[kong]

Just wondering if anyone has any experience on this? I've just laminated some, and should be ready to go on wednesday. It will be about 1 - 1.5mm thick, and I intend to use 1/16" endmills to cut it. All advice is welcome.

[cncadmin]

I cut 1/8", 1/16" thick G-10 with a 1/16" and 1/8" bit no probelm, just make sure you use somthing to suck the dust as it cuts. Also don't run a high feed rate or your bit will flex at least mine did.

[Rekd]

Paul, I've machined carbon fiber before, it chipped quite easily. Do you notice this when routing it also? Use different tool geometry?

'Rekd teh curious

[CAMmando]

Much more abrasive than Glass. Polychrystaline diamond tipped cutting tools provide the best tool life (with the obvious downside of cost and availability. If cutting is limited carbide will work. YOU DO NOT WANT TO BE BREATHING THE DUST !! Good Dust Collection and a mask are advisable. Since cutting fluids are usually a no-no, you may want to try "Boe Lube". It is available from MSC in various forms. It is a lubricant that will extend tool life and does not hurt laminated composite materials. It was developed by Boeing for this purpose. Often carbon fiber laminites are laid up so that a layer of glass cloth is on the outer surfaces. This helps protect the carbonfiber, provides some protection against galvinic corrosion of adjacent parts, and helps prevent splintering of the carbon fibers (particularly if the carbon fiber is unidirrectional tape). In anycase, try to use cutter geometries and toolpathing approaches that will best guard against delamination. If the parts are flat and delamination is a problem, consider sandwiching between sacrifficial sheets. Also if you are cutting alot, consider variable depthof cut (ramping or stepping down) to prolong life of the cutting.

CAM teh run-on paragraph

[cncadmin]

Originally posted by Rekd
Paul, I've machined carbon fiber before, it chipped quite easily. Do you notice this when routing it also? Use different tool geometry?

'Rekd teh curious

I have a pic of frames I cut, and I did have any problem with chiping. My cuts where very clean.

[kong]

Thanks guys, some useful stuff! I have not got dust collection sorted out yet, but my machine is in a box so it won't be a problem.......until cleanup time!I like the idea of sandwiching it between sacrificial layers, if chipping is a problem, but I'll wait and see first. I guess I'm have to buy me some solid carbide cutters now though! Any chance of that picture cncadmin?

[CAMmando]

Try Looking Here


http://starliteindustries.com/designs.htm

[kong]

Thanks for the info, unfortunately I'm in the UK, so I'll have to find something closer to home. It will obviously be worth forking out for the diamond tipped tooling, but I'm just so eager to go!

[kong]

Cammando, I have bee nlooking at various cutters on the net, but the price of those PCD ones are ridiculous over here! About £170 for one ($250). So I would like your opinions on these two:
diamond end mills - if the link doesn't work, goto the shop and then to "diamond" cutters (please!)
solid carbide burrs
Having just spent around $100 to get some decent aluminium cutters, I am a bit broke at the mo, and don't have spare cash to test different cutters. i tried a standard FC3 cutter on the carbon, and i got slite splintering. Apart from that, it was OK. Your advice is appreciated.

[sorincnc]

Kong,
I never had anyproblems with the suff shreading or comming apart. Tool life is not that good.. Make sure that you use carbide tooling. If high speed tools are used they heat up and there comes the problems. Diamond coated tools are the best but extremely expensive. What I have found is that small router bits (1/16 )are easy to find at hardware stores (IE lowes and Home Depot in the dremel tools area). They sell a carbide bit that has diamond shaped bumps on it (looks like a rasp) instead of flutes. That is actually pretty good because it actually grinds through the material rather than cutting it. You might ask what I am doing buying tools at home depot.....well one Sunday afternoon the last bit broke and I had to finish the job so there I was. Please do your self a big favor. Check the material safety data sheet. This stuff is very nasty to your health if not using the proper vacum and mask. Do NOT mess with it unless you can protect your self from breading it.
Regards,
Sorin

PS: If you want to know anything there is to be known about machining CF look up one of the members here. His name is Mark Linder and he is the GOD of machining CF.

[HuFlungDung]

Thanks for that warning about carbon fibre, Sorin. I've never had to cut any yet, but there's always a first time and it's nice to know whats hazardous beforehand.

[sorincnc]

GEEEE Murray,
Is almost 2AM and there we are, tho only ones holding down the fort...Or is it 11 PM for you. I must be addicted or something. I am suppossed to be on vacation and not doing this.....LOL
The wonderfull efects of the jawa bean.
Good Night my friend,
Sorin

[mlinder]

Hey Sorin and Hu,

Mark here. I'm still awake! Of course it's only 10:30pm here.

I cut TONS of carbon fiber laminate material anywhere from .4mm thick to 6mm thick.

Our machines are routers that have major vacuum directly to each spindle head. Even our drill presses have vacuum lines directly at the point of contact.

The vacuums deal with 99% of the dust.

Since most of the parts we make are small and have small internal radii on pockets, we use .062. 093, and .125 dia solid carbide bits. 14,000 RPM and around 24-30 in /min. The quality of the material makes a BIG difference. How it's laid up, whehter its vacuum bagged or presses (pressed is better). I work very closely with my supplier to maintain a good quality material with excellent cutting characteristics.

I'd tell you more, but then I would have to find you - and kill you.

Have a good night!

Mark Linder

[kong]

cheers guys, sorincnc the cutter type you mention was my second link in the last post, it was either the carbide diamond-pattern cutter (we call them "burrs" over here), or the diamond coated end mill. I was already aware of the dust problem, but I have a nice respirator so it's ok.
mlinder, this cf is stuff I lay up myself. As I only use it rarely, it was pressed, but between some MDF with heavy mahines then placed on top, if you know what i mean. Just wondering what type of cutters you are using?

[mlinder]

Kong,

I have attached a pic of the type of router we use. The pic shows what is called a "fishtail" router. We have a point ground on them instead of the fishtail. It lessens the amount of fracturing at the point of entry into the laminate. additionally, down cut works best.

We tried diamond coated tools years ago, but I found that the resin in the material (the "glue" holding the laminate together) tended to gum up, no matter the feed/speed.

Cheers,

Mark Linder

[kong]

Excellent, thatwas the confirmation I was looking for! I will now go spend some cash!

[mlinder]

Kong,

Thanks. Now I have to buy at ticket to the UK... So I can kill you.

Damn. I had other stuff to do this weekend.


Cheers,

Mark Linder

[kong]

Lol!
*/me runs/*

[tauscnc]

Hey guys,
I cut my first carbon fiber part and it was much eaiser then I thought it would be! I also used a fishtail cutter instead of an endmill and then found this post where its suggested by Mark

I used these from Harbor Freight Tools: Reground Carbide Endmills, etc. and they work great!

I used them on my Sherline Mill and since I did not have/want a vaccume to run for sometime I DROWNED the part in 3 in 1 oil as it cut I tried water but it was to runny. After it was done it looked like black slug.

You can find a pic of the Carbon Fin Here

So much fun, not enough time
taus
www.cuttingedgecnc.com

[kong]

Fine work Taus! Now lets see some piccies of the whole chopper!