best tool for cutting square holes in 1/2 acrylic?

[Anonymous]

I'm getting close to starting on my big vivarium. I want to put doors in either side of the tank; each side will be 24x48 inches. The doors would be probably 18x30 or something similar.

What's the best tool? Router? I have no idea.

 

[Anonymous]

Router works well, but that depends on the size of the square holes.

 

[Anonymous]

like I said, 18x30....

 

[Anonymous]

A router would work, you need to either drill a hole in a corner to put the router bit in to start or you need to have a plunge router so you can plunge the bit down through the material.


I will caution you about one thing, you will have to check to see if its true or not. I believe acrylic will tend to crack around any sharp inside corner so you need to make the inside corners rounded.


How big is the sheet you are cutting?

If its not too big you could do it on a table saw by dropping the blade all the way down, laying the sheet on the table saw with it where you want the cut and cranking the blade up through the sheet, then slide the sheet along to the end of the cut and drop the blade out.

that works well when you do not need rounded corners.

Also, a jigsaw will work but you need to make sure it has some sort of magic circle to keep it from chipping out the acrylic.

I think that is all I got for ya.

I am going to be cutting some similar holes in Makrolon (polycarbonate) next week, I am going to use a combination of tools. I am going to start by using a small circular saw and plunging it down through the sheet and cutting the straight bits with that, then a jig saw to cut the corners.

Hope that helps...





By the way, plunging a circular saw down is inherently dangerous, if you haven't done it before, practice on a piece of plywood until you have the technique down pat

 

[Anonymous]

Oh, and don't be behind the saw while you are plunging it down :lol:

 

[Anonymous]

Oh, and don't be behind the saw while you are plunging it down :lol:

Can I ride on the panel like a flying carpet?

Polycarbonate is more soft, and less likely to chip when cut, but it still does if you don't do it properly.

 

[Anonymous]

Oh, I know, I have done it before...

 

[Anonymous]

18x30 hole in a 24x48 sheet. I have a machine shop right down the hall, maybe I'll ask and they'll help me do it.

 

[Anonymous]

That's not to big to do with a table saw.

I would find out about the rounded inside corners, if you look up the actual name brand of the acrylic you have you should be able to find that info.

 

[Anonymous]

Table saw with the specific blade for acrylic will be fine, but don't use regular carbide blade since the tooth can chip the acrylic really bad. Test it on a scrap and you will know what I am talking about.

Router will also be fine. For the round corner, just use 3/4 inch straight cutter. I use a fraction-horse motor and cut thru it with one pass, but for better result, it is best if you cut says, 1/8 or less and do it over 4 or more passes.

 

[Anonymous]

Good call 7E

I forgot to mention you need a special blade....


Those suckers are expensive too....

 

[Anonymous]

Dan, could you use sliding doors and avoid the trouble of cutting out a panel?

 

[Anonymous]

I suppose, but I think the hinged doors will be nicer for this one.


So, I have the acrylic- it came on a 4x8 palette by tractor trailer to my house! The main panels very nicely laser cut.

I have the two side panels in the machine shop here where I work, and our resident master craftsman is going to help me with this. He suggests we build a template to run the router around inside of. He is very good with all kinds of materials, but has never worked with thick acrylic like this before.

Should the bit be high-speed steel or carbide? I want to cut clear through, but I want to preserve the inside of the hole to be the actual door. I can glue thin strips to the inside for the door to close against.

What kind of bit would be best? Do we try to do it in one pass or multiple passes? Any other tips I should know?

Getting scared! The acrylic cost $400. 8O

 

[Anonymous]

>... I want to preserve the inside of the hole to be the actual door.
How much space can there be between the door and the hole? If you can spare 1/2 in of gap all around the door, then use a 1/4 (don't remember if they come in any smaller size, but I am sure they do) router bit to cut the door out, trying to make a clean cut on the hole's edges. Once the door piece is out, you then can work on the edge of the door, knowing that you have about 1/4 inch of space to work around.

So basically, get the smaller router bit you have, and router out the door. Pass it around the hole's edge to get a better cut (if he is good with router, or has access to a CNC, it can be done with one pass) on the second pass. Then go around the door's edges for a cleaner edge. Polish the edge for DannyO good look, and add hings.

 

[Anonymous]

Oh, have you think about how to attach the hing to the door? Acrylic does not work well if you tap and put a bolt on it (1/2 can be fine, but it is kind of heavy, depends on the size of the door), so you may need to use a bolts-and-nuts type of deal to get the hinges on the door. Acrylic hing would be not good for you unless you want to get one of those acrylic piano hing (IMO, use steel hing with bolts and nuts is better)

 

[Anonymous]

Thanks!

Actually I was intending to use acrylic piano hinges, but haven't bought them yet. Can you point me at a link or something of the nut and bold style?

 

[Anonymous]

I would use a carbide tipped bit. That is what I used for mine. Building a template around the outside is a great idea.

if I were cutting this I would make a frame around the outside for the router to sit against and cut about one quarter of an inch deep on the first pass, then drop the router bit down another quarter and cut around again. I do this kind of cutting with routers all the time, its how we cut planks out of boats.

Keep in mind that the router will want to crawl a certain way when cutting, you want to make sure the direction you are feeding the router toward makes it want to pull toward your frame. That way you won't get any funny spots where it crawled toward the inside....


One other thing, its messy cutting and you need to make sure to keep along the edge of the framework clean of chips, or else they will get between the router and the frame and mess your cut up a bit.

I doubt I would try using any bit smaller than 1/4" for that kind of work.


No idea on the hinges.



Did you check to see how big of a radius is needed on the inside corner? I forget if we discussed that or not.

 

[Anonymous]

Just regular stainless steel hinge that you use stainless steel bolts and nut sto attach to the acrylic. I suggest you spend the extra money and get a stainless steel piano hinge if you are concern about cracked door or jam. Some may reinforce the jam with a long piece of acrylic, but I feel that is a bit of overkill. You may want to use stainless steel washer on the nut side so that you won't chip the acrylic if you over-tighten the bolt.

 

[Anonymous]

Do you mean just a regular hinge of this nature, only use nut and bolts?

 

[Anonymous]

Yeah, that's what he means, but if you want a hinge all along ones side get a piano hinge, They can be had in Stainless Steel also. Lots more bolts to buy with a piano or continuous hinge as they are sometimes called, but the bolts will be much much smaller and the load spread over a larger area of acrylic.