I know this is a metalworking newsgroup, but I would assume that plexiglass
is cut with a metal cutter.

How do professionals cut plexiglass? I am going to need to cut some, as
well as rout some of the edges to make them fit into slots.

Would I be better cutting these on a table saw with a special blade, or
using a router blade that has say a narrow width? Maybe even taking more
than one cut, and using a fence as a guide.

I'm going to Google on this, just wanted to know if anyone did this sort of
thing. It has to be a quality finished cut.

Steve

Steve B wrote:
I know this is a metalworking newsgroup, but I would assume that plexiglass
is cut with a metal cutter.

How do professionals cut plexiglass? I am going to need to cut some, as
well as rout some of the edges to make them fit into slots.

Would I be better cutting these on a table saw with a special blade, or
using a router blade that has say a narrow width? Maybe even taking more
than one cut, and using a fence as a guide.

I'm going to Google on this, just wanted to know if anyone did this sort of
thing. It has to be a quality finished cut.

Steve



You can run this on the table saw if you have tuned your machine to run
near vibration free and used a fine tooth blade. Carbide with zero rake
like a blade for aluminum and SHARP. If it is the softer plexi the edges
should be near chip free. The harder acrylics tends to micro chip at the
edges. Cut over size and hand scrape the edge to size. A fast moving
flame will help clear the edge.

I've watched a pro cut and bend acrylic for boat windshields
a dozen times and I'm still amazed how easy he makes it look. Its more
of an art of feel than science.

If you use the router method, use a spiral cutter either up or down
(user preference) and straight edges to control the cut. The bit will
try to jump if you try to free hand it.

Check with your acrylic supplier for solvents. They will help to clear
the edges of imperfections. Just don't touch the edges till the solvents
have completely vapored or you'll leave finger prints.

Good luck

Jim Vrzal
Holiday, Fl.

On Tue, 11 Apr 2006 23:15:12 -0700, "Steve B"
wrote:

I know this is a metalworking newsgroup, but I would assume that plexiglass
is cut with a metal cutter.

How do professionals cut plexiglass? I am going to need to cut some, as
well as rout some of the edges to make them fit into slots.

Would I be better cutting these on a table saw with a special blade, or
using a router blade that has say a narrow width? Maybe even taking more
than one cut, and using a fence as a guide.

I'm going to Google on this, just wanted to know if anyone did this sort of
thing. It has to be a quality finished cut.

Steve


I've just recently replaced the windscreens in my tailwind in 3mm
plexiglass.
commercially the stuff is cut with a carbide tipped circular saw.
I used my table saw with the carbide tipped wood blade that has been
in it now for over 10 years. curved areas I cut with the bandsaw using
a wood blade.
each surface was then edge sanded on a horizontal linisher.
did a beautiful job.

if you ever need to taper the edge I have done this on a piper
cherokee replacement windscreen. the guys used a thicker material then
found it wouldnt fit. an angle grinder with a new metal cutting disk,
blunted off a little by grinding across a brick, does a very near
perfect job if used with a very gentle touch. most areas of the taper
came out transparent off the tool.

the sanding and grinding heats the edge which anneals it.

fresh plexiglass is a pleasure to work with. I think most of the
horror stories come from using old bits that have been laying around
for years.

if you need to drill it use a piece of MDF as a backing piece and dont
let the plexiglass rise off the backing board. a sharp drill with very
gentle feed worked for me in a drill press.

buy a piece of scrap and have a play. it is nothing to be afraid of.
Stealth Pilot

"Mawdeeb" wrote in message
news:XU1%f.6341$wH1.542@trnddc03...

You can run this on the table saw if you have tuned your machine to run
near vibration free and used a fine tooth blade. Carbide with zero rake
like a blade for aluminum and SHARP. If it is the softer plexi the edges
should be near chip free. The harder acrylics tends to micro chip at the
edges.

"Plexiglas" brand IS cast acrylic. The only 'softer' clear plastic glazing
I can think of is polycarbonate -- Lexan. Lexan requires slightly different
cutting techniques, and is ruined - permanently de-polymerized - by almost
any chlorinated solvent.

Plexiglas and other acrylics cut fine with (as you said) a fine-toothed, low
rake carbide blade. Run it slower than for wood to help prevent friction
heating, and keep cutting continuously. Allowing the blade to dwell in the
work will always result in a melt/burn.

Edge touch-up is best done by first using progressive abrasives. This often
will give you as good a finish as you desire. If not, then _soak_ the edge
(only just the edge... don't let the solvent up on the faces) in methylene
chloride for a few moments, then quickly shake off the excess, and allow it
to dry in a dust-free, low humidity environment. It'll come up as clear as
the faces, albeit a little "wavy", like float glass.

