So, I'm putting together an enclosure for my Taig mill, and I'm getting around to the front double doors. It occurs to me that I'll be wiping off a mixture of coolant and fine metal chips, and it seems like the door would scratch up pretty quickly. Is this actually an issue with, say, acrylic or polycarbonate?

If this is a potential problem, I was thinking I could use a sacrificial protective film over the door material and replace it when it gets scuffed up. There's self-adhesive clear protective film that seems to come either in letter-size sheets for protecting artwork, or in humongous rolls for protecting windows. The most likely material I've seen is this 600-foot roll (roolshttp://www.tapesolutionsinc.com/58922.html). That's a lot of film, but it only costs about what I'm likely to pay for the base 1/4 inch door material, and I'd have about 100 changes of film.

Does this make any sense? What would you suggest for door material, and for protective film, if any?

Thanks,
Drew

Keep in mind, I am new to this, so I may just be full of it.

I just plan on replacing the panels periodically. So I designed my interior clear panels to be mounted using bolts through flat aluminum strips and rubber gaskets.

The lower 6 inches of the panels are HDPE, as I figure that is where most of the metal/coolant/lube will end up. The upper parts are simple acrylic panels.

Just a thought.

How did you solve the drain pan problem? I am struggling with that. I figure to use perforated HHPE which is raised up from the drain pan to catch most of the metal shavings. Those will not be mounted, so they can be easily removed to clean. It should also keep the shavings from clogging up the drain pipe.

But for the life of me, I cannot quite get the drain pan design licked.

Hi Skuzzy,

I'm just getting into this myself, so I can't say I know the best solution. For the tub, if that's a good term, I'm doing a variation on this (http://www.jeffalbro.net/cnc/flood-table/). I can't figure out what sort of drain he's using, but I'm putting mine together with a regular kitchen sink drain, more or less like this (http://www.s177152627.onlinehome.us/flood.html). I got rid of the little structure at the bottom of the drain that supports the basket, so the outlet won't clog with the small stuff. That stuff is caught in a paint straining bag in the 5-gallon bucket coolant reservoir.

I can't really picture how big a pile of chips I'll have, but if it all fits in the basket, I can just pull that out and empty it. I would use something with a lager basket if I could find something. You could probably use a shower drain or garden drain and fabricate a basket out of some kind of screen material or hardware cloth.

Have fun with this,
Drew

In a practical sense you may find it is not worth worrying about the plastic getting scratched, you can still see through it okay.

I think you might find those adhesive films impossible to get off once they have been on for a while.

And just in case someone suggest getting the Lexan, Tuffak, Polycarbonate, (all the same thing) with the scratch resistant coating, MarGard it is called or something like that be careful. I discovered that the coating makes it much more likely to shatter when it receives an impact. Regular polycarbonate can often take a good hammer blow with nothing except a small dint; I once had some MarGard stuff shatter just like glass.

Since Lexan is widely used in aircraft windows / canopies, safety goggles and even bullet proof windows, it seems highly doubtful that it would be subject to shattering like tempered glass when struck etc. It would surely be my first choice for material of your need.

One for, One against :D

Since Lexan is widely used in aircraft windows / canopies, safety goggles and even bullet proof windows, it seems highly doubtful that it would be subject to shattering like tempered glass when struck etc. It would surely be my first choice for material of your need.

One for, One against :D

Correct; so I will give you another chance to read the distinction I made:

And just in case someone suggest getting the Lexan, Tuffak, Polycarbonate, (all the same thing) with the scratch resistant coating, MarGard it is called or something like that be careful. I discovered that the coating makes it much more likely to shatter when it receives an impact. Regular polycarbonate can often take a good hammer blow with nothing except a small dint; I once had some MarGard stuff shatter just like glass.

Well it does read clearer with my "2ND" chance, but still dubious about wide spread shattering experience that would be caused by the scratch resistant coating as that coating is also widely used on mil-spec safety glasses.

