Table Saw-Bandsaw-Router-Jig Saw

[cabinetman]

If you were to cut circles out of wood or plywood, which tool would you prefer to use and why.

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[toolguy1000]

huge circles, jig saw. large circles, band saw. small circles, possibly table saw with right jig. really small circles, hole saw.

[tommyt654]

Simply because its so easy, a single screw,piece of rope or string and a plunge router.

[Lonnie in Orlando]

#1 choice = plunge router with pivot arm for circles larger than about 1' diam. Multiple passes. My pivot arm can cut circles up to 5' diam, but it's easy to make a temporary arm for larger pieces. Easy to make an arm that will pivot on a temporary center block that is double-stick taped to the workpiece to avoid making a center hole. A shallow first pass to reduce tear out. The workpiece is stable when it is on / or raised above a flat surface.

#2 choice = bandsaw. Good for smaller circles. Large workpieces can be difficult to handle on my standard 14" bandsaw table.

#3 choice = hole saw in my drill press. Small circles up to about 2-1/2" diam. with a 1/4" center hole. Good for jig knobs. Haven't tried without the center drill bit.

#4 choice = disk sander for small circles. Cut close and use a bandsaw-type jig to true to final size. Or cut close and sand freehand to the final shape. I use a sanding disk for freehand shaping on my BT3000. (screems at the high RPMs of the Ryobe so I don't use it much). I use my 8" Hitachi belt/disk for anything that will fit on the small table.

#? choice - never cut circles on a table saw.

- Lonnie

[dbhost]

Assuming you are talking large circles, say larger than 6".

#1 Choice for me would be plunge router, straight cutting bit and a circle cutting guide. I have it, it's easy to use.

#2 choice for me would be a bandsaw circle cutting jig. I haven't bothered, but I see how they could work well...

I have no clue how you could use a table saw to cut a curve, so I am not going to answer that one at all.

For smaller circles, Hole Saw. They can be used without the pilot bit, it's not super easy to do, but I have done it.

[cwsmith]

Question... You said "Circles IN wood", so I presume you mean "holes" or "cutouts" and not just rounded, oval pieces as the end product.

If I were looking for say, a round table top then I would use a bandsaw for the initial cut which I would make slightly larger than needed. Then I would use a jig or pattern sheet to then "route" those edges to the final size.

If I were looking to cut a circular hole in my stock, I would go the route that the other members have suggested, using a router with a jig.

CWS

[JimD]

I made an adjustable circle cutting jig for my PC routers several years ago. It will cut anything from really small circles up to about a 1 foot radius. For an accurate circular hole, it has become my "go-to" tool. If it is within the range of one of my bits or hole saws, however, I use them. That covers up to about 3.5 inches. For an odd sized small hole, however, I use the router jig.

Jim

[pelligrini]

Depends on the material and diameter, usually a router and my milescraft circle jig, or a quickie jig for larger radiuses.

For smaller circles I'll use a fly cutter on my drill press. I still don't like those arms spinning around, but it does work well.

[cabinetman]

Question... You said "Circles IN wood", so I presume you mean "holes" or "cutouts" and not just rounded, oval pieces as the end product.

I edited the wording (from "in" to "out of") to make it more clear.

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[greenacres2]

Odd that this came up today. I finally got a drum, 30-ish gallon today, came home unloaded it from the car, and immediately set out to get my chip separator started. Plunge router and Milescraft circle jig with cove bit to form the recess for the lip with an 18 3-4" diameter, then cut a 20 1-2" diameter on the same center to finish the lid. Perfect first time.

Did the same thing for the lower circle (inside the barrel) and will use my jig saw to remove the needed lip. Came in the house because i couldn't remember how far back to make the cut--and this was the first thread i saw!!

Several years back, when my son was riding free-style BMX, a skate park owner showed us how to use a circular saw to cut really large diameter curves (think 6' to12') for ramp building. The key was to lower the bit just barely beyond the thickness of the plywood. We used a 7 1-4" in the day, but the smaller diameters today (5"?) would be even smoother. Way easier to control than a jig saw when you're doing it free hand.

earl

[LCHIEN]

Firs of all you didnt specify whether you want to leave a hole (LH) or leave a circle (LC) or leave a Circle and hole (LCH) when done. some methods do Some but not all three options. I also assume you're talking sizes greather than you would do with a reasonble sized hole saw (e.g. up to 2-3" diameter).

I usually use a router, I don't even have one of those $30 and up circle cutting jigs. I usually just use a 1x6 and drill a pilot hole at the center for a pin or a 1/4" dowel/rod/bit and a larger circle near the radius for a template guide bushing with a 1/4" spiral cutting bit. This is the best way to go if you have a large fixed object you want a hole in (like a panel or a countertop.) Good for LH, LC, or LCH Most flexible in terms of size. But the kerf between a hole and circle is the size of the router bit used. You can get 1/8" bits but they pretty fragile for use in a large diameter circle. So at best you can end up with a circle within 1/4" of the hole that is left.

