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Scratchbuilders!: Armor/AFV
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cutting circles
sgtreef
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Oklahoma, United States
Joined: March 01, 2002
KitMaker: 6,042 posts
Armorama: 4,347 posts
Posted: Tuesday, April 16, 2002 - 05:12 PM UTC
Howdy
How are you guys cutting circles out of plastic sheet,as you can tell I am a little new at circle cutting but I need to cut me some. Was thinking paper punch but would not work on thicker plastic.
thanks
TJ
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Florida, United States
Joined: February 08, 2002
KitMaker: 45 posts
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Posted: Tuesday, April 16, 2002 - 07:24 PM UTC
I bought a decent compass at Michael's Craft store (with a little wheel in between the arms). The wheel keeps the arms at the proper size. I also replaced the pencil lead with a metal point from a cheap school compass (hacked it off with a bolt cutter). Just keep one arm stationary and spin the other until you scribe enough to break away the excess. It also works well for transferring measurements from a drawing to the sheet plastic.
CaptainJack
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Luxembourg, Belgium
Joined: March 17, 2002
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Posted: Tuesday, April 16, 2002 - 07:30 PM UTC
Depending upon the size desired there are several options. First you have the "official" compass cutters. These are marketed by all the major tool companies. Barring this I also stock this item. This allows you to cut maximum circles of about 6-8cm circumfrance. Alternatively, there are what is commonly reffered to as dry wall cutters, destined for cuuting holes in "sheet-rock" material. These usualy go from about 2cm circumfrance right on up to more than you would normally require. Surprise surprise I also stock these. Look around and if you have difficulty let me know.

Cheers

Captain Jack :-)
TJ
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Florida, United States
Joined: February 08, 2002
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Posted: Tuesday, April 16, 2002 - 07:33 PM UTC
Whoops...my reply above works well for large circles. I too have had troubles with punching smaller circles out of thick styrene. One thing I tried was cutting discs from a resin gun barrel that I was replacing with a metal one. For that, you would need a razor saw and small miter box. It worked well also. Now all we need is something for the intermediate sized circles.
ArmouredSprue
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South Australia, Australia
Joined: January 09, 2002
KitMaker: 1,958 posts
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Posted: Tuesday, April 16, 2002 - 07:41 PM UTC
Hi there;
I use the pretty same as CaptainJack said above...
And you could also use drills of various sizes(diameters)
Cheers;
sgtreef
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Oklahoma, United States
Joined: March 01, 2002
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Posted: Wednesday, April 17, 2002 - 07:59 AM UTC
Thanks gents will look into that compass cutter you think Hobby Lobby sells that?
ARENGCA
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Arizona, United States
Joined: February 13, 2002
KitMaker: 382 posts
Armorama: 267 posts
Posted: Wednesday, April 17, 2002 - 08:54 PM UTC
Go to OfficeMax or Office Depot (or similar) and get a pair of drafting dividers or a compass. Most of them come with a extra pointed tip, just put that in instead of the lead. Use the pointed tip to scribe the circle you want, very lightly at first and then more firmly. I can get down to about 1 cm with mine, and I think even smaller is possible. The bonus is that you can still use the dividers for tranferring dimensions, etc.

I haven't had much luck with smaller circles. I am planning on getting a punch-and-die set, but can't give up the bucks just now. I have used brass tubing, sharpened, for marking smaller circles, and usually just cut slices from styrene rods with a miter box and saw. If they come out too thick, run them across a piece of sandpaper until they are the right thickness.

