probably not the best thread to ask but since people seem to be talking about it anyways…
Is a hole saw bit suitable for cutting through acrylic without it cracking? I have a 30mm hole saw with a 8mm arbor bit and want to cut through 3mm thick acrylic plexi, I only have a electric handheld drill that goes up to 650rpm. Is it possible to do this?
You know what, that’s actually the exact drill bit I use. The same brand and it has the teeth at the end. I’ll try not to push down when I’m drilling. Thanks for the advice.
I’ve never tried, but I’d be inclined to believe a hole saw would be too aggressive for the plexi - causing it to melt and crack.
P.S.: Happy 4th guys:) - be safe
Drilling Holes in Plexiglas
Ok folks as promised I have a little pictorial tutorial for you on how I drill the button holes in Plexiglas. This is not the only way to drill holes in plexiglas but this gives me a 99% success rate. As with any technique practice on some scrap before committing to the real thing.
I start out by making the frame of the case first then fit the top MDF and plexiglas to the frame. Then using a template I mark the center holes with a scratch awl. Use a twisting motion while you push on the awl but not too hard or you will crack the plexi. After you are done marking the centers use a 1/8" twist bit to drill the pilot holes as seen here.
http://i228.photobucket.com/albums/ee314/KaytrimsKustoms/MakingSticks/DrillingPlexi/PilotHoles.jpg
I drill all the way through both the plexi and MDF. This assures that they are in perfect alignment with each other. Next is to use a spiked spade bit. I have yet to find one in metric sizes so I choose one slightly smaller then the hole I want. 1 1/8" for the 30mm buttons and 7/8" for a 24mm button. Each is ~2mm smaller than the target button hole.
One other key is to use a backing board when drilling. This prevents the plexi from flexing lessening the chance of cracking. If using a hand drill you can leave the plexi in the case with the MDF. Just make sure the case is clamped to your workbench so it can’t move while drilling. This also allows you to use both hands on the drill for better accuracy.
Line up the tip of the spade bit with your pilot hole and slowly advance the bit letting it cut it’s way down until the spikes (teeth) start cutting the plexi. At this point it is not as easy to crack the plexi as long as you have the backer board in place. Keep slowly cutting your way until you are all the way through. Your hole may be a bit rough but that is fine as it will be cleaned up in the next step.
http://i228.photobucket.com/albums/ee314/KaytrimsKustoms/MakingSticks/DrillingPlexi/SpadeBit1.jpg
http://i228.photobucket.com/albums/ee314/KaytrimsKustoms/MakingSticks/DrillingPlexi/SpadeBit2.jpg
http://i228.photobucket.com/albums/ee314/KaytrimsKustoms/MakingSticks/DrillingPlexi/SpadeBit3.jpg
After drilling the MDF with your 30mm or 24mm forstner bit you are ready to finish fit the plexiglas. I use a dremel tool with a sanding drum in the chuck. I also use the router base for better control. The first time I did this I scratched the heck out of the plexiglas even though I left the protecting film in place. So I took a piece of hardboard and drilled a larger hole (1 1/2"). Then attached a piece of felt to one side. Make sure you keep this felt free from wood chips anything else that might scratch the plexiglas. I use an old stiff tooth brush to clean the felt when it gets dirty.
http://i228.photobucket.com/albums/ee314/KaytrimsKustoms/MakingSticks/DrillingPlexi/FinishTools.jpg
Here is the setup in action. I put the MDF and plexiglas back into the case to keep them alligned with eath other. I move the dremel around the hole sanding the plexiglas flush to the MDF. Go in the opposite direction of the bit’s rotation. This makes a perfect fit every time. I also keep a button on hand to check the fit before I call it done. If you don’t have a dremel you can use a small round file. One benefit with this method is that the hole is nice and clean allowing easy removal of the protective film.
I hope this helps out everyone and lessens the wasted plexiglas.
Michael
If you can’t get metric, 1-3/16" and 15/16" serve well enough.
It works fine. Make sure you clamp it between 2 pieces of wood.
Learn something new every day:). Btw, Michael - great post! Thanks for sharing:).
Finally, case is all sanded down, going to put first clearcoat tonight before passing out 
. Crazed…thanks for the tips!
