[eklu65]

What tools do you guys use to ensure a smooth, flat edge after (or during) cutting acrylic? I've been using a plastic specific blade on a dremel, then using a sanding bit to smooth the cut as much as possible, then going over the entire edge with a razor blade. I'm left with some minor unevenness, but enough to cause me to worry about the strength of a weld. Getting a bit frustrated with how much time I'm devoting to this, only to come up with a flawed end result. Any ideas?

 

[Diana]

Attach something to the acrylic as a guide to that when you use the Dremel the guide will stabilize the blade in the straightest possible line.

 

[ichy]

how big of pieces are you cutting?

 

[eklu65]

Attach something to the acrylic as a guide to that when you use the Dremel the guide will stabilize the blade in the straightest possible line.

The blade isn't very big, and the body of the dremel already gets in the way of cutting all the way through the acrylic. I'm sure there's some sort of dremel attachment I could use, however, I just don't know which one.

how big of pieces are you cutting?

I need a length of 4 3/8th", and a width of 3". The acrylic is 3/8th". I also have to cut the weir into the back wall of the tank, which is basically going to start 2" inward on both sides, straight lines, with a 2" gap left for stability.

 

[r45t4m4n]

Table saw for long cuts, a miter saw for short cuts. Light sanding on the edge and then flame polish.
You can probably get away with just the miter saw for the short cuts you are making. I just cut my weir with a table saw a few days ago.

 

[ichy]

If you can send me the stock I can cut those smaller pieces on a laser cutter for you. Don't know if it is worth the hassle for you.

 

[lksdrinker]

I dont think you want the high speed that a dremel offers to cut acrylic. It probably gets too hot and burns/melts more than cuts. You might be better off buying a handheld plastic/plexi cutter and using a good straight edge or using a circular saw with a real fine toothed blade for finish work.

 

[eklu65]

Table saw for long cuts, a miter saw for short cuts. Light sanding on the edge and then flame polish.
You can probably get away with just the miter saw for the short cuts you are making. I just cut my weir with a table saw a few days ago.

A miter saw with a very fine toothed blade and low speed, correct? You say light sanding and flame polish. I have to do some significant prepping on these edges after I cut with the dremel, and they still aren't completely flat. Will those tools really give that smooth of a cut?

Also, my tank is already assembled, and is 30"X20". The weir will be divided into 2 lines, both 12" long. You still think a miter saw or table saw would work if I have to cut those lines 1 inch below the top rim of the tank?

If you can send me the stock I can cut those smaller pieces on a laser cutter for you. Don't know if it is worth the hassle for you.

I would, however, I still need to cut the weir into the tank itself. Since I still have to do that, I figure I may as well just find a solution that takes care of both.

I dont think you want the high speed that a dremel offers to cut acrylic. It probably gets too hot and burns/melts more than cuts. You might be better off buying a handheld plastic/plexi cutter and using a good straight edge or using a circular saw with a real fine toothed blade for finish work.

Are you talking about the handheld manual scraping tool? I used that to cut 1/8" acrylic. It took a very long time, and the cuts were even worse than using a dremel. The acrylic I need cut is 3/8", I don't even want to imagine how long that would take. I know what you mean about the melting, however, the type of blade I'm using greatly minimizes it. It still melts a little, but significantly less than if I were to use a different blade.

 

[Luckybug]

I use an epilogue 85watt laser cutter, I just happen to have. It does a nice job, of course it costs about $20k, so maybe not the most economical!

I have had success with a table saw, then I take a belt sander belt, 120grit, and slip it on to a piece of 1x4 cut to the appropriate length for the belt. Then use the belt to sand out the saw marks. After that, you can use a small machinists square, and a razor blade to finish scrape the edge, follow that with a block and 1200 wet paper, and some scratch remover to polish to a perfect edge. If you are prepared to take your time, and not skip any steps, you will get great results

Here are some pictures of a diy led light I just made for my sons fluval flora

 

[PapHater]

You'll need a router. I know you're not building a tank but it's worth a read. Also sanding is generally a no no since it tends to round the edges.
DIY Tank (Dialup beware), Step by Step - Reef Central Online Community

 

[GraphicGr8s]

I cut it with a good quality blade on my radial arm. Buddy of mine used a table saw. Trued the edges with the router. I wasn't a fan of the way he put the plastic between the fence and the bit making it a climb cut but he never had an accident. And it's what he made his living at.