Cad Drawings and open frame design - Page 2

Lynn · 02-02-07, 01:22 PM

Catia huh, that is some high dollar software and very powerful. It is used by either Boeing or Airbus (maybe both) for aircraft design. (I am a former software engineer for IBM -not for Catia, but I am aware of it as we made some ancillary accessory software for Catia as part of our systems management software fka Tivoli.)

Lynn

Eric · 02-02-07, 09:34 PM

Hiya Lynn,

It sure aint cheap! Catia is the standard software for most all of the automotive industry as well as aerospace.

I have a seat of it at home, and at my office. I have used it in working for Brembo, Ford, Ferrari, Prodrive, and so on.

Catia V4 is the standard, and the new version V5, runs more like solidworks, (catia bought solidworks). So it has simplified the program a bit for the user.

So lets see if we can fool around with it and make some stuff!

Eric

arking · 02-03-07, 01:19 PM

Eric D.

What kind of tubing is being used in your last example picture? The round tubing inside the square with the webbing in between.

General question for all,

In looking at the two '40 frame designs posted to this thread, there appears to be little attempt to triangulate the structure and avoid bending moments within chassis members. I'm assuming this is just to aid in the quick buildup of the frame and that a hit will be taken with the added weight required? Is there any interest in a fully triangulated chassis? I've been working on a triangulated design, and I have to admit the frame looks close to the GTM chassis of Factory Five, particularly the front end.
GTM frame design (FFR)
My ideas diverge from FFR a bit as you move back, though I haven't started analyzing the setup yet---anything can change once that starts. The plan right now is to analyze the structure using a simplified FEA (beam) to shape things up, then figure out if I want to create a CAD model and due a full blown FEA.
How is everyone else visualizing the design/analysis of the shared frame?

Eric · 02-03-07, 09:15 PM

Hi Aaron,

The Chassis tubing you are referring to is an aluminum extrusion.
It is actually a square tube, that has a central round tunnel with an "x" frame from each corner. This allows it to be a conduit for wiring, fluid tubes, etc. It is very strong and very light. I will try to dig up the specs.

That chassis is bonded/bolted/welded together in the same manner as a Lotus Elise chassis

Cheers
Eric

Eric · 02-06-07, 11:09 AM

Quote:

Originally Posted by aaron.king

In looking at the two '40 frame designs posted to this thread, there appears to be little attempt to triangulate the structure and avoid bending moments within chassis members.

My pic is raw. I built that to get the general dimensions right for the chasis to fit suspension and body. I didnt do any triangulation in that pic. Right now it is alot further along.

Quote:

Originally Posted by aaron.king

Is there any interest in a fully triangulated chassis?

That is kind of the idea. Some people have access to FEA programs so could run them through while others have access to dimensions and can supply that, and there are suspension experts looming too. In the end, we could make a killer chassis.

Quote:

Originally Posted by aaron.king

How is everyone else visualizing the design/analysis of the shared frame?

I am just going to post up my DXF file with all the details (what suspension, steering rack, wheel offset and tire size etc.) and people can take it, modify it and re post the file with what changes they made and why. It might end up just being a leech fest for those after dimensions but I dont care. It was alot of time and effort spent measureing everything, no point in hogging it and letting it go to waste.

JohnC · 02-06-07, 02:26 PM

An Open Source GT40 chassis with all plans out in the public domain to be progressively improved upon by an unsung army of bored designers and engineers? Sounds as good as Linux!

Don't forget to include the GNU GPL license and copyleft agreements.

Paul Bearman · 02-06-07, 02:46 PM

I have CAD drgs of the MKI & MKII bodies if anyone wants them. They are not completely accurate but are good enough for body fitment as wheel ctrs, body height door location etc are correct.

Paul Bearman · 02-06-07, 03:02 PM

Forgot to add jpeg

Devin · 02-06-07, 03:35 PM

Rumor has it that the FFR GTM concept started as a GT40 replica but they didn't want to get into the whole legal battle again like what happened with their "cobra" replica.

I was following their GTM concept since its skunk works beginning and know their original frame was a few inches shorter than it currently is (just happened to be the same wheelbase as a GT40) until they stretched it for the improved GTM body work they put over it.

My point is that their engineers put a lot of work into it for safety and rigidity and should fit with our modifications to fit under the GT40 body shells if our design goes that way.

Personally, if it performs better in both road manners and safety, I wouldn't mind straying from the typical spaceframe designs most companies are using right now. Rearranging things like the fuel tank location and battery to make it safer or more balanced and roomier in the cockpit is a sacrifice I would be willing to make for "originality" or whatever that is in a replica...