Good luck.
Ranger74
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Tennessee, United States
Joined: April 04, 2002
KitMaker: 1,290 posts
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Posted: Friday, April 19, 2002 - 06:48 AM UTC
I received a hole punch at Christmas, it came from Micro-Mark. It have five or six punches on a wheel, and a press end, looks like the hole punche you may have had in school, but with six choices. The holes vary from approximately 1/64" to about 1/4". It works great for either small holes and/or small disks. Its not as versitle as a punch set, but a lot cheaper

Ranger74
sgtreef
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Oklahoma, United States
Joined: March 01, 2002
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Posted: Friday, April 19, 2002 - 08:28 PM UTC
Going with the brass tubing route for now. Started thinking of my wood days and remember a set of plug cutters to cut plugs out of wood to fill screw holes with I wonder if used at slow speed would this not cut plastic without melting it. The plugs were 3/8" ,1/2" and I think maybe 1/4" does anybody remember these? Also seen a set of paper cutters at Hobby Lobby does anything from 1/8" up to 1/2" about 5 or 6 in set I guess could punch out of .005 plastic and glue together for .010 needed . What you think?
Thanks for some good replies
GeneralFailure
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European Union
Joined: February 15, 2002
KitMaker: 2,289 posts
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Posted: Thursday, May 02, 2002 - 11:42 PM UTC
There's several ways to cut circles.

For large cirlcles, there's several types of compass-cutters, I refer to the above.


It can be ordered from Micro-Mark for 19.95 USD but if you're a bit handy, many student-type compass can be converted to a circle cutter, if they do not already provide a tool to insert pens or pencils (read : "X-acto knives !).


To make small cirlcles / discs, there's several options.

1) a hole-punching device[b] like used to make shoe-string holes or holes in a leather belt.


You can order it from www.micromark.com for 16.95 USD

2) b]Use a punch & die set




Like the picture shows, such set allows you to drive a metal chisel of the exact size (enclosed with the punch and die set) through the plastic sheet into a metal frame that has the exact same diameter. The result is a neat round hole in the plastic, and a nice round plastic disc/cirlcle. Ideal to make washers, rivets, bolts, etc.

Two companies supply Punch & Die sets : Historex (UK) and Waldron (US).

Waldron's sets come in two sizes, one with larger holes than the other.
Historex"s set comes in two sizes, too. One with round holes (overlapping bothe sizes of both Waldron's sets) and one with hexagonal holes.
Though this is not the subject of this posts, i just LOVE the hex nut set. It makes perfect little bolts. If you're a bit of a scratchbuilder, this is a must have, just as much as a round punch & die set.

To my opinion - shared in several scratchbuilders - Historex is the best buy.
You can find more information on http://www.historex-agents.co.uk. Scroll down to the bottom of that page to "Help with Punch and Die Sets".

Both sets are hard to find in retail, but can be ordered through mail or the internet.

To be complete, here's waldron's address, too :

Waldron Model Products
P.O. Box 431
Merlin, OR 97532 TD
US

3) make your own "punch set".
To make holes of diameters between 4 and 8 mm (too large for a punch & die set, too small for a compass), I use short pieces of assorted metal tubes. It works even better if you make the rim a bit thinner (sharper) with a diamond bur. The thinner the cutting edge, the nicer the cut.
You place the piece of polystyrene on a tough yet flexible surface (a nylon cutting mat works excellent) , place the sharpened piece on tube on top, and bang on it with a hammer.
Short pieces of tube work better than long ones. Try pieces of about one inch. That allows you to hold them without crushing your fingers, and it avoids that they bend when you hit them with the hammer, like longer pieces would.

Good luck !
pipesmoker
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Virginia, United States
Joined: January 31, 2002
KitMaker: 649 posts
Armorama: 379 posts
Posted: Thursday, May 02, 2002 - 11:49 PM UTC
Sgtreef,
I don't know where you live, but if you are in the states check either Harbor Freight, Northern Tool, or a craft store that sells leather craft kits. You can find a wheel-type leather punch, as shown in Generalfailure's post. Some of the tool stores also sell individual punches packed in a rollup pouch.
sgtreef
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Oklahoma, United States
Joined: March 01, 2002
KitMaker: 6,042 posts
Armorama: 4,347 posts
Posted: Sunday, May 12, 2002 - 05:04 PM UTC
Thanks for replies I got a set of cutters for paper will cut real thin plastic sheet. For bigger have to use the brass tubing punches.
sgtreef
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Oklahoma, United States
Joined: March 01, 2002
KitMaker: 6,042 posts
Armorama: 4,347 posts
Posted: Sunday, May 12, 2002 - 05:07 PM UTC

Quoted Text

There's several ways to cut circles.

