Cad Drawings and open frame design

Eric · 04-11-05, 11:35 AM

I have been kicking around an idea for quite some time now and I was wondering if it would work. All the talk about which frame is stronger recently has made me decide it is time to ask.
I want to start a co-operative frame design where I take all the cad drawings I have done for my frame and post them (I would do jpg's too for those without acad to be able to contribute ideas)free for all to see and use. The idea being that people would take them, mod them as they see fit and re-post what they have done. I know there will be alot of freeloaders and people who are not able to offer any improvements, in which case, a donation to the forum would be urged but it will all be voluntary. I have designed my car around the c5 vette suspension as trying to get a car with suspension that is not off of a road car through inspection is next to impossible, but I do have access to rough dimensions of the original suspension, (+ or - an inch).
I am not quite ready yet to post it as I have some cleaning up to do and I dont have the roll cage built as I am waiting to finish the molds and make a body first so I know that everything is right and fits.
So, am I wasting my time? Is there anyone that would contribute? Any thoughts on the idea at all?? I think in the end, if this works, collectively we could build the strongest/lightest frame that would be possible.
p.s., I know alot of you are going to say that there is more bracing needed here and here, but, keep in mind, this is not a finished drawing, by any means.

Chris P. · 04-11-05, 12:05 PM

I love the idea, except I am not making a GT40 - however, we may still benefit from component drawings. For instance, I need a windscreen CAD model (in the event that I end up using a GT40 windscreen), steering rack, etc... I am using SolidWorks - what are you using?

Mark Worthington · 04-11-05, 12:20 PM

Cool idea.

Eric · 04-11-05, 01:50 PM

I am using ACAD, I'm no expert but is it not possible for the 2 to save as a dxf file and share?? As for stuff like windsheilds and the like, I have zero ability to do compound curves, that stuff you need to find elsewhere.
Obviously, if we do this, it has to be all our ideas, no "well XXXX manufacturer does this so lets do that". It all should be our own thoughts or it just defeats the purpose.

daveg · 04-11-05, 02:22 PM

Brilliant idea Eric. I am a total newby with CAD, using DeltaCad mainly and am trying to get to grips with Autocad 2005 [img]/ubbthreads/images/graemlins/confused.gif[/img] Interesting rear suspension, unequal length wishbones? am playing around with semi trailing arms at the moment. As a matter of interest how many scratch builders are there out there?

Chris P. · 04-11-05, 02:50 PM

I don't know what your budget is, but have you seen Alibre CAD? I have read good things about it - It is $600 and $1000 with a bunch of other goodies. CADKEY is now KeyCreator, don't know price or how good it is anymore. FreeCAD may have useful software as well.

Anyway, I agree - no copying other designs, except for maybe critical components. Again, the only problem is I am not making a GT40, but hopefully some components may be the same or similar.

Windscreens wouldn't be too difficult in your case because the method you would require to model it is basically the same method I would have to use in a 3D solid environment - 2D slices and a loft through those cross sections. SolidWorks can output just about anything including ACAD .dxf and .dwg, but I'm not sure if it is constrained to 2D output in those cases. I believe even in ACAD .dxf is strictly 2D - right?

Dave - I am a scratch builder - trying not to hijack this great website but using it as an access point to lots of knowledge and experience. That's something I need to keep in mind - Ron obviously does a lot of work keeping this site running for the GT40 guys, but it's invaluable to anyone else doing a replica or scratchbuild of any car.

I remember back to ACAD10 - I started a 3D design of a 1/4 scale F1 R/C car (never finished, but I did get very far on a fiberglass body plug). I know 3D is doable on later versions - you guys ought to give it a try. You should find out what solid file nuetral formats you can import (I know that ACAD2000 can import ACIS, although they are a pain). When I get around to modelling up things like a steering rack, tranny, etc... if it's the same unit you are using, you can easily use what I have already done.

Eric · 04-11-05, 06:30 PM

The rear suspension is unequal upper/lower A arms with a tie rod end also (very easy to do rear wheel steer if I wanted).
I am using acad 2005, I know I can do simple 3d shapes but stuff like the body work is way out of my league. I might be able to do a windsheild but not well. As for all the other acad stuff, I have no idea what will read what and how, if someone knows any better, lets hear it.

Devin · 04-11-05, 10:29 PM

I think this is a great idea...I could help with body dimensions since this is what I have been researching in order to make my frame design. I have access to most of a body if we need more specific measurements.

I have been making my initial chassis drawings on paper since I don't have access & skill to do it via a computer at this time.

My initial design is based around a Mustang II front suspension and Thunderbird IRS hubs for the rear.

Let's get started!

