Hi Stuart,
Sure here's the layup schedule for those tubes:
[0, 90, 0, 90, 0]
0 deg layers are 300gsm Toray T700
90 deg layers are 300gsm E-Glass ~UD (80/20)
With Regard to electrical insulation, the simple answer is no the inner ply is carbon so in will conduct, although in practice you will not see any deterioration to the interface within the typical lifespan of a component; light aircraft are only now seeing any form of galvanic corrosion between aluminium and carbon after 20 years of use, and even in these cases I don't know of any component failures, The problem will require an electrolyte such as salt water, the problem may well occur more rapidly in a harsh environment such as marine componentry. I can understand your concern, if you wished to insulate between the insert and the tube you could use a method commonly found in the aerospace industry which is to wrap the insert with a single ply of
25gsm glass cloth and
epoxy resin allow this to cure with a
peel-ply and then remove the peel-ply and bond the insert into the tube. however in theory if used with the correct gapping, adhesive should separate the components sufficiently.
I am aware of many Formula student teams (which I'm guessing that this is) successfully use the 14mm and 18mm tubing as wishbones with aluminium inserts bonded in directly.
I would suggest this
epoxy adhesive it is used extensively in critical motorsport and aerospace applications and has excellent performance under high frequencies, the inserts and tube will need to be prepared properly; the insert should run approximately 1.5 times the tube diameter into the tube, in your case with a 14mm I.D. that would be 24mm, the end of the insert should feature a shallow bevel to reduce point loading, knurling of some description on the body would also be desirable as the adhesive will then achieve a mechanical lock. The inside of the tube should be prepared with a good abrasion with 120grit abrasive. To assist the load transfer a lip stop on the insert will help to ensure an even loading into the tube under compression.
With regard to tube cutting, unfortunately we cannot offer this as a standard service for various reasons, however the tube is very easy to work with, even careful cutting with a hacksaw will give good results, I would always advise cutting slightly oversize and sanding back to your final length, this will leave a really clean edge.
Paul StathamEasy Composites / Carbon Mods - Technical