For large cirlcles, there's several types of compass-cutters, I refer to the above.


It can be ordered from Micro-Mark for 19.95 USD but if you're a bit handy, many student-type compass can be converted to a circle cutter, if they do not already provide a tool to insert pens or pencils (read : "X-acto knives !).


To make small cirlcles / discs, there's several options.

1) a hole-punching device[b] like used to make shoe-string holes or holes in a leather belt.


You can order it from www.micromark.com for 16.95 USD

2) b]Use a punch & die set




Like the picture shows, such set allows you to drive a metal chisel of the exact size (enclosed with the punch and die set) through the plastic sheet into a metal frame that has the exact same diameter. The result is a neat round hole in the plastic, and a nice round plastic disc/cirlcle. Ideal to make washers, rivets, bolts, etc.

Two companies supply Punch & Die sets : Historex (UK) and Waldron (US).

Waldron's sets come in two sizes, one with larger holes than the other.
Historex"s set comes in two sizes, too. One with round holes (overlapping bothe sizes of both Waldron's sets) and one with hexagonal holes.
Though this is not the subject of this posts, i just LOVE the hex nut set. It makes perfect little bolts. If you're a bit of a scratchbuilder, this is a must have, just as much as a round punch & die set.

To my opinion - shared in several scratchbuilders - Historex is the best buy.
You can find more information on http://www.historex-agents.co.uk. Scroll down to the bottom of that page to "Help with Punch and Die Sets".

Both sets are hard to find in retail, but can be ordered through mail or the internet.

To be complete, here's waldron's address, too :

Waldron Model Products
P.O. Box 431
Merlin, OR 97532 TD
US

3) make your own "punch set".
To make holes of diameters between 4 and 8 mm (too large for a punch & die set, too small for a compass), I use short pieces of assorted metal tubes. It works even better if you make the rim a bit thinner (sharper) with a diamond bur. The thinner the cutting edge, the nicer the cut.
You place the piece of polystyrene on a tough yet flexible surface (a nylon cutting mat works excellent) , place the sharpened piece on tube on top, and bang on it with a hammer.
Short pieces of tube work better than long ones. Try pieces of about one inch. That allows you to hold them without crushing your fingers, and it avoids that they bend when you hit them with the hammer, like longer pieces would.

Good luck !



Thanks General that is the way to go read other post I found a set of hole punches for paper and will use the tubes method for larger.
CaptainJack
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Luxembourg, Belgium
Joined: March 17, 2002
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Posted: Sunday, May 12, 2002 - 05:22 PM UTC
:-) I also carry and havie in stock a new line of P&D. These are sturdier than any of the other sets I have used, and have a mor sloid support. I'll try to paste photos this week. There is a set of Hex, and a set of round. They retail at 70.00 Euros each. I'm not doing door to door here just informing. I also tried the Reheat type and they are very nice, but the smaller, mico sizes break easily. They are also very difficult to get a hold of! As usual the crew of the good ship Armorama.com receive 10% kudps.

Jack the merchant boy :-)
sgtreef
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Oklahoma, United States
Joined: March 01, 2002
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Posted: Friday, May 17, 2002 - 05:18 AM UTC

Quoted Text

:-) I also carry and havie in stock a new line of P&D. These are sturdier than any of the other sets I have used, and have a mor sloid support. I'll try to paste photos this week. There is a set of Hex, and a set of round. They retail at 70.00 Euros each. I'm not doing door to door here just informing. I also tried the Reheat type and they are very nice, but the smaller, mico sizes break easily. They are also very difficult to get a hold of! As usual the crow of the good ship Armorama.com receive 10% kudps.

Jack the merchant boy :-)



Send up some pics CaptJack and lets have a look.
CaptainJack
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Luxembourg, Belgium
Joined: March 17, 2002
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Posted: Friday, May 17, 2002 - 11:50 PM UTC
Will do. I'll have to take some photos first. Unfortunately I'm a computer dud and can't paste, so I'll probably post them in the review or new releases sectiob.

Jack is back on track!