Author Topic: Cutting plastic  (Read 8397 times)

amessier

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Cutting plastic
« on: October 25, 2006, 04:02:25 AM »
What is the best way to cut plastic

I have been using this and sawing thru
http://www.x-actoblades.com/x15.gif

Then the standard
http://www.x-actoblades.com/x2.gif
to shave the plastic down to a nice smooth edge.


Is there a better way?

zerobxu

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Cutting plastic
« Reply #1 on: October 25, 2006, 05:25:22 AM »
It's going to depend on exactly what plastic you're talking about. Are you talking about cutting the plastic from models? Are you talking about cutting styrene?

Please be as descriptive as possible when asking questions.

For cleaning up a part of a model, yeah, you can use an Xacto (unless you have access to dental tools). For cutting small-diameter styrene pieces (rods, pipes, tubes, angles), I also usually use the Xacto. For larger diameter styrene, I use a hobby miter box. For sheet styrene, I use a large pair of sharp scissors most of the time, but will occasionally use a combination of scribing tool and Xacto knife as well.

If you're talking about cutting a hole in a model surface, then I usually use a pin-vise to drill it out--or drill out the corners and the cut the "lines" out by starting with a scribing tool and then following that with an Xacto.

Of course, other people use other techniques. If you can elaborate on your question, perhaps you'll garner other answers.
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amessier

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Cutting plastic
« Reply #2 on: October 25, 2006, 05:30:25 AM »
Sorry for not explain what I was trying to cut.  I am trying to cut a OOB gundam model chest in half so I can add some styrene to it.  And I am having a hard time with all the sawing and figured there had to be an easier way.

 I have a dremel but that could cause some serious problems.

pu_rplecow

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Cutting plastic
« Reply #3 on: October 25, 2006, 07:48:44 AM »
I'm using this sucker now



It makes very quick work of thick blocks. You'll lose about an mm of plastic or even more. So you'll have to pad it back after you cut. Thats a gunze paint bottle that happened to be there so you can compare the size. Its from xacto too... But you'll have to get a handle if you want the extra comfort. Not important for me.

I highly recommend it if you're doing sawing in future. Takes the pain out of it. Take note you'll have to keep it properly because it can rust a little.
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amessier

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Cutting plastic
« Reply #4 on: October 25, 2006, 08:13:25 AM »
pu_rplecow: Wow pretty much you use a hacksaw for the job.  Im assuming you have a vise you mount the part in?

Major Blah

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Cutting plastic
« Reply #5 on: October 25, 2006, 08:37:49 AM »
Quote from: "amessier"
I have a dremel but that could cause some serious problems.


Actually if you have the disk piece for your dremel it could be used as a cutter.  The problem is that it eats quite a bit of plastic and created some melted crap at the edge, also the cut has a circular profite which is quite annoying (can be finished off with some other tools).

gamerabaenre

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Cutting plastic
« Reply #6 on: October 25, 2006, 08:44:39 AM »
The best method with the most control is to use what pu_rplecow posted.  Exacto makes those hack saw type attachments for exacto handles as well.  I have two, one that is a thinner saw blade and one very similar to the one pictured above.  You have more control since you have a nice straight edge to run against when you are cutting.

Most bandai plastic pieces are hollow so you can cut easier by moving the position of the parts while cutting.  For example, slicing into a chest piece, you can rotate it and ensure that your cut is straight.

Straight edged exacto blades like that #11 are really not conducive to saw type cutting - the pressure applied to try getting that type of blade to do the job of a saw will only increase the risk of serious injury from improper use of the blade.

Dremels are far too powerful to use as a sawing tool on bandai plastic.  The amount of heat generated will leave you with a gooey mess.  Dremel saws are best left to metals and possibly resin.

amessier

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Cutting plastic
« Reply #7 on: October 25, 2006, 10:56:01 AM »
Thank you all.

bhop73

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Cutting plastic
« Reply #8 on: October 25, 2006, 11:12:11 AM »
Something i've learned from car modelers is to use regular sewing thread.  Scribe the path you want to cut with a blade or scribing tool and then take the thread and use it to 'saw' the part.  It'll give you a nice clean cut.

