[Lowcountrygamecock]

I need to cut a 2 inch disc out of a small sheet of lexan. Not exactly sure what size I need yet but I can get a good measurement before I cut it. My question is what's the best way to cut it? I have a hole saw with a removable center bit that I think will be the perfect size. Will that work?

 

[bzguy]

Should work if you use a drill press and clamp it down.
Without the hole saw center bit it will try and "walk".

 

[woodnthings]

make a wooden guide first

Use the holesaw with the pilot bit and saw a hole in a 1/2" thick plywood scrap. Clamp the scrap over the Lexan where you want the hole to minimize waste. Now remove the pilot bit and saw the Lexan using the plywood to restrain/guide the saw.

You may not need a drill press for this method, but it would be best.

 

[ryan50hrl]

Is the inner diameter the correct size?

 

[bzguy]

A 2" hole saw makes a 2" hole, 2&1/8" may come close.

 

[Lowcountrygamecock]

I still have to measure it to see exactly what size I need. It's actually less than 2" but I'll measure and get the right size hole bit. Thanks

 

[rrbrown]

How thick of lexan?

 

[rrbrown]

With the protective coating on the lexan use double sided tape and attach a small wood block to hold the center guide. Using one of these you can set the depth that the center guide can cut into the wood while the cutter cuts the lexan.

keep the wood thicker than lexan and you got it. Just remember to set a stop to only allow the center bit to travel 1/2 way though the block as to not cut the lexan.

 

[rrich]

As Bill says clamp between plywood.

Other hints

Two pilot holes, the first 1/16 or 3/32 and the second the size of the centering bit of the hole saw. The second hole should be through the plywood too.

Also VERY LIGHT pressure. Relieve the saw frequently, lubricate the cut with water and generally just take it slow. You want the hole saw to gently scrape away the Lexan and not just crash through it.

After the hole is cut, you'll probably have to clean up the edges of the hole with some fine sand paper. (400 to 800 grit) Don't sand the surface of the Lexan as it will turn cloudy regardless of how fine the grit.

 

[against_the_grain]

Cutting 1/4 inch lexan isn't to bad. The thicker acrylic (plexiglass), tends to melt easier from my experience. I like rrbrown's suggestion.

Personally, I cut a template into 1/4" ply and used a dremel tool with multi-purpose spiral bit. The base of the Dremel tool is a nice concentric circle. So figuring the offset was easy. Worked really good for lexan.

Use a variable speed tool with the right bit or blade. Don't spin the bit/blade to fast or move the tool too slow or the lexan will melt. Usually there will be some residual material melted to the edge that can be removed either with sandpaper or a utility knife.

If anyone always gets nice really clean edges, I would like to know your method.

 

[jschaben]

If anyone always gets nice really clean edges, I would like to know your method.

These will do it but you still need to watch your router speed and feed rate. Also a bit spendy for an occasional use but leave a very nice finish.:smile:
http://www.toolstoday.com/p-5879-so...stic-cutting-up-cut-down-cut-router-bits.aspx

 

[Lowcountrygamecock]

So I think the hole saw bit is the best option. This doesn't have to be perfect so I'm not stressing a high quality look. I measured last night and need a disc that's 2 1/4. What size hole bit will have an inside diameter that size?

 

[cabinetman]

So I think the hole saw bit is the best option. This doesn't have to be perfect so I'm not stressing a high quality look. I measured last night and need a disc that's 2 1/4. What size hole bit will have an inside diameter that size?

Depending on the brand it will likely be (in round numbers) 2½".

.

 

[Al B Thayer]

So I think the hole saw bit is the best option. This doesn't have to be perfect so I'm not stressing a high quality look. I measured last night and need a disc that's 2 1/4. What size hole bit will have an inside diameter that size?

Your not going to really know the disc size until you cut it. do a test cut first. But 2 1/2" seems too big.

Al

Friends don't let friends use stamped metal tools sold at clothing stores.

 

[tonyuno]

I cut mine with a Forster bit at slow speed.

 

[ryan50hrl]

I cut mine with a Forster bit at slow speed.

How's that going to give him a disk?

 

[tonyuno]

Correct ,I misread his problem.

 

[tonyuno]

Further, my wife works in glass, makes sinks and uses a diamond cutter to cu th base hole, ne'er tried tikis on my stuff as I don!t want to get my wrist slapped.
Thanks for querying my initial reply without getting rude.

 

[against_the_grain]

So I think the hole saw bit is the best option. This doesn't have to be perfect so I'm not stressing a high quality look. I measured last night and need a disc that's 2 1/4. What size hole bit will have an inside diameter that size?

Some of those hole saws of that size require a mandrel . And it might get pricey. If you have a dremel tool or a router, use a spiral bit, it would likely be cheaper to go that route. Thats assuming you have the circle cutter jig for either of those.

Good luck .

 

[cabinetman]

These will do it but you still need to watch your router speed and feed rate. Also a bit spendy for an occasional use but leave a very nice finish.:smile:
http://www.toolstoday.com/p-5879-so...stic-cutting-up-cut-down-cut-router-bits.aspx

That's a CNC bit if I'm not mistaken. If used with a normal router operation, you would need a template for an oversied hole to account for the bit diameter. I've never used that bit, but I'm guessing there is likely a specific speed and feed rate to account for the type and thickness of acrylic.

.