Cutting Carbon Fiber Safely

Hey guys, just recently finished my MPCNC (it’s awesome) and one of my main purposes for it is to cut carbon fiber sheets to make custom quadcopter frames (gotta love fueling hobbies with other hobbies). I’ve seen multiple ways to go about this with other CNC machines, but I just wanted to see any ways people are going about this with their MPCNCs.

It seemed to me that one of the safer ways was cutting in a water bath. I’m using a Dewalt 660 like most other people and just hesitant to get that near water just because I don’t want any splashes screwing me out of $60 and a couple days wait for a new one lol. I’ve seen some people say that vacuuming and wearing a dust mask is sufficient enough, but I have this thing set up in my garage which is attached to my house. I don’t necessarily want any micro particles getting through and into the house (or floating around the rest of the garage for that matter). The other way I’ve heard of people cutting is by using coolant to sort of clump up the carbon dust, but that obviously won’t work in my scenario.

If anybody has any suggestions that would be great!

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Just print a simple shield on the bottom to protect your router from any water splash.
Shouldn’t be very difficult.
Or switch to a DC brushless router, they should be way less sensitive about water.

Yeah, just make a shield. You could try thicking the water with some cornstarch to help against splashing.

We cut carbon at work all the time, but we have big industrial vacume/vent hood thing we call the Snuffleupagus. Because it looks like a mechanical elephant.

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Water bath is your best bet. Maybe a chip breaking 1/16 inch end mill with a 1/8 shank. I don’t trust our vacs and masks to protect 100 percent from that dust, it’s really toxic. I also want to try carbon fiber soon so I can’t wait to see what you come up with.

Yeah to be fair the only time that I’ve cut carbon was also at work, except I used our waterjet. Delamination city. Buuut there also wasn’t a bunch of dust flying around so gotta make some sacrifices.

Yeah I have a 1/16 carbide 4 flute endmill that I’m going to give a go until it goes out. Hopefully the water will keep it cooler.

My idea though is either an acrylic bed with a silicon seal or a similar idea with aluminum angle I can pick up from Lowes or something.

Yeah if it is just carbide not one with a Polycrystalline Diamond (PCD) coating, it won’t hold its edge for that long. CF is very abrasive.

Yeah I’ll have to do that. Hopefully something that I can keep a tool change sort of easy with it on. My main concern is mostly just water + electricity. I don’t know how that would react if it got wet and I’d rather not get electrocuted lol. May have to look into a brushless spindle though.

Likely, yes. Though most of the small spindles you see us use are not brushless. They only have 2 wires so they’re just dc permanent magnet motors with a special bearings and collet systems. What makes them waterproof is more the fact that they’re “real” spindles made to be around all sorts of coolant like floods or misting. On the plus side the dw660 is very dust resistant :slight_smile:

You’re not saying the Dewalt is waterproof (or moreso coolant proof lol) are you? I’m sure I’m just misreading that.

I looked into getting the famous spindle on Amazon that’s $130 or whatever but I was turned off by the fact that it didn’t seem like I could control it with PWM and I could only use the pot to control it. Also the Dewalt is 30k RPM vs 12k.

The DeWalt isn’t going to be waterproof, but it’s meant to be used by contractors to for a bunch of odd jobs. It’s pretty tough. Plus, it has a warranty. Gam3Tech has gone through several sets of brushes on his, which are meant to wear out. I would do what I could to keep it clear of moisture, but I would sacrifice it before dropping $130 on a Chinese spindle.

You’ll also get much larger dust if you evacuate the chips before cutting them even smaller.

Would it be crazy to suggest putting the whole thing on wheels and rolling it outside when cutting CF?

Well…if I unscrewed the table from the wall…

It’s a possibility. I ended up using the wall as a sort of rigidity brace because the garage cement isn’t too even for whatever reason and keeping it level was going to be a pain otherwise. So I may end up rebuilding the table or maybe welding one (who knows) that had wheels on it. The thought was already in my head when I saw somebody else’s on a cart.

I wanted to cut my own CF frames as well but it is more expensive than just buying them pre-cut. CF (real CF) is expensive.

A mist system would be ideal, I have used water a few times. Usually it gets flung off as long as you have minimal flow and good aim. If it does creep up it is hard to get it past the collet. I wouldn’t worry about the spindle so much, the bearings on the rollers and the steppers are way more likely to get soaked from the flinging.

Actually, a few droplets of water in the spindle motor should have no effect. The motor wiring is made of magnet wire, which is coated with a very resistant resin, so waterproof.
The only non waterproof part is at the top, where the brushes are located. That where you should avoid water. But here again, as long as you do not pour gallons of water on it like a moron, should be no problem. XD

I would be more concerned about the spindle bearing rusting than electric issues. Just for safety: ground your water bath to the earth wire of your main plug, in case there is any problem. And avoid touching the water while the spindle is plugged, always cut the power first. Just common sense.

But anyway, just use the CNC to cut a shield out of wood, it’s really no rocket science, no need to overthink such an easy issue.

True, it also depends on what size of frame you cut aswell. I don’t know if you were cutting for something more the size of an aerial photography rig or a racing/mini quad. I’m mostly into the racing quad stuff so iirc I could get ~4 completed sets (give or take one) from 1 piece of 4mm and one piece of 2mm thick 200x300 sheets. Most of the mid end frames use 3k twill, so I picked up that and ended up getting those for $80 a few months back. I justified it because some of the more popular frames cost well over $100 each, usually just including the carbon pieces, standoffs, and hardware. I just wanted my own frame because I’d be the only one with it and I work in a machine shop so I have an idea of how much something like that can end up costing if you don’t send out your files to somebody who’s done quad parts before lol.

But thanks for the reply I’ll be sure to look into a mist setup aswell.

P.S. Thanks for designing this, you did a great job! I would say you have no idea how it felt to see it cutting something or drawing something for the first time, but I know you know exactly how it feels haha.

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I want to see what you come up with, I have a solid little quad now but no where to fly it…I had no idea how far these things have come in the last couple years. This new little bugger is fast, like way too fast. So I am sure If I can find a place to fly I will break my current frame in no time. So if yours is solid I won’t have to make my own.

I’ll be sure to post what works for me!

And I’ve got a few different sizes. Most of mine swing 5" props, one of them has 3" props and it’s faster than it’s big brothers. I mean no doubt in my mind it’s over 80mph. Sometimes with FPV it’s a bit hard to tell how fast you’re going, but this thing is pretty outrageous. My 5" ones are pretty quick to and I like them better because the extra momentum carries them more and it just feels more natural. Anyway, if you have a CF frame on yours that is even half decent CF quality, it’ll take a good crash or a really unlucky crash to break it. The worst I’ve done so far was a little bit of delamination and a little crack on some 1.5mm thick stuff. I’ve hit poles, trees, grass, had a failsafe ~100ft over cement…

Definitely post what works. There is kind of a void when it comes to carbon fiber. Haven’t seen any videos of the mpcnc cutting it yet. Maybe you and your drones can race my 105mph rc car :slight_smile:

Wow. My last crash broke my aluminum frame and two of my motors. Snapped the shaft on one motor, and the other one was pulled off the frame, stripped out the screw holes.

Sounds like me and you crash the same Barry.