CNC milling a Plexiglass LED sign

Awesome!

I want to try now!

Id proudly hang that up!

Ok thoughts.

I've heard nothing but awesome things from Onsrud Upcut
https://www.youtube.com/watch?v=f8FVAQep7Xs

It's hard to tell if you ar 3d maching or just 2d? I would stick with 2d on this. I would try and do very fine step over on the finish pass to get a consistent surface finish on the x/y plane. Also I would stay shallow. Google acrylic light up signs and you will see what I am referring too.

Now take this with a grain of salt as I have never made a sign out of acrylic. Just thoughts. I could be dead wrong on the finish passes.

Thanks for the bit info. I'll have to see how much that Upcut bit cost.  It's done with 3d milling. 
Couple of mistakes I made were.
1. Wrong type of plexiglass.  (should be cast not the extruded I have on hand)
2. Wrong type of bit (was using a dremel rotozip bit - only 2 flute bit I had on hand)
3. Milled from the front instead of the back.  (Milling from back will leave a smooth front finish and should show up better when lit)
4. Still new to milling so I'm sure there are other settings I could set to get a better finish.

I will be doing this again with a 2 flute ball end bit and milling from the back.  I'm still learning about milling, so I will have to see if I can figure out how to do a finishing pass.

I'm using V carve Pro.  I have some of those 2flute from ebay already on order. should be here today or Saturday.

I have never used v carve. In cambam there is a setting for roughing clearance. I add 0.25mm for the initial cutting process and then run one more final pass at the final depth with the roughing clearance set to 0.

Already is