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Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 1:55 pm
by LTHOMPS
I have a few pieces of Lexan/Polycarbonate material but I notice most people use acrylic. Is there a big difference in appearance and cut? Can I use the polycarbonate I have? Does one material have more light coming through as opposed to the other?

Re: Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 2:27 pm
by LTHOMPS
While I am still waiting for a reply, I did a cut in poly and lit it up. I don't see anything. Still waiting on an answer before I go spend money on acrylic.

Re: Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 2:32 pm
by LTHOMPS
I used a diamon drag bit and the quick engrave feature from aspire. Heres the final product. Is my cut not deep enough? I will go back and do a deeper cut using a v-bit.

Re: Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 2:33 pm
by LTHOMPS
Heres the final product, I forgot to add ti in the last message.

Re: Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 2:46 pm
by LTHOMPS
OK, I just a v-cut which is deeper and it looks better, but still not as bright as I want. Is this because it's polycarbonate as opposed to acrylic. The material is 3/8" thick.

Re: Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 3:07 pm
by PaulRowntree
I am not the expert on this, but my one example of cutting polycarb looked foggier than my one example of acrylic ...

Re: Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 3:45 pm
by tonydude919
You have to use cast acrylic. I get mine from http://www.estreetplastics.com/Plexigla ... r_s/21.htm I use 3/8", also I only go down to about .01-.02 deep using a 90 deg v bit, other people use diamond tip. Check out my facebook page fpr the acrylics I've done.

Tony

Re: Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 5:39 pm
by LTHOMPS
Tony: OK. I will go buy a piece from Home Depot quickly and try it. Thanks.

Re: Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 7:10 pm
by martin54
Polycarb & acrylic are quite different which is probably why your having problems with light transmission, other thing you would need to watch is if your using an internal grade of polycarbonate & it gets to close to direct sunlight it will yellow fairly quickly.

Make sure it is cast acrylic you buy & not extruded. There is a price difference & you can machine extruded but the results will not be any where near as good.

You can either v carve or use diamond drag bits, I have used both & think the subject can make a difference which looks best although most of what I have done has been diamond drag.

Try doing a search as it has been talked about quite a bit, there are a few posts in the vcarve pro section of the forum.

Re: Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 7:57 pm
by MarkJohnston
Home Depot doesn't sell cast acrylic at least where I live. The estreettplastic where Tony told you about is a great supplier of the cast acrylic. That's where I go. The Home Depot acrylic melts very easy when cutting. I've used drag bits, vbits and ball nose bits all with great success. You need to slow down you router or spindle to around 7000 to 10000 RPMs or you will melt it. Also take shallow cuts and fairly high feed rates. Do search on acrylic signs here on this forum to get a lot of discussion on how to carve acrylic.

Mark

Re: Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 8:30 pm
by Xxray
Poly is not suitable for edge lit, does not transmit light well.
If you are using a drag bit I don't think cast/extruded should be a factor, but for a v bit it is.

Re: Question About Edge Lit Signs

Posted: Tue Dec 31, 2013 9:52 pm
by ChrisInEstes
Yup, you need cast acrylic if you're going to machine it. The extruded stuff, like Home Depot sells, just melts and gums up the works. There may be plastic wholesalers & retailers in or near your location, so check on that too.

Chris

Re: Question About Edge Lit Signs

Posted: Tue Jan 07, 2014 11:19 am
by LTHOMPS
First, thanks for all of the replies.
Here's an update. So I went off to Home Depot before seeing some of your responses and bought a piece of acrylic. I assume it is extruded. I cut the following sign that is attached to this post. I did not adjust the spindle rate. ( which I now see was a mistake because it appears I had some minor melting). The other difference is this time I used 5050 LEDs instead of 3528s in the first two pictures. So, I think this looks a lot better and with the other suggestions I should be able to get this where I want it. I will now get cast acrylic and lower spindle rate and try again. Thanks.