Balanced suspension design
Balanced suspension design
(OP)
I am a member of the Purdue Mini-baja team and I recently began working on our suspension setup for the coming year. I was looking through Carroll Smith’s latest book, Racing chassis and suspension design and found a very interesting paper from Erik Zapetal SAE # 2000-01-3572
This design allows the four suspension modes to be independently varied and I believe this would be very useful for an off road vehicle such as ours. I am currently thinking about using a damper at each wheel hydraulically connected to four other pistons on the balance plate similar to what is shown here.
http://www.uspto.gov/web/patents/patog/week10/OG/html/1280-2/US06702265-20040309.html
I am hoping that such a design would decrease the weight compared to our current coil over shocks that each use two large springs stacked on top of each other.
Our mini-baja vehicles typically weigh about 450lbs and have about 12” of suspension travel using fully independent A-arm suspension. WE are also limited to 10 horsepower.
So I am looking for a more experienced persons thoughts on such a design or any additional information you may have about this system. I think this system would work well but I’m afraid it might end up being either to heavy, complicated, or expensive when compared to coil overs.
Here is a link I have found that is also related to the topic.
http://members.cox.net/rseike/nowarp/
Thank you for your help
Eric Eveslage
This design allows the four suspension modes to be independently varied and I believe this would be very useful for an off road vehicle such as ours. I am currently thinking about using a damper at each wheel hydraulically connected to four other pistons on the balance plate similar to what is shown here.
http://www.uspto.gov/web/patents/patog/week10/OG/html/1280-2/US06702265-20040309.html
I am hoping that such a design would decrease the weight compared to our current coil over shocks that each use two large springs stacked on top of each other.
Our mini-baja vehicles typically weigh about 450lbs and have about 12” of suspension travel using fully independent A-arm suspension. WE are also limited to 10 horsepower.
So I am looking for a more experienced persons thoughts on such a design or any additional information you may have about this system. I think this system would work well but I’m afraid it might end up being either to heavy, complicated, or expensive when compared to coil overs.
Here is a link I have found that is also related to the topic.
http://members.cox.net/rseike/nowarp/
Thank you for your help
Eric Eveslage
RE: Balanced suspension design
What sort of modelling software do you have? Could you build a full dynamic model and simulate its performance over 'typical' events?
I have a hard job believing that a 10 hp 220 kg machine with such short wheelbase and narrowish track needs to worry about warp, but then I don't know what you expect to be able to do, and how refined current designs are.
As a practical observation KISS has a lot going for it in off road applications.
Cheers
Greg Locock
RE: Balanced suspension design
A rock crawling event was added two years ago and all the teams struggle with it. Our solution last year was to use four-wheel drive. 4wd added about 50 pounds and 8” to the length though. So I am hoping to get better articulation with the balanced suspension and get rid of the 4wd.
A month ago my plan was to just keep a similar setup but refine suspension points and find better shocks. Some of the other guys wanted to use inboard suspension but I don’t see any real advantages to it.
I think your last line pretty well sums it up.
Thanks
Eric
RE: Balanced suspension design
If you are using ADAMS/View it should be easy to design your complex spring system from scratch. If you are using Car then it might be rather difficult, as you'll need to modify the template.
If you are using View look at the example for cable controls - it includes a god summary of how to write equation based linkages, which will be easier than modelling the linkage piece by piece.
http://support.adams.com/kb/faq.asp?ID=kb9364.dasp
Cheers
Greg Locock
RE: Balanced suspension design
RE: Balanced suspension design
RE: Balanced suspension design