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View Full Version : Carbon Fiber struts for IRS



lvrpool32
08-10-2011, 10:28 AM
I bought some carbon fiber tube (good stuff from Rock West Composites) to make the spreader bar for my 69 vette. Now because I ordered a specific size the minimum amount was a 72" length...and I only needed 15"!
So anyway I have been looking at other uses for this stuff and I am thinking about making the camber struts on the rear out of them (and expanded to the 4 link I plan on making this Winter)
Now I have the industrial epxoy, I would be using mild steel threaded bungs you can get from Speedway, the same process I used for the spreader bar, but my main question/concern is what type of forces are applied to these struts? Theres no twisting force , so I am thinking length wise (wheel trying to move in and out) and maybe a little front to back (which would probably be taken up by the heim anyway). Anyone have any thoughts?

Nick

killer69
08-10-2011, 04:59 PM
your braver than i am!!!!

how good is your glue?

lvrpool32
08-10-2011, 05:42 PM
Its Loctite 9430, its a room temp curing, two part epoxy designed for structural bonding. It also has high peel and shear strength and its also heat, oil/gas resitant.
Nick

speedy79
08-11-2011, 07:15 AM
Can you put the inserts in with the adhesive and then roll pin through the tube and insert for extra security. My buddies are from an off road background and they always cringe when I talk about suspension components because I come from a dirt track background where I would turn a dirt late model down into the corner at a 110 mph with 5/8" aluminum tubes for trailing arms, tie-rods and strut rods with 1/2" bolts holding it all together. lol

Just re-thought that idea, it would only work if you had longer inserts made so the roll pin didn't interfere with the rod end. duh! It's morning I guess, lol

silver69camaro
08-11-2011, 09:43 AM
There typically is a twisting force on those but if you are using heims that should be negated.

According to the data sheet of Loctite 9430 the shear strength is only about 2000PSI. I might be missing something because that is awfully low for what you want. Have you done this before? Do you have the means to test the part in tension before use?

T_Raven
08-11-2011, 11:20 AM
Thanks for the source! I just bought my old R1 back that has some damage to the seat section of the frame. I was wondering where I could get CF tubing to build a new seat frame.

Here's the damage. I'm thinking I could weld brackets for heim joints where the square tubing is welded on and and make adjustable CF rods to replace the aluminum tubing. It'd look sweet and I could adjust my seat angle.
https://static1.pt-content.com/images/pt/2011/08/damage002-1.jpg

Bjkadron
08-13-2011, 03:47 PM
There typically is a twisting force on those but if you are using heims that should be negated.

According to the data sheet of Loctite 9430 the shear strength is only about 2000PSI. I might be missing something because that is awfully low for what you want. Have you done this before? Do you have the means to test the part in tension before use?


I too looked up the data, and Assuming you had a 1.5" dia tube with a 1.5" long insert you would be looking at over 16,000 pounds. I would look for a stronger resin but it should be doable as long as the surface area of the surfaces... And definitely test first. But then, I also have access to a good sized UTM to test things like that which I know is not the norm.

What are the specs on the tubing? and the planned inserts?

vette427-sbc
08-13-2011, 04:00 PM
By 4 link, do you mean a setup that will get rid of the halfshaft as a suspension arm? If thats the case, Im not sure I would want cornering forces pulling on the glued-in rod end sleeves. No technical data to back up that thought though :spank2:

I would really like to see your plans for the 4 link if you care to share :cheers:

Bryce
08-13-2011, 08:29 PM
Structural adhesives are used alot in aerospace and even bicycles. I am sure you could design something to work. But I would be concerned with fatigue loads as well as limit loads. I would suggest not driving the car on the street unless you have performed these tests.