Advice on material for project

[reiser25]

I have a project for my church that I need advice on. They want it to look something like the image shown. My issue is what material to use for the leaves to be attached to? The leaves are recycled stained glass from an older part of the church and will have the donors names printed on them. In order for these to be read they need to be on some sort of standoff and mounted to a clear material. I do not have much experience machining Lexan or Plexi and my two concerns are edge finish and cracking from the holes for mounting the leaves. Any advice would be great! Thanks, Josh

[chiloquinruss]

My first guess would be to use clear silicone caulk as the adhesive, no screws. Russ

[bleeth]

Machining the clear backer is pretty straightforward as long as you are OK with not having polished edges. Otherwise I would have them done on a laser as hand polishing all those little parts would be a real chore. For standoffs you can get ones made for mounting letters from Gemini and mount the flange to the plastic backer with a little super Glue Gel. You just drill a hole in your board and insert the post with a dab of adhesive (silicone works fine here) shot onto the pin first. As long as you are a licensed shop Gemini will register you or if not point you to someone who resells. If you don't have a laser guy handy there are a couple on the forum and one of my business neighbors does lasered acrylic for a living and ships stuff out all the time.

http://www.signletters.com/Sign_Components/InstallationSupplies.html


BTW: For your clear mounting base use extruded Acrylic for best and cleanest machining.

[letterman7]

Machining plex isn't hard, you just need a single straight flute and run it at a fairly slow forward speed, if the plex is thin. For mounting, I can almost guarantee, based on your photo, that there are countersunk screws under those leaves somewhere. The leaves themselves will hide the screws, even if it's stained glass. Of course, the question to be asked is does the background need to be clear? The branches of the tree in the sample photo don't go through the leaves, so why not try to come up with something a little different - actually mill a tree image in a nice mahogany or something and mount the leaves on the tree. Easier for you and a nicer looking end product for them.

[twelchPTM]

I would sugest polycarbonate, It machines almost exactly like acrylic and is much more impact/crack resistant. when using any type of acrylic/polycarb material, screw holes should be oversized to prevent stress cracks. I would also sugest creating the cut file for the two parts from the same vectors that way the back panel can be a solid sheet instead of multiple tiny leaves