drilling/cutting holes in plexi?

[squire]

i going to start cutting the holes out in my CP plexi overlay,
if you dont mind what do you guys suggest to cut the plexi holes out with?
so i dont get that nasty chiping etc..

thanks so much
squire

[shardian]

You can sandwich it between 2 pieces of wood...

[NightGod]

Flush trim bit and a router.

[shardian]

Flush trim bit and a router.

Not applicable to button holes...

[fatfingers]

Flush trim bit and a router.

Not applicable to button holes...

And why not?  I was thinking for my button holes I would drill (?) a smaller hole to fit the bit and then flush trim it from there?!?!?

[shardian]

Well jeez, if you want to go thru 10 times as much effort as you need to, and thoroughly enjoy overkilling things, then go right ahead.

[somunny]

One thing I found when drilling plexi that is clamped betwwen two pieces of wood is that you have to really be careful to not let the plexi wander on you. 

What I did was clamp everthing together and drill pilot holes for the button on (or closest to) the four outermost corners of the panel.  Then I pushed nails through the pilot holes.  This will keep all the layers stationary throughout the process.

Obviously, you'll have to pull the nails to drill the last four holes but it's much easier to re-position the layers four times than 25 or thirty times.


Steve

[ahofle]

I had good results with a spade bit.  If you put the drill on a very high speed and use LIGHT pressure, it will just start to melt through the plastic.  I think the chipping comes when the bit catches (pushing down on the drill too hard, drill not spinning fast enough, etc).   Definitely practice to get the hang of it.

[AtomSmasher]

Flush trim bit and a router.

Not applicable to button holes...

On my CP I used a regular drill bit in reverse to drill (melt) holes big enough for the flush trim bit to fit into.  I then used the flush trim bit and quickly cut out all the holes.  It pretty much guarantees that you won't chip or crack the lexan and you know for sure that every hole is in exactly the right place.  Its extremely fast and easy to do, takes only a little longer then just drilling alone and you don't have to sandwich it between two peices of wood.

[AtomSmasher]

Just to emphasis this.  When using a regular drill bit on plexi/lexan, always set the drill to reverse, it will melt through the plastic instead of cut through it.  If its set to forward it can easily snag and crack the lexan/plexi.

[ChicagoDave]

I used the sandwich method (mdf - lexan - scrap mdf) and a 1 1/8" Forstner Bit to cut the holes for the buttons.  To cut the hole in the lexan for the trackball, I used a flush trim bit and a router.

[MYX]

Flush trim bit and a router.

Not applicable to button holes...

It's what I did. Less worry about chipping and cracking.

[squire]

thanks for the help...
i also have a hole bit like what the use for drilling holes for door knobs how would that work? think it will chip or even crack the lexan?

[ChicagoDave]

thanks for the help...
i also have a hole bit like what the use for drilling holes for door knobs how would that work? think it will chip or even crack the lexan?

The teeth are pretty far apart so it would be pretty rough on the plexi.  If you try that method, have the drill in reverse and melt the plexi instead. 

Try a test piece first! 

[ahofle]

thanks for the help...
i also have a hole bit like what the use for drilling holes for door knobs how would that work? think it will chip or even crack the lexan?

The teeth are pretty far apart so it would be pretty rough on the plexi.  If you try that method, have the drill in reverse and melt the plexi instead. 

Try a test piece first! 

I had to use a hole saw for my trackball hole (didn't have access to a router/flush trim bit at the time).  It worked OK, but it left a very rough cut (lots of jagged melted plastic).  I just had to sand it smooth and then it looked fine.  Of course, make sure you are using the center guide drill bit with the hole saw (or whatever it's called).

[Ken Layton]

This is what I use for button holes and joystick holes: a DULL hole saw. Drill halfway thru with it then flip over and finish from the other side. Quick, easy, and without chipping/cracking.

[bvicarious]

You could take measurements and have an engraving shop cut the holes with a laser cutter. You'll never get a smoother or more accurate cut. 

[leapinlew]

Well jeez, if you want to go thru 10 times as much effort as you need to, and thoroughly enjoy overkilling things, then go right ahead.

I don't believe it to be overkill. I've had more luck drilling through plexi using a smaller bit than a 1 1/8" bit, and for me it was easier to align the CP to the Plexi. On my showcase cabinet I detailed how I cut my plexi - you can see it here: http://forum.arcadecontrols.com/index.php?topic=55021.0

But here is a quick run down -

First thing I did was clamped the CP to the plexi


Then I flipped the plexi over and drilled out a 5/8th hole. my flush trim bit was 1/2" and 5/8" bit would make a large enough hole for the flush trim bit to fit.


Drilling done! You can see the router ready to flush trim them up.


Flush trim router bit makes short work of the plexi.


I've heard of people going either direction and haven't reported any problems. You do what you think is best. I wouldn't go so far as pointing out this method as overkill or taking much more time than using a 1 1/8" drill bit. I can drill through plexi much faster with a 5/8ths than a 1 1/8th. YMMV

[deadkenndys1105]

When I cut mine I just clamped it down and drilled it.  I had to be very careful tho.

[amerish]

When I was ready to cut the holes for my plexi, I fiirst did my control panel case and top with all the holes cut out, I then placed the plexi on my control panel (keeping the protective paper on the plexi). I put a lit flashlight into the control panel and that caused the light to shine through the plexi so I knew exactly where the holes were. I used a plung router bit to put a hole into the center of each button then used a flush trim router bit to clean each hole. The results were perfect. No problems.

[squire]

well i drilled some holes and it came great i used one of these

ill take some pics when i get a chance thans so much for all the info..

[Bones]

Plexi and Polycarbonate(Lexan) are two different materials. If you have polycarbonate you won't have any troubles with a spade bit.

I drilled pilot holes with a normal drill bit and then went for it. There was no melting or cracking or splintering.... It was as easy as --stooling-- in bed and kicking it out with your feet.