Wet Cutting Solutions for Composites G10 /Carbon Plate

My primary concerns with cutting Fiberglass composites and even Carbon plates are 2:

1) Eliminate the micro dust particles (Extremely important!)
2) Have a high quality cut and precision on the material.


Any suggestions to adapting a 4x4 ft CNC router to allow flat 1/16" thk fiberglass material to be cut under water? I am thinking making a custom pool bed the size of the router table from some plastic, or maybe purchase a large enough plastic tray, but have not just figured ut the way to attach the fg sheet to such setup without ruining the wet bed, since the cutters must go through the material all the way. MY other concern which is the least of my worries is moisture getting to the machine itself or the motor, maybe a way to deflect the air from the router motor away from the water bed. or using a dedicated spindle and keepi9ng the motor higher above the Z axis.

Any suggestion would greatly be appreciated, as I am in the middle of a job that at the moment I am wet cutting manually (Hand spray at hand) just to get the job finished.

how about flood cooling the same that is on most cnc mills
all you would need is a tub for the router to sit in with a drain to the coolant tank (eg. like a cut up 20 lt container) and a pump (I have used a 1000lt/hour pond pump with a head of 2.5 meters and some 1/2" irragation tube and smaller tube for the directional hose ) it pumps great for my Taig cnc mill plenty of flow would keep the dust down and would be easier to dispose of when the coolant is no good

Unless you are using a totally enclosed fan cooled motor......you had better keep the water away from the "electric" motor! Now on the other had there are servo motors that are designed to run in a wet environment that you might could use as your spindle motor. As far as holding the f/g under the water you will need to build a fixture to elevate the f/g off the bottom of the pool and use something else to to keep it weighted down.

Why don't you just use a good dust collection system? People cut these materials every day with a collection system. There are several type of filters that will trap down in the micron sizes.

Mike

To my knowledge there is no vac system that will remove harmful dust particles, even at the micron level, there is no garantee that the dust will not get airborne somehow, part finish is greatly improved by cutting wet.

I figured out a way to make the pool and support the material under coolant, I am sure someone out there must have built something similar for the same application, but at the moment mine it is experimental and I have to build a much bigger pool container. I am thinking Water Jet machines must work under the same principles since they use water and must use a pool bed for it.

Unfortunately, I cannot run a tub under the machine, like most industrial high speed CNC centers use, because my CNC Router is not designed to be under coolant spray constanly. The pool bed seems more desireable, I built a small pool from a piece of cutting board plastic material I found at a dollar store , it is 1/2" thick and it is about 12"x16" , so I let the router machine a pocket 1/4" deep, enough to place a small sheet of G10 under it, with 4 small screws at the corners for support of this pool frame to the table sacrificial board, and 4 other smaller screws to support the material inside the pool bed, filled it with coolant, I also made a baffle for the Router motor so there is no water to motor splash or air form the motor fan spitting up the coolant. The motor's fan exhaust air hits the baffle and spreads the air horizontally instead of vertically, now. If I get a bit more elanborate, I could make a different baffle to have the air spill up on the side of the router motor, or simply replace the direct router motor with a waterproof spindle. Maybe later on.

Now I am going to build the bigger bed for this router.

I also have to think about how to filter the mud residue so that I can trap the mud in a bucket and recycle the coolant. Maybe build a series of mesh filters so that it works by gravity, since my roture sits up high I will need to pump the recycled coolant flow up and over the material inside the pool, so there is also constant movement of residue and this is not laying on the pool as the parts are being cut. Also the pool idea is more desireable from a perspective that I can still use the router multipurpose. Remove the pool when I want to use the router for other work.

Are there any specific pumps that might work for this application? Thanks for the thoughts and suggestions.

For pumping coolant with chips/dust/etc in it you want a pump with a large clearance (between the bits that move in the fluid and the bits that don't). A pond pump will do, at least for a while, or you can get coolant specific pumps, which are often called suds pumps. I bought a 400gph into 6' head pump for GBP ~80.

Perhaps when you try it you'll prove me wrong, but I expect that, especially if you have a high speed spindle, your tool will fling loads of coolant out of the tub, so you need a way of dealing with that.