Devin

Eric · 02-08-07, 09:46 AM

Hey guys, I dont want to throw this thread off track, but I wanted to get a bit of feedback...
I have been drawing some wheels lately, and I liked the idea of a deep wheel with an old Cromadora or Campagnolo feel to them. Possibly for Gt40/Lola etc replicas, or whatnot (could be good for the RCR P4). This wheel is drawn in a 17x12.5 size.
If you guys like this type of thing, let me know, and if I should put this in a neew thread, i will do that too.

Cheers
Eric

arking · 02-09-07, 07:04 PM

Eric,

You'd probably get more exposure for the wheel in a new thread.

I think it would be neat to have a Campy look-alike, yet have it deal with the kind of characteristics (like larger positive offsets and diameters) that are popular today.

Aaron

Fuoriserie - Italo · 03-06-07, 08:57 AM

Quote:

Originally Posted by Eric D

Hey guys, I dont want to throw this thread off track, but I wanted to get a bit of feedback...
I have been drawing some wheels lately, and I liked the idea of a deep wheel with an old Cromadora or Campagnolo feel to them. Possibly for Gt40/Lola etc replicas, or whatnot (could be good for the RCR P4). This wheel is drawn in a 17x12.5 size.
If you guys like this type of thing, let me know, and if I should put this in a neew thread, i will do that too.

Cheers
Eric

Eric,
Nice wheel design and great chassis project
keep it up

Cheers
Italo

dimitris64 · 03-11-07, 03:26 PM

Hi everybody!I'm a newbie and this is my first post.A few words on my background first;My name is Dimitris,I live in Athens,Greece,I have some engineering studies and practice under my belt( that was 18 years ago but I revived it recently),and I love the GT40, among other things!I love its proportions,its shape,its stance,its history,Jacky Icx from whom I have an autograph etc.etc.!!But there are also points that I dislike;The rear suspension with these awful radius rods,the very stiff but incredibly complicated chassis,the placement of the fuel tanks outboards next to the passengers(safety & dynamics reasons) plus more. In other words I advocate an engineering "clean up" of the car the way Ford did with the GT,but in tandem with the means and abilities of the small guys,home builders and in my case wannabes.It's evident from the designs that nobody cares about engineering authenticity,why not start then from some modern principles?Central placement of the fuel tank(longitunally or transversally).Integration of the rollbar with the rest of the chassis and especially with the engine compartment.This goes hand by hand with the triangulation of the engine and rear suspension area.Modern rear suspension with unequal A arms,toe link and why not, pushrods for the more adventurous.A little space for a spare tyre(deflated and small size obviously) and some luggage!!Remember we're talking about a road car! How about functional windows?I'm sure there are talented engineers in this forum who could find a solution without altering the cars' character.There are many more ideas that can be presented and debated so that the design minded guys would put them into cad. I suggest that we do this in a more organised way so that it would make sense;how?I cannot say, i'm inexperienced with forums.The older hands must help here. Anyway thanks for tolerating me.
Greetings Dimitris

Henro · 03-12-07, 10:03 AM

I am busy with cad drawing for gt40 to and would like if u could e/mail me yours so that i can compare it with mine will send u mine so that u can have a look

Henro · 03-12-07, 10:05 AM

will u email me the drawing to veiw will send u mine just busy with syspention detail my e mail is henro@standerton.co.za

Fuoriserie - Italo · 03-12-07, 02:23 PM

Quote:

Originally Posted by Henro Pretorius

I am busy with cad drawing for gt40 to and would like if u could e/mail me yours so that i can compare it with mine will send u mine so that u can have a look

Could you post one of your Cad Drawings for us to see....

Eric · 03-12-07, 09:49 PM

Henro, not sure who you were talking to but I sent you a dxf file of mine. Keep in mind, it is not complete or "cleaned up" so you will find alot of usless lines and parts as you open up the layers.

Michael Fox · 03-22-07, 01:34 PM

does anyone have a windsrceen file i could use to test fit in my cad program?

TudorMiron · 03-31-07, 09:21 AM

Hi All,
It's my first post but I was fallowing this forum for some time now. I'm working as tech. director in racing team - very similar to F3. Have a bit of engineering background including CAD/CAE applications.

Here's my 2 cents.

jpkuehne - to my mind push/pull rod type suspension is not used not to just lighten unsprungs which is very important in itself. In formula cars aerodynamic cleanliness is nice advantage as you mentioned. In sport cars apart of unsprung mass, main reason is infinite possibilities with motion ratio – raising/falling or both at the same time.

Eric D – great models! Look mighty cool indeed.

Cheers
Ted

PS: Sorry for my English