Drilling through plexi

[Dopa]

Hello guys, I'm preparing a new project and I will be having some plexi panels on my case. I want to drill some holes at them and I want them dead straight. I'm thinking of using cobalt drill increasing in diameter from 1 to 2.5mm which is the final diameter of the holes. Since cnc laser can't cut the plexi panel on the sides I have to do it with Dremel or a drill? Any ideas guys? Anyone did anything like this before?
Thanks in advance!

 

[trents]

The challenge when drilling or sawing plexiglass is that it melts. Go very slowly to minimize heat. Keep rotational speeds and pressure to a minimum. Drizzle some water over the boring area to dissipate heat. I would not think using a Dremel would be a good idea because the super fast rotational speed will cause melting. Use something where you can turn the RPMs way down.

 

[knoober]

And you are dead on correct to make incrimental increases in the diameter if the hole. Depending on what type/thickness of Plexiglass you are using it can be prone to cracks and splits. Take a look at the modding subsections for some additional info on working with different kinds of plexi. GL

 

[maxfly]

if you can get ahold of a drill press it would make the dead on part much easier than free handing it.

 

[Dopa]

Thank you all for the replies! I can get this drill press: https://www.skroutz.gr/s/314551/Einhell-BT-BD-501.html but the plexi panels I want are as high as 451mm and I want to drill it on the top. So it's a bit hard to do that on the drill press or am I not seeing something?Any tips for it? I will be using 10mm thickness XT plexiglass and I need a 3mm depth hole. Any tips?

 

[Alaric]

A wrap of tape on the bit is an easy way to mark the depth. Taping the plexi before you drill is a good idea, too.

 

[Dopa]

A wrap of tape on the bit is an easy way to mark the depth. Taping the plexi before you drill is a good idea, too.

Why tape the plexi?

 

[knoober]

The tape will help protect the surface of the plexi from random damage and helps prevent cracks.

 

[trents]

Thank you all for the replies! I can get this drill press: https://www.skroutz.gr/s/314551/Einhell-BT-BD-501.html but the plexi panels I want are as high as 451mm and I want to drill it on the top. So it's a bit hard to do that on the drill press or am I not seeing something?Any tips for it? I will be using 10mm thickness XT plexiglass and I need a 3mm depth hole. Any tips?

At the top? Do you mean you are sinking holes into the edge of the plexi?

 

[Dopa]

At the top? Do you mean you are sinking holes into the edge of the plexi?

Yea exactly! 6 holes in total, 3 on top edge, 3 on the bottom edge. Is masking appliable there?

 

[Alaric]

I always tape the surface I'm drilling with plexiglass, but I don't have a drill press. It does help prevent cracks, but drilling slow with a sharp (new) bit is more important.

 

[Mr.Scott]

At the top? Do you mean you are sinking holes into the edge of the plexi?

Yea exactly! 6 holes in total, 3 on top edge, 3 on the bottom edge. Is masking appliable there?

mmmmmm..........tricky.
How much plexi you got?

 

[Dopa]

I always tape the surface I'm drilling with plexiglass, but I don't have a drill press. It does help prevent cracks, but drilling slow with a sharp (new) bit is more important.

I will be getting new cobalt drill bits for it and starting cobalt thread taps later as well

mmmmmm..........tricky.
How much plexi you got?

Well I can get some spare parts of plexi at the same thickness if that's what you're asking. Three parts need holes on the edges like that.. Top, back and mobo tray.. Do you think 10mm thick plexi can bend on the weight of a mobo + GPU mounted on it?

 

[knoober]

New bits will cut plexi like a hot knife through butter. That's a good thing but dont be caught by surprise. You could end up drilling deeper than you intend by mistake.

Practice with scrap is probably a good idea. I think I would lay the workpiece flat on a bench and try to send the bit on horizontally. Much easier than trying to throw a 400mm+ vertically on a drill press. You can always tape a torpedo level to your drill to make sure you are horizontal (Thanks Bob Villa ). Note that your workbench must be level also for the torpedo level trick to work

 

[Mpegger]

If drilling in the edge will be a problem, have you considered some other method of attachment which may be easier? Hinges? Square rods of plexiglass drilled/tapped then glued along the edge?

 

[Dopa]

New bits will cut plexi like a hot knife through butter. That's a good thing but dont be caught by surprise. You could end up drilling deeper than you intend by mistake.

Practice with scrap is probably a good idea. I think I would lay the workpiece flat on a bench and try to send the bit on horizontally. Much easier than trying to throw a 400mm+ vertically on a drill press. You can always tape a torpedo level to your drill to make sure you are horizontal (Thanks Bob Villa ). Note that your workbench must be level also for the torpedo level trick to work

Did think of that but, If I understand what you're saying, getting the drill press head rotated sideways to drill the edge is not possible unfortunately! I will most probably be bolting the drill press ,without its base, at the edge of my workbench and then put a flat wooden box underneath to set the plexi there.

If drilling in the edge will be a problem, have you considered some other method of attachment which may be easier? Hinges? Square rods of plexiglass drilled/tapped then glued along the edge?

Yea, originally I was thinking of creating aluminum corners that will help connecting the two plexi parts together and generally all the other parts that I want to connect, but that's not what I want styling-wise..

@knoober, I can get my hands on glass drill bits.. Do you think it would be better? Since they are designed to drill through glass without cracking it, I believe it can have the same result with plexi..

 

[knoober]

Im not sure you are going to get any gain from glass bits. A good sharp steel/wood bit will cut plexi like a hot knife through butter. That doesnt mean it isnt worth trying, Im just not sure there will be gain/need for something specialty like that

If you have a good plan with the drill press that is probably best. I was talking about strapping a bubble level to a hand drill (if a drill press wasnt available). It helps quite a bit over trying to eyeball a perfect 90 degree hole.

 

[Dopa]

Im not sure you are going to get any gain from glass bits. A good sharp steel/wood bit will cut plexi like a hot knife through butter. That doesnt mean it isnt worth trying, Im just not sure there will be gain/need for something specialty like that

If you have a good plan with the drill press that is probably best. I was talking about strapping a bubble level to a hand drill (if a drill press wasnt available). It helps quite a bit over trying to eyeball a perfect 90 degree hole.

It's ok.. I got a drill press. I will have to set the RPM "manually" as it has fixed RPM sets. You have to change some belts and some pulleys. I'm thinking of having it running at about 600 RPM, sounds good?

 

[Robert17]

Actually you can get away with 100-200 rpm considering the materials, diameter of the holes, skill level. Slow and easy should be your mindset.

 

[Dopa]

Actually you can get away with 100-200 rpm considering the materials, diameter of the holes, skill level. Slow and easy should be your mindset.

Will check if that's possible coz I can't recall seeing such low RPM set ;/