I finished paint modding my new case for the next build.... but... the next thing to do is cut a big hole in my lid/side panel for a window and then a round hole in the window for a fan...
I got the lid/side panel all taped up reading it for the cut.
But do have a question of the plexiglass/Lexan.......
I purchased a nice piece of Lexan and was wondering what is the best way to cut this so as to give the best finish without shattering.....
I had purchased a Multipurpose Cutting kit for my Dremel (it contains a cone shape thing with a funny looking drill bit that drils upwards... kinda ones that you would use to cut holes in dry wall but it says you can use on plastics) for the attempt of cutting the Lexan.
I have both straight and curve cuts that needs to be done.....
What is your experiences when it comes to cutting Lexan/plexiglass....
Do you know any CNC Millers?? If you want it done like a pro, that's the way to
do it. You must know someone who'll do that as a favour. It'll take no less that half
hour to set and cut. For a friend, i'd do it for free!
Whatever advice you get, first try the cutting method in an area that is non-critical. A totally scrap piece if possible, but if not...for example, if you have a 120mm hole to cut-out, try cutting out a 50-60mm hole in the middle of the 120mm hole.
Different speeds with the same bit will produce different results.
I also recommend supporting the target piece 100% under its entire surface, cutting through both the target piece and the supporting sacrificial piece.
Be sure to cover-tape BOTH sides of the target piece's surface to minimize fractures.
I used a regular power jigsaw. The edges were not presentable but they were all hidden, so it worked for me. The heat from the blade ended up melting the plastic some, but it was fine. You could probably find a way to polish the edges if you need that.
For a hole, you can't beat a hole saw on a drill press. Perfectly round and very quick.
Tools for working on wood should be fine for working on Plexiglass. If you use a hole saw, make sure you use a drill gun with enough torque (heavy duty) and mount a pilot drill in the center. Otherwise, it may end up sliding around causing more damage. But plexi should be much easier than metal, though.
Absolutely I will be trying different methods on scrap pieces before actually doing the final cut.
I know that if using jig saw or a dremel tool that speed of the bit is important that you dont melt or shatter the cut.... And also the speed at which you push/pull the tool through the material is important at the same time. I also considered using a fine tooth haxsaw blade as well....
If anyone else have experience with working with this stuff, please drop your suggestion into the bucket... much appreciated.
I use a portable battery-operated circular saw withg a blade that is made for cutting plexi to cut plexi glass. The blade costs only about $5. A drill should go right through the plexi and the edges can be sanded with a power sander or a hand sander. It comes out really nice. I did this when I made a cover for a window well.
I actually work in hardware at lowes so this is up my alley haha, the fastest way would be with a circular saw but you dont need to spend all the extra money for a "vinyl/lexan" blade, just buy any blade with some fine teeth and spin it around so the back of the teeth are what make contact with it and not the point. Depending on how thick of stuff your using you could probably even just use a box cutter.
maybe a few months behind, but cutting fan holes into Plexiglas and lexan, ive had very good luck clamping the plexi between two 3/4 (one by lumber) and using a hole saw, the heat from drilling the wood will get the saw hot enough to partially smooth the hole into the Plexiglas and the hole in the wood will hold your saw in place. pilot hole both the lumber and the Plexiglas with a bit the same size as a hole saw pilot bit, then use the pilot bit to line the plexi and lumber up for clamping. i have run the hole saw through a few lumber scraps first to heat it up and it seems to smooth better, but this method will never produce a factory finish, though, it does do far better than sanding etc. haven't tried it myself but use a propane torch on the cut edge for a few (short) moments while it is still clamped between the one-bys to flame polish the cut edge. if you light your wood on fire (shouldn't by torching only a few seconds but things do happen , smother or blow it out as quick temp changes will cause stress cracks (experience talking here). remove your clamps and you should have a perfect hole with little to no edge chipping and a decent finish. oh and use a fairly high speed with very light pressure, you want the hole saw to chew very thin layers at a time. hope someone finds this useful.
As a former plastic fabricator of 20+ years and having worked with thermoformed and thermoset plastics, I will throw in my 2 cents into the "for what it's worth" barrel.
Lexan and acrylic are both thermoformed plastics which basically means that heat is used for them to achieve their shape. This makes heat the "enemy" when mechanically fabricating them.
Run all boring and cutting at a slow speed. Woodworking tools will work - to a point. Orbital sabre saws will work with a medium blade and medium speed - the finer the blade, the slower the speed (IIRC mine are Vermont "F" series).
I use a carbide tipped 7-1/4", 40 or 50 tooth AB blade in a saw mounted upside-down in an old piece of cabinet grade plywood for portability. My 12" Unisaw at home has a 80 tooth TC blade. The biggest enemy of circular saws is vibration. I have only 1/16" clearance beteen the blade and table. I fasten a piece of 1/8" luan doorskin over the table of the Unisaw and run the blade up through it for chip-free cutting of acrylic. Polycarbonate (Lexan) is softer and more forgiving, but failure to run the blade high may result in severe kickback.
Wood drill bits will work but care must be taken at the moment of breaking through the backside. Someone else mentioned 100% backup - I totally agree. Clamping is also recommended. If the bit grabs, you'll be "wearing" your project, along with a little blood. I personally grind my boring tools with a flat face instead of the standard chisel edge that comes on wood and steel bits. This makes for a little more heat, but practice with feed rate and/or using a pecking motion helps. When properly ground, backup is not required.
To minimize vibration, I template route with standard, 2-flute carbide bits with 1/2" shanks and tip bearings in a 1hp, under-table router. Most of my work involves heavy gauge materials of 3/8" thick or more.
Good luck and be safe. A successful project is not only defined by the quality of the work in it but also the number of fingers remaining on your hands at the end!!
First off, just learned that Plexiglass and Lexan are not the same thing. Just read a blog on it last week here. http://www.iplasticsupply.com/1316/is-plexiglass-the-same-as-lexan/
Second, the Plexiglass stuff breaks pretty easy. I tried it with a scroll saw and made lots of tiny broken pieces , but nothing worth keeping. The lexan polycarb stuff just didn't break at all. Used the scroll saw and made perfect parts. Works great. Good luck
All of the answers are spot on, the one thing that I found, working with polycarbonate (Lexan) in the Optical Industry is that in addition to the methods mentioned, another helpful hint is lightly sand around the edges of the drilled hole to avoid stress cracks from forming. Avoid chemicals,especially acetone base ones as they will weaken and cause the poly to crack. Also, threadlock and lock tite are to be avoided, they will cause stress fractures.