I'm part way through adding a flood coolant system to a K2 KG-3925-G CNC router. I want to cut aluminium alloys with it, but the coolant system would flush fibre composites just as well. Time will tell if the attempt is wise, but I think it is or I wouldn't be trying. :D I'll post about my efforts on the K2 forum soon.

IMHO, I think you'll be better off with a flood coolant system, since you'll need to solve all the attendant problems anyway (mostly to do with splashing), and a propper flood system is versatile.

Good luck with whatever you do, and please let us know how it goes?

Leo

Leo thanks for that reply, I have made several improvements to my wet cutting bed by pure need of neccesity and not finding what I needed.

Here is a picture of my smaller setup, uses a shallow water bed fixture, the hardest thing in making such was making it with enought rigidity so that the parts would not move inside the tub. Also making it water tight. I tried plastic, metal trays of all sorts, but none gave me the rigidity required.

I decided it was best to cut one from scratch from aluminum. I found a fish tank pump that worked great...it is one that is driven magnetically so the pump is sealed.

You can waterjet carbon fiber w/ great results... The panels I've had done are appx. 1.5mm thick... As long as the punch through is off of the cut and lead in, you're good...

There's a gasket shop local to me that has cut them w/ strictly water, no abrasives...

Quote:

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Originally Posted by 05fmtc

You can waterjet carbon fiber w/ great results... The panels I've had done are appx. 1.5mm thick... As long as the punch through is off of the cut and lead in, you're good...

There's a gasket shop local to me that has cut them w/ strictly water, no abrasives...

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What shop would that be? and do they have a number?

I have the same issue as the original poster here. I have a Yoocnc 6040, (see Yoocnc X6-1500 X4-800 3020 3040 6040 series - carving-cnc.com and look at the 6040). I want to add a rigid water bath "tray" to mill G10 FR4 plates in. The main reason is to keep down the dust, and a secondary benefit is cooling. So looking around, I saw some acrylic and corian water tray examples, but none with nice threaded inserts down in the bath to attach clamps. The nice thing about cell cast acrylic, is that it is used to make aquariums and joints can be solvent welded using weld-on 4, yielding leak-free joints, like for acrylic side walls attached to a thick base of acrylic. I am drawing up a plan for one of these in sketchup, and will post here when I have the thing reasonably worked out.

I'm in the process of doing this sort of thing for cutting carbonfibre, I'm going to lay up a rigid fibreglass tray that I will fix a thick hdpe sheet into that I can either screw fix or adhesive fix my stock to, I was going to make it as a bath but I think flood cooling will be an easier option for me, will keep the dust and cutting temps down nicely

I cut G10 up to 1/2" thickness dry using PCD endmills, namely Onsrud SERF and SERFIN cutters. Cut really clean. I just use a dust shoe for the dust; the problem is that the swarf seems to expand and pack slots and pockets. I made a custom dust shoe with short/ 1-1/2" bristles which keeps the shoe close to the work. Also my dust shoe moves independent of the spindle, so you can keep the same shoe height throughout the job.

I am aiming to cut g10 wet because my shop is smaller than many master bedroom closets, and I don't see any better way on the cheap to kill the dust in such a tiny room.

For a flood "coolant" pan, I decided to have a aluminum sheet metal pan made for me by Killarney Metals

Attachment 271826

The idea is the same as this video below, which shows how to add an acrylic pan below the table, except that unlike this acrylic example, by using the thin sheet metal instead, I don't have to saw the edges of my table extrusions off to allow clearance.

this youtube video

There should be juuuusssst enough room to allow the vertical walls of the pan to fit between the table edges and gantry uprights without touching the moving gantry parts.

Attachment 271830

I purchased a submersible pond pump from Home Depot online, (free shipping over $50), and I am looking at putting the pump and rough filter in a pail with perhaps this "Gamma Seal" cap system which screws tight onto a standard 5 gallon pail. I would run the plumbing out the top, and include a bypass valve to be able to reduce flow at the spindle nozzle, without blocking the flow out of the pump. I will post more details after I get it working.

