Cut lexan better with hacksaw

VEX Robotics Competition Discussion VRC
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I saw people suggesting different tools for cutting lexan in this post, but I didn’t see anyone talking about the methodology for better results.

Is there necessarily a correct way to use hacksaw on a piece of lexan?
Is there a way that you came to favor over the years?
Are there any tips that you have regarding the operation of a hacksaw?

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We always use a band saw, or in a pinch a dremel

Just make sure your blade is sharp, and that you let the blade do the cutting, otherwise you’ll go through those hacksaw blades really quick

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I’d like to use a band saw or a dremel, if I had one.
As it stands, though, I don’t have either.

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Lexan/plexi is best cut with power tools
What you could do is buy smaller sections and carefully hand cut them
An angle grinder might be a way to do it but i think that would melt the plexi from it spinning so fast

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dremels are useful for a lot of stuff, but i dont recommend cutting lexan with them. yes, they can do it, but they typically melt the plastic and it will ruin your cutoff blade. most dremels run between 5-35k rpm so there’s a ton of heat generated from all the friction. if you want to cut lexan i highly recommend either getting a pair of aviation snips (basically scissors used to cut sheet metal like aluminum and steel, and are more than strong enough to cut plastic), a scroll saw, or a bandsaw

(note that a bandsaw or a scroll saw can be used for tons of other applications outside of vex; i highly recommend checking out the bandsaw im linking in particular. it’s served me very well. i cut grade 5 titanium with it pretty regularly, and it’s more than good enough for plastic alu and steels )

here’s some links to check out-
Some snips:McMaster-Carr

An amazing bandsaw - https://www.amazon.com/WEN-3970-Metal-Cutting-Band-Stand/dp/B01CHP7EFY/ref=mp_s_a_1_55?dchild=1&keywords=wen+bandsaw&qid=1600347696&sr=8-55

Some scroll saws (I’ve never used one but i’ve heard great things about these models)-

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dont do this… from experience this is a terrible idea

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I figured
Aviation snips/tin snips are a good thing to have around anyway thats a terrific idea
and a file/sandpaper, plexi edges can be pretty rough after you cut them

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belt sander is awesome i recommend one of those too. dremel and a vice can work really well for sanding operations on lexan if you go slow enough but i don’t recommend it for cutting it. even when sanding it’ll melt the lexan a little, but if you go gentle it can come out pretty clean

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Have you ever considered cutting it with a box cutter/Exacto knife?

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I have tried that before and all it tends to do is score the plexi
Great for custom designs on it
not so great for cutting
alternatively you could drill a ton of holes along the edge you want to cut

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If you score it enough then bend the plexi it normally breaks, its my favorite way to cut plexi now because of how accurate i can make the cuts (also quick side note I use polycarbonate not plexi so idk about the differences between them)

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This might actually be something that I can try. I’ll have to see if I have any box cutters lying around, but I’m pretty sure that I’ll at least be able to buy it somewhere around. Thanks for the sugestion.

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Wowl, I love this thread. An EXACT question

and then posts about everything but how to cut with a hacksaw. Nice!!

@chri5 To cut with a hacksaw

  1. Get a blade that is at least 24 teeth per inch. (If you go for 32 TPI, that will also be the perfect blade for metal cutting.)
  2. Place a strip of masking tape on where you want the line to be. This gives you a surface to mark the line and it helps reduce chipping.
  3. Mount the lexan in a vise or some other device to hold it tightly. You want clamping near where you cut, you don’t want the sheet flopping around as you cut into it.
  4. Cut with slow, even strokes, try to use 4-5" of the blade. Doing rapid short strokes heats that section of the blade and starts the melty process, that leads to binding of the saw and sloppy edges.
  5. If it’s a long cut you may need to reposition the sheet in the vise.
  6. Once the cut is done, run a fine tooth file down the edge to smooth it.
  7. Peel the tape and you are done!

Good luck on your cuts!

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massive thanks

I didn’t manage to find a box cutter during the past 30 minutes, so I was about to give up.

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well i will now give this another shot. I did not think to bend it. Now that seems obvious

thanks man

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I would just use like really big steel scissors that are made to cut things like that.

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Snips are actually quite good at many things, can confirm.

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I recommend a CNC router, making a good G code, excellent cuts and very precise shapes can be designed. My machine also machines aluminum and soft metals. Although I have not cut polycarbonate sheets with it, good results are achieved. If anyone is interested, they can write to me personally.

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I do have a CNC router in my school, it’s just that my coach seems to be against the idea of using it to cut polycarbonates.