Well it does read clearer with my "2ND" chance, but still dubious about wide spread shattering experience that would be caused by the scratch resistant coating as that coating is also widely used on mil-spec safety glasses.

Where did I say it was widespread?

I simply pointed out that I have had experience with the coated polycarbonate shattering under treatment that did not shatter normal polycarbonate.

Well, when you treat materials to make them harder they generally become more brittle, more inclined to break under tension than to stretch. If the whole thickness of the material is hard/brittle it'll all break in a hurry, like glass, or steel that's hardened all the way through. If you're really careful to harden just the outside and to leave the inside somewhat malleable, like in a good sword, for example, the hardened surface will nick, but the whole thing won't shatter.

So I can buy that a hardened version of polycarbonate would be brittle, able to take high stress up to a point, but then shattering, because it can't bend.

Thanks for all the suggestions,
Drew

Where did I say it was widespread?

You did not need to say it Geof, it was inferred, at least to me, when you said "be careful" and "I discovered that the coating makes it much more likely to shatter", I am not doubting your experience at all or even saying you are wrong, only that I am just very suspect that it was the coating that was the cause of your experience. Doubtful it can be proved by either of us that it was / was not the cause. so I guess it is, after all, what "we" believe that makes it true to each of us.


So Drew, get the Lexan or similar w/or wo the coating, either way you still will have some tough durable and long lasting material to look through.

Also, it occurs to me that you'll probably scuff up the plastic less if you sluice the fine chips off, rather than grinding them against the plastic by wiping them off.

Thanks again,
Drew

I wonder if certain food wraps might work.

Interesting possibility. If they're clear enough, and you can get them to lay flat, it might work. I'll check back in if I find something that works.

There's a company that makes visors for motorcycle helmets. The sell you a stack of sheets that you peel off during the race. I wonder what material that is.

Alternatively, you could create a frame supporting a piece of black fiberglass window screen, which would deflect the chips before they hit the plastic sheet. Coolant might fill the spaces in the screen though, impairing visibility.

A trip to a junkyard might yield a piece of flat tempered safely glass from a bus or hatchback, which could be added to the inside of the enclosure.

A trip to a junkyard might yield a piece of flat tempered safely glass from a bus or hatchback, which could be added to the inside of the enclosure.

Thats what I have used in the past, and in some cases a specialty glass place will cut it or supply it, I got the idea when I retrofitted an older leblond lathe that had it, it is extremely hard and does not scratch.
They can also supply the rubber moulding to mount it in, you need a nice radius on the corners.
The toughest glass I ever found though was hardened glass windows used in locomotive cabs, came across some in a locomotive scrap yard once.
Al.

There's a company that makes visors for motorcycle helmets. The sell you a stack of sheets that you peel off during the race. I wonder what material that is.

I have a woodworking faceguard-air-filter that takes replaceable self-adhesive overlays. That's what got me thinkin' in the first place. The overlays I have are probably PVC, but they might be acetate or Mylar, which is to say they're some sort of clear glossy plastic sheet.

- Drew

Thats what I have used in the past, and in some cases a specialty glass place will cut it or supply it, I got the idea when I retrofitted an older leblond lathe that had it, it is extremely hard and does not scratch.
They can also supply the rubber moulding to mount it in, you need a nice radius on the corners.
The toughest glass I ever found though was hardened glass windows used in locomotive cabs, came across some in a locomotive scrap yard once.
Al.

Just to avoid any confusion, we're probably talking about laminated safety glass, the glass-plastic-glass sandwich typically used in windshields. Tempered glass breaks more easily, but into thousands of relatively harmless small pieces. That's generally used in side windows, and I don't think it can be cut without shattering.

The tempered glass would help on the mill side of a plastic door. On it's own it wouldn't help much if something heavy shot out of the mill (I hope that never happens). The laminated glass would work great. A bus or train windshield would actually be flat, and could be cut down.

Thanks for all the suggestions,
Drew

So, I'm putting together an enclosure for my Taig mill, and I'm getting around to the front double doors. It occurs to me that I'll be wiping off a mixture of coolant and fine metal chips, and it seems like the door would scratch up pretty quickly. Is this actually an issue with, say, acrylic or polycarbonate?