LLoyd

"Steve B" wrote in message
news:JV0%f.386$QP4.328@fed1read12...
I know this is a metalworking newsgroup, but I would assume that plexiglass
is cut with a metal cutter.

How do professionals cut plexiglass? I am going to need to cut some, as
well as rout some of the edges to make them fit into slots.

Would I be better cutting these on a table saw with a special blade, or
using a router blade that has say a narrow width? Maybe even taking more
than one cut, and using a fence as a guide.

I'm going to Google on this, just wanted to know if anyone did this sort
of thing. It has to be a quality finished cut.

Steve


I've cut it on my table saw using a fine tooth blade. Needed to cut VERY
slowly with 1/8" plexi to prevent chip out until I realized I finally had my
excuse to make a zero clearance insert and then it was no problem.

Steve.

"Joseph Gwinn" wrote in message
...
| In article JV0%f.386$QP4.328@fed1read12,
| "Steve B" wrote:
|
| I know this is a metalworking newsgroup, but I would assume that
plexiglass
| is cut with a metal cutter.
|
| How do professionals cut plexiglass? I am going to need to cut some, as
| well as route some of the edges to make them fit into slots.
|
| Many people use a carbide-tipped tool to score the sheet, which is then
| snapped off by bending the scored line over an edge. Just like cutting
| glass. This leaves a very clean edge.
|

I've used this technique many times for relatively thin plastic of almost
all types, but never for anything thicker than .100" or so. How would it
work (if at all) for .220" Plexiglas?

Norm

On Wed, 12 Apr 2006 11:24:58 GMT, the renowned "Lloyd E. Sponenburgh"
wrote:


"Mawdeeb" wrote in message
news:XU1%f.6341$wH1.542@trnddc03...

You can run this on the table saw if you have tuned your machine to run
near vibration free and used a fine tooth blade. Carbide with zero rake
like a blade for aluminum and SHARP. If it is the softer plexi the edges
should be near chip free. The harder acrylics tends to micro chip at the
edges.

"Plexiglas" brand IS cast acrylic. The only 'softer' clear plastic glazing
I can think of is polycarbonate -- Lexan. Lexan requires slightly different
cutting techniques, and is ruined - permanently de-polymerized - by almost
any chlorinated solvent.

Plexiglas and other acrylics cut fine with (as you said) a fine-toothed, low
rake carbide blade. Run it slower than for wood to help prevent friction
heating, and keep cutting continuously. Allowing the blade to dwell in the
work will always result in a melt/burn.

Slow as in feed or SFM? Would a fixed-speed (4800 RPM) cheapie Ryobi
saw (USD $170 or something like that at Home Depot) do a really good
job with a nice USD $50 Oldham 100 tooth carbide saw blade? Maybe need
blade stiffeners? I'd like to some small production lots of 3-6mm
thick transparent Plexiglas.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

I've used this technique many times for relatively thin plastic of almost
all types, but never for anything thicker than .100" or so. How would it
work (if at all) for .220" Plexiglas?

Norm

Just fine! I make the score very deep with multiple passes with a home-made
scorer'er.

In article JV0%f.386$QP4.328@fed1read12,
"Steve B" wrote:

I know this is a metalworking newsgroup, but I would assume that plexiglass
is cut with a metal cutter.

How do professionals cut plexiglass? I am going to need to cut some, as
well as route some of the edges to make them fit into slots.

Many people use a carbide-tipped tool to score the sheet, which is then
snapped off by bending the scored line over an edge. Just like cutting
glass. This leaves a very clean edge.

How much must be taken off for the sheet to fit into the slot? I assume
that the slot width isn't a common sheet-goods thickness.


Would I be better cutting these on a table saw with a special blade, or
using a router blade that has say a narrow width? Maybe even taking more
than one cut, and using a fence as a guide.

I'm going to Google on this, just wanted to know if anyone did this sort of
thing. It has to be a quality finished cut.

Wet sanding works very well.

If you need to drill holes, flood cooling with water is very useful.

The intent is to keep the plastic from melting from the friction and
gumming things up.

Joe Gwinn

"Spehro Pefhany" wrote in message
...
On Wed, 12 Apr 2006 11:24:58 GMT, the renowned "Lloyd E. Sponenburgh"
wrote:
Plexiglas and other acrylics cut fine with (as you said) a fine-toothed,
low
rake carbide blade. Run it slower than for wood to help prevent friction
heating,

Slow as in feed or SFM? Would a fixed-speed (4800 RPM) cheapie Ryobi

Slower SFM. If you have just a bit of set on the teeth, rather than a
narrow-kerf blade, you can run pretty fast, but since the material is
cooling the teeth, you have to adjust your feed rate to keep the blade and
plastic cool.

