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Bob Davis
05-25-2009, 11:37 PM
I'd like to produce acrylic awards in-shop, so I'm looking for a way to cut 20mm clear acrylic.
In the past we have used a bandsaw or a circular saw to cut acrylic for bases to attach 8mm clear laser-cut pieces to, and this has been quite successful. We use a belt sander to clean up the edges of the bases and the frosted look is quite attractive. However, cutting the acrylic is quite slow and laborious on a bandsaw and also requires a bit of time straightening edges,so I'd like to speed up the process.
I'm looking at getting a table saw. Never used one before, but how hard can it be..?
After checking the web I discovered that these suckers are very dangerous. Apparently 60,000 accidents a year in the U.S., which is around one each 9 minutes. Nearly all of these result in the loss of at least one digit, usually more. The idea is starting to look less attractive, but I don't intend to use it a lot so maybe I can still make it work.
Does anybody here have any experience with cutting thick acrylic on a table saw? Any clues on best blade type, size/power requirements, problems?
The plan is to use it to cut pieces for bases and uprights, most with straight bevelled edges that are cleaned up on the belt-sander. Possibly route a few edges.
Any advice appreciated.

Bob

Rodne Gold
05-26-2009, 3:33 AM
We do exactly what you want to do using a table saw and a overhead mitre/cut off saw.
The secret is in the blades , you need a non ferrous blade or a plastic/perspex cutting blade. If you can lube the blade whilst cutting , you will get a FAR better cut than dry - but this is not always possible.
We have found that a matte or frosted edge often goes down better than a polished one
Check these out
http://www.tokerbros.co.za/custom_acry_20mm.htm

Frank Corker
05-26-2009, 4:48 AM
...Apparently 60,000 accidents a year in the U.S., which is around one each 9 minutes. Nearly all of these result in the loss of at least one digit, usually more.

Well he can't have many more digits left to go then! Definitely down to the blades with saws. I cut 20mm acrylic with a 45w, smooth it with belt sander and wet/dry, then flame polish. If you are using a high speed saw you need to watch out for 'chipping', certain cast acrylic will end up with tiny little chunks missing where the saw blade has just passed over, they are hard to remove.

Bob Davis
05-26-2009, 5:48 AM
Frank,
Now if I had said "A man in the U.S loses a finger every nine minutes" you would have been right on it.

Bob

Bob Davis
05-26-2009, 6:00 AM
Thanks for that, Rodney.
Do you use a specific blade for thick or thin acrylic? I have read (but I can't remember where) that thin acrylic around 3mm is best cut with a blade of 60 - 80 teeth, but that thicker acrylic requires fewer teeth so that less heat is generated or the acrylic will begin to melt.
The actual melting doesn't worry me too much as the edges will be sanded back anyway, but I'm thinking that expansion and grabbing the blade would have undesirable consequences.
And I just had the ugly thought that statistically there have been two table saw accidents occur while I've been writing this little note.

Rodne Gold
05-26-2009, 7:00 AM
http://www.maizey.co.za/component/option,com_docman/task,doc_download/gid,228/Itemid,235/
will give you all the info you need re blades etc

Mike Null
05-26-2009, 7:02 AM
I use a Freud plastic laminate blade with a zero clearance insert in the saw table. It has about 80 teeth.

Prashun Patel
05-26-2009, 8:14 AM
A common tablesaw accident is kickback, which ironically is most prone to happen with light, thin, flimsy things like plywood and...acrylic.

Splitters and kickback pawls mitigate this to an extent, but standard splitters don't raise and lower with the blade, so when cutting thin stock there is a lot of space between the back of the blade and the splitter. A riving knife is a better option, since it raises and lowers with the blade. They're found on the more spendy cabinet saws, but Grizzly and Bosch (and probably others) do have lower priced 'contractor' saws that have them.


There are also good aftermarket splitters and blade guards that are more convenient to use than the stock guards, which means you'll be less prone to go Commando and take off the splitter/guard altogether (which, TRUST ME, you'll be tempted to do, as you get dangerously more comfortable with your tool....

Dave Johnson29
05-26-2009, 9:54 AM
and take off the splitter/guard altogether (which, TRUST ME, you'll be tempted to do, as you get dangerously more comfortable with your tool....

