machining carbon fiber

[Chris Parish]

Hey guys:

 

I have a cuastomer machining carbon fiber laminate using a 1/8 dia onsrud dia cutter..Any recomendations on SFM and chip load.. I looked at Cimco and at ME consultant but didn't find anything for carbon fiber..

 

Any thing would help.. Thanks

[Colin Gilchrist]

PCD coated cutters are the only tools that will stand up to significant cutting in carbon fiber laminate. You can use carbide, but it will wear very fast. For PCD tools we go 300-600 SFM, .0005-.002 per TOOTH depending on cutter size. For a 1/8" tool I would try .0002-.0004 per tooth. I bet that Onsrud won't last too long...

[Jim at Gentex]

We machine composites here all the time and we have one particular production part which has some tight tolerances.

 

I agree with Colin...it wears tools like crazy.

 

We've had the best success with Data Flute diamond coated end mills. We are running a 1/4" diameter flat end mill at around 500 SFM and .001 chip load per tooth. I get around 20 parts per cutter before the dimensions start to go away, then I replace it.

[Matthew Hajicek - Singularity]

It's also important to vacuum up the dust as it's cut, or it will get into your machine and wear it out.

[Thee Rickster ™]

Would CVD diamond cutters be an option for

minimal wear?

 

Belmont Equipment is a good supplier for them.

[Hardmill]

quote:

---

It's also important to vacuum up the dust as it's cut, or it will get into your machine and wear it out.

---

Screw the machine, breathing that stuff is waaay hazardous.

If you dont have the proper equipment you got no business

machining that stuff.

 

 

PEACE

[Colin Gilchrist]

Check out these guys:

 

Diamond tool info

 

They have some good information on PCD tools and natural diamond tools as well. I would go with PCD if it was my money. What kind of tolerances do you need to hold with your .125 endmill?

[monty]

We do a lot of carbon fibre machining(plunging and sloting) and cheapest option for us was using a uncoated micrograin carbide cutter with 45deg helix at very slow speed of 50m/min and feed of 0.2-0.3mm per tooth. It gives very good thick chips and I can slot up to 6 metre long with one 8mm cutter($30/-).

Problem with using expensive cutters with high cutting speed was that chips were like powder and were hazardous for health and bad for machine. The other problem was that since we don't use coolant on carbon fibre as soon as cutter gets blunt at high speed it melts the peice and we were geting too many rejects.At slow rpm as soon as I get powdry chips I know it is time to change the cutter.

HTH

[Colin Gilchrist]

Good ideas Monty. The powder is a real health hazard. I like the idea of getting big chips...