Carbon fiber on CNC machine

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#1

Hi everyone,

I’ve had some fun in the past moulding some carbon fiber parts by using 3D printed moulds (and a set from EasyComposites: https://www.easycomposites.co.uk/forged-carbon-fibre-kit), see photos below, and sometimes some of the features can be too small to get in the mould (or the mould will keep them stuck in them and rip it apart, not ideal). The photos below are for different methods of using CF: one is moulded via the kit I linked, the other one is the more traditional sheet of CF epoxied on the part itself.

I was wondering if it would be fine to use the mini CNC to cut some features out of some similar parts? I’m happy to even buy a few cutting tips and leave them at the workshop if there is any worry of wear and tear :slight_smile:

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#2

@CNCtechs? @Kyle?

#3

Would be very interested in working with carbon fibre. When cutting carbon with a handsaw we use foam, gloves, respiratory protection, and do it in a well-ventilated space. In small shards it’s much like asbestos, and there are reports of asbestosis in the cycling industry from working with cf.

#4

I’ve never worked with carbon fibre… I’m very interested.

My worry on the CNC is just about the dust and micro fiber… It won’t be healthy for the messy room… But again i’m no expert with the material

#5

Yes fair, I guess the Henry hoover might not be sufficient for the dust - would we need some more aspiration for it potentially then? Could the aspiration from the laser cutter be used for both?

#6

Not that I know of

#7

Fair, and do we think that it would be fine to do on the large CNC then once the space is enclosed with the door etc?

#8

The extractor is way better there but i’m still concerned about health… Again this is me not having enough knowledge, but shouldn’t we treat carbon fibre or glass fibre particles as they do with asbestos? Isn’t there water involved to damp down the dust?
I’m only meaning sanding/milling process i think moulding it’s ok ( actually keen to learn it with CF)

#9

That’s my understanding of cutting and drilling cf, fwiw.

#10

Yeah, this video shows an application where they have a “milling bath” to keep the dust within water:

I guess this would be a fairly easy to do thing on the big router, but maybe not so easy to get on the small CNC?
I might workout a small jig at some point to allow this and then we can review together and see if you’re happy with this measure? What fo you think?

#11

I have an idea for an aluminium camera house done on the cnc and for such job you need coolant… Every time i envision it, it has always ended in flooded woodshop and people running and screaming everywhere… So… Happy to try :stuck_out_tongue:

I can bring my armbands, you bring rugs to dry everything

#12

But seriously, i don’t see a problem with the bathtub assuming it works, i have lots of “accessories” ideas for the cnc…
In regards of the CF… Still think we need a broader assessment to work with it in the space… For instance: what do we do with the water once the milling is done? Draining down the toilet? In that case I’ll be furious…

What do you think?

#13

Ps: whatever i say doesn’t stop the project… It’s only my view

#14

Hi Frederico,

I agree, we need to do a full risk assessment and a clear SOP for how to work with machining CF product. Happy to take that under my hat to review later on! I’ll try to see what’s the state of the art on this front to replicate what makes sense in the Space!

And on what to do after with the water, I would see if being filtered before discarded but just my thoughts on the fly. :slight_smile:

Cool, glad that there is a way forward anyway!

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#15

Hi everyone!

Just started finding some time for this. So here are my thoughts:
Overall most machining shops don’t seem to take much bigger steps than having aspiration by the spindle to take away the dust but I agree that it would still represent a hazard overall and that wet cutting with underwater milling would be preferential.
Taking into consideration that you would ideally be tempted to use coolant with the CNC to mill some aluminium (I am keen on that too!), I was thinking that an easy way forward could be to enclose the whole mounting plate, represented here:

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Now adding 4 ‘walls’ to it:

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My idea for these would be to use 5 to 10mm aluminium plates which would be stiff enough over the length to not bow away, plus thick enough to be tapped to add the following clamps to each junction:

Between the plates and the mounting plate we would have seals running to take up the gaps and keep the water/lubricant in there. Same between the plates themselves.
That system is mainly so that we can remove it. If we didn’t need to remove it then we could look at threading the aluminium mounting plate where the grooves are not running and that would simplify assembly. It keeps the depth of cut of the machine as is currently but means that the clamps that are used to clamp the part down will be wet/lubricated.

Further to this, we could add tapped holes on the plates on the groove sides to purge the lubricant out to make cleaning easier.

Just a quick Saturday morning thoughts – thought I would share before going much further on design work, and later on with testing.
Maybe we could have a sit down brainstorm of how to make it work?

#16

I’ve messed about a little with CF and have successfully repaired several bike and bike related stuff. My understanding is CF is not recognised by the body as a threat because carbon is what the body is made from. So once it’s entered the body it doesn’t get rejected and hangs around - a problem.

When I work with it I try to use reasonable precautions, extraction, wet sanding, mask, gloves etc., where possible. There’s far less of a risk when moulding and laying up - apparently.

Anyway, wanted to pitch in to follow and because I am looking to do more CF making…

#17

Thanks for contributing!

@Federico / @CNCtechs > Would you see any problem with me trying to make an enclosure for the CNC bed as I mentioned above? (Though refined the idea so that the sides perpendicular to the grooves would be compressed to the mounting plate via long leadscrews to allow for easier installation, but still Ideating in progress :))

Cheers!

#18

Just to be sure i understand… The enclosure is for the mini cnc bed and you want it to be waterproof so to mill the CF submerged?

If so i would say no for a number of reasons, the first and most important: the first spill of water will result in ruining the machine as none of the components are designed to be water resistant.
If the system works, we don’t know how to recycle the water and, again, flashing don’t the toilet it’s NOT an option for me.

On the other hand, if i misunderstood your idea and the cf will be milled without water… We are back on the first problem: cf dust… We are not equipped to manage it.

As i said before, in my opinion, we shouldn’t milling cf in the space. I’d love to learn how to work with it but for the benefit of the makerspace community ( and my lungs) cf, fibreglass and friends ( do i need to specify asbestos?!?!?) Should not be introduced in dust form.

Please if anyone has direct experience working with the material ( i don’t) and can correct me I’ll be pleased to change my mind.

Thanks
Federico

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#19

Alright… So yes you understand correctly, it was about having a waterproof bed to have no dust form creating.

So would any waterproof solution of the bed be ruled out anyhow? So your post a bit above about using lubricant for your camera casing was just a dream but nothing that you think is realisable? :sweat_smile:

From the research all of the manufacturers (and suppliers) seems to only be recommending using extraction to deal with the dust. But I agree that water would be safer from my point of view too.
In terms of recycling the water, as I said before, either filtering the water to get only the fibers in the filter would be a solution, otherwise we can use water solidifying agent to turn the whole solution solid and dispose of it that way so that it is not volatile.

Thanks

#20

In the post i said i would love to mill a camera housing, not that i’m planning to do it… Beside that on the big cnc it would be easier as all the mechanics are above the bed and not below, so you would only need to deal with the water splashing up, as the bed has no electricity/ components ( it would be a mess of wet mdf anyway)… Said that, I’m not saying that I’m in favour of milling submerged on the big cnc.

Regarding your tank design… If it’s waterproof there is still the issue of protecting the spindle and everything above the bed…

If that would have been my cnc machine i would have experimented exactly as you were planning to do, but it’s not, not only… It’s everybody’s.

Regarding the manufacturers recommendation, we don’t have a very good extraction on the mini cnc, poor Henry is doing its best, we should give it a medal ( and clean it from time to time).

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