Forgot to ask, Michael, do you groove your frame to rest the MDF and plexi top over? Or do you use cleats underneath? I’m asking, because a friend of mine wants me to build him a case, and I’m considering going the groove route.
oooooooooooooohhhh VMA! I’m doing the final drumrolll! Let us see it when the case is fully sanded. :rock:
Michael, I did have a question for you. This week being a long holiday weekend, I tried to finish up my 1 player joystick which I have been working little by little the whole week.
How do I center the joystick template for the mount?
On your post, #157 on this page - http://forums.shoryuken.com/showthread.php?t=191757&page=7
The template you labeled “2nd”, I have something like it also. However with the 5 pilot holes drilled for the joystick mount, how do I precisely center this template so that when I put the sanwa joystick mounting plate, the mounting plate’s center hole aligns with the plexiglass’ hole?
second question: Michael how long did that dremel last you?
Michael, as always - 
@ Kustoms
I do the same things for cutting plexi! Putting all layers, drilling a pilot hole through all of the layers, then I cut the holes in the layers individually using a drill press.
Oh and I like the idea of a woodworkers forum area! I’d def. do a whole thread about staining wood, or even a video! I know how to stain pretty good!
hi guys, any tips on cutting mdf into perfect square using chisel or other methods without using template?
Also, Im interested in making dovetail joints. Is there any guides on this?
It can be done either way. I route out a groove for the bottom using a rabbiting bit. Then I use cleats for the top. I have to do that because of the design of my cases. But if you are doing a normal straight sided case you can route a groove in both top and bottom. If you can afford it, get a multi rabbiting set like this one. By replacing the bearing you adjust the depth of the rabbit.
I use a short ruler going diagonal from corner to corner on the template. Line up the center hole with the ruler and do the same for the opposet diagonal. You may have to do this a few times to make sure it is centered.
I am still on my first dremel tool. Of course I don’t use it much nor do I use it or full speed much the time. I just use the slowest speed that will get the job done. Also if the motor wares out you can replace the motor brushes and you should be good to go again.
Google is your friend but here is a nice short video showing the steps for hand cut dovetails… http://villagecarpenter.blogspot.com/2009/06/handcut-dovetails-video.html And here is another longer one giving much more detailed instructions… http://sandal-woodsblog.com/?s=klausz+AND+dovetail
TTFN, I’m off to do a little home improvement.
Michael
Thanks Michael:).
Zebra…are you referring to the recesses for joystick and plexi? What tools do you have at your disposal?
No problem :tup: Glad it worked well. Now, when you sand the clearcoat you do 1000 grit until it is no longer glossy at all, then 1500 and finally 2000. If you can get you can do 3000 too :looney: After that you will have to finish it up with a polishing compound.
If you get a run in the clear just let it dry, don’t try to remove it while it’s wet and do not sand it! If you get one I’ll help you remove it (razor blade ).
I wonder what effect sanding the clear with sharpening papers will do? Definitely something I want to try.
–edit–
For chisels, they are tough but pretty fun. I used one to make the recess in some MDF for a JLF. It’s hard to get perfect but it rolls along quite nicely once you get the hang. Only problem is I made a boo-boo and messed up the hole in the center for my joystick because of the angle of the chisel. Had to use body filler but all is well now
i wish i had a bigger house so i can get a lil workshop in the garage. american houses are so much bigger in general damn the size of the British Isles.
K…this after 2 coats clear. One more coat, and final sanding:). After that, I’m gonna avoid sanding for a while…lol. Once again, please forgive the image quality.
Damn that’s nice vma!
Been trying to sand down a recessed button space before priming it for painting, and so far no luck. I’ve hit the rest of the case with 320 grit but the recessed button area 1/4" is presenting a problem for me. I lined it with a thin coat of wood filler but after it dried the sand paper is unable to pick up the corners, and i dont want to take an edge to it and end up ruining the case… any tips?
omg that video on those handcut dovetails brought a tear to my eye. haha
Thanks Crazed…and again - the pointers much appreciated!
I have to say that after seeing work like Michael’s and 3cks’ and others, and talking to you, I’m inspired to refine my finishing skills. It’ll come in real handy for finer work:). Thanks guys.
V.
:wow: go vma!