Radius gauges?

[Scratch]

I’m looking for ideas on what you guys use for radius gauges. When building stuff, I often need to trace a circle of some sort for some reason. I look around and try paint cans, buckets, cups etc. trying to find the right one. Other than just cutting a bunch of donuts (which would have two sizes on each one) does anyone here have a good solution or product they’ve found, like something adjustable maybe?

I’d like something from about 1/2” to 10”

[djreiswig]

Compass?

[ROKCRLER]

Scratch, have you seen this? Slight modifications and you have whatever circle you want.
https://www.swagoffroad.com/products/sw ... cle-cutter.
I bought one back before i got my table.

[weldguy]

I 2nd the compass. Bought a large one on Amazon for around $15 and I find it very helpful. I too used to try and locate different diameter paint cans, rolls of tape, etc.

[djreiswig]

Screenshot_20230809-214507.png

[weldguy]

Great idea above from djreiswig

[adbuch]

Scratch, have you seen this? Slight modifications and you have whatever circle you want.
https://www.swagoffroad.com/products/sw ... cle-cutter.
I bought one back before i got my table.

Thanks Mo! I also bought one from Swag back before I had my table, and still haven't used it. But I do sometimes use one of several compasses I have to draw circles or circular segments onto poster board or cardboard to make templates.

David

[adbuch]

Screenshot_20230809-214507.png

Djreiswig - that is a nice looking diy compass you have there! I have something similar store bought. I don't remember where I got it, but it looks similar to this one.

David

large compass.jpg

[adbuch]

I 2nd the compass. Bought a large one on Amazon for around $15 and I find it very helpful. I too used to try and locate different diameter paint cans, rolls of tape, etc.

Weldguy - in the past I too have used paint cans, tape rolls, welding bottle caps, weigh lifting weights (the round ones with a hole in the middle), or anything else I could find laying around the shop that was close to the size I needed. Sometimes I would cheat a little bit by moving the can, etc. to make a slightly larger circle. Another easy, pretty quick, and accurate method would be to use a sharpie/pencil attachment on the cnc plasma table and simply draw the size (or sizes) of circles you need on cardboard, paper, etc.

David

[adbuch]

I could see where having a bunch of pre-cut "donuts" might be handy as well. Something like these plywood donuts, or maybe cut some similar from sheet metal on the cnc. I might also be tempted to cut some from 1/8" Masonite (hardboard) on my cnc router.

David

donuts.jpg

[adbuch]

Or maybe something like this cut from 14 ga. or thicker.
David

circle template image.jpg

circle template.dxf

[Scratch]

Thanks all, a bunch of great ideas you have. If anyone has any others please post them!

[acourtjester]

David that drawing is slick, you being a tool manufacturer start marketing them Really only need a semi circle.

[AREA]

Great ideas here. Gotta get me a big compass.

[Joe Jones]

Compass?

Yep! OLD SCHOOL!

Joe

[adbuch]

David that drawing is slick, you being a tool manufacturer start marketing them Really only need a semi circle.

Thanks Tom! I would be more comfortable working with the complete circle so that once I have the center established and aligned, I don't chance any misalignment as I rotate/reposition the template. It is easy enough to fill in the gaps in the drawn circle left by the spokes in the template. If you cut one, please show us your finished result - either cnc plasma cut or cnc router. I'm surprised I couldn't fine one like this already commercially available.

David

[ROKCRLER]

Thanks David!
cuts great and takes the place of most all the random crap i look for when looking for radius'
I hit it quickly with a wire cup, still needs cleaning up. 16ga, 350ipm 45a

[adbuch]

Thanks David!
cuts great and takes the place of most all the random crap i look for when looking for radius'
I hit it quickly with a wire cup, still needs cleaning up. 16ga, 350ipm 45a

Mo - thanks for posting that! It looks just like had envisioned. I could also see where it might be handy to have one for circles in between - say 1.5", 2.5", 3.5", etc. Maybe I'll draw up one like that as well.

David

[ROKCRLER]

The in-betweens would be good, but not necessary i don't think. These can be fudged up to make the needed radius and lines extended.
I want to engrave the sizes on the next one for reference, but this killed the coffee lid, roll of tape, bottom of spray can, dog bowl.... all of it.
Its one of those, why didn't I do this sooner....Thanks again.

[ROKCRLER]

Or... half and half?

[adbuch]

The in-betweens would be good, but not necessary i don't think. These can be fudged up to make the needed radius and lines extended.
I want to engrave the sizes on the next one for reference, but this killed the coffee lid, roll of tape, bottom of spray can, dog bowl.... all of it.
Its one of those, why didn't I do this sooner....Thanks again.

Mo - you are quite welcome! Here is the file with the sizes added for engraving.

David

circle template with sizes.dxf image.jpg

circle template with sizes.dxf

circle template with sizes.svg

[Joe Jones]

Here is the file with the sizes added for engraving.

David

Did you allow for kerf width?

Joe

[ROKCRLER]

Here is the file with the sizes added for engraving.

David

Did you allow for kerf width?

Joe

That's adjusted in sheetcam for me.
Drawing dimensions matched cut dimensions for me.

[tinspark]

Thanks all, a bunch of great ideas you have. If anyone has any others please post them!

Here is one that Hypertherm makes.
Honestly we always made our own circle cutters by simply cutting a hole in a given plate large enough so that the torch nozzle slipped through and duct taped the torch tight to it then had a sliding coupling with a hole and a nut welded on with a wing nut to tighten it to whatever radius size was needed. the coupling also had a short sharpened tip to locate the center of the deaired radius. Very similar to the Hypertherm $150.00 jobber as depicted in the attached picture. But cost almost nothing. Mine is 30 years old and still works great. Also have one with a shaft coupling welded to it for my cutting torch,, But honestly since I purchased my cnc several years ago, most of my applications are doable on my cnc machine.
This one from Hypertherm looks real nice though

Edit: but after reexamining your question I think you were referring to drawing a circle not cutting one. so.......
Beam compass for me as well for drawing circles..

[adbuch]

Here is the file with the sizes added for engraving.

David

Did you allow for kerf width?

Joe

That's adjusted in sheetcam for me.
Drawing dimensions matched cut dimensions for me.

Kerf width is compensated for with the cam portion of the process. In Design Edge, it would be adjusted under "Settings, Offset/Convert". In SheetCam, it would be adjusted in the "Jet Tool" tab. For engraving the numbers, I would normally set my kerf width to zero and cut "On Path" ("Same as source" for DE users).

David

kerf width de.jpg

kerf width sc.jpg