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**Mike Van Veghten** · 08-09-2007, 06:41 PM

Depending on the material...most definatly the steel.
Plain ol cold rolled steel would be a good cheap material. Thats what I made mine from.

No multi piece stainless!
"One" piece...heat treated...304 would be good.
Not a fan of aluminum on the front.

What caliper would be they for?

Mike

**whacker** · 08-09-2007, 06:45 PM

The stainless is definitely stronger, the cast will dissipate heat better. I guess the real question is how much strength do you need and how fast do you want to get rid of the heat? If the stainless laminate is exposed to a lot of heating and cooling, it could delaminate pretty fast. Both parts look great, though!

**sbca96** · 08-09-2007, 07:58 PM

The application is the matching rear 12 inch Cobra brake for my 13 inch
front Cobra brake. I explained in great detail on Racing Studebakers
why the multipeice wont work right. Jim, just finish the Ford bracket
with the info I provided and everything will be fine.

[^][8D]

Not a fan of aluminum huh? Better not step on an airplane again![

]
I posted the FEA analysis, feel free to read up in it Mike.

Tom

'63 Avanti, zinc plated drilled & slotted 03 Mustang Cobra 13" front disc/98 GT rear brakes, 03 Cobra 17" wheels, GM alt, 97 Z28 leather seats, soon: 97 Z28 T-56 6-spd, Ported heads w/SST full flow valves, 'R3' 276 cam, Edelbrock AFB Carb, GM HEI distributor, 8.8mm plug wires

**Dick Steinkamp** · 08-09-2007, 08:15 PM

quote:Originally posted by sbca96

Not a fan of aluminum huh? Better not step on an airplane again![

]

I sold my full service FBO a couple of years ago. All of the aluminum airplanes we worked on had steel brake caliper brackets.

**sbca96** · 08-09-2007, 08:18 PM

Thats interesting, Dick. I am surprised they didnt use 7075-T6. It is
stronger than most steels. Strange to bolt a steel caliper bracket to
an aluminum suspension. At any rate 6061-T6 and 7075-T6 is used for
structural material in commercial jets, that's what I was refering too.

Tom

**StudeRich** · 08-09-2007, 08:59 PM

What aluminum suspension? All Boeing airplanes and most others, have all steel landing gears, hundreds of tons of load and lots of wear and stress cannot be trusted to any soft weak materials like aluminum!

StudeRich
Studebakers Northwest
Ferndale, WA

**sbca96** · 08-09-2007, 10:47 PM

Soft and weak? The Corvette has been getting by with an all aluminum
suspension since the 80's. I apologize for my assumptions about air
craft, considering that 6061-T6 and 7075-T6 are "aircraft structural
grade aluminum" it seemed that they used them for more then toilet
seats. I guess I can check with my buddy who works at Boeing for the
facts and figures, but neither 6061 or 7075 is "soft and weak".

Some numbers for comparison purposes :

ShieldSquare Captcha

http://www.onlinemetals.com/productguide.cfm

1144 (Stressproof-equivalent) steel
Yield PSI 100,000

7075-T6 aluminum
Yield PSI 73,000

12L14 steel (free machining)
Yield PSI 60,200

1018 steel (common cold rolled steel)
Yield PSI 53,700

6061-T6 aluminum
Yield PSI 40,000

A36 steel (common hot rolled steel)
Yield PSI 36,300

304 stainless steel
Yield PSI 31,200

A366/1008 steel (commercial quality cold rolled)
Yield PSI 26,100-34,800

Tom

quote:Originally posted by StudeRich

What aluminum suspension? All Boeing airplanes and most others, have all steel landing gears, hundreds of tons of load and lots of wear and stress cannot be trusted to any soft weak materials like aluminum!

'63 Avanti, zinc plated drilled & slotted 03 Mustang Cobra 13" front disc/98 GT rear brakes, 03 Cobra 17" wheels, GM alt, 97 Z28 leather seats, soon: 97 Z28 T-56 6-spd, Ported heads w/SST full flow valves, 'R3' 276 cam, Edelbrock AFB Carb, GM HEI distributor, 8.8mm plug wires

**PlainBrownR2** · 08-09-2007, 11:20 PM

Ask him about the Aloha Air Boeing 737 accident as well Tom. Of course after a few thousand pressure/depressure rounds on that airframe in conditions like that, aluminum might have a tendency to become soft and weak. I don't doubt aluminum, cmon they make intake manifolds(hmmm Stone's pieces?), from the stuff, some of it from recycled aircraft. And more than a fair share of aircraft take off/land everyday on aluminum structures. But be careful about assumptions that are too broad.

