RFQ ___________Control Arm

[ratrace2]

hello Gentlmen:


This is a very simple request.

I need two aluminum control arms.

Material: 6061 T6
File format: upon your request(includes all dimensions).

Thank you.

[Donkey Hotey]

This is a very simple request.

I'll do them for a million dollars each for the first two, every pair after that is a half million dollars.

You're going to need to include a .STP or .IGS file for anybody to even begin to quote on something like that.

I don't think you have any idea how complicated those parts are. Just the raised letters alone will be a huge machining expense. Then there is the issue of those reverse chamfers that blend into the end bosses. No clue how you think those are going to be machined but, from the photo, they aren't machinable without a sinker EDM ($$$) or making it as a cast part.

You really should consider greatly simplifying the design. It will drastically reduce the cost. You're still probably looking at $1,000 for the pair.

[Matt@RFR]

Also, are you completely, absolutely, positively sure that you want to make control arms out of 6061? I'd be asking for a release of liability before machining something like this, bare minimum.

I used to make road race style 3-Link kits and we used 1.25 x .095 4130N tubing for our lower control arms. I bet they were the same weight, if not lighter than your design, and much stronger for sure. Oh, and a whole lot less expensive!

Also consider that if a piece of road debris is kicked up and dings your aluminum control arm, that makes a stress riser. Not a good situation.

[Donkey Hotey]

I kind of assumed they were for a big RC car or something. Yeah, if we're talking about real car parts...uhhh...

[ratrace2]

I'll do them for a million dollars each for the first two, every pair after that is a half million dollars.

You're going to need to include a .STP or .IGS file for anybody to even begin to quote on something like that.

I don't think you have any idea how complicated those parts are. Just the raised letters alone will be a huge machining expense. Then there is the issue of those reverse chamfers that blend into the end bosses. No clue how you think those are going to be machined but, from the photo, they aren't machinable without a sinker EDM ($$$) or making it as a cast part.

You really should consider greatly simplifying the design. It will drastically reduce the cost. You're still probably looking at $1,000 for the pair.

Let me see, Donkey Hotey wants:

File format: IGES....ok. couple of days......
Raised letters: change to recessed letters.. . .ok
Chamfers that blend into the end boss:... .. .just get close with what ever end mill you use.


OK......DH.

[DareBee]

You could drop me the SolidWorks part.
We also require DIMENSIONED drawings with TOLERANCE schedule, unless you are OK with us making it up ourselves.

[stang5197]

Also, are you completely, absolutely, positively sure that you want to make control arms out of 6061? I'd be asking for a release of liability before machining something like this, bare minimum.

I used to make road race style 3-Link kits and we used 1.25 x .095 4130N tubing for our lower control arms. I bet they were the same weight, if not lighter than your design, and much stronger for sure. Oh, and a whole lot less expensive!

Also consider that if a piece of road debris is kicked up and dings your aluminum control arm, that makes a stress riser. Not a good situation.

There are several companines out there that make these arms out of 6061. Not saying it is the best way, but there are out there.

Here is a local company that makes them; http://www.metcomotorsports.com/prod...p?prod=MCA0003

Notice the the price, for a prototype pair you are looking at twice the cost listed on there site.

[Donkey Hotey]

Raised letters: change to recessed letters.. . .ok
Chamfers that blend into the end boss:... .. .just get close with what ever end mill you use.

You're missing the point. The letters are complicated to do at all. It doesn't matter if they're raised or recessed, there are all of those corners to deal with on the letters and all of the narrow gaps between them. You have that embossed pretty tall and the gaps look really narrow. That means a tiny endmill, nibbling out a tiny amount of material at a time, for a very long time (to get the depth).

I'm not saying it's impossible but, the mill might be nibbling away at the lettering for 2-3 hours (just for the logo). At $65-100/hour for machine time, plus the cost of tiny carbide endmills and you can figure out what that logo is going to cost (by itself).

As for the chamfer, it doesn't even look possible. It looks like a closed angle with one vertical wall and one angled wall. There is no way to make that unless you consider a 5-axis machine with a specially ground cutter to be ordinary. It's a nothing feature that will drive the cost of your part out of sight.

[ratrace2]

You're missing the point. The letters are complicated to do at all. It doesn't matter if they're raised or recessed, there are all of those corners to deal with on the letters and all of the narrow gaps between them. You have that embossed pretty tall and the gaps look really narrow. That means a tiny endmill, nibbling out a tiny amount of material at a time, for a very long time (to get the depth).

I'm not saying it's impossible but, the mill might be nibbling away at the lettering for 2-3 hours (just for the logo). At $65-100/hour for machine time, plus the cost of tiny carbide endmills and you can figure out what that logo is going to cost (by itself).

As for the chamfer, it doesn't even look possible. It looks like a closed angle with one vertical wall and one angled wall. There is no way to make that unless you consider a 5-axis machine with a specially ground cutter to be ordinary. It's a nothing feature that will drive the cost of your part out of sight.

Ya know, you might try a v-groove bit and just set up the letters in CNC to trace a stick letter, that would work....fast too. That might create a nice "facet" of sorts. Or, you could fill the grooves with a tinted epoxy. Or, just fill them with black paint.

[ratrace2]

Also, are you completely, absolutely, positively sure that you want to make control arms out of 6061? I'd be asking for a release of liability before machining something like this, bare minimum.

I used to make road race style 3-Link kits and we used 1.25 x .095 4130N tubing for our lower control arms. I bet they were the same weight, if not lighter than your design, and much stronger for sure. Oh, and a whole lot less expensive!

Also consider that if a piece of road debris is kicked up and dings your aluminum control arm, that makes a stress riser. Not a good situation.

Not a bad situation, though.
I could go to a 7000 AI: double the strength qualities of 6000 AI.
THanks for the input though. It's nice having guys around that speak up and
shine an import light on things.

[Cruiser]

I agree totally with what is said so far and will add that you are showing it with installed bushings, no spring mounting, and some form of bracket which may or may not be part of this.
The only thing that is wanted or needed is the basic part with its necessary geometry's. Don't show the bushings etc. but do show the details of where they go and the dimensions involved ! Complexity is going to be extremely expensive. Your part would be better cast or maybe forged. then just machine in the pockets and mountings.
designers and machinist/mechanics have always been at extreme odds with one another !

[ratrace2]

I agree totally with what is said so far and will add that you are showing it with installed bushings, no spring mounting, and some form of bracket which may or may not be part of this.
The only thing that is wanted or needed is the basic part with its necessary geometry's. Don't show the bushings etc. but do show the details of where they go and the dimensions involved ! Complexity is going to be extremely expensive. Your part would be better cast or maybe forged. then just machine in the pockets and mountings.
designers and machinist/mechanics have always been at extreme odds with one another !

Excellent advice, Forging might be a better approach.

Man, you guys are the best, though. Really, I have a hundred new Ideas and they will all be better because of this feedback. As the designer of this part, I can accomdate all of your concerns, improve the original design, and still get what I want with improved safety/durability qualities.

EDM is one of the techniques for the Letters that some might think about, all the mold making guys know about it. Most of my work in the past has been with composites and mold making.

You say: "designers and machinist/mechanics have always been at extreme odds with one another." Of course.

Since the machine has it's defined parameter and the imagination knows no bounds.....................................


Thanks, ratrace2