Why aren't there aluminum radius arms?

[PIP]

I'm planning to lift my new to me 1994 FZJ80 and want to correct castor with new arms. I've read a lot about the Slee and Delta arms, but what I don't quite follow is why nobody is making them from 7075 aluminum? Is it material cost? Is it fear of aluminum in a critical suspension component? I have made many suspension links for high performance motorsports suspension from 7075 and it has become the material of choice for many where it can be used. Plus you aren't stuck with either powdercoat or zinc- Type 3 hardcoat anodize is very difficult to beat for long term durability.

Arms could be made that were the same strength as Slee steel arms while weighing less than stockers. The material cost would be significantly higher, but the labor involved in handling and cost of shipping would be lower.

Thoughts?

 

[landtank]

Bring them to market.

 

[Dusten]

I'm planning to lift my new to me 1994 FZJ80 and want to correct castor with new arms. I've read a lot about the Slee and Delta arms, but what I don't quite follow is why nobody is making them from 7075 aluminum? Is it material cost? Is it fear of aluminum in a critical suspension component? I have made many suspension links for high performance motorsports suspension from 7075 and it has become the material of choice for many where it can be used. Plus you aren't stuck with either powdercoat or zinc- Type 3 hardcoat anodize is very difficult to beat for long term durability.

Arms could be made that were the same strength as Slee steel arms while weighing less than stockers. The material cost would be significantly higher, but the labor involved in handling and cost of shipping would be lower.

Thoughts?

Damage to the arm while wheeling requiring replacement?

 

[PIP]

Damage to the arm while wheeling requiring replacement?

The majority of links I've made from 7075 have been for rock crawling/bouncing and mud racing. It often happens the entire vehicle weight is on one lower link. I haven't heard of any damage that warrants replacement with the projects I've been involved with. The only time I've made replacements is when there's a design change. I've seen a couple sets of DOM links wadded up from mixing HP with traction, but I have not seen it with solid 7075.

If they were type 3 hardcoat anodized the surface gets real slick. Type 3 is neat stuff, many aluminum firearm parts are type 3. It's about .002" thick and harder than a file. It's also about 5-10 times the cost of standard anodizing and only comes in 2 colors, but it's a vastly more functional coating compared to powdercoat or zinc plating. I think rocks would need to work overtime to scratch hardcoat 7075.

I suppose heavy radius arms aren't a detriment on rocks. I don't know that heavy arms do you any favors in other driving situations though.

 

[OGBeno]

Toyota has now switched to aluminum control arm assemblies with the 300 series.

I would think there is some engineering specifications from material sciences that lends some credibility to future aluminum suspension/control arm applications being instituted.

 

[PIP]

Toyota has now switched to aluminum control arm assemblies with the 300 series.

I would think there is some engineering specifications from material sciences that lends some credibility to future aluminum suspension/control arm applications being instituted.

I know that A6061 alloy was the primary alloy used for many OEM automotive forged suspension components 10+ years ago. Today they have introduced new high strength/high elongation alloys and are making things like 4x4 steering knuckles from such alloys in many current production vehicles. I do not know what these new high-zoot alloys are. They are made in bar form by the mill run only to the spec of the OEM. Not an option for a low volume aftermarket automotive product.

I would not consider 6061 as being good enough for an 80 series front radius arm. 6061 is lower strength than mild steel. Step in the wrong direction IMO.

7075 is what an airplane's critical structure is made of. Such as where the wings attach to the fuselage.

 

[Dusten]

The majority of links I've made from 7075 have been for rock crawling/bouncing and mud racing. It often happens the entire vehicle weight is on one lower link. I haven't heard of any damage that warrants replacement with the projects I've been involved with. The only time I've made replacements is when there's a design change. I've seen a couple sets of DOM links wadded up from mixing HP with traction, but I have not seen it with solid 7075.

If they were type 3 hardcoat anodized the surface gets real slick. Type 3 is neat stuff, many aluminum firearm parts are type 3. It's about .002" thick and harder than a file. It's also about 5-10 times the cost of standard anodizing and only comes in 2 colors, but it's a vastly more functional coating compared to powdercoat or zinc plating. I think rocks would need to work overtime to scratch hardcoat 7075.

I suppose heavy radius arms aren't a detriment on rocks. I don't know that heavy arms do you any favors in other driving situations though.

That's what I was curious about. Thanks.

 

[Delta VS]

Likely going to have a hard time making the numbers work with 7075. Could be some bitchin arms, no doubt, just not easily sellable.

Really need to stop and think about what benefit being lighter would bring as well. The call for less unsprung weight is kind of silly when you have 35+” MT tires and HD wheels on a beefed up solid axle.