I use both alot. Polycarb is used because it's dense and shatterproof (from shock; it can shatter from crazing), but it's very soft and scratches if a moth farts in the same room.

Acrylic is harder than polycarb but still easy to scratch; for example, I made aquariums out of acrylic and the care instructions included 'clean only with cotton cloth; paper towels will scratch and cloud the surface'.

There are coated versions of both that increase scratch resistance, but honestly, they only slightly increase the durability in my experience. Also, so you know, both acrylic and polycarbonate absorb water (just not very much) and if they get wet for a few hours, they will bow and warp considerably. Aquariums that use the stuff are designed to either not use flat surfaces or overly thick panels for that reason. And scratches, cracks or chips (like in the edge from cutting) will craze from moisture and eventually crack/crumble the panel. You have to anneal the sheets after cutting to mitigate this problem.

Honestly, if you care about longevity, there's no substitute for glass.

Do you have any pictures of the enclosure to post?

Correct; so I will give you another chance to read the distinction I made:

And just in case someone suggest getting the Lexan, Tuffak, Polycarbonate, (all the same thing) with the scratch resistant coating, MarGard it is called or something like that be careful. I discovered that the coating makes it much more likely to shatter when it receives an impact. Regular polycarbonate can often take a good hammer blow with nothing except a small dint; I once had some MarGard stuff shatter just like glass.



Polycarbonate on its own scratches very easily.

If your not using any sort of heavy volume mist or coolant system:

How about a mesh door(screen door.....).

Although I would be interested to see if the chips would get caught


I would just make it replacable

What about laminating the plexiglas from the inside, maybe this might be a possibility?

Laminating is a good idea, but Plexiglass (Perspect) Acrylic isn't the best material because it can shatter much like glass does.

Lexan, Polycarbonate is your friend. Its negative aspect is that it may yellow, and is often coated with a UV inhibitor for this reason.

[When we were kids, we shot at a pair of polycarbonate safety glasses with a bBB gun. It's didn't go through.

CD's DVD's are supposed to be made of polycarbnate, but some aren't, perhaps being made of clear ABS. To tell which is which, you can try to bend them (carefully) if they break, they are ABS, Acrylic, or polystyrene. If you can bend them in half without breaking, they are probably polycarbonate.

Clear ABS often has a slight purple tint seen through the edges.]

If you do make anything out of acrylic, it's good to make holes for fasteners a little large, because acrylic expands and contracts quite a bit, and it cracks easily from interference with the fasteners.

My previous enclosures have used acrylic windows. To be honest, I've never had a problem with chips on the windows - dry chips don't fly that far on my mill, and wet ones fly even less far. Coolant on the otherhand goes everywhere!

I actually used two sheets of 3mm acrylic separated by about 25mm on double skinned doors as noise reduction is one of my requirements from an enclosure. It worked pretty well IMHO. I don't know how it'd take a heavy impact - but I'd guess that the doors would just fling open and absorb some of the impact energy -though this won't work on bi-fold or sliding doors. Even if the inner sheet shatters, the outer one is there to contain the fragments. Not had to test that out the hard way though.

One thing I would say though is that prelonged exposure to oil based water soluble coolant seems to make acrylic and PVC very brittle. I have tried using an acrylic sheet as coolant tray - it worked pretty well, but when I came to dismantle the enclosure, it just came apart in my hands when I tried to flex it a little.

If anyone is currently constructing a coolant enclosure, I'd encourage them to be very generous with the bore of their drain holes - chips form scourer like nests very quickly, and have no trouble filling 1 1/2" pipes! I'd also suggest that if you can plumb in some fixed piping to actively wash down your coolant pan at the end of the day, you'll save a lot of tedious brushing of chips from under your machine.

Well, my enclosure is almost done. I went ahead and used 1/4" polycarbonate for the sides, top, and door. The door is made from two left-over pieces.

I formed the basin by hand from aluminum sheet and used 1/4" masonite for its backing.

