Plexi cutting advice needed.

[pharoah007]

So I finialy got some artwork (SouldDraw) for this MAME CP.

I also finally got a piece of plexi big enough

I do not want to mess this up, so I thought I would post asking advice and showing the tools I have at my disposal for this job...

First, the CP....


And the Plexi..


The plexi is 1/8 thick


I will cut the holes for the buttons/joystick first, then I will either get a "draw knife" to cut the pexi along the cp frame, or a flush cut router bit... pros and cons of each please??


Here are the tools I have at my disposal.

Drill...



Drill press...



Hole saw...




Forsner (?) bit



Hole saws...specific 3" one for the trackball hole...




So, what are everyone's recommendations for me to accomplish this task with the tools at hand?  All advice is welcome as a REALLY do NOT want to mess this up, this is the final touch!

Thanks in advance to all!

[Sjaak]

First drill a hole with a conical drill bit, then use a router with a flush trim bit. Do this for the button/joystick hole as wel as the outside.

I have done this a couple of times and never had any problems with cracks.

[shponglefan]

I've always cut my plexi as follows:

a) Button/joystick holes: hand drill + hole saw
b) Edges: router + flush trim bit

Flush trimming plexi edges is a breeze.  I find my router goes through the plexi like butter.  And when drilling out button holes, the key is to go at a slow/steady pace and remember you're melting it out, not actually cutting.

Also, this probably goes without saying but practice on a small/scrap piece first!

[apfelanni]

i would drill the plexi mounting screw holes first. be careful not to crack it . then do a rough cut on the panel plexi outside . maybe with  additional + 5-10 mm via table or jigsaw.
then screw the plexi with 1/4 - 1/2  of the screws , so its fixed and cant move in any direction. then drill some entrance holes in the button ,stick and trackball holes. be patient not to crack the plex , go slowly . use a router with a new and sharp trimbit to cut the holes out and flush the edges. it will be 100 % exact and doesnt need proskills. u may practice that first on some crap wood or the cut off plexi piece. if u do the button holes first u can screw in some buttons and keep the panel screws off . makes it easier to route around the panel .

i only use the holesaw if i can pilotdrill the overlay and the panel together , otherwise it wont match 100 % . the key to succes is patience and practice. and good equipment of coz .
with a new quality bottom bearing trim bit its like a walk in the park . found some pics of an old project. panel > plexi clamped > entrance hole > use miauuuuxxx machine > some buttons screwed in > tschacka  ... were done .

ps. keep the protective film als long on the acryllic as possible to avoid scratches . dunno why i removed it --BINGO! Either that, or I was attempting to say "before" but it was too many letters to type-- routing. and make sure u route in the right direction , best in 1-2 passes.

[ChadTower]

Sandwich the plexi between two similar sized pieces of wood.  Clamp it down tightly.  The biggest cause of cracking plastics when drilling is that the bit tries to lift the plastic as it goes through.  The flex cracks the plastic.  Especially with plexi that thin.  Definitely clamp it between a couple of pieces of MDF or plywood and drill that way.

[shponglefan]

i would drill the plexi mounting screw holes first. be careful not to crack it . then do a rough cut on the panel plexi outside . maybe with  additional + 5-10 mm via table or jigsaw.

While I'm not a particular fan of using a jigsaw to cut plexi, I will say this: make sure to get a blade specific for cutting plexi if you do.  Otherwise, it's much more difficult.

[macattack]

When I used to use a hole saw to cut plexi holes, the safe method is to cut with the drill in reverse. Less grabbing.

[kz1911]

RUN IT IN REVERSE, MAKE SURE IT'S FLAT SURFACE AND SUPPORTED UNDERNEATH

[dandro]

If your going to use a jigsaw, best way for support is to grab a large piece of Styrofoam and put it underneath. The plexi is supported and the blade cuts through the foam, easy peasy.

[BobA]

Just a note.  You mentioned a 3 inch hole saw for your TB.   The hole for a 3 inch trackball is less then 3 inches because it mounts at with less then the full diameter protruding.   Measure your trackball in its mounting location to make sure you get the right size hole to fit.