The bandsaw is OK but its LC only. I've not done this but looks straightforward. Sort of limited in size - you might have to pretrim to near size to make this work.

I've seen the table saw method, it would work too but limits the size. LC only. Basically you need a pivot on a sliding miter table. Set the pivot on the SMT one radius away from the blade. Start ot with a workpiece squared to just over the diameter of the desired circle. Drill a hole matching the pivot int he center. put the center over the pivot and push the workpiece into the saw cutting off one corner. Repeat for the four corners to make an octagon. Then rotate about 22 degrees and make it 16-sided with 8 more cuts. By now you can push the pivot up to about even with the leading edge of the saw blade (saw running) and lock the SMT in place. Now rotate the piece slowly and you'll cut all around it. until you have a circle. Keeping the blade low will probably help.

There's also the jig-saw/disk sander method. LC only.

[cabinetman]

Firs of all you didnt specify whether you want to leave a hole (LH) or leave a circle (LC) or leave a Circle and hole (LCH) when done. some methods do Some but not all three options.

The parameters were edited to clarify and remove doubt whether it was a hole in plywood or wood, or if it was to get a circle out of plywood or wood. If you're still unsure, assume you want to wind up with a disc, or a circle. The band saw is likely the only tool that would limit the cut to only getting a circle out of larger stock, without a feed in cut.

I also assume you're talking sizes greather than you would do with a reasonble sized hole saw (e.g. up to 2-3" diameter).

Good assumption on that one. That's why I didn't list it.

The bandsaw is OK but its LC only. I've not done this but looks straightforward. Sort of limited in size - you might have to pretrim to near size to make this work.

I've seen the table saw method, it would work too but limits the size. LC only

On the bandsaw, the size is not limited. The only limitation would be is how much waste would be cut off, and if that would fit the throat depth. But, to solve that, the piece could be sized appropriately before cutting, with nipping off corners with any cutting tool/machine. IOW, just to be clear, example: if a circle is desired, to cut close to the line with a jig saw first. Size then would be no limit, as the piece to be cut can be supported to the outside of the blade.

Ordinarily, what I do is to start with a square, find the center, and make a small hole on what would be the back. Using a supporting substrate, outrigged to the table, set a nail (like a 6d finish nail) into it on center, and cut off the head at an angle leaving about ¼" protruding, at the distance of the radius desired. The substrate is set on the nail, the blade cuts at the line of the circumference.

There is also no limit on the table saw, if there is/are wing tables. One on either side of the blade, wide enough to support the stock being cut.

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[LCHIEN]

the limits for table saw and BS I was alluding to are not actual physical limits but limits in a reasonable size for outrigger and handling of the circle. I would think about a 2-3 foot radius would start to get unweildy from my perspective, although I'm sure much larger could be done with large outriggers and maybe a second person to help.

OTOH, for large circles the workpiece being fixed has its advantages and the router can safely be moved if necessary in sections or arcs and with the operator sitting on the workpiece if necessary. Just a single beam a little over the radius in length needs to be made rather than large supporting outrigger at the right height and distance from the blade and capable of supporting at least four directions of the front, back and sides of the circle.

In addition the router would require no pretrimming of the workpiece to near size...
On the negative side the router would require supporting the workpiece on a sacrificial support that might get cut into a little bit. Or maybe not if you are real careful and leave a hair to cut with a knife and clean up with a sander.

[cabinetman]

the limits for table saw and BS I was alluding to are not actual physical limits but limits in a reasonable size for outrigger and handling of the circle. I would think about a 2-3 foot radius would start to get unweildy from my perspective, although I'm sure much larger could be done with large outriggers and maybe a second person to help.

There's not always a second person around. The question is not on how unwieldy the procedure is, but rather the space that is available. Once set up, its just a matter of standing in one place, and just rotating the subject piece. I've done 7' diameters using these methods.

OTOH, for large circles the workpiece being fixed has its advantages and the router can safely be moved if necessary in sections or arcs and with the operator sitting on the workpiece if necessary. Just a single beam a little over the radius in length needs to be made rather than large supporting outrigger at the right height and distance from the blade and capable of supporting at least four directions of the front, back and sides of the circle.

In addition the router would require no pretrimming of the workpiece to near size...
On the negative side the router would require supporting the workpiece on a sacrificial support that might get cut into a little bit. Or maybe not if you are real careful and leave a hair to cut with a knife and clean up with a sander.

The problem with using a router and a trammel arm is that it can be a reach for some diameters. The theory reverts back to space again. If there is clear floor space, or one provided by a bench of sorts, that may permit walking around the subject piece guiding the router. I wouldn't recommend getting on top of the subject piece, as that would require a very sturdy support system. In addition, you have the electrical cord to manage, and being able to clear the trammel arm for its rotation.

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[RAV2]

Cut 15 circles - approx 7" in diameter, in 1/2" PT plywood to drop flower pots in - with a router. Worked like a charm. Little messy. Still have the circles stacked in the wood bin.