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I need to move the hinges on the dustcover of my HW 19 MK IV. I will need to drill new holes to accomplish this. As this dustcover would cost +/- $200 to replace, I want to be sure I don't damage it in the process. Can anyone give me safe method for doing this?
Thanks,
Ken
Follow Ups:
Use a bit made for plastic. See also tips.
Drill bits for plexi:
The special plexi bits work extremely well. I keep several different ones on hand. I do prefer to use a press, though and a masking tape over the surfaces. Be careful as the bits heat up quite a bit, and a cooler bit cuts better, as the heat causes the plexi to bond to the bit. You can spray water on as you drill for cooling. Of course with just a few holes, you may think this unnecessary, but it helps.
Are these the ones with the extended, sharp shoulder? You know, the first part that touches after the point. I can see how the water would be of great benefit. Many times I have had good results spraying WD-40 as I drilled or cut with a jig saw.
Good luck dude. I have ruined/cracked 2 dust covers in my lifetime trying to do the same thing for my old turntable-building projects.Now I just cover my current table with a king sized pillowcase. Not a very elegant solution, but hey, I gave up trying any DIY's for this...
There are special drill bits for plexi-glass, they can be gotten at plexiglass supply stores if not at your local Lowe's or Home Depot. You must also have a drill with adjustable speed control. You must drill the hole in the plexiglass at slow speed.
You probably should use an awl to make an indention where you want the hole. This will help keeping the drill bit from skipping across the smooth surface of the plexiglass and scratching it.
Thanks for the tips. However, by HW-19 and busted cover have been gone for many many moons.
I have a TNT Jr. plinth now and will not be venturing into any more modifications of that plinth. It's already been cut'n reamed to fit my tonearm.
I will probably pick up the cover that is made by Gingko. It's quite nicely made.
Use a somewhat dull bit. Brand new, sharp bits bite too aggressively and tend to chip or even shatter thin plex.
One of my projects is to replace the clear portion of my fairing and the drilling part will be AFTER i've cut and bent the plexiglas already. If I mess up the holes at this point, hours of labor will be LOST! I dread the 'grab' or 'sucked in' things happening. Maybe I should invest in the proper bit AND use the other things mentioned.
About 1/2" thick would be plenty. This will help steady the bit and prevent tearout. Like the other said, use a fairly slow bit speed.
Get another small piece of PG if you can, to practice on.
Putting tape on the backside may reduce edge chipping when you break through. If you drill a small pilot hole, it should be about the same size as the center solid section, or "web" of the larger drill. If the pilot hole is too big, the large drill may get "sucked in".
Please don't take offense but this is bad advice. If you drill a pilot hole the next drill will wobble all over the place and crack the hole edge. The drill point needs constant contact with the workpiece and if you drill a pilot hole, this contact will be broken.The proper way is to "dubb" the cutting edges of the drill prior to drilling. This slightly dulls the sharpness of the drill so it won't suck through as well as offering a better finish.
PS: Place your workpiece on top of a piece of material to back it up. The more rigid the setup, the better results you will obtain.
FWIW, I've machined and drilled acrylic over the past 25 years. Good luck.
to get best location.just don't go too deep,you don't want to break through.
enjoy,
mark
In all my years as a machinist, I've never drilled a pilot hole for drilling plastic, but I thought it might be ok as long as it was not bigger than the web of the larger drill. But then, I've always used a proper setup on a mill, and not a hand drill. Thanks for the correction.
Also, drill through some masking tape applied over the site for the holes. It's easier to mark position, and willstop the drill skidding across the surface and ruining the finish....
Cheers
Tim
This sounds like a job for a hand drill, if you have one. Nice and slow.If you don't have one, they are worth having around...for ultimate control. The last one I bought was a small plastic jobber at Sears...
You need a special drill bit to do this. A "brad point" would be ideal, preferably in a drill press.The next best thing is to take a regular jobber's bit and blunt the rake angle on the cutting edges. This can be doen with a few swipes on a sharpening stone. The blunt angle will prevent the bit from "grabbing" while cutting into the plexi and ruining the hole.
Be sure to start with a small pilot hole before drilling the final hole.
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