[Kerrys]

I would cut oversized blanks using a bandsaw then make a pattern of the size circle I need. Attach the pattern to the blank and using a pattern bit in a router trim the circle to size. This would require making a V shaped fence for the router table to hold the pattern and blank on two sides while trimming to size.

 

[jozicrum]

Sounds like a bong for non-potheads.

both of these things are correct....

 

[AidenBunny]

I am using a 4 inch hole saw

 

[Tony B]

if I had to cut a lot of these circles, I would make an over-sized circular template and use a 1/4" diameter or smaller bit either with a bushing on the plunge router or a flush trim bit with the bearing on top. I have cut lots of round holes that way and they go fairly quickly.

 

[cynrich]

I wanted a bunch of 3/4" x 4" discs for a project once, so I cut a bunch of squares out of 3/4" plywood the size a little bigger than my discs needed to be and stacked a few at a time with some hot glue, then ran them through the bandsaw to make a "cylinder" that I just heated and pried apart. The extra glue was easy to remove with the heat gun and sanding. I made 24 this way and it didn't take long--6 passes of 4 layers of 3/4" plywood.

 

[gmercer_48083]

Hole saws are not precision tools. Theyre meant for construction, to put a mostly properly sized hole in something. Some runout on the saw is to be expected, and the larger diameter will magnify any runout present in your drill press (and unless youre using a milling machine, i can pretty much guarantee you have a decent bit of runout in the machine). If you want a clean cut, hole saw just isnt the best thing to try. A circle cutter like this would be a much better bet: https://www.amazon.com/General-Tools-55-Cutter-Adjustable/dp/B00004T7P1

Make sure the cutting bit is dead sharp, clamp the stock down firmly, and most importantly you need some way to keep the plug in place as well. Use some double-sided tape to stick the stock to be cut to a backer board, then just barely cut into the backer. The tape should keep the plug from turning into a projectile when the cutter breaks through the stock

Using the fly cutter circle cutter suggested in this post would be dangerous if used without the center arbor bit to guide it.

 

[gmercer_48083]

If you want to save the circle (disk), and you have a band saw... you can make a circle jig for the saw, that has a nail or pin that your blank pivots on to saw the disks quickly.

 

[jozicrum]

Using the fly cutter circle cutter suggested in this post would be dangerous if used without the center arbor bit to guide it.

noted. It came in the mail. I won't test my luck.

 

[epicfail48]

Using the fly cutter circle cutter suggested in this post would be dangerous if used without the center arbor bit to guide it.

Only if youre running it way too fast without properly securing the workpiece. Run it slow and make sure that both the waste and the plug are secured and as long as you dont decide to poke the spinning bit, nothing adverse is going to happen

 

[gmercer_48083]

Only if youre running it way too fast without properly securing the workpiece. Run it slow and make sure that both the waste and the plug are secured and as long as you dont decide to poke the spinning bit, nothing adverse is going to happen

I respectfully disagree. I feel the odds of securing the plug without a center arbor would be risky... especially when the original poster (being new to this tool) has never seen or used a fly cutter. The odds are that drilling 60 holes without a center arbor (in my opinion) is asking for an accident. I am sure that most people that have used one would agree.

 

[FrankC]

The centre bit is there for a very good reason, it is an accident waiting to happen not using it, what anyone here does in their own shop is their business, recommending it to others is totally irresponsible.

 

[jozicrum]

The centre bit is there for a very good reason, it is an accident waiting to happen not using it, what anyone here does in their own shop is their business, recommending it to others is totally irresponsible.

Thanks for all the feedback. My hole cutter came and originally I thought I would just return it since the circular template I am using is working fine. I am going to use the hole cutter with the center bit so I can get some experience with it, but I don't think I will end up using it for this project.

 

[FrankC]

Wise decision.

 

[epicfail48]

sure the cutting bit is dead sharp, clamp the stock down firmly, and most importantly you need some way to keep the plug in place as well. Use some double-sided tape to stick the stock to be cut to a backer board, then just barely cut into the backer. The tape should keep the plug from turning into a projectile when the cutter breaks through the stock

I respectfully disagree. I feel the odds of securing the plug without a center arbor would be risky... especially when the original poster (being new to this tool) has never seen or used a fly cutter. The odds are that drilling 60 holes without a center arbor (in my opinion) is asking for an accident. I am sure that most people that have used one would agree.

Well, i guess its a good thing i addressed the matter of securing the plug in my first message then. Almost like i provided a method to keep the plug completely secured when i made the suggestion.

Im also sure that most people who have made a trepanning cut in much more difficult materials would agree that its perfectly safe so long as you take the proper precautions, just like any other operation in a shop environment. People do this in steel all the time, making a trepanning cut in wood isnt hard, as long as proper precautions are taken, like what have already been outlined

 

[gmercer_48083]

Well, i guess its a good thing i addressed the matter of securing the plug in my first message then. Almost like i provided a method to keep the plug completely secured when i made the suggestion.

Im also sure that most people who have made a trepanning cut in much more difficult materials would agree that its perfectly safe so long as you take the proper precautions, just like any other operation in a shop environment. People do this in steel all the time, making a trepanning cut in wood isnt hard, as long as proper precautions are taken, like what have already been outlined

Maybe you could explain in detail... how you would safely use a fly cutter to cut a hole to save the disk and not use the center mandrill/arbor, and to do it on a drill press. I would like to know how you will safely hold the 1/4" veneered mdf. OP said he needs to save 60 of the disks cut using your method. I am sure many other members would like to know also.