questionsneed help building a gigantic light table

vote-for23vote-against
vote-for6vote-against

When I heard what she was wanting to do, I really wanted to let her do it on her own. She's amazingly skilled and crafty it just wasn't going to work the way she wanted. Plus, her tool supply consisted of a hammer and a single phillips screwdriver. She was thinking she could just nail everything together.

So now since I am involved, I really want to help her make something that will be killer and work well, it's just a bit beyond anything I've made before so kind of at a loss.

Really hoping with all the technical and construction brains we have here, I can get some help and rock this thing out!

vote-for7vote-against

I have minute experience with dealing with acrylic, the thing that I have found was acrylic cracks easily, so predrill holes and use screws. I would imagine you could turn some acrylic to use as clear supports. My experience with acrylic is it cuts ugly so you may need to trim up the edges. YMMV as I have very little experience, and would like to see what others have to say. Last time I worked acrylic it was my preinternet days.

Do you have any led Christmas light for a proof of concept?

Good luck.

vote-for10vote-against

By no means am I professional, so take this for what it is.

You can buy table legs at about any home store. They're already grooved and they would look nice (depending on if it's your style or not). If you're trying to save money, a newel post will likely be less expensive and you can cut off the portion you don't need to make the leg look as you please. To give you an idea of strength, a 2x4 made of pine (top condition) can support well over 500 lbs. You'll have four of them, so unless your table weighs 2000 lbs, you'll not need to worry about that.

If you're going to use a 1x4 rail all the way around the table, use oak or maple. They have a higher strength and won't bow over time. I highly suggest you connect them to the table legs using a Kreg Jig pocket screw. It puts the screws through the end of the board at a perfect angle and allows for a good, solid connection when done properly.

vote-for10vote-against

You shouldn't need to run more than one center support through the table if you use oak or another hard wood (not pine). Put the legs in about 6 inches from the edge and you'll have just a 36"x72" span. Top it with a finished 3/4 sheet of plywood (about $40-45 at your local supply). They come in all sorts of finishes (Oak, Birch, Poplar, Maple, etc) for added strength.

Sounds like a fun project, but with a couple of useful tools, it should be fairly simple to complete.

Good luck!

vote-for5vote-against

Consider polycarbonate instead of acrylic. Polycarb is way stronger although it is more expensive. For something that is probably going to last, like a table, it may be worth the upgrade.

vote-for7vote-against

LED rope lights should work for a light source. If you use a board for a center support, stand it on edge instead of laying it flat. More strength, won't bow, and will block less light. Especially if you use a 1" X 3" of 1" X 2". I believe I've seen dowels made of acrylic. If you can find a supplier that stocks them, they make a nice transparent center support.

vote-for9vote-against

1. Go to your local hardware store or framing shop and grab some 90 degree/1/8" aluminum edging. Also get a mitre saw if you don't have a crosscut table saw at home, some JB Weld, blue tape, and Vaseline.

2. Get some butcher paper and draw a 2'x3' square (or whatever size you chose) on the paper.

3. Measure and mark the aluminum along the pattern keeping in mind that the mark you make on the outside will be the tip of the square and there is 1/8" of material you need to account for. Mark a second set of aluminum pieces for the bottom.

4. Cut the pieces and test the fit. Then cut the second set of pieces.

5. Apply JB weld to the joints and use painters tape to hold them together.

6. After the JB is set, mark and drill two holes on each side. Use a file or sandpaper to clean up any burs afterwards.

vote-for4vote-against

If you want yo use an acrylic dowel or something like that for a clear center support, I know you can get such things at McMaster-Carr online. I can't comment on the strength or stability of such things, but I know you can get some thick stuff (such as 1" x 4" acrylic bars).

I agree that LED strips would probably work well. If it were me personally, I would probably try to put in sets for red, blue, and green and control the levels of each with a microcontroller to allow for any color, but that's probably just the engineer in me.

vote-for8vote-against

7. Mark and cut the plastic to fit (do not remove the brown paper sticker on the plastic, even after cut).If you don't have a table saw at home take it to home depot and cut it (cruddy edges won't matter in the frame) or use a jigsaw with a fine tooth plastic cutting blade.

8. Tape the plastic to the frame using painters tape and mark the holes with a sharpie. Then drill the holes with a plastic bit. Remove the brown paper attached to the plastic and attach the plastic with machine screws.