 

[dsmud4u]

Aluminum is fine on a sedan for various control arms when they are massed produced. I wouldn’t trust aluminum for radius arms on our heavy rigs. It’s brittle and forget about trying to fix it in the trail if you have to.

Shipping cost is the least of our worries when we’re considering overall cost. I’ve seen some bumpers out of aluminum but I just shake my head.

 

[PIP]

Likely going to have a hard time making the numbers work with 7075. Could be some bitchin arms, no doubt, just not easily sellable.

Really need to stop and think about what benefit being lighter would bring as well. The call for less unsprung weight is kind of silly when you have 35+” MT tires and HD wheels on a beefed up solid axle.

Yeah, the material cost is high, but the labor is different. I can imagine the labor in fixturing, welding and deburring the arms you make is no small factor in the product cost.

Just as i look at the Slee arms and would not enjoy loading those blanks in the machine not to mention the time to machine steel and hard tooling costs are significantly higher than aluminum.

From a manufacturability perspective a part that can be made 100% on CNC's without babysitting can often compete with a product requiring hand work like fitting and welding. Radius arms from solid would be made in 2 ops. Multiple machines can be fed by one person.

 

[nukegoat]

Steel is an amazing material folks

 

[Delta VS]

Yeah, the material cost is high, but the labor is different. I can imagine the labor in fixturing, welding and deburring the arms you make is no small factor in the product cost.

Just as i look at the Slee arms and would not enjoy loading those blanks in the machine not to mention the time to machine steel and hard tooling costs are significantly higher than aluminum.

From a manufacturability perspective a part that can be made 100% on CNC's without babysitting can often compete with a product requiring hand work like fitting and welding. Radius arms from solid would be made in 2 ops. Multiple machines can be fed by one person.

Quick google puts 1.5x4 (not big enough) 7075 at 462$ in 48” lengths. In bulk easily get that below 450. So call it 900 in material for a set. A machine big enough to machine those in two ops is not cheap. Labor is not cheap. Answering questions isn’t cheap. Etc. Etc.

And again, same strength, less weight, what does that bring to the table? 1% weight savings on unsprung weight, when it’s not really needed? There are maybe 5 people who are cycling 80 Series suspension at a frequency such weight savings would benefit.

 

[FMC80]

@nukegoat I laugh at 99.9% of the s*** you write. Some of its educational but all of it is comedy.

Need titanium arms.

 

[Delta VS]

Need titanium arms.

Now we talkin

 

[PIP]

Quick google puts 1.5x4 (not big enough) 7075 at 462$ in 48” lengths. In bulk easily get that below 450. So call it 900 in material for a set. A machine big enough to machine those in two ops is not cheap. Labor is not cheap. Answering questions isn’t cheap. Etc. Etc.

And again, same strength, less weight, what does that bring to the table? 1% weight savings on unsprung weight, when it’s not really needed? There are maybe 5 people who are cycling 80 Series suspension at a frequency such weight savings would benefit.

I don't mean to imply steel arms are bad, not at all. I crunched some rough numbers and the cost to make just one set from 7075 for myself wasn't bad at all. That got me wondering why nobody seems to do it.

WRT the hardware to machine them that's not a problem. I could spit out a finished set every 35 minutes. Most anyone who competes in manufacturing could make these just as efficiently.

Your material cost numbers are threefold of what 1.75" thick USA 7075 costs on a wholesale level.

 

[Delta VS]

I don't mean to imply steel arms are bad, not at all. I crunched some rough numbers and the cost to make just one set from 7075 for myself wasn't bad at all. That got me wondering why nobody seems to do it.

WRT the hardware to machine them that's not a problem. I could spit out a finished set every 35 minutes. Most anyone who competes in manufacturing could make these just as efficiently.

Your material cost numbers are threefold of what 1.75" thick USA 7075 costs on a wholesale level.

Well get busy then!

 

[gummycarbs]

What would be the point? Our rigs are already fat, heavy pigs. It would be like giving my mom running shoes for Christmas.

Plus, when you scrape a bunch of your low-hanging radius arm off on a rock, you can fire up the Harbor Freight MIG welder and put the material right back on.

 

[PIP]

What would be the point? Our rigs are already fat, heavy pigs. It would be like giving my mom running shoes for Christmas.

Plus, when you scrape a bunch of your low-hanging radius arm off on a rock, you can fire up the Harbor Freight MIG welder and put the material right back on.

I was thinking that the cost to make some nice arms from fancy aluminum is probably lower overall than steel.

 

[nukegoat]

@nukegoat I laugh at 99.9% of the s*** you write. Some of its educational but all of it is comedy.

Need titanium arms.

Truly the real question is whether I am self aware

 

[Delta VS]

Truly the real question is whether I am self aware

“Hmm, the eternal question”