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Fabman
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« on: October 06, 2008, 07:36:52 PM » |
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Hey everyone...new kid on the block here...was wandering if anyone here has built an all aluminum frame and chassis out of just aluminum?...using rivets and epoxy instead of welding.  |
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jntramey
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« Reply #1 on: October 06, 2008, 08:21:04 PM » |
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Aircraft, although subject to significant stresses, are not designed to be strong enough for the pot holes and other tortures of our roads.
You'd be popping rivets left and right. The epoxy might be a good idea, but all aluminum chassis would be VERY expensive, and not very strong compared to steel. Enough stress in the right place and instead of bending, your car would snap that cast aluminum like a twig.
keep looking. A carbon fiber composite would be stronger and way lighter, but again, very expensive.
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The Kit Cars Forum
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« Reply #1 on: October 06, 2008, 08:21:04 PM » |
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Hughes
Patron Class Member
Full Member
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Posts: 110
Perfection isn't a goal... It's a standard.
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« Reply #2 on: October 06, 2008, 11:06:38 PM » |
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Fabman,
I am a Composite Engineer in the aerospace industry for General Atomics Aeronautical Systems, building un-manned areal vehicles for the government (Predator A, Predator B, Sky Warrior, etc.). All of our aircrafts (and airframes) are build using carbon fiber composites. Please note that areal vehicles are made to twist, flex, and bend to accommodate the turbulence found at altitude. It is hard to relate an airframe to a car frame as they are two entirely different beasts, and require different aspects into the engineering.
However, I do believe that the Arial Atom has its chassis built from aluminum... but again, it is welded. I would have to strongly recommend against using rivets and epoxy as a structural material bond. There ARE advanced composite components that aid in the assembly of these types of structures, but again, they weren't designed for your type of application.
-Hughes
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Bobi1
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« Reply #3 on: October 06, 2008, 11:54:38 PM » |
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Aluminum profiles + rivets + epoxy resin = 1996 Lotus Elise's chassis ==> also used in Tesla Roadster and some other cars
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Fabman
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« Reply #4 on: October 07, 2008, 06:15:11 AM » |
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Thanks for the rely guys...I knew there had to have been some exotic performance applications...I wasn't sure if anyone here has done this before...I was looking at alternative designs for a new project I had in mind...so should I scratch the whole ideal of aluminum then?...I kinda had my heart set on doing something unusual...I wanted to stay away from fiberglass because it is very messy and time consuming stuff to work with and using exotic materials such as Kevlar is just not in my league...as much of a good welder I am welding steel, I was trying to keep the weight down.
Maybe a smaller diameter steel chassis would work...I was wanting to use 6061-T6 .063 sheet for my body panels...I can get these at a good price...this material is quite strong and this could be riveted to the space frame to provide extra strength...I would use a 2X3 main frame rail system for the base or do you feel that would be over kill?
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FastAndFunky
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« Reply #5 on: October 07, 2008, 06:36:04 AM » |
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Just stick with the normal space frame welded design. Like that says if its not broke dont try and fix it  Seems to have worked for years so why risk something going wrong Thanks for the rely guys...I knew there had to have been some exotic performance applications...I wasn't sure if anyone here has done this before...I was looking at alternative designs for a new project I had in mind...so should I scratch the whole ideal of aluminum then?...I kinda had my heart set on doing something unusual...I wanted to stay away from fiberglass because it is very messy and time consuming stuff to work with and using exotic materials such as Kevlar is just not in my league...as much of a good welder I am welding steel, I was trying to keep the weight down.
Maybe a smaller diameter steel chassis would work...I was wanting to use 6061-T6 .063 sheet for my body panels...I can get these at a good price...this material is quite strong and this could be riveted to the space frame to provide extra strength...I would use a 2X3 main frame rail system for the base or do you feel that would be over kill?
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Bobi1
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« Reply #6 on: October 07, 2008, 07:49:53 AM » |
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Thanks for the rely guys...I knew there had to have been some exotic performance applications...I wasn't sure if anyone here has done this before...I was looking at alternative designs for a new project I had in mind...so should I scratch the whole ideal of aluminum then?...I kinda had my heart set on doing something unusual...I wanted to stay away from fiberglass because it is very messy and time consuming stuff to work with and using exotic materials such as Kevlar is just not in my league...as much of a good welder I am welding steel, I was trying to keep the weight down.
