Steel Bell Cranks/Rockers

[ScottW]

Just curious, for those who've fabricated their own bell cranks or rockers from steel, what plate thickness(es) have you used?

[ScottW]

Just curious, for those who've fabricated their own bell cranks or rockers from steel, what plate thickness(es) have you used?

[Marshall Grice]

.049, .065. could probably get away with .035 with out too much trouble. depends on how much time you have to analyze.

[TGrau]

We have used 0.090" for a number of years now and haven't had any problems.

[kwancho]

I would be worried most about it getting bent or out of plane on some way. Why wouldn't you cut the same weight rocker out of a thicker piece of aluminum, which would resist bending better?

[WAM BAM]

For those who've been to outer space, how much moon juice does it take to get the moon(s)?

Why do you bother answering questions like this? Be an engineer and figure something out for yourself. Your questions shows about as much understanding and mine does...

[ScottW]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">For those who've been to outer space, how much moon juice does it take to get the moon(s)?

Why do you bother answering questions like this? Be an engineer and figure something out for yourself. Your questions shows about as much understanding and mine does... </div></BLOCKQUOTE>

This is obviously a person of great intellect. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Marshall Grice]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Why do you bother answering questions like this? Be an engineer and figure something out for yourself </div></BLOCKQUOTE>

damn, calm down. It doesn't hurt to ask for a little validation every once and a while. Not like he was asking how to design rockers from scratch.

[HenningO]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Alex Kwan:
Why wouldn't you cut the same weight rocker out of a thicker piece of aluminum, which would resist bending better? </div></BLOCKQUOTE>

The resistant from bending mainly comes from the fact that you have separated the two sheets of metal by a certain distance. Think sandwich!

[NetKev92]

I thought that we were all about that standing on the shoulders of giants stuff. Nobody here invented the racecar or discovered F=ma, so what's wrong with learning from each other? Besides, how do you design a structural part if you don't know the true loads? You've got to make a lot of assumptions and you could just end up with garbage. Sanity checks are great. At the least, his part shouldn't be any lighter than yours if he can't do the analysis to perfect it.

On Moon Juice:
http://www.nasa.gov/mission_pages/constellation/ares/index.html

[kwancho]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by HenningO:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Alex Kwan:
Why wouldn't you cut the same weight rocker out of a thicker piece of aluminum, which would resist bending better? </div></BLOCKQUOTE>

The resistant from bending mainly comes from the fact that you have separated the two sheets of metal by a certain distance. Think sandwich! </div></BLOCKQUOTE>

Yeah, you're right. I'm just thinking of some weird worst case scenario where something pushes up at some odd angle.

[NetKev92]

Alex, Henning, you both have points. With bent sheetmetal, you can get that depth between your structural elements for bending strength like a sandwich panel as you describe. If you wanted to make a machined or cut-from-plate part, aluminum might be nice because you can use almost 3 times the thickness for the same weight. You just go for the required bending strength one way or the other.