1964 Studebaker Commander R2 clone
1950 Studebaker 2R5 with 170 turbocharged
[img=left]http://i158.photobucket.com/albums/t102/PlainBrownR2/DSC00003.jpg?t=1171152673[/img=left]
[img=right]http://i158.photobucket.com/albums/t102/PlainBrownR2/DSC00009.jpg?t=1171153019[/img=right]
[img=left]http://i158.photobucket.com/albums/t102/PlainBrownR2/DSC00002.jpg?t=1171153180[/img=left]
[img=right]http://i158.photobucket.com/albums/t102/PlainBrownR2/DSC00005.jpg?t=1171153370[/img=right]

**rusty nut garage** · 08-10-2007, 05:41 AM

The Aloha 737 became a convertible because of the procedure used to treat the metal prior to assembly. All the aircraft built during this time frame had to go under extensive sheetmetal repair. The crown on the fuselage top were removed and the metal was inspected and corrosion treated the reinstalled. Very manhour extensive. So it not the aluminum thats the problem its the corrosion that weakened the aluminum.

quote:Originally posted by PlainBrownR2

Ask him about the Aloha Air Boeing 737 accident as well Tom. Of course after a few thousand pressure/depressure rounds on that airframe in conditions like that, aluminum might have a tendency to become soft and weak. I don't doubt aluminum, cmon they make intake manifolds(hmmm Stone's pieces?), from the stuff, some of it from recycled aircraft. And more than a fair share of aircraft take off/land everyday on aluminum structures. But be careful about assumptions that are too broad.

1964 Studebaker Commander R2 clone
1950 Studebaker 2R5 with 170 turbocharged
[img=left]http://i158.photobucket.com/albums/t102/PlainBrownR2/DSC00003.jpg?t=1171152673[/img=left]
[img=right]http://i158.photobucket.com/albums/t102/PlainBrownR2/DSC00009.jpg?t=1171153019[/img=right]
[img=left]http://i158.photobucket.com/albums/t102/PlainBrownR2/DSC00002.jpg?t=1171153180[/img=left]
[img=right]http://i158.photobucket.com/albums/t102/PlainBrownR2/DSC00005.jpg?t=1171153370[/img=right]

Russ Shop Foreman "Rusty Nut Garage"
57 SH (project)
60 Lark VIII 2dr sd (driver)

**jlmccuan** · 08-10-2007, 06:27 AM

A little of my history on the laminated bracket. We have used this method for many years to prototype and prove designs on custom punches and dies for press tooling. It's quite remarkable how long this construction lasts in 250 ton and larger presses, as long as it is through bolted tightly. Goes downhill pretty fast if the tension comes off the bolts and pins. Never had a catastophic failure, just a deterioration of the profile geometry resulting in out of spec parts. Many times, we can use the laminated tooling for production several years and many thousands of parts with the addition of some hardened wear inserts. Seems to work pretty well when the load applied is parallel to the lamination. Oh well, it was just a little "after hours" project.

Jim

1966 Avanti II RQA 0088

**sbca96** · 08-10-2007, 08:13 AM

Jim, I wish I had the tools available to play like that, I have more
than most it seems, though I can not operate the machinery myself. The
yield strength of 304 is actually less than 6061-T6, and then you have
more than one piece. When you do the FEA, make sure you input each of
the parts as a separate entity. Only the 3 bolts that mount, and the
two bolts for the caliper will be the union points. The stress risers
will be around each hole and at the bond. You will need to check the
yield point of your bond material against the maximum heat it will see
transfered to it from the caliper/differential.

I think that the general feeling machining it from a solid is better.

Tom

**jlmccuan** · 08-10-2007, 08:45 AM

Definately agree that a solid would be better. With a sheet of 3/8" stainless well over $1000, I wanted to be sure my dimensions were right first. Sort of like your masonite template. I had enough drop laying around to build up a laminated piece out of 3/16". After I cut it and it fit, I started wondering about just using it. The Ford bracket gets pretty thin in some places where the extra holes are. Of course, there isn't much of a lateral load on it.

If you look at a brake system as a heat sink (and I do), there are other issues that arise that I just don't have any experience with. But I do have access to thermocouples and transmitters with data logging to see what sort of heat is getting to the brackets and fasteners. That might be a fun project too.

Jim

1966 Avanti II RQA 0088

**sbca96** · 08-10-2007, 11:01 AM

Agreed, there is the issue of the existing holes in the bracket, and
the counter bores for those holes, but none seemed to compromise the
integrity of the bracket. Keep in mind that for the rear you can take
liberities that you would never do on a front brake bracket. Even the
laminated piece will probably work fine in the rear that only does 30%
of the stopping (on a good stop). You are correct in that there is
little or no lateral force on the bracket, only what is transfered to
it from the caliper being bolted offset to one side of the rotor. The
main force is radial, and in that regard its plenty strong.

Tom

**Mike Van Veghten** · 08-10-2007, 11:26 AM

Tom I do have a small clue about materials.
I have worked in the areospace industry as a Manufacturing and Test Engineer for over 35 years!! How do you think I knew where the "E" and the "A" go!!

So now...who has the materials experience.
I work with these materials most every day. What's not realized is the loads put on these parts.
Some materials work better for some things than others...RIGHT...
Take Kevlar...a bullet stopper right...most rifle bullets will go thru aluminum or thinner (.250 or .312) steel. As me how I know that! Carbon Fiber CAN also be stronger than steel. BUT with todays technology...I also wouldn't use that for a caliper barcket on a car much over 1500lbs.

Aluminum on the Vette...do I have a story. Ask Mr. Turner (the brake guy) about our conversations a few years ago!!
Do "you" know what grade aluminum is used on the Vette...or the heat treatment applied? So...what aluminum IS best...do so tell us?

So now where's the logic?

I stick by a good steel or heat treated stainless steel.

And by the way...I prefer to ride IN planes rather that getting ON one! So windy on a wing!

Mike

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