Maybe a smaller diameter steel chassis would work...I was wanting to use 6061-T6 .063 sheet for my body panels...I can get these at a good price...this material is quite strong and this could be riveted to the space frame to provide extra strength...I would use a 2X3 main frame rail system for the base or do you feel that would be over kill? The chassis of Ultima GTR uses thin tubes plus riveted aluminum panels. The bad news is that the chassis and suspension are full with engineering mistakes. It's OK with the safety unless you hit another car. Factory five uses similar way to build their chassis, because it's cheaper and faster. But I wouldn't feel secured in such chassis. They are light and faster, but you don't need to go faster to the hospital. Another disadvantage is that the vibrations will loosen the rivets after several months or years. Stick with the old-fashioned way and use steel tubes with welded steel sheet. |
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Fabman
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« Reply #7 on: October 07, 2008, 09:29:39 AM » |
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The chassis of Ultima GTR uses thin tubes plus riveted aluminum panels. The bad news is that the chassis and suspension are full with engineering mistakes. It's OK with the safety unless you hit another car. Factory five uses similar way to build their chassis, because it's cheaper and faster. But I wouldn't feel secured in such chassis. They are light and faster, but you don't need to go faster to the hospital. Another disadvantage is that the vibrations will loosen the rivets after several months or years. Stick with the old-fashioned way and use steel tubes with welded steel sheet.
You talk of going to the hospital and yet most of these kits are built using fiberglass hollow bodies over a steel chassis...is that not just as dangerous? As far as the vibrations to loosen the rivets, wouldn't epoxy solve this?...if epoxied, the panels would not be allowed to shift or vibrate loose. Thanks for all the great responses. |
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Bobi1
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« Reply #8 on: October 07, 2008, 10:21:07 AM » |
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The chassis of Ultima GTR uses thin tubes plus riveted aluminum panels. The bad news is that the chassis and suspension are full with engineering mistakes. It's OK with the safety unless you hit another car. Factory five uses similar way to build their chassis, because it's cheaper and faster. But I wouldn't feel secured in such chassis. They are light and faster, but you don't need to go faster to the hospital. Another disadvantage is that the vibrations will loosen the rivets after several months or years. Stick with the old-fashioned way and use steel tubes with welded steel sheet.
You talk of going to the hospital and yet most of these kits are built using fiberglass hollow bodies over a steel chassis...is that not just as dangerous? As far as the vibrations to loosen the rivets, wouldn't epoxy solve this?...if epoxied, the panels would not be allowed to shift or vibrate loose. Thanks for all the great responses. If made properly, the steel tubular chassis can be few times more safe than most large SUVs. And when I spoke about loosen rivets, I have in mind the chassis of Ultima, Factory Five, Lotus 7 replicas and other manufacturers that attach the aluminum sheet with rivets only. You may look at Internet about the welded aluminum chassis of RCR (Race car replicas). Welded aluminum chassis is stronger than the bonded or riveted one. |
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Fabman
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« Reply #9 on: October 07, 2008, 11:12:29 AM » |
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Rev & ton
Thanks for the reply and I apologize for the confusion about your rivet statement...so I would assume that you would agree that the epoxy would make the chassis much stronger then with just rivets alone?
I know that welding an aluminum chassis together would do a much better job for strength...have you welded aluminum with a MIG gun before...they sell a kit to convert my Lincoln into an aluminum MIG welder.
The reason for the light weight is because I want to build a chassis similar to the popular design that made the VW bug so famous for...the stock VW pan and suspension are both out dated and heavy...I wanted to build a rolling suspension that various bodies could be attached similar to the bug body was attached.
My quest for the design would allow the builder to attach a coupe, a truck body or a convertible body on the same chassis...I am still in the design stage at this point and appreciate any input...the reason for the design is to build a inter city type Ute where the builder can change bodies in a matter of just a few hours if he wishes...the bodies them selves would be simple to build and light enough to change...of course he would also have to build the various bodies to swap during the different seasons of the year or just build the one.
The design is as simple as the VW was...the IC Ute will only hold two adults and some groceries...the power train will come from a motorcycle to help keep weight down...my goal is to design a small vehicle that can be easily built by the average person with a simple design and when finished, be able to get 50mpg...most cars on the road only have one person in the car...or build a one person type vehicle that has plenty of power and can be used year round and will be easy to park.
The body will be of just 6061 T-6 panels that will be riveted to the chassis for ease of build and ease of replacing damaged panels...no paint, to reduce costs and weight and simple flat panel safety glass...it might sound boxy but it will be a design challenge to make it look appealing to others...I feel that if you make it both fun and exciting, I might start a new trend...the X-Box by Toyota was just that, a box...but as you can see...many X-Box's are now tricked out with fancy body mods and performance up-grades.
Thanks for any input and hope to get started as soon as I sort out a final design choice.
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