Paul Bearman · 04-12-05, 06:37 PM

Sounds good to me Eric.
I use AutoCAD 06/LT as well as Inventor. I've recently purchased Alibre & have been impressed with it's simplicity & ease of use. I will be using Alibre to update a 3D drg of the GTD chassis I completed last year. I'm by no means an expert but will certainly throw in my 2 cents worth.

Kalun D · 04-12-05, 07:08 PM

I'm interested, but I'm not painting my roll bar pink, no way.

pmerrick40 · 04-13-05, 07:09 PM

I'm interested too, but I'm not too sure how much help I can be. As I've no chassis design experience whatsoever.

I've been thinking of scratchbuilding a spaceframe GT40 chassis for a while, simply to save money for elsewhere in the build, but getting hold of chassis drawings was proving difficult, until now it seems.

At the moment I'm looking to use Mk3 Ford Granada rear hubs and brakes with Sierra front hubs and Granada brakes, but this may change depending on what I can get my hands on here in the UK.

I have a little experience in AutoCAD, mostly 2D, but to be honest I still prefer to lay out my drawings using my trusty drawing board.

I look forward to seeing how this thread progresses.

Paul

A newbie.

Paul Bearman · 04-17-05, 06:18 AM

We've just purchased the latest IronCAD software. I haven't had chance to use it fully yet but it does appear to be simpler than some of the other 2D-3D software I have previously used. Anyone else used this?
Web site: IronCAD
Below is an image of a chassis as posted on their web site from CARBONTECH.

jpkuehne · 01-28-07, 10:02 PM

Nice design - at least what I can see. I'm curious why they chose to go with the pushrod/bellcrank/midline coilovers - kind of seems like bling to me, at least on the front - unless they're trying to unload sprung weight.

Pretty designs, but a lot of work if it's JUST for show. And you've got to stuff a radiator in there somewhere too. Now if it's for a formula car, well then that would make a bit more sense...

Chris P. · 01-29-07, 10:07 AM

In racing, time is everything when it comes to testing. Putting the dampers / springs in one spot where you can quickly and easily get to them both (and the sway bar) saves lots of time. Also, it's an effort at descreasing unsprung weight.

Lynn · 01-29-07, 11:50 AM

Eric,

I like the drawings you posted! I have to say that I thought your VW dimensioned chassis was nice, but a little over built perhaps. I think you are definitely headed in the right direction.

As you all can, no doubt, tell, Eric is not a newbie at this. I think his talents will be valuable here at GT40s.com!

Lynn

arking · 01-29-07, 11:13 PM

Hi everyone,

This is an interesting idea. Like others, I'm presently designing a chassis, but it is not for a '40. It would be nice (and motivating!) to have others to chat with during this portion of the project. I'm in the process of getting all my dimensions so I can start loading the frame into a FEA package. Does anyone have the dimensions of C5 'vette suspension components, front and rear? (I keep waffling back and forth between the 'vette suspension and a S2000)
I don't know how interested you'd be in my type of frame design--the plan is to have a center tunnel--but I'd be willing to correspond with all who are interested. Count me in...

Aaron

Eric · 01-31-07, 01:49 AM

Arking- go here Performance Trends and download the suspension analyzer program. Install it, inside you will find that someone has gone through the effort of measuring all the C5 suspension points. It is accurate. If you want to do the S2000 route, next time I get one in the shop, I could measure it up as best as possible with a tape measure but you might have to clean up some of the dimensions. I think I would probably go with the C5 stuff just for the fact it is alot beefier looking.
Lynn- I gave up on the VW stuff, just didnt look right. I made some molds with a friend of mine who did the body resto on 1024 and the 2 of us are putting our efforts together so we can both have one. If all goes well, 1 should be running by August. It has been a long road and I trashed my back last march and have just started working again, which is why this hasnt really progressed anywhere. I have been working on it again now and hopefully in the next 2 months or so I should have the cad stuff finalized.

Chris P. · 01-31-07, 02:23 PM

Hey - I was just at a SolidEdge presentation and found out that they offer FOR FREE a complete (I believe it's complete) 2D drawing package.

Check it out: Solid Edge Free 2D Drafting Software - Version 19 - SolidEdge is one of the leading mid-market 3D CAD systems, so I'm assuming their 2D package is really good. It's a 239MB download and you do need to fill out a registration form so they can email a license key. It's only for Windows XP. Have at it!!!

Jeroen · 01-31-07, 05:01 PM

Hello,

As you can see in the newbie section I also designed my frame in 3D. I used the drawings from the site of http://www.webguy.ca/downloads/kitcarplans/kitplans.php. It looks like the chassis of a GTD but i read on different sites that the dimensions of the drawings where incorrect; so fare it looks good to me.
Keep up the good work and I'm always open for new ideas.

Greetings
Jeroen