Looking for some good modding plexiglass

[Jammer]

Hey all,

Sorry if this thread is in the wrong place, I poked around for awhile and couldn't decide where it would best fit, but obviously mods, feel free to move if it's wrong. My bad.

I'm making a glowing LED mousepad. I've built the LED circuit and it's working (off USB power, W00T!) and I'm looking for a piece of plexiglass that is no smaller than 8.5"x11"x3/8". I've been calling local hardware stores, Lowe's, Home Depot, etc. and have had a hard time tracking down a piece that thick yet that small in surface area - most places that sell that thickness of plexiglass or acrylic sell it in huge sheets, which is obviously more real estate than I need (and more money than I want to spend). If anyone has any ideas for where I could get that kind of thing (or if anyone has some they'd be willing to sell for a decent price) I'd be very interested. Any info at all is appreciated. I'll send you a sweet picture when I get it done

Thanks for your help.
Jammer

 

[agent420]

Check your local glass shops.. they often stock some of that.

 

[Michael Daly]

Specifically, ask for scraps that they have from cutting big sheets to window size.

You could also check plastic suppliers. If you're in or near a big city, there should be a plastic materials outfit that will stock different plastics. They might also have leftover bits.

Does it have to be plexiglass (acrylic sheet - plexiglass is a brand name)? You might be able to use polycarbonate or another sheet clear plastic.

 

[markkleb]

Check your phone book for a local plastic company.

Also try
http://www.interstateplastics.com/

or Tap plastics.

 

[Mohonri]

To me, 3/8" seems to be a bit on the thick side for a mouse mat. Are you sure that's the size you want? I know my local Lowes carries 1/4", and they almost always have some sort of scraps they can part with for cheap.

 

[Jammer]

Yeah, 3/8" is pretty thick. It has to be thick enough to cut channels in so I can put the LED circuit underneath and not have it have to be raised or something. 1/4" would probably do it, but I'm a n00bie with the Dremel, so I want to have a little leeway. It's a great idea for a weekend project if anyone's interested. Check out

http://metku.net/index.html?path=mods/glowpad/index_eng

P.S. I found a local plastics company that deals plexiglass. $15.00 for a 3/8" piece cut to the size I want - not bad. Thanks a lot for your help, everyone. I'm also willing to answer questions about the mod above if anyone has any - I learned a few things doing it myself.

Take it easy all,
Jammer

 

[Mohonri]

You might consider getting the router collar for your dremel and a router bit. That'll let you remove some of the material in the middle nice and evenly.

 

[Jammer]

That's a good call, Mohonri. I'm getting the plexiglass today, so I should be finishing it up on Sunday - I'll report back for anyone that's interested. Thanks all.

 

[termite]

I definitely agree with Mohonri, the router collar is great working with plexi. The router bits will work ok, I tend to use the high speed cutter bits. Word of caution, even at its lowest setting, a Dremel will melt plexi, use minimum pressure and go slow.

 

[Mohonri]

I definitely agree with Mohonri, the router collar is great working with plexi. The router bits will work ok, I tend to use the high speed cutter bits. Word of caution, even at its lowest setting, a Dremel will melt plexi, use minimum pressure and go slow.

I guess I need to get a smaller router bit--my Dremel tends to chip, rather than melt, the plastic with the 1/4" router bit I have.

 

[termite]

I guess I need to get a smaller router bit--my Dremel tends to chip, rather than melt, the plastic with the 1/4" router bit I have.

Yes I have had the same problem with the router bits, as far as the melting I was referring to the high speed cutting bits, I tend to use those as my routing bits.

 

[Michael Daly]

I guess I need to get a smaller router bit--my Dremel tends to chip, rather than melt, the plastic with the 1/4" router bit I have.

Router bits are made for high speed and Dremels aren't slow, so you have a basic incompatibility between the tool and the material. Not unworkable, but...

Looking at the web site, I wonder if you couldn't just insert the LEDs into the edge of the plastic rather than route a groove underneath? That way, you'd just need to drill a couple of holes for each LED - smaller diameter for the body, larger for the flange at the LED base. Drill press here - at low speed with sharp bits. If you drill deep enough, the leads and wires will be entirely inside the plastic. The only groove you'd need would be on the edge - perhaps as a stepped edge along the bottom. A stepped, polished edge around the entire pad might reflect the light as a frame - you might have to experiment with a scrap of plastic to see.

Anyway... just an idea.

 

[Mohonri]

Router bits are made for high speed and Dremels aren't slow, so you have a basic incompatibility between the tool and the material. Not unworkable, but...

Exactly. The router bit (*made* for a dremel) isn't the best for plastic. If you had a bit with smaller "teeth", it would melt the plastic. What you really need for this is a mill--something around a few thousand RPM (instead of the couple-of-tens-of-thousands you get with a dremel) and smaller cutting surfaces, to grind/sand off the plastic instead of trying to cut it.