If removing blades and knives is good enough for Norm, it is good enough for me. :eek: ;)

I use an 8" miter saw and a 10" table saw for aluminum and plastics including 'pex, nylon and Delrin. Both have all guards removed.

In both I use Freud no-ferrous blades with high tooth count (80 in both I think) and no guards or knives. I also have painted (red paint) all the dangerous places to have a finger or hand. The red paint is dribbled to emulate blood as a constant reminder not to get complacent.

http://routerbitworld.com/Non-Ferrous-Metal-Blades-s/138.htm

WARNING: Remove the saw blade guards at your peril.

I am still able to keep my shoes on and count to 10. :D

Albert Nix
05-26-2009, 12:45 PM
Me too!! Well may be 9 3/4.

James Jaragosky
05-26-2009, 1:06 PM
Me too!! Well may be 9 3/4.

In the late 70's I worked in a machine shop cutting 4x8 sheets of materials like Bakelite, Plexiglas, acrylic, and asbestosis:eek:
The dust collection was little more than a shop vac, and the blades we used were not carbide but rather like a grinding wheel material. we cut all thickness if material just fine; the blade was rather thick if I remember correctly it was around .25.
My point is that it is a lot more difficult to cut off a finger with one of these blades, but not impossible. injuries with this type of blade are like those you would get from a grinding wheel.
All tools can be dangerous if used improperly.

Bill Morrison
05-26-2009, 1:07 PM
If you go by statistics you might want to quit driving too. Your questioins about cutting acrylic have been answered and the only thing I wanted to add was don't wear long sleeves or anything that the sawblade can grab. What might be a small cut could be amputation if a blade grabs cloth and pulls your hand or arm towards it. Use push sticks and if possible find a friend to how you the basics of a tablesaw. Never get in a hurry. You will do just fine, using common sense and do some reading on the internet about tablesaw basics.

Good luck

Bill Morrison

Doug Griffith
05-26-2009, 1:21 PM
If you go by statistics you might want to quit driving too. Your questioins about cutting acrylic have been answered and the only thing I wanted to add was don't wear long sleeves or anything that the sawblade can grab. What might be a small cut could be amputation if a blade grabs cloth and pulls your hand or arm towards it. Use push sticks and if possible find a friend to how you the basics of a tablesaw. Never get in a hurry. You will do just fine, using common sense and do some reading on the internet about tablesaw basics.

Good luck

Bill Morrison

I knew a guy who did exactly that. By himself. His sleeve got caught in a radial arm saw and it pulled his arm 90% through mid-forearm. He had to finish the job to keep from bleeding to death. Then he ran to the hospital a few buildings down carrying his arm and they sewed it back on. Now he has a big man arm that steps down to what looks like a little boy's arm. Besides not wearing long sleeves, don't use dangerous equipment alone.

Scott M Smith
05-26-2009, 10:45 PM
That is a cool table saw. but one thing i can recommend about using a table saw, use a push stick! You could even make one on your laser out of acrylic.

art baylor
05-26-2009, 11:38 PM
That's amazing safety technology! Just a nick on the hot dog.

When I was in plastics, we used an overhead or panel saw on three rails. The acrylic (or what ever) was clamped tight on the table and the saw ran above it to cut. 120 tooth 12 inch carbide blade.

Art

AL Ursich
05-27-2009, 9:25 PM
I wondered how the Sears Twin Saw would work? Two blades going in opposite directions...

AL

Ed Harrall
05-27-2009, 10:49 PM
As a teacher reading this post, I will first say that the table saw like any other should be respected! PLEASE DO NOT REMOVE GUARDS! If you do not like the factory ones them get a good overhead guard. When we cut plastic we use a zero clearance insert. We do not use the splitter/kickback insert, because the plastic is slick and hard enough that it will not stop the kick back. I cut 2" blocks with a Frued non-ferrous blade. Do not use acrylic for a push stick as is will Shatter. The best material that I have found to use to make push sticks from is color core plastic, or just spend the $5.00 and buy one THIS IS A MUST! much cheaper than replacement fingers:eek:

Ed Harrall