7075-T6 Aluminum Links
- Thread starter MStudt
- Start date
MStudt
official vendor
Damn Canadians!
I've got an old South Bend Lathe that has about an 1-1/4 bore on it. This is by far the best tool that I have. They're so much fun to have around; even if you're just messing around on it.
Strength, flexibility, grease fittings, and rebuildable.
Heims suck on links that are daily drivers. Even with the ones I build now I wouldn't use heims. I use a poly bushing on the axle side, and a rebuildable Flex Joint on the other.
JayRolla
New member
Never knew originals had a week spot. Also didn't know you cant rebuild stock lca's. And man I need to grease them all the time.
MStudt
official vendor
There is no per say weak spot, just not as thick of material. You can rebuild stock lca's and uca's, but it sucks. You can either cut/burn/press out the old bushings, but they're in there pretty good.
IBallEngineer
New member
I used a South Bend as a young man to make some brass bushings. I remember thinking damn this machine is old, but awesome. That was 35 years ago. A friend has a Bridgeport Mill and a Cincinnati lathe in his garage, but by the time I get him to move his 57 Chevy and all his other crap, I could could chisel the part from granite. When he dies I'm taking them to MY garage.
MStudt
official vendor
The older lathes are still better than the new ones! They were build to withstand the end of world, and seems they were made to a higher standard as well. The South Bend I have is from the 70's, and that's old than I am!
JayRolla
New member
That is very true, it is a big pain in the ass. I know my buddy that runs a Nissan GTR trans shop will just set all his motor mounts in front of his propane torch heater and burns them out. Fun stuff!
JayRolla
New member
Where you slamming them on rocks, trees, small children?
Nelsonmd
New member
Haha, I figured this thread would get alot of opinions.
Just a couple of comments on your comments... feel free to comment on my comments regarding your comments.
There are thousands of different steel alloys and Al alloys. If you pick a low grade steel used in I-beams and large structural applications, then yeah, your UTS is going to be lower than expected when compared to a high strength Al alloy; Women aren't faster than men because you had a female sprinter race a fat guy and she won... Steel uts goes up, up, and up from A36. 7075 Al is on the high end of Al's, and is also on the high end of density too, so you don't tend to save weight over steel. But UTS isn't even my first concern for this application.
I didn't mention galvanic corrosion because it's not one of my primary concerns in this case. I am more concerned with the design as he has described it.
Of course the design determines how "strong" the link is (whatever that means to each of you...). My point is that to make the Al link as "strong" or more appropriately, robust to all the loads it will see in application as the original links, it needs careful design and has to be much larger than the original links (or just more intentionally shaped), and will cost way more. The design he described didn't sound to me to be in any way better than the stock link, which is why I gave my misgivings about it. Tube vs Tube, steel is better. If you introduce molding or machining a billet to form them, then sure maybe Al starts to have some advantages, though cost won't be one of them...
You're right that there's nothing fancy about the stock links (KISS... simple is good!). You're wrong that it is EASY to make a stronger one out of Al. To make a stronger one out of Al requires some real engineering which, no offense to anyone here, Mstudt isn't going to be able to do. Not because he isn't good or doesn't know enough, but because he isn't going to spend tens of thousands of dollars testing and refining his design. It's possible, but it's not easy.
If this just comes down to people wanting some bling $hit on their rigs, then I am not going to sugarcoat anything for them and not tell them just spent $400 to make their truck worse. If they claim that it is "stronger" or whatever, then I will correct that, because stronger actually means something, it's not just a feeling.
Bottom line, as described, I don't think the link is going to be "stronger" than the stock links. Looking at Icon's 6061 links and Toytec's 7075 links, they have clearly gone through a few design iterations. The ICON's I wonder if they have a steel sleeve in there for the heim to thread into, and the Toytec's are basically what MStudt is talking about, except that they're solid 7075 and use Heim's with compliant bushings.
Just a couple of comments on your comments... feel free to comment on my comments regarding your comments.
There are thousands of different steel alloys and Al alloys. If you pick a low grade steel used in I-beams and large structural applications, then yeah, your UTS is going to be lower than expected when compared to a high strength Al alloy; Women aren't faster than men because you had a female sprinter race a fat guy and she won... Steel uts goes up, up, and up from A36. 7075 Al is on the high end of Al's, and is also on the high end of density too, so you don't tend to save weight over steel. But UTS isn't even my first concern for this application.
I didn't mention galvanic corrosion because it's not one of my primary concerns in this case. I am more concerned with the design as he has described it.
Of course the design determines how "strong" the link is (whatever that means to each of you...). My point is that to make the Al link as "strong" or more appropriately, robust to all the loads it will see in application as the original links, it needs careful design and has to be much larger than the original links (or just more intentionally shaped), and will cost way more. The design he described didn't sound to me to be in any way better than the stock link, which is why I gave my misgivings about it. Tube vs Tube, steel is better. If you introduce molding or machining a billet to form them, then sure maybe Al starts to have some advantages, though cost won't be one of them...
