Engineering a sway bar

[Omaliyo]

First off awesome out on the project!

Are you getting your BS or MS in mechanical engineering?

I'll be going to FSU to get my BS in ME..... Can't wait to be designing projects like this..... Love all the calculations and time that goes into things like that...

Your draft of the parts is completely diff from how im learning how to draw lol (measurement layout wise)

[Aptyp]

awesome project

[TwoJ's]

why not make a sliding mount for the ends so you can adjust the stiffness? (AKA GC's solution)
You could sell a ton of front swaybars with that configuration.

Now that I get to thinking about this, I am not sure that I have seen GC's version of the adjustable sway bar. Do you have a link or a picture that will show the "sliding mount"? I have seen some like IE's adjustable sway bar that simply has three holes in it, but this is not a desirable solution and is just an easy way out. I would be interested in seeing what this sliding mount is that you're talking about.

I think that if I were to go this route, I would not want any moving parts on the bar itself.

Edit: I google'd and found something that may be what you're talking about. I know this isn't the right bar, but is this similar to what you are talking about?

[TwoJ's]

I remembered that I had some pictures from an abandoned design for the bar ends. A while ago I was waiting on my material to arrive, so I went to the machine shop and made up some bar ends that I intended on using.

There just happened to be some 1" 4130 bar at the lab that was to be used for Jominy tests for the metallurgy course. I turned down a .5" length, .750 diameter section that would be fitting inside the sway bar.



I then had to take it over to the mill. I wanted the thinner portion to be cut with a relatively tight tolerance so I chucked it in this indexer. I used a dial indicator to ensure I had everything mounted properly and made the cut on one side. Without annealing, 4130 is not the best material to machine, so I was only taking .010" off on each cut. That wasn't bad, just made it monotonous. After making the first cut I just rotated the indexer 180 degrees, set the table accordingly and went for it on the other side.





I then rotated it 90 degrees and made the hole.



In the end, it looked good enough, but I wasn't satisfied. With this design the part that the links would bolt to is parallel with the bar and I had intended to change the geometry of the bar to accommodate. This design was also flawed because I did not leave enough of a radius for the adjustable links that I will be making to sit flush. I have since changed my design and as you can already tell, I am keeping the stock geometry. Next week I will make the ends.

[fryerfighter94]

And this is for a class for mechanical engineering? Interested in taking same major, getting emails from colleges already. Mind if I ask about the classes and what kind of stuff you do, and how its applicable (i.e. where do you plan to use your engineering, motorsports, you mentioned suspension analysis). Cool project good work on it too!

[TwoJ's]

Are you going to heat treat the bar? The area's at which you are welding are going to anneal and have internal stresses still. It has to cool from 1550 °F at no faster than 50°F per hour until 900°. Then air cooled. Do you have a furnace to accommodate this control?

Very cool project!

Thank you. Where are you getting these numbers? I'm not denying anything, just curious. The TTT's, and input from a number of sources would disagree with you. There is definitely a stress concentration like I stated in the OP, but I believe that stress-relieving with an oxy-acetylene torch will be sufficient.

why not make a sliding mount for the ends so you can adjust the stiffness? (AKA GC's solution)
You could sell a ton of front swaybars with that configuration.

You know, I have pondered this. I originally wanted to make it as simple as possible because I thought I would have to spend way too much time sending the material to someone that had a CNC bender and the proper die. Now that I have gotten it nearly complete, I will consider other design considerations.

And to be honest, I don't know if I want to sell a bunch of parts. First, I would have to make a completely new jig. The one that we used before was welded to the table in the welding lab and it just can't be left there. I would have to make something that could be stored in a relatively small place. Also, the time I have already and would be putting in to the development is quite significant. I likely would get quite efficient at making them, but with the cheap ass e30 community I really don't see it as being feasible. IE will keep me from being profitable because they likely have their shit made in China.

Having said all of that, I did bend a second bar with half-hearted intent on selling it. When I am finished with the project, I will figure out a price that I could operate at and then see if the market would allow it.

oh yeah duh hahah

i link i found about welding 4130 material

http://www.lincolnelectric.com/knowl...hrome-moly.asp

Yep, I was actually reading Lincoln's recommendations earlier. My materials professor also has some TTT diagrams that give me numbers to back up my decision.

[erik325i]

Very cool project.

Erik

[!kid]

He has to weld the end pieces on. Very cool project.

oh yeah duh hahah

i link i found about welding 4130 material

http://www.lincolnelectric.com/knowl...hrome-moly.asp

[Skafrog]

why not make a sliding mount for the ends so you can adjust the stiffness? (AKA GC's solution)
You could sell a ton of front swaybars with that configuration.

[HarryPotter]

i dont think he was welding on the bar.

He has to weld the end pieces on. Very cool project.

[!kid]

i dont think he was welding on the bar.

[learningcurve86]

Are you going to heat treat the bar? The area's at which you are welding are going to anneal and have internal stresses still. It has to cool from 1550 °F at no faster than 50°F per hour until 900°. Then air cooled. Do you have a furnace to accommodate this control?

Very cool project!

[Colorlesss]

$ shipped to 18018 ?

[kishg]

very nice..

[TwoJ's]

Thanks guys.

what kind of material are you using for the sway bar? just a mild steel ?

No, it is 4130 1" OD, .120" wall Cold DOM.