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zan29
02-21-2014, 12:24 PM
Does a picture/grayscale come out as good on a clear plexiglass as a lithopane?

cnsranch
02-21-2014, 12:56 PM
Can't use Plexiglass - has to be cast acrylic like Corian - Plexiglass will simply melt into a pile of goo around your bit.

zan29
02-22-2014, 04:34 AM
I saw a plexiglass carving yesterday done with a CNC. A grayscale was used so I was wondering if photos could work. Thanks for letting me know!

bergerud
02-22-2014, 10:28 AM
Plexiglass is actually a trade mark name. It can be cell cast or extruded.

200k
02-22-2014, 10:28 PM
Don't even try Plexiglass. It will melt around the bit until it builds up a large enough ball to be thrown off by centrifugal force into the guts of the machine. For me at least one of these little monsters got lodged into the y truck belt and stalled out the motor and chewed up the teeth of the gear. Cost >$100 for a new Y truck motor assembly.

You CAN use Lexan, which I have used numerous times. I am currently making a set of 20 trophies for a RC sailboat regatta called the Geezer 'Gatta for over 50 y.o. sailors. Attached are some photos of the first cut prototype of this year's trophies. Once I get the pattern I like (without text) then I can resize it for the different finishes (1st place, 2nd place, etc.) I have five places for both individual and team winners (3 person teams). The 1st place is 8" tall, 2nd is 7" and so on down to a 4" tall 5th place trophy. This Lexan vertical will have a fancy hardwood base to finish it off. The last group photo shows the trophies for last year's regatta. They had an mirrored Plexiglas base that I cut on the table saw.

The bottom line is: YES you can carve on clear plastic if it is the right kind of plastic. BTW, you carve the BACK of the piece using the reverse of the pattern you want to see including any text.

200k

200k
02-22-2014, 10:48 PM
BTW, I forgot to add some things in my last post. I carve using the same settings I use for lithopaning (is that a real verb?) in Corian. My Lexan is 1/4" thick and I use a jig to hold a 12" x 24" for the Carvewright. Lexan throws off lots of little statically charged cutting chips that stick everywhere inside the machine even with aggressive dust collection. I have a serious dust collector hooked up to my machine and the inside stays very clean when I cut wood products but the static cling is tough to combat. I usually stop the machine several times during a long carve and suck out as much as I can with a shop vac, crevice tool, and a little brush. I haven't had the jammed truck problem with this method. I also recommend you use a very sharp or brand new bit. A dull bit will leave lots of little tiny feathery bits hanging on the carve that are a real pain to remove. They hang on tenaciously and you have to meticulously remove each one. Lexan is tough stuff even in little tiny bits.

Also leave the polyethylene protective sheet on the Lexan while you carve and it will protect it from a ton of little scratches that you will notice only after you have finished everything and hold up to the light. I had to redo some carves because of these seemingly minor scratches that suddenly show up huge and ugly after I finished the piece. Polishing them out is a possibility but that's not easy either. Leave the protective plastic on until you are completely done and you will save a lot of headaches.

Attached is one more photo of one of last year's trophies. It comes out very nice looking if you take care.

Good luck!

200k
02-22-2014, 10:55 PM
Dang it! One more thing. The sailboat pattern I used is made from an actual photo that I put into Photoshop, tweaked it a bit to get it how I liked it, put it into grayscale, and then imported it into designer through Pattern Editor (I think that's the one) and made it a pattern. It took about five tries to get it to look exactly how I wanted but most of the problems were with my photo tweaking, not PE.

Now, I think I've answered everything...maybe.

200k

fwharris
02-22-2014, 11:15 PM
200k,

Nice job on the trophies. Another thing you can do with the cast acrylic is to carve the back side like 200k said and edge light it with led lights. This is one I picked of the WWW as an example.

zan29
02-23-2014, 06:20 AM
Thank you so much for all that information. Maybe it was Lexan I saw the other day.

bergerud
02-23-2014, 09:31 AM
Lexan is also a trade name. It could be cast or extruded acrylic. Just be sure what you carve is cell cast acyclic and not extruded acrylic.

dbfletcher
02-23-2014, 09:47 AM
Lexan is polycarbonate. Unlike acrylic, it can be cold formed.

CW-HAL9000
02-23-2014, 10:15 AM
200k where do you buy your lexan?

bergerud
02-23-2014, 10:20 AM
Lexan is polycarbonate. Unlike acrylic, it can be cold formed.

Thanks Doug. I thought Lexan was a generic name for many products. The Lexan I have used seemed just like extruded acrylic.

liquidguitars
02-24-2014, 03:15 PM
Well done, Nice layout and application!

200k
03-04-2014, 10:13 PM
200k where do you buy your lexan?

I have bought some from a local plastics supplier, but my latest purchase was from US Plastic online site which even with shipping costs was cheaper. It's best if you buy what you need for a long while and consolidate the shipping rather than buying a sheet, 1/2 sheet, or 1/4 sheet each time you need one.

200k