Here's some text I took from a thread on automotiveforums: (these are not my words)

There's a few tricks that I found:
1. It takes about 30-60 seconds of sawing the thread back and forth before it really starts to cut the plastic. Just keep sawing until the thread heats up from friction and eventually it will start cutting through the plastic.
2. You have to be careful not to put too much pressure on the thread because it will break. I broke the thread about 3 or 4 times before I got the hang of how much pressure I could apply.
3. I used a 100% cotton quilting thread, which is a bit heavier than plain sewing thread you might find around the house. It didn't break nearly as much.

There's also this way.
http://www.briansmodelcars.com/tutorials/tutorial.asp?TutorialID=4&CurPage=1

RoboSmurf

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Cutting plastic
« Reply #9 on: December 04, 2006, 05:12:02 PM »
I use one of these from micromark. Its great for cutting sheet styrene. Plus I have the saw as above with a nice miter block and a selection of small squares and engineers rules.

Cutting Guide

Oliphont

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Cutting plastic
« Reply #10 on: December 04, 2006, 06:48:02 PM »
I havent had alot of experience with cutting a chest, but i have used the tools im going to mention extensively, and watched my father use them when i was younger (he has been an avid R/C Modeler for over 20 years).

Id prolly suggest getting a thin saw like what purplecow showed, my father had one come in one of his xacto sets, and then use a miter box. Its really handy for straight even cuts. Id recommend like said above to scribe the line where you are going to cut first with either an xacto knife, or very long light passes with the xacto saw (?name?).

It will most likely get rid of alot of the plastic on the chest, and some plastic residue will most likely stay on, so you'd have to deal with filling that back in, and sanding a bit.

hope this helps

Wolfsburg

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Re: Cutting plastic
« Reply #11 on: August 01, 2007, 10:23:29 PM »
Hello

I'm not here to hi-jack this thread but I'd rather not create another topic about cutting so here goes. (following rules.. I think)

On previous models I've failed I used toe nail clippers to snip them from their plastic moldings. Yet I see some people using heavy duty cutters and saws. I'm rather new but this confuses me. Are higher grade model plastics harder to cut?

And what is an appropriate grit sanding paper to use when sanding down those nubs on the models?

Sorry for bumping this thread to the top.
I am rather new. Having built models at age 14 I did not have the patience. But now I believe I'm prepared to start this hobby up since I'm much more prepared... or am i?

clee-cm

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Re: Cutting plastic
« Reply #12 on: August 01, 2007, 11:12:47 PM »
I am one of those plastic modelers who use a heavy duty cutters or a hand saw of some kind to cut my model parts from the sprue tree.

There are several reasons why I do not use a toe nail clipper, the first one is that I like leaving part of the sprue on the part after I remove it from the plastic tree, a large cutter requires less effort to cut through the plastic. There can be up to several different types of plastic that are used in a kit, some harder than others, for example, the Bandai MG Sazabi has several different types of plastic in the kit so a normal set of wire cutters will easily cut through the plastic.

With the right set of cutters, you can cut the sprue from the model clean off, the nail clipper's cutting blade is concave, I find it hard to work with a nail clipper for this reason. If you are going to build 1/100 scale kits and larger, the sprue that attaches all of the parts can get very thick so a set of large cutters and a hand saw is a must for cutting plastic.

The nub on the parts can be removed with 400 and 220 grit sand paper.

* I deliberately left out the X-Acto knife and blades, but I do use them...
« Last Edit: August 02, 2007, 02:09:49 PM by clee-cm »
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DrDazzle

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Re: Cutting plastic
« Reply #13 on: August 02, 2007, 09:59:55 AM »
I guess I will throw in what I use.

Tubing(Metals and Plastics) - K&S Tubing Cutter
Styrene Sheets - XActo or similar blade (Technically Excel for me). The trick is not to cut through the sheet but to score and snap it, unless it is super thin.
Parts(From runners) - Excel sprue cutters (most hobby tool companies make these of course)
Parts(Splitting) - XActo Saw (They usually come with two saw types, one fine and one coarse. Generally it is also easier to cut in one direction, and not back and forth).

Hope this helps.