Sup w/them 2024 Fall Projects?
#4231
#4232
race car (tubular) suspension and "bending" (of thin rod heim joints). whew a simple link would have been more productive.
https://www.formulastudent.de/pr/new...-of-fs-design/
no math. car salesmen mumbling/punching the numbers to arrive at an answer is not cool lol
https://www.formulastudent.de/pr/new...-of-fs-design/
no math. car salesmen mumbling/punching the numbers to arrive at an answer is not cool lol
Last edited by ViciousLSD; Jan 31, 2022 at 04:38 PM.
#4233
It's not over engineering, when you engineer something you don't design to the failure point, have a safety factor that you shoot for. Depending on how critical the part in question is determines how high of a safety factor you need to shoot for. When you're talking about a part that keeps the car traveling in a straight line when it's supposed to be, it's a pretty important part.
Tensile strength means nothing to this arm because the concern is in a bending or shear load condition. Rule of thumb is that usually shear strength is only 1/3 to 1/2 of the tensile strength.
If you look at race cars they do use rod ends. They use them everywhere. But none of them will be used in bending conditions.
If you have no option and MUST put a threaded fastener in a bend/shear condition they it must be very very oversized for the application.
I wouldn't take what Dallas has said with a grain of salt, he's right on everything he's said.
None of these rod ends are undergoing bending loads...
Tensile strength means nothing to this arm because the concern is in a bending or shear load condition. Rule of thumb is that usually shear strength is only 1/3 to 1/2 of the tensile strength.
If you look at race cars they do use rod ends. They use them everywhere. But none of them will be used in bending conditions.
If you have no option and MUST put a threaded fastener in a bend/shear condition they it must be very very oversized for the application.
I wouldn't take what Dallas has said with a grain of salt, he's right on everything he's said.
race car (tubular) suspension and "bending" (thin rod heim joints), whew a simple link would have been more productive.
https://www.formulastudent.de/pr/new...-of-fs-design/
no math. car salesmen punching the numbers to arrive at an answer is not cool lol
https://www.formulastudent.de/pr/new...-of-fs-design/
no math. car salesmen punching the numbers to arrive at an answer is not cool lol
#4234
#4235
#4236
unbolt one end of the lower arm and drop ur car back down onto its wheels and watch which way the wheel goes.
Also how many months of the year do u keep your car underwater to make ur hardrace arms go like that that is impressive lol
Also how many months of the year do u keep your car underwater to make ur hardrace arms go like that that is impressive lol
#4237
let me help you, so you dont get verbally abused by tech
thats an opposite scenario from evo aftermarket control arms and looks quite problematic. it actually experiences a higher force since wheel has leverage.
this seems like typical topic for FSAE/mech eng'g, they use the tiniest parts. we dont use those tiny heim joints, not even on swaybars
thats an opposite scenario from evo aftermarket control arms and looks quite problematic. it actually experiences a higher force since wheel has leverage.
this seems like typical topic for FSAE/mech eng'g, they use the tiniest parts. we dont use those tiny heim joints, not even on swaybars
#4238
let me help you, so you dont get verbally abused by tech
thats an opposite scenario from evo aftermarket control arms and looks quite problematic. it actually experiences a higher force since wheel has leverage.
this seems like typical topic for FSAE/mech eng'g, they use the tiniest parts. we dont use those tiny heim joints, not even on swaybars
thats an opposite scenario from evo aftermarket control arms and looks quite problematic. it actually experiences a higher force since wheel has leverage.
this seems like typical topic for FSAE/mech eng'g, they use the tiniest parts. we dont use those tiny heim joints, not even on swaybars
#4240
another angle so you might see 'rod ends in bending'
another pic i found googling this topic/ (another engineer's design)
I'm not defending STM's new control arm. I'm never buying that since it has their logo and has too much exposed threads
another pic i found googling this topic/ (another engineer's design)
I'm not defending STM's new control arm. I'm never buying that since it has their logo and has too much exposed threads
#4241
Dallas already showed you the math. Your FSAE example has almost no moment length acting on it. It's also a low bend angle, which lowers the total bending load going through that joint..
I'm going to see myself out of this convo now, like everyone else has. Everyone seems to be on the same page about this except you, and if what's already been said here isn't registering for you then there's nothing more I can say to convince you otherwise.
I'm going to see myself out of this convo now, like everyone else has. Everyone seems to be on the same page about this except you, and if what's already been said here isn't registering for you then there's nothing more I can say to convince you otherwise.
#4242
I've been running those exact Momentum's for 2 years now. Hard bounces, full send it mode especially the forces it saw at Daytona and the bus stop, including 1 off road there, 0 issues and still straight as an arrow.
Now, that's not to say Dallas's observation is wrong, it isn't, but proof is in the pudding and the paper is just a proof. I took the risk even though he yelled at me for it, likely just to annoy him haha. "I" would recommend them. But I'm just a different type of engineer
If he were to ...I dunno..make the right one then I would have bought it in a heartbeat LoL. The adjust-ability combined with Austin's E bolt deletes is king. One COULD produce a threaded rod that had the same tensile strength of a cast alum chunk of metal no, if we're all talking theory here.
Now, that's not to say Dallas's observation is wrong, it isn't, but proof is in the pudding and the paper is just a proof. I took the risk even though he yelled at me for it, likely just to annoy him haha. "I" would recommend them. But I'm just a different type of engineer
If he were to ...I dunno..make the right one then I would have bought it in a heartbeat LoL. The adjust-ability combined with Austin's E bolt deletes is king. One COULD produce a threaded rod that had the same tensile strength of a cast alum chunk of metal no, if we're all talking theory here.
Last edited by Balrok; Feb 1, 2022 at 07:31 AM.
#4243
I've been running those exact Momentum's for 2 years now. Hard bounces, full send it mode especially the forces it saw at Daytona and the bus stop, including 1 off road there, 0 issues and still straight as an arrow.
Now, that's not to say Dallas's observation is wrong, it isn't, but proof is in the pudding and the paper is just a proof. I took the risk even though he yelled at me for it, likely just to annoy him haha. "I" would recommend them. But I'm just a different type of engineer
If he were to ...I dunno..make the right one then I would have bought it in a heartbeat LoL. The adjust-ability combined with Austin's E bolt deletes is king. One COULD produce a threaded rod that had the same tensile strength of a cast alum chunk of metal no, if we're all talking theory here.
Now, that's not to say Dallas's observation is wrong, it isn't, but proof is in the pudding and the paper is just a proof. I took the risk even though he yelled at me for it, likely just to annoy him haha. "I" would recommend them. But I'm just a different type of engineer
If he were to ...I dunno..make the right one then I would have bought it in a heartbeat LoL. The adjust-ability combined with Austin's E bolt deletes is king. One COULD produce a threaded rod that had the same tensile strength of a cast alum chunk of metal no, if we're all talking theory here.
#4244
I just wanted to bring this to light. I never understood probably because a lack of deep technical knowledge, but I've always seen heim or spherical bearings radially loaded in off road racing like Baja and so on, but axially loaded in power sports. Ie snowmobiles, quads, etc . . . Are they technically different joints? Different coverage of the hemisphere ?
#4245