[dandro]

so funny thing... I was reading this thread as of this morning (before) I went and cut my own plexi top... guess what I did whilest drilling one of the pilot holes for the router? yup... cracked the sucker.. 

used that broken piece to experiment... turns out, it seemed alot easier and no cracks to just change the router bit to a Template Bit, turn the router on and just plunge cut the hole. Did this for all the holes and then swapped out for the flush trim bit.. Wha-lah....  Seemed like less work as you really just don't want to go throwing your largest drill bit at it... but then again, I may have done something wrong at the beginning, $15 later I found a solution that worked best for my over zealous self.. 

[selfie]

Don't stuff around, you have a router, do it properly. Have a read of my thread http://forum.arcadecontrols.com/index.php/topic,119165.0.html

As Dandro said, use a router bit to plunge cut the holes then use a flush trim bit EVERYWHERE. If you don't have any extra material to practice with don't even try to drill it. Use some clamps to hold it it place and then use some buttons to hold the acrylic down when you cut the outside shape flush. There is no need to cut it to size first, as long as you move the router against the direction of cut and don't go too fast you will have no dramas.

[rablack97]

Don't stuff around, you have a router, do it properly. Have a read of my thread http://forum.arcadecontrols.com/index.php/topic,119165.0.html

As Dandro said, use a router bit to plunge cut the holes then use a flush trim bit EVERYWHERE. If you don't have any extra material to practice with don't even try to drill it. Use some clamps to hold it it place and then use some buttons to hold the acrylic down when you cut the outside shape flush. There is no need to cut it to size first, as long as you move the router against the direction of cut and don't go too fast you will have no dramas.

+1......there's no cleaner, less wasteful way than a router......

By the time you ruin and re-buy your plexi, could of just bought a router.....

[pharoah007]

Thanks everyone for the input. Great write up selfie.

I got it all holes cut and just need to trimm the excess.  I am going to purchase one of the "scoring Knives" for this.

I do have a router, but no flush trim bit.

I ended up sandwiching the plexi between 2 pieces of wood, one being the CP so I could use the holes as guides.

all worked well...but I will not know until I get home this weekend and unclamp it (away with work).  I do not think anything cracked.   

I used a bi metal hole saw (pics) and I did not notice any diff between cutting in forward or reverse.

I will snap some pics when I get home.

thanks again all.

[a1pharm]

Good Luck

[dandro]

Don't stuff around, you have a router, do it properly. Have a read of my thread http://forum.arcadecontrols.com/index.php/topic,119165.0.html

As Dandro said, use a router bit to plunge cut the holes then use a flush trim bit EVERYWHERE. If you don't have any extra material to practice with don't even try to drill it. Use some clamps to hold it it place and then use some buttons to hold the acrylic down when you cut the outside shape flush. There is no need to cut it to size first, as long as you move the router against the direction of cut and don't go too fast you will have no dramas.

+1......there's no cleaner, less wasteful way than a router......

By the time you ruin and re-buy your plexi, could of just bought a router.....

isn't that the truth,.. 

[jdbailey1206]

I prefer the following method myself. 

   


But seriously.  This method from youtube seems to be pretty solid.



And if you want an idea on how to bend the material Le Chuck did this for his Darkade. 



(I would recommend a heat gun.  Less heat and you have more control.)

Remember to take your time.  Plexiglass is one of the easier materials to work with.  You just have to have patience.  Don't rush and its worth while to get a spare piece and experiment.  Have fun with it and don't get frustrated.  I once did a whole sculpture out of plexiglass.  If I can pull it off a trained monkey can.  Or even an untrained one for that matter. 

[pharoah007]

Got it all done

I did some holes in forward and some in reverse.  Remember I had the plexi sandwiched between the wooden CP and a sheet of wood....

The holes in reverse had some "melt" around the edges that needed to be "chipped off"....the holes cut in forward did not and were less work in the big picture.

Sorry, I did not snap as many pics as I should have....but here is what I have.

This is the tool I bought to trim the edges...Just ran it allong the edge of the wooden cp and along the plexi...





Hacked the +12V DC off the CD rom drive in the CP and ran it to the buttons and trackball