cuttingsawwoodworking
How can I cut the arc as shown in the photo?
I have a circular saw. I have a jig saw.
I thought I might calculate the center of the arcs circle and (using a line tied to my circular saw) cut the curve on a clamped down 1 x 4.
I don't have a very steady hand when it comes to using my jigsaw so I don't want to draw an arc and then cut it.
How do professionals cut arcs?
The arc I want to cut looks like this:
Most fun.
Fastest.
Most likely to have on hand.
Slow.
Slower.
Slowest.
Longest reach.
Cut right to the chase
Requires lots of training, food, and cleanup (thanks @SteveJackson for pointing this method out).
By popular demand (don't use on PT wood)
No affinity to Ridgid, just the first brand in the list when searching for reciprocating saw.
The most likely solution is to create a template and use a router with a bit that follows the template. The router would also be used for easing over any sharp edges.
photo credit, sample image, not a product recommendation
Best Answer
Whenever I want an arc that accurate I use my 3hp router (a smaller rated router will do too, just for smaller scale work) screwed to a shop made pivot (trammel) and make repeated passes, next pass deeper than the last to complete the cut.
A circular saw may make that tight of a curve if you set the saw shallow enough to just cut through the material. It will be quite rough, not recommended for finish work
Here is the formula to figure the radius of a given arc.