If your teeth have any appreciable set, you'll need to cut a few thou.
large, and abrasively clean up the edges.

LLoyd

"Steve B" wrote in message
news:JV0%f.386$QP4.328@fed1read12...
I know this is a metalworking newsgroup, but I would assume that plexiglass
is cut with a metal cutter.

How do professionals cut plexiglass? I am going to need to cut some, as
well as rout some of the edges to make them fit into slots.

Would I be better cutting these on a table saw with a special blade, or
using a router blade that has say a narrow width? Maybe even taking more
than one cut, and using a fence as a guide.

I'm going to Google on this, just wanted to know if anyone did this sort
of thing. It has to be a quality finished cut.

I've been using a non-ferrous carbide blade from Tenryu or a plastic-rated
blade from Forrest to cut acrylic sheet on a Hammond Trim-O-Saw, which is a
sliding table saw. The saw was used a few decades back by printers to cut
lead slugs. The finish is smooth enough for my purposes but by no means
dead smooth. Square/rectangular pieces come out with opposites parallel to
1 or 2 thou if sawn with reasonable care.

Here's a picture of the swan edge on some 1/4" acrylic sheet cut with 3
different blades - the Tenryu cut the middle one:

http://member.newsguy.com/~mphenry/AcrylicBlocks-1.JPG

Mike


--
NewsGuy.Com 30Gb $9.95 Carry Forward and On Demand Bandwidth

"Steve B" wrote in news:JV0%f.386$QP4.328
@fed1read12:


How do professionals cut plexiglass? I am going to need to cut some, as
well as rout some of the edges to make them fit into slots.


You can get a table saw blade made specifically for acrylic with the proper
tooth shape and set. They are REALLY expensive. An 80-tooth triple-chip
carbide blade is very close, and will produce just about the same results.

The real secret (which I haven't seen mentioned here yet) is to scrape the
edge after sawing, rather than sanding. Take an old hack saw blade and grind
the back edge flat (perpendicular, lengthwise on a belt sander works best).
Clamp your piece vertically, stand at one end, hold the back of the blade
across the work edge with both hands and draw towards you. Think 45-degree
negative-rake lathe tool. When you get the angle, pressure, and speed right,
it'll make sort of a hissing sound and leave a near perfect finish. Expect
to practice a lot if you haven't done this before.

Then you can move on to flame-polishing, buffing, or gluing. Pick only one
though. Particularly don't flame-polish, then glue. The acrylic will craze
on you.

- Bruce

"Lloyd E. Sponenburgh" wrote in message
...

snip------

, albeit a little "wavy", like float glass.

LLoyd

Did I miss the boat? Isn't float glass lacking in waves? That's why the
process is used---because it makes flat glass.

Harold

"Harold and Susan Vordos" wrote in message
...

"Lloyd E. Sponenburgh" wrote in message
...

snip------

, albeit a little "wavy", like float glass.

LLoyd

Did I miss the boat? Isn't float glass lacking in waves? That's why the
process is used---because it makes flat glass.


Yeah.... duh! CAST glass.... like the old 1800's stuff.

LLoyd

"Lloyd E. Sponenburgh" wrote in message
m...

"Harold and Susan Vordos" wrote in message
...

"Lloyd E. Sponenburgh" wrote in message
...

snip------

, albeit a little "wavy", like float glass.

LLoyd

Did I miss the boat? Isn't float glass lacking in waves? That's why
the
process is used---because it makes flat glass.


Yeah.... duh! CAST glass.... like the old 1800's stuff.

LLoyd



Chuckle!

You an old fart like I am, Lloyd?

I find I'm saying things that make little sense with regular frequency. I
don't recall doing that as a young guy---but then I knew everything then.
:-)

Harold

"Harold and Susan Vordos" wrote in message
...
Chuckle!

You an old fart like I am, Lloyd?

I find I'm saying things that make little sense with regular frequency. I
don't recall doing that as a young guy---but then I knew everything then.
:-)

HEY! I resemble that remark!

LLoyd

I find I'm saying things that make little sense with regular frequency.
I
don't recall doing that as a young guy---but then I knew everything then.
:-)

Mark Twain said something like - I have a good memory of my youth about many
things. Most of which never happened.

Steve

It also helps alot to have the removable plate that the blade passes
thru have the very narrowest slot possible Sometimes easy to make a new
one of phenolic or hard wood. Put it in place and run the spinning blade
up from underneath.
An easy way to get a good start on smooth edges is to scrape them. I
like to use a scissor blade held almost vertical. Takes a nice clean
shave