Need a little help, I’ve got a print that requires me to cut some plexiglass sheets and put them in mid print. I’ve been using a Wescott rotary trimmer that I got at Walmart for a while, but the guide is plastic and has started bending. I need to make long straight cuts (12ish inches) in 1.5ish mm thick plexiglass. Anyone have some suggestions on something I can replace that junky little cutter with? I don’t want one of the ones that looks like a pizza cutter since the cuts really do have to be straight.
Larger pieces, a table saw.
Small items you can use something like this with a ruler.
Had to cut Acrylic sheets to strips before, only 8mm thick though…
The scoring, like you would do for glass, works - but only for certain types of acrylic.
Those sheets meant to be more shatter resistant often make it hard to snap the scored parts snap off.
It really helps to have a vice and bit on angle iron with a nice and sharp edge.
Secure the angle iron in the vice with some double sided tape or magnets.
Place the sheet in with the score line flat with the angle irons.
Grab a chopping board or whatever else you have that is sturdy and flat and add some doubled sided tape to it.
Place on the angle iron and then push on the sheet firmly using both hands.
Now you use the board to evenly apply pressure to the sheet until it snaps off.
Don’t use super strong tape on the board if you have to snap multiple strips off as it will lift the cover film off the acrylic sheet.
Something used for photo albums or such that is cleanly removable will do - or use some vice clamps if you can properly place them.
There is another option though - plastic cutting blades for the jigsaw.
I prefer this for anything above 5mm thickness.
Wood and steel ones are easy to find as singles but the ones for plastics usually come in sets with wood and metal saw blades.
Look for the slim but wide ones - about as wide as the normal ones.
The narrow ones are great for small holes and curves but no good for straight cuts.
Place your sheet onto a table and prefer to use a non slip mat or a strip where you clamp things down.
Use a long enough spirit level, sturdy plank of wood or whatever you have to clamp the sheet down - where you need to cut with the jigsaw.
Means the spirit level or such is place so that when you push the jigsaw against it it will cut where you marked the acrylic sheet.
Make sure this is equal on both ends then cut.
Most jigsaws do come with a slide in glider to do just that but it can be tricky to keep those straight and aligned.
Some work well, some not at all.
If your jigsaw has it then please try it first on some scrap or wooden stuff.
The key for getting great cuts is to use a plastic blade, to push firm against the guide and to NOT use a too high speed on the saw to prevent the plastic from melting.
Also do not force the saw through the plastic, let it do it work…
I just use a dremel with a cutting disc. I put blue painter’s tape on the plexiglass, mark my cutting lines on the tape, and cut with the dremel. Always works for me.
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I think @FatherOfTeens is likely working on small pieces of acrylic.
When I work with 8’ x 4’ Acrylic sheets, the go to tool that I use is a tracksaw with a new 40 tooth blade. If I need to finish edges I use a router and flame polishing.
Jigsaws can be a bit of a problem, as you mentioned, the acrylic really needs to be clamped solidly. IMHO using a jigsaw on 1.5mm thick acrylic isn’t a good idea, on thicker sheets, jigsaws work quite well.
FYI If you want to drill acrylic, use a drill bit designed for plastics.
You don’t say what tools you have available, or what your budget for new tools might be.
Lasers cut Acrylic like a hot knife cuts butter. But ones with enough power for this aren’t all that inexpensive. I own a Glowforge 40W Laser and I cut Acrylic with it all the time.
For drilling/milling Acrylic (which I sometimes do on my Taig CNC), I use a “one flute” end mill. Rotary cutting generates heat that can melt the plastic. A single flute cutter has the lowest friction and generates the least amount of heat.
You might consider an Ultrasonic Cutting Knife. I’ve got one of these, too. Basically looks like a heavy-duty Xacto knife blade attached to a big handle. But electronics in the handle vibrate the blade at 40K cycles/second. This lets the knife cut through stuff an Xacto would never have a hope of cutting through. Including sheet Acrylic. I bought it specifically to use to remove stubborn supports from my prints, but have found a bunch of other uses for it.
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Key point = “You don’t say what tools you have available, or what your budget for new tools might be.”
But I think this thread has covered all tool options now 
Sorry all, storms took out the internet for a few days…felt like I was back in the 80s reading books lol. I survived but my kids pretty well thought the world had ended 
I’ve been buying 12"x12" 1.5mm thick plexiglass off of amazon (I know there’s cheaper options but Prime shipping means I don’t have to keep a ton of it on hand.)
I’ve been using one of these, bought from walmart a while back to cut it:
Westcott Carbo Titanium Trimmer
Like I said in my original post, it worked well, but the plastic guide rod has worn down and now the cutter head moves around.
I’m mainly making long straight cuts. Honestly, something similar to what I’ve been using, but maybe a bit more heavy duty would be perfect. I bought a bypass cutter, but it tends to grab the plexiglass and pull it meaning the cuts get all screwed up.
I’ve got a full woodworking workshop, with all the associated tools, but honestly, something like a jigsaw is just overkill and requires me going out to the shop, finding the right blade etc etc. A laser cutter would be awesome, but just not an expense I can justify right now.
I’ve been using just a razor blade since the tool started messing up, but it’s a pain in so far as I need to clamp the ruler, then sit there and draw the blade over it time and again.