Cut thin acryl plate with router?

[nordemoniac]

Hi!
Can I cut acryl with a router? I have a very thin (1mm?) poly styrene (or something) plate which I would like to cut. Is it possible to use a router for this? I have a couple of thin router bits which seems good for the job, I'm just worried it'll all shred!
My jigsaw is cracking the plate.

[Vigo]

I'd think it would work, but would probably work best if you sandwiched it between a couple layers of wood. I think the standard CD Jewel cases are made of 1mm polystyrene plastic, so if you want to test it on some cheap material, that would be a good source.

[apfelanni]

sandwich , clamp it nice so it cant wobble and use a sharp bit . though i havnt routed 1 mm , only 2 mm plexi. 

[Dawgz Rule]

Router will work but don't hesitate. The high speed will melt the plexi.  I had better success with a jigsaw with a fine blade.  I layered the plexi between two pieces of scrap wood and made the cuts.  Worked great.

[TopJimmyCooks]

get a small laminate trimming bit and go fast. 

http://www.woodcraft.com/Product/2008080/6588/Whiteside-SC28B-Standard-Flush-Trim-Router-Bit-14-CL-14-SH-112-OL.aspx

you can drill a 1/4" pilot hole with a sharp bit to start button holes. 

[nordemoniac]

Excellent!

I'll try to find some plates to sandwich it with.

Thanks guys! Maybe I'll finally continue with my upright cabinet this weekend! 

[Franco B]

Router will work but don't hesitate. The high speed will melt the plexi.  I had better success with a jigsaw with a fine blade.  I layered the plexi between two pieces of scrap wood and made the cuts.  Worked great.

A router bit will not melt the acrylic, its impossible for the router bit to rub and build up friction as any material is cut away before it can start to rub.

A router cuts acrylic beautifully. I have plunged cut 1/4"-1/2" bits though materials 2-16mm thick

I have not cut 1mm plastics but you can cut 2mm acrylic fine with no problems. It's much easier to route plastics on a router table rather than freehand.

[Dawgz Rule]

Hate to disagree but I've seen it do just that.  Could have been a number of things that created the "perfect storm" but it is very much possible.  None the less, the easiest thing to do is a test run on a piece of scrap and see what you get.  Better safe than sorry.

Some links that talk about that very thing....

http://www.doityourself.com/stry/how-to-cut-plexiglass-with-a-router
http://www.routerforums.com/general-routing/25558-routing-lexan-plexi.html

[Franco B]

I hate to disagree also but it shouldn't do that.

I must have cut 500+ acrylic panels out and not once has the material melted as its being cut. If there is one thing that I know about, it's routing acrylic.

I even tried to get a piece of acrylic to melt as you described but it's impossible. This is a 1/2" bit I ever so slowly plunged into a piece of 6mm (1/4") acrylic at 25,000RPM and then left for 10 seconds or so. Does it look melted to you?



The only time you are going to get heat issues is if you can't clear the acrylic swarf/shavings and head builds up in the waste. This is nothing to do with the work piece heating up. This is to do with too low feed rates and/or failure to remove the chips with a vac etc. Using a bit with dull edges or the wrong cutting edge geometry may also cause issues.

Acrylic will not melt if you use the right tools and techniques.

[Dawgz Rule]

Appreciate the effort you put forth to prove otherwise but I stand by my observations because......I have seen it. Obviously, others have encountered the same issue or we wouldn't see posts at other sites about the same thing. A simple Google search can confirm that. Although new to this forum, I thought the point of it was to help others which is what I was attempting to do.  

Different plastics have different melting temperatures.  Lexan, for example, has strength but a lower melting point than others.  I don't doubt the fact that you have never seen a router melt acrylic but if someone else has (for whatever reason), I would tend to give that person the benefit of the doubt versus stating that it is "impossible" and dismissing them. Experience obviously is a factor (as is equipment and technique).  Considering the fact that the author hasn't cut 500+ pieces of acrylic, I wouldn't want them to be lured into a false sense of security, believing it is "impossible" to melt acrylic with a router.

What works for some people doesn't work so well for others which is why my last bit of advice was to try it out on a piece of scrap first.  In doing so, they can test their experience and technique before taking the router (or saw) to a piece of acrylic they may have spent hours drilling.

Wish I still had that piece of acrylic so I could post a picture but I do not. However, here is one more link that talks about.......melting acrylic with a router.

http://www.bcae1.com/plexi.htm
 

[Franco B]

Appreciate the effort you put forth to prove otherwise but I stand by my observations because......I have seen it. Obviously, others have encountered the same issue or we wouldn't see posts at other sites about the same thing. A simple Google search can confirm that. Although new to this forum, I thought the point of it was to help others which is what I was attempting to do. 

It's no effort at all, I was in my shop routing at the time.

Others obviously have encountered the same issue as you. We need to find out what was causing the issue for you guys. What kind of routing operation was you doing? Can you give any specifics?

Yes, the point of these forums is to help. I didn't say you wasn't.

Different plastics have different melting temperatures.  Lexan, for example, has strength but a lower melting point than others.  I don't doubt the fact that you have never seen a router melt acrylic but if someone else has (for whatever reason), I would tend to give that person the benefit of the doubt versus stating that it is "impossible" and dismissing them. Experience obviously is a factor (as is equipment and technique).  Considering the fact that the author hasn't cut 500+ pieces of acrylic, I wouldn't want them to be lured into a false sense of security, believing it is "impossible" to melt acrylic with a router.

