Waterjet cut diamonds in my I-beam axle saturday!

Strapping the axle to a vibration table and running it through a few hundred thousand (or more) cycles would be a better test.

 

safe sucks danger is cool as hell

 

Spoken like a "rat rodder" haha

 

I know safety counts, every piece I have built on this project is probably over kill! Some of you said why didnt they do that 40-50 years ago? Well I think it would have been difficult to lay out a diamond with a mill, I'm not a machinist I'm sure it could be done. So about 40 percent on this board probably welded some piece or another on their front axle or other suspension part with a small welder. Safe? Is it really? How many shade tree mechanics and guys that are running small buzz boxes and getting away with it. Or are they? There was a thread on here not to long ago with some batwings or something like that breaking off the axle when the car drove over some railroad tracks. You guys that are welding with a 100,120,130 amp buzz box really think your welds are penetrating. Guess what, dont be surprised if those break as well! I see so called car builders do it all the time! Now thats scary to!

 

Unless I missed it, I saw no mention of whether this axle is an original or a repop. Two scenarios, one is an aftermarket axle of unknown quality. Two is an original 70 or 80 years old with who knows how many miles and twisting cycles on it already. I also see no mention of magnafluxing either before or after. You don't really even know you started with a good piece. Maybe not necessary until you start whittling away at it because you got plenty of meat on it to make up for any weakness. This goes against one of the first engineering rules I ever learned, sharp edges create stress risers. A simple bending test may not show any flaws, cracking will be caused by cyclic stresses.

However at this point it's OK. It's just another idea that after a second look, maybe isn't such a good idea. It's not on a car yet and hasn't run a single mile. I'll be the first one to raise my hand and say I've redone stuff after giving it a critical assesment. Don't like doing it and don't do it very often, But sometimes you just don't see it 'till it's right in front of you. Rethink it and do it over. No harm, no foul.

The scary thing here is not the axle, the scary thing is people defending it.

 

PM 38Chevy454 - he's the HAMB Metallurgist...it's what he does for a living.

Corners = stress risers = cracks.

Anytime you move a piece of metal, you introduce three stresses - tension, compression, and shear...this is basic stress. Fatigue is the repetitive application of stress.

This axle will likely have a lower ultimate load than one without any holes cut in it, but still be well within safe boundaries. But we rarely operate at ultimate loads.

Where it falls short is it's resistance to fatigue over time...

 

I'd trust that diamond axle over many of the shit "suicide" front ends I've seen built and fawned after on this site.

 

Wow this thread exploded fast lol. I saw it a bit after it was posted and know people would have a lot to say. And until someone is going to call chassis engineering and see what there forged dropped axles are designed to handle. then solid model his axle in auto desk inventor and do an FEA analysis on it, then compare the numbers.

we can drop these speculations. I don't live anywhere near the Dakotas so this isn't my engineering problem.

Btw I saw a flying turd yesterday! Landed on my shoulder damn birds

 

I'd just like to add one thing, don't take any of this stuff personally. That's the benefits here you get a lot more knowledge in a combined group than singular people. Most everyone here, with the emphasis on most, are just looking to keep you and others safe. This hobby gets enough shit from the politicians and lawmakers that just don't understand b/c a select few will put unsafe modifications on their car with little to no experience and kill someone. And you are absolutely right about inexperienced welders with inadequate equipment, a 110v welder is no good for chassis/suspension fab.

Is your idea original? HELL YES!!! That in of itself is cool as hell, just take what advice has been given and maybe go back to the drawing board with it.

 

Shapes!

 

wow..i cant believe some of the responses...your buddy has a 250 k machine...im sure he knows more about how to use it and how those dialmonds will affect the structural rigidity of the axle then anyone here!!! For cripes sake he builds parts for power plants!!! Well I bet dollars to cents you will never see a crack!!!! anyone wanna put their money where their mouth is???...Well I like it... NICE JOB!!!
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I'll take that bet!!! $250, so based on your dollars to cents when you lose you owe me $25,000... now will YOU put your money where your mouth is?

anyone wanna be proxy for this?

