 btw)
i had a bit of a fire
Nice job,
Looks pretty! be careful and keep some safety stuff around the work area, a large blanket helps a lot.
If you remember and have the time can you please pass the file of the box?
Best regards,
Cobra289
[Edited on 2/9/08 by Cobra289]
Nice job,
Looks pretty! be careful and keep some safety stuff around the work area, a large blanket helps a lot.
If you remember and have the time, can you please pass the file of the box?
Best regards,
Cobra289
About the steering arm extensions; on a Dax Rush they seem to consist of welded parts: the weld is just beneath the thick section in this picture.
quote:
Originally posted by Mave
About the steering arm extensions; on a Dax Rush they seem to consist of welded parts: the weld is just beneath the thick section in this picture.
Hi, im new to this, have been using this site during my build, suggest you add some tubes in front sections for wishbones mounting strength as has been suggested previously (studies done by uni)
Hi, im new to this, have been using this site during my build, suggest you add some tubes in front sections for wishbones mounting strength as has been suggested previously (studies done by uni)
you have email cobra sorry it took so long chap!
can you confirm what you mean about the wishbone strengthening andy? is that the y bars? ill put pics up later but i think ive decided to put y struts
in, but have the long peice running from the front to the v's at the back removable, a bit like a strut brace but at 90 degrees obviously, so
there is more room to get the engine in and out if need be what do people think?
if you search using cymtriks, he has drawings etc for the chassis mods, i have added all that he has suggested, & some extra ones for roll cage mounting posns, as i have incorperated a full cage on mine.
Any welded component in the steering arms is an automatic SVA (and MOT) failure, which is why everyone uses screwed extensions and locknuts. This is
the equivalentof the track rod/track rod end connection.
That steering arm may be on a Dax, but it isn't how Dax extend thelrs.
Cheers
Chris
getting on with my build, ive fully welded most of the chassis now, just got a few worries about the bleedin size of my engine! but here are the pics
Looking good!
Awww that little engine looks tiny in there! No excuse for not going for the proper engine bay 'R' tubes - you know it makes sense!
Liam
haha yeh, that baby is so monsterous im going to get it all fitted and then put removable y tubes in a think! otherwise im never gonna fit anything in i dont think!