Acrylic help needed

Rob Keeble

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GTA Ontario Canada
Ok so i know i can cut a piece of acrylic with my table saw and have successfully done so. BUt now how do i route the stuff so i can make a curve? I did some the other day and it fuzzed up and melted and did not give me the edge i was looking or expecting to get.

Can you more experienced and educated guys pass on some tips please. I have a 2 huge sheets at least 8x4 and 1/4 thick but they pretty useless to me unless i can make em do more than straight edges.

H...e...l...p please
 
You want to cut a curved edge on 1/4" thick acrylic, if I read your post correctly. And you want to use the router how? I am not clear. Are you looking for a curved perpendicular edge or are you looking for a shaped profile? I can help better if I knew. I have done a lot of acrylic cutting and have used the router with acrylic. There are few tricks but I need to know more. Just sayin...
 
Cut it on the bandsaw; sand the cut edges to 400 grit; then (lightly and quickly) run the flame from a propane torch over the edges. That's called "fire polishing" and will give you a factory-looking perfectly clear edge.

Try it on a couple scrap pieces first, to get the feel of the torch.
 
Thank you for the replies.

Well here is what i am wanting to do.

Take a piece of 1/4 acrylic and cut a rectangle out with the internal corners being rounded out.

I tried first using drills and forstner bits to get the corners. Then tried cutting the pieces between the holes on the router.

In this case i could not use the bandsaw.

I am looking to have a perpendicular edge when done and looking to have duplicate round corners on the interior of the rectangle.
Also looking to be able to be precise on my dimensions.

Not sure i can do what i want with what i have as tools.

If i was simply cutting a clear base for my router i would not be that concerned with dimensions or edge finish but in looking to use the acrylic as a template after i need it to be smooth and clean cut.

Sent from my MB860 using Tapatalk
 
Thank you for the replies.

Well here is what i am wanting to do.

Take a piece of 1/4 acrylic and cut a rectangle out with the internal corners being rounded out.

I tried first using drills and forstner bits to get the corners. Then tried cutting the pieces between the holes on the router.

In this case i could not use the bandsaw.

I am looking to have a perpendicular edge when done and looking to have duplicate round corners on the interior of the rectangle.
Also looking to be able to be precise on my dimensions.

Not sure i can do what i want with what i have as tools.

If i was simply cutting a clear base for my router i would not be that concerned with dimensions or edge finish but in looking to use the acrylic as a template after i need it to be smooth and clean cut.

Sent from my MB860 using Tapatalk

The secret to routing this stuff is cooling.. It will melt and that's where the problem comes in. Also the chips get caught and remelt..

Some things that help and practice or test before you use your good piece.

Cool ..... a stream of compressed air directed at the bit will often be enough to make you successful.
Use a 2 fluted bit so there is ....more time for cooling between bites.....
Cut it out rough then make a finishing pass..this gives chips room to get out of the way and more time less time per revolution to heat the bit..
Sharp bit so it cuts rather than tears off the acrylic.


I have even seen it suggested that you cut in a pan of water for even better cooling...
I found the biggest help was having room for the chips to clear. Once you start melting you are done...

Chatter marks can be cleaned up with fine sand paper and flame polishing..

For cutting you can use a scroll saw to remove most of the waste and then a template and router for finish cut...

What you are doing is treating in more like metal work than woodworking..

Here is one example of actual work being done. Notice that all cuts are only trimming and the chips are flying.....

http://www.melevsreef.com/acrylics/routing.html

And a you tube video showing how easy it is..

Again notice the chips a flying no place to wedge and get hot..
http://www.youtube.com/watch?v=dqoQRtFnFZM


Good luck...
Garry
 
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I knock the corners off with a band saw and hand sand as Jim suggests, but you said a bandsaw would not work. Are the corners concave as opposed to convex?

Another conundrum. You are using the end result as a template. May I ask for use with what tools. Acrylics will not hold up to being used as a template for routing. When a bearing at 23,000 rpm meets the plastic, it melts a divot into the edge. That's the reason for the question.

Also, FWIW, the proper router bit for plastic has cutting edges at an angle to the shaft - called helical cutters. The cutting edges peal off waste and throw it away from the cut faster, reducing the melting effect of the waste.
 
Thank you for the excellent replies i appreciate you all saving my bacon very much:thumb:. Carol my corners were internal to the piece so a scroll saw would have been more appropriate. Will use a piece of mdf instead now.

After this contribution i have scratched the idea completely. Had not thought of Carols point of the bearing causing a divet. Was going to use it for a template. Would have been good to use to align given you can see through it. Now might use it as a carrier.

Well i got so much of this stuff for free from a friend of mine when their factory closed it will be three generations before its used up. Wish it was not costly to ship otherwise i would dish it out to anyone who wants some. Just could not stand to see the stuff go in the bin.
 
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