9. Get your light source, I recommend using fluorescent rectangular bulbs or rip apart a goodwill fluorescent desk lamp (with long bulbs). They are cheap, they need no programming, transformers or other mounting BS. Fluorescent lights are also 300% brighter for dispersed light. Turn on the lights and hover the plastic above them until you are satisfied with the amount of light and the spread. Have someone help you mark the right height.

vote-for8vote-against

10. Make 4 straight cuts to your aluminum stock using the height measurement you just took.

11. JB Weld the 4 posts you cut to the inside corners of the bottom portion of the frame (the one without the plastic).

12. Place the tops of the 4 posts to the inside corners of the top frame (the one with the plastic) and tape them in place.

13. Drill through each of the 4 posts where it meets the edge of the top frame making sure not to hit the plastic. Remove the tape and de-burr.

14. Cut a thin sheet of black corrugated plastic to fit all of the sides and glue it in place. Cut two sheets for the bottom but DO NOT glue it down.

vote-for7vote-against

15. Take the bottom out and place the lamps where you want them. Drill holes and zip tie them into place where you need them.

16. Stick the bottom back in with the lights attached. Ten cut a "C" where you want the cords to come out. Do not cut a complete hole or light will come out.

17. Attach the top using 4 more machine screws and you're done!

vote-for4vote-against

How thick/stiff is the acrylic? Is it a single 7' x 4' piece?

What kind of projects will she be using the light table for?

Will this be a permanent fixture in the room, or will you want to put it away when not in use?

vote-for5vote-against

@skispeakeasy: Holy crap! Wow. Thanks for the detailed response. Definitely going to be using some of your ideas.

vote-for4vote-against

@straub: I wondered about having some fun and using different colors and a controller. Not having any experience at all in that, how difficult is it to figure out for someone more or less handy? How expensive? Have any suggestions for a site to go check out some products?

vote-for4vote-against

You haven't answered an important question: what is the intended purpose of the light table when it's finished? That will affect the materials and construction details.

I'd suggest you start by going to your local glass/plastics dealer, and discuss what you want to do. They will give you expert advice about what kind of top to use (there are many different types of plastic and glass), the material strength, and amount of support needed. Have them do all the cutting, too!

You'll get a lot more brightness per dollar if you use fluorescent tubes. LED lighting is still a relatively new technology and the price point is very high, compared to fluorescent. OTOH fluorescent will develop more heat inside the table, so you may need to take that into account.

Finally, white paint on the inside bottom of the table will reflect less light than you expect. I'd suggest something more reflective. How about a metallized mylar foil... something like a space blanket?

vote-for4vote-against

@crowbite: It's going to be used as a craft table. Mostly to backlight some large drawings and also for doing multiple glass projects.

She already has the top - a 7ft x 4ft x 1/2in sheet of #2447 acrylic.

vote-for4vote-against

@bingo969: You might try something like this. I haven't used any kind of off-the-shelf product like this myself (I'm more of the design the circuit, solder everything myself kind-of-guy) so I don't know where the best place to look is, but it seems like this one will serve your purpose well and seems to have everything you'd need included (power supply, controller, LED strip). My main concern would be if it's bright enough. Also it might be a problem for you that the strip comes in one long piece. You can likely cut it into pieces and parallel them as long as you're careful about where you cut them and how you attach them.

If you're using LED lighting, I don't think you'd need to worry about getting the bottom to reflect as @crowbite suggested. LEDs are pretty directive.

If you're confused or need any help with the electronics let me know and I'd be glad to help.

vote-for2vote-against

This is very similar to what @straub suggested, but has four 2' strips instead of the single strip. It has a remote and can change color/light quality. It looks like they can be trimmed; an amazon review says there are scissor icons every 6" where it's safe to cut. I've seen it at Costco for around $20, maybe $25, and it can be extended up to 20"/10 strips using the extension kit.

Thank you to everyone who has offered advice and suggestions! I might attempt to make myself a small light "table" for crafts, although I'm thinking 12"x12" and maybe just a simple wood frame, attach polycarb or acrylic on top, and slip an LED rope light underneath when I want to use it on a regular table.

@bingo969: Good luck! I think several of us would love to see pictures when you two finish!

vote-for1vote-against

@neuropsychosocial: You can find them much cheaper on ebay. I was going to back light my TV I hung on the wall.