[The basic formulas for bidirectional weave composites]

Unfortunately, I have misplaced that article. 

 

@John Kimball can you share any resources concerning basic math and physics for composites?

 

[The basic formulas for bidirectional weave composites]

I read a fascinating article in Racecar Engineering magazine.  The article broke down all the major formulas for suspension and steering geometry into easy step by step instructions with descriptive examples.  This was a simple process that did not require CAD.  It only needed a scientific calculator. 

Is there any resource that can walk me through the basic math and physics regarding structures that consist of layers of bidirectional weave composites, core materials and the resins?

 

[landing net]

Perhaps there are two words to consider in this CF application?  Galvanic Corrosion.  

Are you using any alloys in this application, because galvanic corrosion might become an issue in water.

[Favorite Youtube channels for composite projects?]

I have seen all the youtube videos from Rockwest.  I am wondering which other channels you like watching for information on composite projects?

[Does anybody do this anymore? (Scale Model Chassis Testing)]

  

4 hours ago, lo_0l said:

Hey @Mongo!

I don't think so. From what I've seen modeling have gotten so darn good they rarely use full scale models. Though they do eventually test full-scale models to verify things.

I'm not sure that I'd use chipboard, but there are most definitely some materials you could take advantage of. I think the problem with composites for mainstream vehicles is cost/consistency right now. You're starting to see it more and more as they work out the kinks though!

Were you thinking of doing a full composite chassis or just partial?

My plan is for the chassis to be composite and the suspension/control arms to be alloy.  I was thinking of making a 1:10 scale model in a cheap material.

 

[Does anybody do this anymore? (Scale Model Chassis Testing)]

Everything seems to be on the computer these days.  I want to create a composite car chassis.  Does anybody make scale models to use for load tests when they are designing a chassis?  I want to put some chipboard (or other cheap material) in a laser cutter (or water jet) and build a scale model for testing its rigidity.  Would there be any advantage to testing a physical scale model over a virtual model in the computer?  Race teams still use a wind tunnel for scale models.  Do they use the models for any other load tests?

 

[Joining CF panels with rivets and adhesive. Questions about sheer loading, torsion, etc.]

@John Kimball  I have been reading the scientific journal that you had posted in your previous comment.  Where can I access all the supporting cited sources from the paper?  There are 129 sources attached that I want to investigate and I don't want to pay for each publication.

[Ekoa fabric vs. galvanic corrosion.]

@John KimballWhat do you mean by "Loft and volume is needed to increase the value"?  What is loft?  What is "the value"?

 

[Joining CF panels with rivets and adhesive. Questions about sheer loading, torsion, etc.]

I am hoping to find some load test data on CF panels joined with brackets.  I want to learn about CF panels being secured with angled brackets using adhesive, rivets, bolts, or a combination and see how they compare to single piece structures that came out of a mold.  My goal is to utilize an effective fabrication process to create a strong, but lightweight structure that uses minimal tooling.  No plugs, no molds, no need for vacuum bags, etc.  Just order flat panels that are cut on a CNC table and delivered to my door ready to be assembled.

 

[Joining CF panels with rivets and adhesive. Questions about sheer loading, torsion, etc.]

Are there examples on the internet of super strong structures with panels being riveted together?

What about joining two panels with an angle clip that is riveted and bonded?

[Ekoa fabric vs. galvanic corrosion.]

@lo_0l.  I understand that for a composite Ekoa is a good sound deadener.  Vibration needs to be considered.

[Hi, I'm Jacky!]

Welcome Jacky!  My name is Mongo and I am researching how to build a CF car chassis as well, so that makes us buddies!  😃  Everybody is super friendly and the staff from Rockwest frequents these forums.  They provide a wealth of information.

[Greetings!]

Hello Sean.  I am looking forward to hearing more about your work and interests in this forum.  Take care.

[Hello!]

Welcome, Monica.  I look forward to reading your posts.

[Ekoa fabric vs. galvanic corrosion.]

For my CF chassis, can I use Ekoa fibers as an insulator bonded between metal fixtures and the CF layers to prevent galvanic corrosion?

[Composite chassis design questions]

What would it take for a hobbyist to design and construct a chassis for a road car (not race car) out of composites?  Note:  this chassis does not need to be crash tested.
What percentage of labor is spent on the computer designing and verifying vs. actually constructing the chassis?  

[Reusable Rubber vacuum bagging. Cost/Benefit discussion.]

I saw a video where a company uses a system to create reusable rubber(?) vacuum bags.  I was wondering, at what usage do these systems make sense?  Will I need to use it to make 25 copies of 1 part before I start to see the benefit?  50 copies?  100?

[Seat project.]

I need to create a seat for my car.  I want to form the seat to my body.  I have found videos demonstrating a couple of methods on YT. 

The first is use expanding foam, from a hardware store, into a trash bag.  
Pros   1.  Cheap   2.  Simple

Cons  1.  Very exothermic reaction.  Could be uncomfortable.

           2.  Sets into shape way fast.  Not very workable before setting.

           3.  Cannot trial fit before pouring in foam.

           4.  Foam can shrink or distort when pulling a mold off of it.

 The second method is using foam beads and epoxy in a bag using a resin transfer method.

Pros   1.  Can preform the seat shape with beads in the bag.

          2.  Takes time to set.  More opportunity to make minor adjustments

          3.   Epoxy retains dimensionality better than expanding foam.

Cons  1.  Very exothermic reaction.  Could be pain.

           2.  Expensive

           3.  More complex.  Need vacuum pump and accessories normally associated with composite work.

Which method do you feel will yield a better outcome?  I think the epoxy and foam beads method is the way to go.  But I have questions.

How do I tackle the resin transfer process and prevent the foam beads from causing problems?  I don't want to draw a vacuum only to see my vacuum pot fill with thousands of beads.  I want complete saturation of the beads.
 

[Hi! My name is Mongo.]

I will be taking some online classes to learn and I might pick up a small certification here or there, but I will not be pursuing an engineering degree.  

[Creating a carbon fiber structure with tongue and groove joints?]

I am looking for a way to create a lightweight, load bearing structure using flat panels that have been cut with a CNC.  Then, join these panels together in a more tongue and groove / wood joinery type method.  Is this possible?  I assume it will not be as rigid as a structure built out of a mold, but how much will I be losing?   

[Constructing a Nearly Indestructible Salad Bowl]

How is a vacuum bag debulk procedure different to the procedure that creates the final part... (different other than simply not introducing the heat to melt the resin)?  Can I reuse the bag for several debulks?  Can I reuse the bag for the final part?

[Hi! My name is Mongo.]

Bootstrapping.  Why?

[Hi! My name is Mongo.]

I am here to realize my dream of designing and constructing my own car from the ground up.  I will be using a lot of composites and I need to get an education to help me with many projects.  Thanks for reading.  I hope to get to know all of you real soon.