 

That is a very good point. Splitting the bones and moving the mounting points outward introduces the twisting moments. Hopefully, the beam in question was designed to handle these additional forces.

 

Just sayin, would you bet your life on it? or your wife and kids? How about my wife and kid or any other people that share the road with you?

nothing personal fellas, just dont see that as anywhere near safe.

 

really? they give you an education in engineering with those machines? or they require one to get one? I think not. lol. this is some of the funniest shit I've ever heard.

 

dude you are from outer space..he does not even have the car built yet!!!!...and yea i will bet ya any day...i hope someone shuts this thread down!!!!!!!
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well after reading the first 135.... I'm able to say that most really do understand basically what is going on with diamond cut axle. later fellas.

 

Why's this topic getting so personal? Chill out, bruddas!

 

old bone, calm your old bone down it was a joke man don't break your exclamation point key.

 

I'm I too late for the bet??????

 

I didn't read all 8 pages, but it looks like you've been well-beaten for your engineering mistake. A long time ago a friend told me "There is a reason airplanes have round windows." Keep that in mind.

 

Not for nothing, but that does not mean a thing. The owner of the water jet machine is a jobber. He cuts metal according to specifications that, in the case of power plant parts, were created by ENGINEERS.

The guy who washes the skyscraper windows is not the same as the person who knows how to design a window that won't blow out.

None of us knows for sure if that axle will crack, and if so, under what conditions. However, many many folks on this thread have absolutely, positively identified that there is no way that this is best practice.

To the OP, statements about how other cars have been built in a substandard manner, possibly more substandard than yours, is no defense. Since you are a fabricator, help take the hobby to a higher level instead of a situation where the best you can hope for is betting on the come.

 

Cool as that axle looks I don't think I'd run it. I'm not saying it isn't safe because for all I know it may be plenty safe for your particular application.
I'd just be afraid that I'd have to spend too many hours arguing with everybody.
I really like the idea that you came up with something different and original but I've got to admit that the possibility of stress cracks occurred to me too.
My guess is that YOU may crack from the stress of defending the axle long before the axle itself ever lets go.
Maybe re cutting the diamonds into ovals or something would work. I know that wouldn't be as original but it would still look good.

 

Shame ya can't run it,,it is kinda neat,,wonder if there was this much discussion way back in te day when the first guy drilled holes in his axle....hhmmmmm

I say A+ for creativity ,,in general,,,and we learn from mistakes,,hopefully you can find a way or use for it.

 

O k i understand . Putting a V8 in a frame that was designed for a 4-cylinder is unsafe due to added weight and torque . Heating and stretching a forged I-beam axle to make a dropped axle is unsafe. Chopping the top on a vehicle alters the bodys structural strength. There is less head room in the event of a roll over and the butt welds that are holding the roof may fail so that's unsafe. I have had to have windshields chipped by rocks thrown by cars with fenders. So fenderless cars are unsafe to everyone around the car. Dam i think i will crawl in to my safe place and hide.

 

Lots of perils. Gotta understand them and make your choices.

This one is not so intuitive, that is, unless you've been specifically schooled by somebody. Combination of metalurgy and stress mechanics.

There are others. Like pressure vessel rupture. Bridge truss failure. On and on.

Makes life interesting if you knew of the danger and wieghed it and made your choice.

Just plain scary, though, if you never even conceived that the danger was there. Its happened to me before and makes you appreciate the knowledge of others and hope they share it.

 

Ya wouldnt want that going on in ya pants !

 

PROBLEM SOLVED! The diamonds look so cool you should set that as a theme for the rest of the car and put diamond shaped wheels on it! Nobody's ever done that before either and it'll sure be an eye catcher. Besides, the wheels won't turn so the car won't move and there will never be any danger from the axle breaking at highway speeds!

 

I liked diamonds, triangles and squares when i was a kid, but they never worked for me.

 

Ollin, I couldn't help it. I know, I know, the corners are rounded.