Cutting large circles and rings

**rmks2000** · #1 06-05-2010, 07:22 AM

At the risk of bringing up a duplicate thread, I'm posting this question. I have searched the forum but have yet to find my answer. It is probably somewhere, but I figure that this is the quickest way, and maybe spark a tutorial from someone.

OK, some quick background: I've got tons of great models and although my skillset is a little above the beginner level, I won't build them until my skills improve. With that in mind, I've got some armor models that I would love to build but need to know how to cut circles and rings consistently, such as tank wheels. In the past, I've cut them using knives (as per Golden Bear's techniques), scissors, or an Olfa cutting compass, but the consistency isn't there. Any ideas, or is it just a lot more practice?

Bob

bagpiper · #2 06-05-2010, 07:33 AM

Yogi put a tip in one of the threads about using a drill bit template. I was hunting for the thread but can't find it. But it looks something like this:

I know you can get these a lot smaller and both in metric and imperial sizes.

Not sure if this helps or not mate but is another option to consider. I understand fully about the lack of consistency when trying to cut circles though. Good luck and I hope you get some of the masters chip in with some words of wisdom.

Cheers
Jim

**airdave** · #3 06-05-2010, 07:51 AM

I find circles relatively easy with my small pointed scissors.
The smaller the better for smooth control when curving.

I have a drill bit template...
I suggest you buy a good one, they come in steel! so they won't cut or wear out.

Unfortunately, I have only ever found a drill bit template that goes up to about 1/2"...so not much good for larger holes.

I do have a larger Circle template in my art kit, but it is nylon/plastic...so it will get damaged by a knife.

I have been looking in the "scrapbooking" section of Walmart, and a couple of other stores.
There are a couple of interesting circle cutting devices out now.
Both around the $30 range but both have devices and attachments for cutting circles from about 1/4" up to about 8".

Only drawback is the need to purchase specific knife attachments that fit the units.

But at some point, I think I may try one.

**rmks2000** · #4 06-05-2010, 07:59 AM

Dave

I'll have to check out the cutting circles at Walmart. I think Billy L. uses one but it is really expensive. After seeing Michal's Japanes tank (POTW), it amazed me how he was able to cut so many wheels so quickly and consistently. I asked him on his build thread, but he hasn't responded yet. I guess I could send a PM.

**Thomas Meek** · #5 06-05-2010, 08:42 AM

rmks2000;

I am no "master," and any "words of wisdom" I may have are purely accidental, but I am never at a loss for free advice:

Cutting accurate circles is a perennial problem in this craft. There are many devices to help make it easier, and I have tried most of them. For circles up to about 1/4 inch (5mm) there are various punches available that work quite well if you can get them aligned with the printed circle on the pattern.

For larger circles, there are compasses, circle guides and lots of other gizmos. Various builders swear by one or another of these, but they all require a lot of practice to get really good consistent results. Compasses are difficult to get sized and centered precisely, while circle guides are very tricky to use as well.

After trying all the gizmos I have been able to find or invent (and spending a lot of money doing so) I am convinced that the best way to cut circles is freehand, either with scissors or knife. It takes a lot of practice, but once your hands learn how to do it they will remember.

You could print a sheet of circles and use it for practice without destroying any precious patterns. Choose your weapon and go to it. Nobody will tell you it is easy, but it does get better.

**rmks2000** · #6 06-05-2010, 08:52 AM

Thanks guys. I guess it's like the old Carnegie Hall joke - practice, practice, practice!

**B-Manic** · #7 06-05-2010, 08:54 AM

I agree with Thomas. Cutting large circles is best done by hand. It requires a little practice but the results are best. Make small continuous cuts without removing the blade from the cardstock. Turn the cardstock often to maintain the proper cutting angle and remember a circle is just a series of angled short lines (calculus 101).

~ Douglas

**looker** · #8 06-05-2010, 09:24 AM

Quote:

I've cut them using knives (as per Golden Bear's techniques), scissors, or an Olfa cutting compass, but the consistency isn't there.

The key to consistency when using any sort of single blade device (knife freehand or circle cutter) on paper or card is to be gentle and gradual. Only cut part way through over a small arc of the circle before lifting the blade out of contact with the work. That saves the blade from starting to wander. Adjust your position and grip, and be prepard to take the time to step round the circle more than once, several times in thick card.

**B-Manic** · #9 06-05-2010, 09:58 AM

all these circles were cut by hand

You can see how large they are here

I cut one set per side. They range in thickness from one sheet of cardstock to over 1mm. The point others have made about having to make several passes around the circumference is very important. It took me several hours to cut out both sets.

I think the results speak for themselves.

**mbauer** · #10 06-05-2010, 11:43 AM

B-Manic,
Very im pressive build! Great photos showing outstanding details!

RMKS2000,

Other templates to look for would be in the drafting supplies. Lots of circle sizes, if you can find them. Since AutoCAD and other drafting programs have made manual drafting obsolete, to find them you will need to look up drafting supplies in the yellow pages. Offic e Max and Depot stores used to carry stuf, but not any more here in ALaska.

Mike