| Project by Peter O | posted 353 days ago | 681 views | 2 times favorited | 18 comments | ![]() |
I find that I draw a lot of circles and arcs in the shop. Every time I need a circle, I scurry around looking for the can or jar or bottle or washer or something that is just the right diameter. Usually, I settle for something close that, if I angle my pencil just right, will allow me to describe something representing a circle if you stand back far enough. Well, I’d had enough! I wanted something better.
I mounted the router on the trammel and put in a ¼” spiral bit. I carefully set up the trammel for each radius and cut the series of arcs. With ¼” slots I can put my pencil against either the inside or outside edge of a slot and get two radii from each slot. Now I can draw arcs on every 1/8” increment between 7/8” radius and 6” radius. I flip the template around the centerpoint to get a full circle.
I had planned to use forsner bits to create smaller radius holes in the middle of the template, but it is much harder to find the center of a hole than the center of an arc, so now I’m not sure about the holes. My trammel slipped on the 5” radius arc resulting in much shouting and stomping around. After the 3” arc, the narrow strips of plastic were begining to show some flex, so I made quarter-circles the rest of the way out.
The material is 1/8” lexan and the template is approximately 12” wide x 18” long. Sorry I didn’t take the photo with a dollar bill – I don’t remember when I last saw one of those!
-- Coffee is best with a fine layer of sawdust on top. -- http://www.north40custom.com
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18 comments so far
rikkor
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8574 posts in 412 days
posted 353 days ago
What a good idea. Thanks.
-- Maplewood, MN
Bob #2
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2082 posts in 559 days
posted 353 days ago
Very cool idea Peter and easy to store too.
Regards
Bob
-- A mind, like a home, is furnished by its owner
toyguy
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487 posts in 375 days
posted 353 days ago
Just what I need…..running out of cans and stuff…...
-- Brian's Table Top Toys http://home.mountaincable.net/~bgraham/
rpmurphy509
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292 posts in 392 days
posted 353 days ago
Excellent idea!
-- Still learning everything
bryano
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541 posts in 471 days
posted 353 days ago
nice jig Peter. I could use one of these myself.
-- bryano
gbvinc
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374 posts in 484 days
posted 353 days ago
Excellent idea Peter! Mass producing them yet?
Jeff
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968 posts in 631 days
posted 353 days ago
Very useful. Favorited!
-- Jeff, St. Paul, MN
Douglas Bordner
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2735 posts in 601 days
posted 353 days ago
Looks like something Starrett would make. Really nice.
-- "Bordnerizing" perfectly good lumber for over a decade.
jembo
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104 posts in 551 days
posted 353 days ago
You should be running to put a patent on this, thats not a joke, run…......
-- James - Geneva, Switzerland
dennis mitchell
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3048 posts in 852 days
posted 353 days ago
like a drafting template…back when people drafted with pencils. Cool
-- http://www.woodsongsfurniture.com
Dadoo
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1557 posts in 528 days
posted 353 days ago
I do that “shouting and stomping around” dance once in awhile too.
You should be able to fill in the 5” mistake area with epoxy and reroute it.
Question is, does this jig suit your needs?
-- Bob Vila would be so proud of you!
mrtrim
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1548 posts in 418 days
posted 353 days ago
exellent peter i think most everyone would need one now and then
Chip
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1058 posts in 630 days
posted 353 days ago
Great idea Peter. Thanks.
-- Better to say nothing and be thought the fool... then to speak and erase all doubt.
Thos. Angle
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3430 posts in 500 days
posted 353 days ago
That’s nifty, Peter.
-- Thos. Angle, Owyhee Design, Oregon
cajunpen
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5345 posts in 603 days
posted 352 days ago
Pretty clever Peter. That’s using the old noggin.
-- Bill - "Suit yourself and let the rest be pleased." http://www.cajunpen.com/
Karson
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13640 posts in 938 days
posted 352 days ago
Great Peter.
After you went to quarter slots, you could change to the next 1/8” on the next quarter, so that you would have a smaller template and more Lexan for another jig.
-- Karson Southern Delaware karson_morrison@bigfoot.com
Peter O
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695 posts in 412 days
posted 352 days ago
Hey, guys, thanks for all the great comments!
Dennis – yeah this was based on the “hole/circle template” that I used when I was doing manual drafting some years back. I was going to buy one, but they are too small. So I scaled it up.
Jembo – great idea, but like Dennis says, a similar template has been around for drafting for years. No matter how good the idea, tools are pretty hard to patent – especially when they are something like a series of slots in plastic! And the cost of aquiring a patent can drive the cost of the product up enough that it will convince potential buyers to just build it themselves in ther shop!
Dadoo – I haven’t decided whether to fix it or make another one (I’m a bit of a perfectionist). But so far it does suit my needs very well!
It took me over an hour to make this thing, but if I set up for one more, I could just as easily make 10 more. Does anybody want one if I’m making them?
-- Coffee is best with a fine layer of sawdust on top. -- http://www.north40custom.com
gbvinc
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374 posts in 484 days
posted 352 days ago
You bet. If you get enough interest, throw one on the stack for me.