Look also at CNC Cookbook's explanation of flood coolant systems to see more. I will add a filter for really fine stuff after the pump, and have some kind of mesh filter in the pail above/prior to the pump.

Now with all this water splashing around, I need to reconsider my wooden cnc enclosure, at least in the long run. PVC pipe and sheet perhaps?

The pic of the wooden enclosure is actually my setup.

Attachment 271832

The fancy version with all the windows is too tall, due to sliding vertical window clearance and too complicated.

Attachment 271834

I will probably simply paint the wood for now, to prevent water damage, and later I foresee a pvc pipe-based enclosure with .75" pvc on bottom, and maybe something cheaper on top. Magnets to hold polycarbonate/acrylic panels to the sides. Just brainstorming on that one.

Attachment 271836

The key thing in such a PVC pipe and /75" or 1" sheet-based design is that slots can be cut near or circularly offset from the 4 vertical pipe upright holes, and a NPT tapered pipe plug can be screwed into a NPT threaded hole in the sheet at the center of the slot, to expand the narrow bridge of material formed by the slot, to grip the pipe very tight. Such threads get larger as they progress into the hole; tapered, so it expands the material to grip the pipes going through it. See a video by Dan Gelbart below, where this very useful clamping idea is demonstrated and explained. His demo uses aluminum, but I bet .75" thick PVC would work so long as the plug is not overtightened. Maybe use a PVC plug instead of a metal one.

Youtube video by Dan Gelbart

That's about it for now.

I forgot to mention, I put these stepper motor covers on my stepper motors to splash-proof them to a minimal extent, and they neaten the appearance and wiring/connector arrangement. I am looking for better solution, because these are only rated ip40, which maybe really isn't good enough for the long run. Do higher IP rated covers exist?

For the stepper motor covers, see:
CNC4PC

Pain in the you know what to install, because:
I had to melt off the hand wheels from the ends of the shaft for each motor.

It required a lot of soldering and wire tracing.

I had to grind down the 4 stepper screw ends a little to allow the cover screws clearance in the opposite direction within the 4 threaded holes of the stepper motor body.

But pretty nice result when done, assuming you don't break off any stepper motor screws.

Would be nice to have a bolt threading tool or nut of the right size to tidy-up the damaged threads of the ground-down screws, before reinserting them into the motor. For example, screw a nut or threading die onto the threaded screw shaft prior to grinding, then remove it using tapping fluid to help reform the ground thread on the way off.

I may have to look into sealed stepper motors, if such a thing exists. I could rubber band some ziplock bags over the motors, but they would overheat. Route the coolant for the spindle through stepper motor cooling blocks, under the zip locks? Getting a little crazy there. Do stepper motor cooling blocks exist? Hmmm. My steppers run a bit on the hot side, even though I have the driver cards to go to 1/2 current during inactivity timeout. Normal running current is to spec, I think 3 amps if i remember correctly.

All of this and more to try to make a dry hobby router wet. But it looks promising so far.

Here is a brief update on my water pan made by Killarney Metals added to my YooCNC 6040 chinese router. Here is a image of the dimensions again:

Attachment 279816



The pan fit perfectly; a little wiggle room between the uprights and no scraping and enough room for travel, and 2 mini sink drains from Lowes on one end.

I drilled the holes a little large for the table screws and drilled and 2 small sink drains with a 2.5 inch circle cutter and finished with a Dremel rotary tool using sandpaper cylinder Dremel tool.

I put silicone in the holes before aligning and tightening them.

Stainless M5? x 12mm long as per the acrylic pan example video I referred to earlier in this thread. Fasteners from Albany County Fasteners. Very fast and well-packaged, btw. Recommend them for fasteners.

The pump is a German-made fountain pump from homedepot.com
Home Depot Aquarius 370-GPH (Gallons Per Hour) Fountain Pump, Model #37229, Internet/Catalog SKU 204684430

A no-contact rotor in this pump insures no rubbing of particles between the moving pump parts. In other words, the sides of the turbine wheel do not seal against the pump casing, so little wear happens from abrasive particles in the water stream.

