# Alternate method for cutting plastic?



## ledlurker (May 20, 2004)

I am tired of generating dust when I cut into plastic parts to mod flashlights. I have seen hotwire methods to cut styofoam and the like. It there a commercial hot wire cutter available that would do the job. If not, any ideas on building one?


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## Atomic6 (May 20, 2004)

First:The fumes are deadly. secondly, the hotwire is for low density styrofoams. The higher density plastics will wire-but at the expense of sloppy cuts and lots of toxic fumes. They do make thermal knives. Google on "thermal Knife"


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## McGizmo (May 20, 2004)

You can also get plastic welding and cutting tips for the Weller soldering guns. For more bucks, there are some specialized heat guns that have tips that allow for plastic welding with plastic rod. I picked one of these up to use for some SMD experiments and work so I haven't tried it on the welding aspect.

BTW, I moved this thread; hope you don't mind. /ubbthreads/images/graemlins/blush.gif


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## idleprocess (May 20, 2004)

I imagine that using a hotwire cutter on high-density plastics could signifigantly deform the piece, since plastics tend to have relatively low thermal dimensional stability - or alter the chemistry in the vicinity of the cut in unpredictable and unwanted ways.


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## ledlurker (May 20, 2004)

I was hoping to find something that could cut cleanly through a Mag reflector and switch assembly.

I guess I will look around for a mini-lathe


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## gadget_lover (May 20, 2004)

The lowly dremel tool has a thin metal saw blade available. I just used one today to trim the "cam" (tail???) from a D cell mag reflector. I cheated by mounting the reflector in the chuck of my lathe to turn it while the spinning saw blade did its thing. That made sure the cut was nice and even.

Daniel


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## bobisculous (May 20, 2004)

If you have too much money, like 10 grand, you can buy a home laser cutting kit /ubbthreads/images/graemlins/naughty.gif. Versa Laser makes quite the kewl home computerized laser cutters but they start at 10 grand and only go up from there. But they can do darn near everything. Check it out, Versa Laser 
Cameron


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## idleprocess (May 21, 2004)

Epilog makes laser engravers that can cut plastic parts easily.

Just, uh, be careful cutting reflectors - 50 watts of IR laser power isn't trivial.


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## Echo63 (May 22, 2004)

the hotwire cutter is easy to make - just a length of nichrome wire in a frame - run 12v through it and adjust the current (use a current adjustable Power supply) to get the temp you want.
the guys above are right though - it wouldnt really work on a mag reflector - they work best on styrofoam, Ethafoam etc.
(great for cutting wing cores for model aircraft)


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## Doug Owen (May 22, 2004)

[ QUOTE ]
*led-lurker said:*
I was hoping to find something that could cut cleanly through a Mag reflector and switch assembly.



[/ QUOTE ]

The nice X-acto folks make two "Razor saws", fine tooth back saws, the wider one (deeper cut) should do the job in two or at most three passes. A minute or so each. Check it out.

Doug Owen


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## McGizmo (May 22, 2004)

As Doug has suggested some of the saws are a good idea. There are jewlers saws that look like a small coping (sp) saw and you can get blades that have a kurf that is really small!


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## Atomic6 (May 23, 2004)

Come to think of it-A dremel tool and one of the cut-off wheels makes a decent plastic melter-...I mean cutter. I just used one of these today to cut the battery case off of a Cauterizing wand to replace the power pack.


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## milkyspit (May 26, 2004)

I usually use my Dremel to cut the cams off Mag reflectors. Sometimes I use the tiny spinning saw blade, and other times use one of the abrasive cutoff wheels. The secret with the abrasive wheels for NOT melting the plastic (at least not much) is to run at a fairly low RPM and make a series of quick, short cuts instead of cutting continuously.

Hacksaw works too. /ubbthreads/images/graemlins/naughty.gif


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## andrewwynn (May 31, 2004)

Dremel makes a new cutting wheel for cutting and shaping non-metal... i.e. wood and plastic... i fashioned some plastic windows for a pinewood derby car yesterday and it didn't make any dust i can recall... It does melt the plastic a bit but i was cutting perhaps a little too fast... the 'melted' part sorta ends up stuck after the cut but rubs off and the cut is extremely clean.

The cutting wheel is on the pricey side for dremel... about $14-15.

I just bought the new dremel saw-kit... has a 1 1/4 inch saw blade and an off-set so you can cut vertical cuts up to 1/4 inch deep... haven't tried it yet but it should do a pretty good job on plastics long as you only want to cut 1/4 inch or less away from the bottom of the saw.

-awr


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## ledlurker (Jun 15, 2004)

Ok, thanks, forgot about this thread with everything I have in the fire


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