Suspension analysis programs

[slngsht]

Any good free ones out there?



I actually started playing with my own - just to play around... so far I have the roll center calculation down, can rotate the frame, calculate lower ball joint position. I kinda stopped at the upper ball joint, but it's not that hard. Of course my little model doesn't do anything with steering, etc... and since I can see how it all works, I'm not as motivated now http://www.usa7s.com/aspnetforum/images/emoticons/lol.gif



So, I just want to play around with one that's already working before fabbing up my front suspension.



The only free one I know of is "wishbone" which is DOS based.

[slomove]

Come on, we are professionals.....



You need > this (http://www.design-simulation.com/DDM/SolidEdge/ddmp/index.php) http://www.usa7s.com/aspnetforum/images/emoticons/biggrin5.gif



You don't even need to drive your car anymore. Just simulate the fun http://www.usa7s.com/aspnetforum/images/emoticons/cryin.gif







Gert

[slngsht]

good lord man. I already spend too much time on the computer http://www.usa7s.com/aspnetforum/images/emoticons/lol.gif

[scannon]

There is a suspension design spreadsheet available on the Miata.net forum. I haven't used it so I don't know how good it is.



http://forum.miata.net/vb/showthread.php?t=32121



Skip

[slngsht]

Thanks Skip. I think that one helps with roll bar, etc...



I'm looking for one where I can design the general suspension layout.



I will keep that one handy though. http://www.usa7s.com/aspnetforum/images/emoticons/cheers2.gif

[slngsht]

Still playing around with this... I need to finish doing the contact patch calculation to get a better roll center result, but things are looking promising.



My calculations are still off compared to an off the shelf program that I have, but all the basics should be correct, so it's a matter of debugging what's going on.



Here are a couple of screenshots of a little graphic I put together to visualize what's hapenning.



http://www.usa7s.com/forum/uploads/20070324_215047_RollCenter1.JPG



http://www.usa7s.com/forum/uploads/20070324_215129_RollCenter2.JPG

[slngsht]

http://www.usa7s.com/aspnetforum/images/emoticons/hurray.gif significant improvement tonight...



My numbers are very comparable to Roll Center Calculator by Performance Trends http://www.usa7s.com/aspnetforum/images/emoticons/thumbsup.gif



At 4 degrees roll, with the same setup, they get:



RC(X,Y): 3.8,3.7

Camber left: -1.15, right: -5.22



I get

RC: 4.04,3.69

Camber left: -1.14, right=-5.21



I need to improve the location of contact patch in my program, as I did a quick and dirty calc on that one. Everything else should be dead on.



This was a little easier than I thought.



http://www.usa7s.com/forum/uploads/20070326_220015_RollCenter3.JPG

[bsimon]

http://www.mitchellsoftware.com



Pretty good stuff, although 500 clams might be a bit out of range for most of us. You can get a no-save demo version with Warren Rowley's book "An Introduction to Race Car Engineering" at;



http://www.rowleyrace.com/publications.htm



If you are serious about suspension design, the Rowley book is a great resource to have around. A bit more detailed than Van Valkenburgh's work.

[slngsht]

I had used Mitchell years ago... in the late 80s

[sb427f-car]

Are you using macros to change it? I wish I had been a member of Delaware's SAE team (kicks self in arse). I remember one guy messing with excel and macros and had an excellent setup to calc. out all that stuff.



Oh well...things happen for many reasons, guess I shouldn't complain. Definately post up your finished excel product. Additionally, there is one on the locost board, but not visual in nature.

[slngsht]

Yes, basically vbscript.



Got the pushrod setup working tonight. I think I'm going to stop here - these are the pieces I need for the new front suspension.



http://www.usa7s.com/forum/uploads/20070327_232202_RollCenter4.JPG



http://www.usa7s.com/forum/uploads/20070327_232237_RollCenter5.JPG

[sb427f-car]

I've been so busy lately, this has taken a back burner...but please (if you're willing), post up your program!

[slngsht]

I've been so busy lately, this has taken a back burner...but please (if you're willing), post up your program!



I want to add a few lines to it and make it available to club members as a benefit http://www.usa7s.com/aspnetforum/images/emoticons/yesnod.gif



I have to do some cleanup to it now since I added the bellcrank and pushrod.