The water leaves the pump, goes through a PVC threaded 1/2, and proceeds to a T. One side goes up to a valve above the cover and back down to bypass the pump (to allow reducing pressure without loading up the pump). The other goes to a hose bib to 1/2 inch clear vinyl tubing to a whole house water filter. From there to the z axis bracket, then flexable Loc Line for aiming, and out to the work piece. Then down the mini drains from Lowes, little ones, and into under-sink plastic fittings to combine into a T, and down 1" Clear vinyl tubing. Into a piece of 3 inch Black ABS pipe from Home Depot, holding a nylon panty hose stocking using a 3 inch black ABS end cap. (This thing fills like a sausage with G10 dust, pretty good filter) Then the water finally leaks out of the stocking into the bucket. This bucket has the pump about 6 inches from the bottom, hanging from plumbing, secured to a Gamma Seal lid, which screws onto a standard 5 gallon bucket. The valve is above the lid, and everything else is below, except for the 3 inch black abs drain pipe in the center.

The 3 inch black ABS pipe scrap was used to make a cylinder that clamps onto the 80mm spindle to enclose the rotating tool somewhat and reduce splashes and rooster tails over the rim of the pan. The short section of the pipe is cut down the side with a chop saw, to allow it to open up and fit onto the 80mm spindle. The slot which remains conveniently allows a place for the counter-torque tool changing wrench to fit to the spindle flats.

The blown filter in the whole house filters can be washed out in the sink and reused a few times at least. Plus they are cheap. Get the filter casing that is clear type, so you can tell when your filter is getting full. I am using the Glacier Bay model from Home depot. It was one size smaller than the biggest I saw on display. The biggest did not use a transparent case, so you could not see inside to the filter.

The pan took over a month to ship, as promised, and cost like $280.00 or so, but is very well made, and precise to the dimensions I asked for. This is important to have good sheet metal precision with such little clearance for the pan to fit between the X axis gantry uprights.

How does it work? Excellent. I have cut both 1/2 inch G10 parts, as well as a large PCB, and it does it's job. Water is contained, no leaks and very little overspray over the pan. However, I needed to add that collar to the spindle made from a short section of ABS 3 inch pipe, to get there. Before the collar, sometimes water spray from corners would spray up over the pan. So use the collar, but leave room for clamp clearance. Use simple flat clamps cut from sheet with a bolt to the t-nut. Low profile is good.

I am very pleased with my new setup. I will post some photos when I find time. I am happy to answer any questions from other folks looking to attempt this kind of water pan thing for cutting G10 or PCBs.

Ok, as promised, here are some photos of my YooCNC 6040 upgrades for wet cutting FR4 G10 laminate. Hope someone finds this useful.

Two things worth noting, the 1/2" clear vinyl tubing is attached to a hose bib below the cover, not above it. This prevents spills should it somehow come free, though this seems unlikely. Also, with this Gamma Seal lid and drain into the center of said lid, when the filter is full and the water overflows over the top, it gets captured by the recesses of the lid top and this avoids a spill.

Nylon socks work well too. Use two, because the hanging mass stretches out the sock/stocking and opens the pores/holes more. Better to not open them more than necessary with stretching forces.

I get about three 12 X 12 X 0.1875" blank workpiece changes out of a whole house 5 micron blown filter cartridge before swapping it out. Your mileage may vary.

I have now been using the aluminum water tray on my YooCNC 6040 for some months now, and I want to say it has been problem and leak free.

I now use a regular white athletic sock for catching particles in the drain water in the ABS pipe above the sump bucket. The G10 dust collects inside and forms a long sausage shape that I can simply throw out.

I changed to using the pleated paper water filters that fit the Home Depot whole house water filter cylinder.

I found that the pleated paper filters (which also fit into the same canister) don't diminish the water flow nearly as much as the other kinds to be found at Home Depot, like the blown plastic foam filters.
But don't forget to change them out when you do a complete water dump and change. Paper filters don't seal very tightly due to being, well, paper, and will thus eventually begin to bypass the filter around the top and bottom seals. They are cheap enough for the use you get out of them.