Lexan (polycarbonate) is tougher than acrylic. It is also not as hard as acrylic meaning less heat is generated due to friction. Both materials can be cut with no problems with the right tools and techniques.

I still think it is pretty much impossible to melt the material at the cutting edge. The cutting edge geometry on router bits is designed to effectively remove material. If material is removed effectively then the heat produced during cutting is transferred to the swarf/chippings and is exhausted.  If the swarf/chippings can not be removed or allowed to build up then you will get problems as I stated in my post above. There is a good informative post in one of the links you have provided that also says this:

Machining is best done with either spiral cutters or O-flutes (see Onsrud Cutter's web site) but the best approach in trms of feeds/speeds is the fastest fed speed you can manage but with a reduced spindle speed (12,000 to 14,000 rpm if you can manage it). this produces a true curl chip rather than just dust and reduces the amount of "churning" (where waste is cut then recut before being expelled from the cutter flute). "Churning" increases the friction causing the waste to heat up and potentially melt-back onto the surface. If at all possible arrange for extraction by a vacuum cleaner (which will also help cool the cutter), use larger diameter cutters if possible (bigger cutters and cutters with larger diameter shanks help dissipate heat) and consider either an air blower or a water spritzer bottle to cool the cut.

Experience does play a part yes, this is why I'm posting and trying to help.

I'm not trying to give anyone a false sense of security. I'm stating that I have done a lot of work and I have never encountered material melting at the cutting edge.

We also don't want to scare anyone off from using one of the best tools for cutting acrylic/plastics. You said that the high speed of routers melt material. We don't want to misinform people.

What works for some people doesn't work so well for others which is why my last bit of advice was to try it out on a piece of scrap first.  In doing so, they can test their experience and technique before taking the router (or saw) to a piece of acrylic they may have spent hours drilling.

Wish I still had that piece of acrylic so I could post a picture but I do not. However, here is one more link that talks about.......melting acrylic with a router.
http://www.bcae1.com/plexi.htm

I completely agree with you. You definitely want to practice any new tools/techniques on scrap material.

Happy routing 

Oh, any before I forget, this is some 1/2" polycarbonate plunged cut with a 1/2" bit 



I should be working on some plastics this afternoon. I'll see if I can get some photo's of churning and see if that's what you were experiencing. If I can get something to use as a tripod I'll see if I can't get some video too 

[Dawgz Rule]

I would appreciate that because my router is one of my favorite tools.  To be able to use it more effectively with acrylic would be a big plus.  You defnitely have me wondering as to how I managed to pull that one off.

[TopJimmyCooks]

I don't know where Nordemoniac is but be careful and investigate/test the material you have on hand. For instance, there's a lexan class product sold at Lowes stores in the eastern US under the Optix brand name that, in the thinner sizes, will melt upon routing and leave a hard white chip or residue that will stick to the workpiece and throw off guide bearings, etc.  Optix is also easy to crack while drilling if the bit is not sharp and the work is not well supported. 

Franco gives good advice- always have a path for the chips to get away from the cutter for best results. Also, test different cutting bits, materials, speeds, etc. to get the best results. 

[Dawgz Rule]

Eastern US....check.   
Lowe's.....check   
Optix brand....check. 
Thinner sizes....check.

 I think we have a winner.  It makes perfect sense to me because that is the only place I have purchased it from and I have always had that problem.  The only way I could get reasonable results was to work quickly.  That is also why I started doing a lot of cuts with a jigsaw and formica blade.  You learn something every day. 

A big thank you.....Now, what to do with that big piece I just purchased....

Anyone else know of brands to avoid?  What about Home Depot?  Those are about the only two places that stock acrylic in my neck of the woods.

[Dawgz Rule]

Also, Franco B....thank you for your effort in trying to determine what the root cause was here.  I was starting to think that I must be pretty inept with my router and table.  In the end it seems to have been the poor choice of material.

[yaksplat]

The key with machining is always more feed and less speed.  Crank it through with the least amount of speed necessary.  I tend to do acrylic at a much lower speed than wood, but i also think that it's important to have as many cutting surfaces as you can have.  Use a 2 flute bit over a single flute.

[TopJimmyCooks]

Dawgz - it's usable, i used it for all the CP tops on switchcade.  I didn't cut it at all by any other method than routing with a bit like the one I posted earlier.  I went as fast as i could, only slowing down at tight corners.  Saws/snips cause cracks to run out like crazy.  to avoid cracking when drilling starter holes for inside cuts, I used a very sharp 1/4" bit and had the Optix on a flat piece of wood, so that when the bit went through it didnt crack.  I also broke or jacked up some pieces while learning the ropes.

It's tougher to work with than that stuff franco's routing, but doable.  The thin thickness helped me because I had a lot of recess mounted sticks, TB, etc, so I wanted to use 3/4" mdf for the top, therefore needing thin lexan. Next time I'd try to get a 1/2" top and 1/4" lexan. 

[Dawgz Rule]

Yup, purchased it for a control panel. I'll still use it for but will follow your techniques.  

I used the thin stuff too because I was trying to hide make a nice smooth surface that would cover up any holes.  So, I used a 1/2" MDF, 1/8" board, and 1/8" Lexan.  The end result was nice because the T-Molding wrapped around all three layers and the surface as smooth as a babies bottom.  The Lexan was the worst part of the project.