You're right that there's nothing fancy about the stock links (KISS... simple is good!). You're wrong that it is EASY to make a stronger one out of Al. To make a stronger one out of Al requires some real engineering which, no offense to anyone here, Mstudt isn't going to be able to do. Not because he isn't good or doesn't know enough, but because he isn't going to spend tens of thousands of dollars testing and refining his design. It's possible, but it's not easy.
If this just comes down to people wanting some bling $hit on their rigs, then I am not going to sugarcoat anything for them and not tell them just spent $400 to make their truck worse. If they claim that it is "stronger" or whatever, then I will correct that, because stronger actually means something, it's not just a feeling.
Bottom line, as described, I don't think the link is going to be "stronger" than the stock links. Looking at Icon's 6061 links and Toytec's 7075 links, they have clearly gone through a few design iterations. The ICON's I wonder if they have a steel sleeve in there for the heim to thread into, and the Toytec's are basically what MStudt is talking about, except that they're solid 7075 and use Heim's with compliant bushings.
turbodudey2
New member
So... I'm an engineer. I just did some quick calculations, and I'll say right up front just in case anyone was still wondering: 7075 AL links are waaaay stronger than the OEM LCAs. (I don't actually know the dimensions or material specs for the stock links, so I can't put an exact number on them.)
Here's a comparison that might put it in perspective though: Everyone is familiar with the aftermarket Toytec links - .375" wall DOM tubing. Pretty much bombproof, right?
7075 T6 AL links are 16% stronger than the Toytec links. So... I would say 16% stronger than bombproof is still bombproof. Plus 7075 T6 still maintains very good fatigue strength and fracture toughness.
Solid aluminum links have been used for many years on professionally built crawlers and buggies specifically because of their increased strength over steel, light weight, and the ability to run smaller diameter links to increase travel and clearance.
Here's a comparison that might put it in perspective though: Everyone is familiar with the aftermarket Toytec links - .375" wall DOM tubing. Pretty much bombproof, right?
7075 T6 AL links are 16% stronger than the Toytec links. So... I would say 16% stronger than bombproof is still bombproof. Plus 7075 T6 still maintains very good fatigue strength and fracture toughness.
Solid aluminum links have been used for many years on professionally built crawlers and buggies specifically because of their increased strength over steel, light weight, and the ability to run smaller diameter links to increase travel and clearance.
D Farms
New member
sorry mr engineer, you missed the entire point here. sure the links are plenty strong. the problem is threading into aluminum with stainless steel or any other type of steel is not a good idea. the thread strength on aluminum is a lot lower than steel, not to mention that most aftermarket joints come with a bung(a peice that gets welded on to the end of the tube that has threads in it). a possible solution would be to braze bungs into the ends. but that takes some skill and some time and money, and wouldnt be as easy as just boring, and threading the ends of aluminum bar stock.
this is the same reason they dont make lug nuts out of aluminum. when you have no volume constraint a lower density metal like aluminum can be used, unfortunately the threads are constrained by volume and just wont be strong enough in aluminum.
this all being said you could also use aluminum to sleeve over steel arms. that would add a lot of strength.
this is the same reason they dont make lug nuts out of aluminum. when you have no volume constraint a lower density metal like aluminum can be used, unfortunately the threads are constrained by volume and just wont be strong enough in aluminum.
this all being said you could also use aluminum to sleeve over steel arms. that would add a lot of strength.
turbodudey2
New member
Sorry, wrong again... mostly. You are correct in assuming that aluminum threads will yield before steel threads of the same pitch and diameter.
However, a proper threaded connection is not the weakest point in the assembly. So it will not make any difference in the comparison of steel vs aluminum in this case.
The weakest link is the rod end itself (generically referring to all categories of spherical misalignment fasteners here).
Feel free to do the math yourself, if you like.
My only point in all of this is to say that this is not a bad idea by any means. If the OP has the material and the machinery to fabricate the aforementioned product, it will certainly be stronger than the OEM links and probably stronger than most commercially available aftermarket steel links.
D Farms
New member
right, have you done the fea on the exact design hes going to use? have you accounted for the galvanic reation between the two dissimilar metals, what about heat expansion. its not about strength per say but more about when the thread needs to be moved or should not be moving. what happens when the joint binds? will the rod end unthread it self or over tighten?
its more complicated than the aluminum is stronger because there is more of it.
its more complicated than the aluminum is stronger because there is more of it.
D Farms
New member
the bung is clamped in the end, thats a good way to do it, but it needs to be done on a cnc mill.
MStudt
official vendor
There are no bungs in those. They slot them so it can act as a clamp on the thread.
I'm wondering how you would put a steel bung in an aluminum link. Would you have a galvanic reaction between the two dissimilar metals?
I just wondering because everything was making sense until this. Maybe I just completely missed something though?
D Farms
New member
you would braze it. just google braze stainless steel to aluminum or read this
https://www.google.com/url?sa=t&sou...jAMs-Z4B-oGYK1GkA&sig2=KxPoKEdbKwIp8XbCFj1V9A
https://www.google.com/url?sa=t&sou...jAMs-Z4B-oGYK1GkA&sig2=KxPoKEdbKwIp8XbCFj1V9A
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