Gallery, Projects and General > How do I??
Drilling holes in carbon fiber
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No1_sonuk:
Would drill bits made for glass or ceramics work?  Drills for tiles should be available from a local DIY store.
kellswaterri:
Carbon can also cause the drill to wander a bit.  I dont really know why, I've always suspected that the weave of the fabric can pull the tip of the drill over a bit.

I worked with the stuff in the aircraft industry for a long time, the drills we mostly used were akin to a ''Masony drill''  Tugsten tipped, sometimes we used pure Tugsten ...depended on how the material was laid up///formed and type of material ie. Kevlar...in most if not all cases a ''JIG'' was used when boring thus no wandering of the drill...in some cases a Diamond drill or diamond rota cutter may have been used.
John.
Sorekiwi:

--- Quote --- BTW... what race team? My buddy works for Brumos DP race team in the Rolex series.

--- End quote ---


I've always done open wheel cars.  In the US it was Indycar as well as the various feeder series - Indy Lights, Formula Atlantic etc.  I've never done much sportscar work, but a lot of my friends have started doing that in the last few years.

I got sick of all the travel, and spending every weekend over the summer working, so at present I'm doing something else.  But I do miss it, and may go back   :bang:
Lew_Merrick_PE:
I do a fair amount of work with carbon fibre structures.  We normally use a coated "reamer" to "size" holes after they are pilot-drilled with a carbide drill.  We start with a hardened piece of drill rod with a diameter that will be correct once the cubic boron nitride (Borozon -- brand name) abrasive (purchased by size) is applied (plasma bonded).  The end is tapered (7.5° of taper) so that there is a "lead" of abrasive to open up the (undersize) pilot hole.  The shop that has been doing this work for me (since the late-1970's) has a broad array of such "reamers" now in stock.  These are not inexpensive tool bits!

One thing to remember about carbon fibre is that it has nearly zero resistance to abrasion.  Some of the early carbon fibre antenna and solar array supports failed rather spectacularly due to the abrasion from rotating about (aluminum-bronze) pivot-clevis-pins.  (You may remember some embarrassing satellite failures in the early-/mid-1980's.)  A bit over a year ago, I qualified the use of a carbon fibre leaf-spring for a (classified) military application.  The "trick" was to place lubricant-impregnated acetal rollers over the "pins" that the leaf-spring drove to prevent abrasion.  Without the "rollers," the spring failed in less than 20 cycles!  We passed 10,000,000 cycles with the "rollers."

I know that on highly-stressed aerospace and military structures that they make "wound" carbon fibre inserts that are placed in the lay-up tool with the "cloth" punched for a close fit.  Extra resin is laid in around the inserts before curing in the autoclave.  The inserts provide an accurate hole size in the form of a flanged bushing with an "invar" (a nickel alloy with a 0.0 coefficient of thermal expansion) insert/inner bushing.

None of these as implemented are appropriate to the home shop type, but they might give you ideas.
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