joining carbon tubes
tegwin - 14/2/14 at 11:19 AM
I am in the process of building a rig to hold my camera, part of it requires the joining of 25mm OD (22.2mm ID) rolled carbon fibre tubes at 90
degrees.
The "usual" way of doing this is to use aluminium clamps and some plate to form a corner joint. I don't like this as its a bit clunky..
It doesnt really make use of the benefits of using composite tubes either
So was trying to find some sort of insert that I could bond into the tubes to form the corner. A nice cast alloy elbow with "legs" to bond
into the tubes would be nice but I can't find anything...
Another ideas was to mitre the tubes and use flat sheet carbon to create an insert to bond the two tubes directly together... not sure this would be
easy...
Weight is an issue..
Anyone any thoughts or experience doing this?
luke - 14/2/14 at 12:17 PM
Just spoke to collegue of mine who works alot with carbon in his spare time.
He says the only way is to make a T piece that the tubes slot into, Almost as if you were taking a T off your drain pipe. This will gibve the joint
the strength and rigidity you require.
hope it helps
Luke
rash12 - 14/2/14 at 01:17 PM
put an endex tee inside and glue it
tegwin - 14/2/14 at 01:26 PM
What do you mean by endex?
rash12 - 14/2/14 at 01:28 PM
a plumbing tee without the solder rings so its nice and smooth probably cost pence
twybrow - 14/2/14 at 01:35 PM
Does it need to look blingy? If not, mitre/fish mouth as needed, and then wrap with carbon (or fibre glass if you are cheap!). That is how joints are
made on bike frames that can be constructed using pre-made tubes.
40inches - 14/2/14 at 01:41 PM
Something like this?
eBay
tegwin - 14/2/14 at 01:41 PM
It does need to look tidy sadly so I am not keen on wet wrapping the joint.
Copper pieces might work... If I could find a 90 degree elbow with 22mm od that would be brilliant but apparently they dont exist. Likewise a 25mm or
1" ID would work but cant seem to find them either.... Would be a really tidy solution though!
tegwin - 14/2/14 at 01:43 PM
quote:
Originally posted by 40inches
Something like this?
eBay
That could work. Not sure how strong it would be really dont want any flex (or snappage)
I guess it will need to be able to support a 1Kg mass at about 300mm lever arm.
40inches - 14/2/14 at 02:27 PM
quote:
Originally posted by tegwin
quote:
Originally posted by 40inches
Something like this?
eBay
That could work. Not sure how strong it would be really dont want any flex (or snappage)
I guess it will need to be able to support a 1Kg mass at about 300mm lever arm.
The joiner is made from PA 66. Looks like it my be up to the job link
amalyos - 14/2/14 at 03:24 PM
quote:
Originally posted by 40inches
quote:
Originally posted by tegwin
quote:
Originally posted by 40inches
Something like this?
eBay
That could work. Not sure how strong it would be really dont want any flex (or snappage)
I guess it will need to be able to support a 1Kg mass at about 300mm lever arm.
The joiner is made from PA 66. Looks like it my be up to the job link
It's PA66 Glass filled, it won't bend, but may snap if to much load is put on it. Why not buy 2 and test one 
tegwin - 14/2/14 at 03:26 PM
Might give it a go! Could really do with a 90 elbow of the same design!!
YQUSTA - 14/2/14 at 04:33 PM
What about getting a square sheet of carbon and cutting it diagonally then sandwich the two tubes between them with some bolts going through the whole
lot.
rash12 - 14/2/14 at 06:20 PM
overflow pipe elbows are 21.5mm id so will be very close od to what you want might be worth a look