How to cut 24" circles out of 1/2" thick maple plywood in LARGE quantities?

[Byron Lu]

I need to cut 50 to 100 round circles out of plywood in batch every month. Right now I cut with laser machine but they always have brown edges I have to sand off. Speed wise about cutting one circle for 3 minutes with laser.

So what would be the fastest way to cut such circles in bulk? I read about some ways: routers, jig saws, band saws, table saws, etc. But I am not sure about how fast each method cut large circles out of 1/2" plywood as I do not have experience with these methods. Can anyone with experiences advice which way is the fastest in cut circles in bulk?

Thanks in advance.

[Matthew Curtis]

I would stack them up and cut a pile of them on the bandsaw with a circle cutting jig.

[Malcolm Schweizer]

If you go to my post “I now get paid to play with tools...” I’m building 56 arched doors. I cut the arch on the bandsaw with a simple jig- plywood with a screw at the pivot point. It helps to have a massive 3-phase bandsaw with insane inertia that plows through anything. It takes literally less than a minute per arch. If it were me, I would stack them up 3 or 4 high and make multiple circles at one time.

0A286241-435F-4628-9131-A12A0C69F8CF.jpg

[johnny means]

What are some other parameters? Can the have a hole on the middle? How precise do they need to be? How clean an edge do you need?

[lowell holmes]

If you do not have a good bandsaw, it is time to go shopping.

[Brian W Evans]

I don't have one (yet), but wouldn't this be a perfect job for a CNC router?

[Steve Jenkins]

I don't have one (yet), but wouldn't this be a perfect job for a CNC router?

Yes it would. If you need a full 24” you wil only get 3 pieces from 4x8 sheet of ply. You might look at pricing 5x5 Baltic birch

[Bill Space]

Yes it would. If you need a full 24” you wil only get 3 pieces from 4x8 sheet of ply. You might look at pricing 5x5 Baltic birch

I could be wrong, but my gut is telling me a 4x8 sheet should be good for six pieces 24” in diameter.

[Byron Lu]

WOW thanks so much for the replies. It seems the consensus is to use a bandsaw to cut 3-4 pieces each time. Sounds like the most efficient way. CNC routers will be quite bit slower as I understand.

Other parameters: I need the edge to be clean and smooth. A tiny hole on the back of the circle will be okay but not on the face side. Would be nice if no hole at all.

I can usually cut a 4x8 into 8 pieces of 24" rounds (well 23.5" each instead). The laser edges are very smooth but with the brown burning edges. Can a band saw cut it with a smooth edge?

I can only use a single phase bandsaw if this is the direction to go as it will stay in my garage. Any recommendations on what type/brand/config of the bandsaw suitable for my purpose?

Again thanks so much for your help!

[David Buchhauser]

WOW thanks so much for the replies. It seems the consensus is to use a bandsaw to cut 3-4 pieces each time. Sounds like the most efficient way. CNC routers will be quite bit slower as I understand.

Other parameters: I need the edge to be clean and smooth. A tiny hole on the back of the circle will be okay but not on the face side. Would be nice if no hole at all.

I can usually cut a 4x8 into 8 pieces of 24" rounds (well 23.5" each instead). The laser edges are very smooth but with the brown burning edges. Can a band saw cut it with a smooth edge?

I can only use a single phase bandsaw if this is the direction to go as it will stay in my garage. Any recommendations on what type/brand/config of the bandsaw suitable for my purpose?

Again thanks so much for your help!

Byron,
Could you cut them slightly larger in diameter, then sand off the burned edge. Perhaps you could post a photo of one of your finished parts so we can see the actual extend of the "burned edge".
David

[Rob Luter]

I could be wrong, but my gut is telling me a 4x8 sheet should be good for six pieces 24” in diameter.

Only if the router bit is 0.0" in diameter.

[Kevin Jenness]

The o.p. said "I can usually cut a 4x8 into 8 pieces of 24" rounds (well 23.5" each instead)."

Any cutting method is going to require some sanding depending on the finish requirements. If the circles are cut with a compression bit in a cnc router at a reasonable speed the cleanup will be faster than sanding out burn marks from a laser or the corrugations from a bandsaw, and the faces will be free of tearout due to the bit design. A circle jig on an oscillating edge sander would probably be the way to go for quantity production.

I expect the Axiom router mentioned with a 2.2 kw spindle will cut 1/2" ply with a 3/8" bit in one pass but overall machine rigidity and the hold-down method have to be stout enough to counter the cutting forces to get a good result. A vacuum table is the best option for this sort of work. There are a lot of options out there so do your research and try to "buy the cnc you need the first time".

As suggested previously, it would pay to sub out a batch to a cnc shop to see the process and assess whether a router would be a good investment- it definitely can add a great deal of capability to a small shop.

[Brian W Evans]

We don't know what you're making, or what else you make, so it's hard to tell if a CNC would be the right choice for you financially. It does seem like it has the potential to speed things up quite a bit, but if you've got nothing else to do while it's working or if your profit margins are thin, it might not make sense.

IMO, the next best option is to improve the sanding process. Definitely don't do it vertically - get some kind of oscillating belt sander and make a table, as others have suggested. The easiest way is with a hole in the center of the circle and a pin to index off of. If you don't want the hole, here's a possibility:

circlesander.png
Cut out a very slightly bigger circle from a sheet of ply and mount it on top of a solid sheet. Sand or cut the jig along the top until it just kisses the top of the circle, leaving a small opening. Mount the jig to your sander. To sand, drop your rough/brown circles into the hole and rotate by hand.

Frankly, circles will always be easier with a hole in the center. Can you use a dowel or some putty to fill the hole?



Edit: Sorry, decided to edit my diagram after posting, but couldn't figure out how to delete the previous versions.

[Bill Space]

Only if the router bit is 0.0" in diameter.

Since the OP really only needs 23.5” the point is moot, as he likely can get 8 pieces from a 4x8 sheet.

But it if he really needed 24” or slightly larger circles, couldn’t he get six of them out of a 4x8 sheet by offsetting the center points of the circles somewhat? Wouldn’t work for rectangles or squares, but with circles it would probably even be possible to get six circles larger than 24” diameter. This is what my minds eye was telling me...

Apologies to the OP as this really is a tangent to his question.

[Brian Holcombe]

Seems like the perfect job for an Aigner Cirquick mounted to a shaper after the part is cut oversized via laser.