The basin also contains a 'catcher' around the drain to catch large chunks and contain them in an area easy to reach. The coolant bucket has an internal bucket which the drain empties into and the drain pipe runs through stainless steel screen so as the coolant fills the internal bucket the screen should catch any remaining metal trying to float up due to agitation.

Hopefully that will keep most all the metal particles which could damage the pump contained.

Things left to do. Finish the coolant system, add a low volume fan at the top to extract heat from the enclosure. Not sure if I need to, but I have a small peltier cooling block I can add to the coolant system to extract heat from the coolant. Add a flourescent fixture across the top. Build a tool holder in the table. Mount the control eletronics.

Being my first mill and enclosure, I hope I did not make too many rookie mistakes.

Hehe. No news is good news,...I hope. Or you guys are too busy laughing yer tushes off at the newbie. :)

Everything looks really good, but if you're going to make a flood system, you'll need to make sure everything is water tight (100%). I've finished my fourth enclosure now, the last three were for just catching chips only. I'll take a few photos and video tomorrow and post them in new thread to check out. Oh and make sure anything that might be made of steel is painted and sealed.


PS: Great idea with the shelf brackets for support, I might have to try that! :)

"Lexan, Polycarbonate is your friend. Its negative aspect is that it may yellow, and is often coated with a UV inhibitor for this reason."


So buy the UV stuff to prevent this?

Any reason why it turns colors (coolant)?

All the screws and washer,s exposed to the interiior, are stainless steel with neoprene backed washers and all the aluminium around the polycarbonate was caulked prior to assembly. I took a water hose and sprayed into the box with as much pressure as I could get out of it and no leaks.

I filled the basin with water to the bottom of the mill and no leaks there are 3 days. The seal around the door (not in place in the picture) is protected by a 1.5" shelf extending from the inside of the door towards the mill. No direct splash is possible to the seal.

I was considering sealing the entire interiior in epoxy. Overkill?

I used outdoor silicone and outdoor paint for the best seal. The silicone works great, but can be a little sloppy at times. You'll also need to make sure that the coolant you decide to go with doesn't eat the epoxy or seals.

Being an owner of a glass business by day and production machinist by night at a tool and die shop I can probably give ya a good idea. The laminated mentioned earlier is the best as if it breaks it stays together but your looking at least $11 per sq.ft. . Tempered ($7)which is stronger but as mentioned earlier breaks into thousands of little pieces when it breaks(its strength is in front impact, weakness is the edge). Plexi and lexon just don,t cut it, they scratch and coolant just fogs it all up. For my machine I,ll use 1/4 clear laminated. But if I really was concerned about glass breakage 3/8 tempered is very strong, damn near unbreakable( because of its thickness the outside layer of glass gets tempered and the very center half tempered creating a very strong glass). In my 7 years of glass work , I,ve never seen 3/8 tempered break. Besides how often do you expect a chunk of metal to go flying off your Taig? I work with all sorts of milling machines and have never seen anything fly off other than HOT chips!! Goto a salvage yard and find ya a nice aluminum window and incorporate it into your enclosure, just change the glass out to lami or tempered.
good luck !

Twocik, I used the GE Silicone II caulk for the sealing chores. I am looking at trying "Liquid Ice" for the coolant. I have read it does jnot have any odor. As the mill will be in the house when I am all done, I want to try and keep the Wife unit happy and minimize the smell.

The coating I was looking at is the stuff they use on garage floors. It should be up to the task.

Yes I think the silicone you're using is fine, just make sure it's water repellent.

I use Liquid Ice and it's great, no stinky smell, not really to oily of a finish left on the part, non toxic (but I wouldn't say it's ok to drink :) ). Time to time I've had coolant/WD40 splash me in the face and lucky I had my safety glasses on, but this stuff isn't suppose to burn or cause any harm at all ( I believe it's made with animal fat and a bunch of other stuff). However I haven't gotten any in my eyes and always take precaution, but it's definitely safer than the others especially if you have kids.