[jozicrum]

I am using a 4 inch hole saw on a Wen 10 in variable speed table top drill press. I want to keep the plug that comes out of the hole saw and don't want a hole in the muddle of the plug from the arbor it. I have my workpiece (1/4 inch MDF with walnut veneer) clamped down at multiple points. My RPM is 600. I have had some luck with no arbor bit, but I have ruined a lot of pieces as well. I need 60 plugs. I have used Diablo hole saw and Hole Dozer hole saw. IT seems that both of these have a good bit of wobble (the drill press is fine). My questions:

Am I crazy thinking I can get away with a 4 inch hole saw giving me a clean cut plug with out an arbor bit?

Should I expect 4 inch hole saws from Diablo and Milwaukee to not have run out? Because theya re very wobbly. My drill press runs true. chuck is good. other bits are fine, and smaller hole saws dont have as exaggerated of a wobble.

Also - I am brand new to Woodworking Talk and appreciate the expertise that I have already found on here.

 

[epicfail48]

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

 

[jozicrum]

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

Thanks for the feedback. That circle cutter looks great! I will give that a try.

 

[sunnybob]

Depending just how accurate you need the plugs to be, there is a way of getting a reasonable result but it means more work. The hole saw will run out if there is no centre to start, so if you use over sized stock, then set the pilot drill to just protrude by an 1/8" . Then as soon as the teeth are engaged in the wood remove the drill and carry on. Afterwards you just cut the stock to the desired thickness.
Like say, its a lot more work, and if you want 60 of them, I would suggest finding somebody with a lathe, to turn a 4" round stud and then slice off your thicknesses like cutting a pastry roll.

 

[BigJim]

Cut a hole in a scrap piece of plywood using the pilot. Place the plywood with the hole on top of the piece you want to cut without the pilot and clamp in place. Using the top piece of plywood with the 4 inch hole as a guide, cut your hole in the good material. Using a steel wire brush, clean the teeth on the cutter as you make light cuts, it will save the piece from burning.

 

[John Smith_inFL]

I have about 4 of the circle cutters (knuckle busters) and used to use them frequently.
but, with my experience, they REALLY need the center pilot bit to be safe and effective.
if you choose to remove the pilot bit, it will take a lot of practice with the work piece securely clamped to the drill press table. and the drill press itself secured so it won't move.
what is the project that you need a round plug with no center hole ??
I just noticed that you need sixty each of the plugs. wow. what is the project ??
this may be a job for a CNC if you can work the cost into your project.

and a note - the "circle cutter" is really a "hole cutter" it will not cut perfect plugs: but it will cut a perfect hole. the plug will have a lip somewhere on the plug that has to be sanded off.
I can provide a sample photo if you need to see it.

 

[woodnthings]

Cut a hole in a scrap piece of plywood using the pilot. Place the plywood with the hole on top of the piece you want to cut without the pilot and clamp in place. Using the top piece of plywood with the 4 inch hole as a guide, cut your hole in the good material. Using a steel wire brush, clean the teeth on the cutter as you make light cuts, it will save the piece from burning.

Exactly as Jim says. ^
This is like making a hole saw "guide". It will locate the hole and stabilizes the hole saw when you place it in your workpiece. You must clamp them down together for it to work. This will work fine, but you may have to lift out the saw to clean out the teeth occasionally, as you progress downwards.
I would avoid "fly cutters " at all costs. They are one of the most dangerous tools you can use on a drill press.

 

[Tony B]

What is your goal? Do you want the hole or is it the disk that you want?
if it's the disk that you want, then the lathe idea is probably the quickest and easiesst way to go

 

[Dave McCann]

What is your goal? Do you want the hole or is it the disk that you want?

Or,,,,,,,, do you want both? A hole in the sheet of Walnut veneerMDF and the mating plug of Walnut veneer MDF?

a Wen 10 in variable speed table top drill press. I want to keep the plug that comes out of the hole saw and don't want a hole in the muddle of the plug from the arbor it. my workpiece (1/4 inch MDF with walnut veneer) I need 60 plugs.

ASSUMING,,,,,,,,,,, that you only want the plug;
What tools do you have available?
Do you have a router table? If so I might suggest rough cutting over size "plugs" out of your sheet of 1/4 veneered MDF and then trimming to size with a pattern bit. Use double sided tape to secure the rough cut blank to the top of the pattern (in this case a round 4 inch diameter plug) then run the pattern up against the bearing while the cutting edge trims the MDF to size.
pattern bit: Freud 1/2" (Dia.) Top Bearing Flush Trim Bit with 1/4" Shank (50-102), Red - Freud Router Bit - Amazon.com

If you do not have a router table the same thing can be accomplished with the drill press you already have. Not my first choice but it can be done. In this case you will need a flush trim bit so the shank is above the cutting edge.
flush trim bit: Amana Tool - 47102 Carbide Tipped Flush Trim 3/8 Dia x 1/2 x 1/4" Shank - - Amazon.com

Crude drawing of the set up for trimming the rough cut oversize blanks to finish size. I would suggest making the pattern/template with 1/2 or 3/4 inch material. Again, use double sided tape to secure the rough blank to the pattern.
The router table would be the best most ridged set up. The drill press will work, just more runout and vibration.

 

[CharleyL]

If no center hole, I would make a template and use a router with a guide bushing and a down spiral cutting bit. The template and how well you stayed against it would determine the accuracy of your plugs, but it isn't that hard to get them within a few thousandths, and with very clean cuts. A hinged template and a sacrificial piece below the work would minimize edge tear-out as well.

For clean holes, I have Forstner bits for sizes up to 3 5/8. Any need for holes larger than this is done with a router, circle guide, or template.

I make several passes at increasing depths of about 1/4 per pass or less, but the final pass is always less than 1/8" of material plus the cut into the sacrificial board, so usually a bit depth on this pass of 1/4" as well (1/8" in work, and 1/8" in sacrificial piece) . Using hinges on the template keeps the template and the sacrificial board in line with each other, so you can avoid the need for new sacrificial material for each cut. It will work like a zero clearance insert to keep the bottom edge of your routed piece as free from tear-out as possible. The result is plugs with no center hole and clean cut edges, plus clean cut holes, also with minimum tear-out.

Charley

 

[Zeus_cat]

I would use a laser cutter if you can find one. In my rocket club we use a laser to cut centering rings for rocket motor mounts in 1/4 inch ply. Inner and outer diameter of the rings need to accurate for the rings to be useful. Also, the kerf from a laser is almost negligible. The wood will require a bit of sanding to eliminate the burn marks.

 

[jozicrum]

Cut a hole in a scrap piece of plywood using the pilot. Place the plywood with the hole on top of the piece you want to cut without the pilot and clamp in place. Using the top piece of plywood with the 4 inch hole as a guide, cut your hole in the good material. Using a steel wire brush, clean the teeth on the cutter as you make light cuts, it will save the piece from burning.

I think this is also a good bet. I might also try to stack a few blanks so once my template is set with my blank underneath it, i can get a few out of each pass. As someone mentioned - those hole cutters look dangerous. I did get one and am curious to give it a try, but will likely go the template route with the hole saw. I don't have a router and I think that needs to be next on my list after seeing all this feedback.

 

[jozicrum]

What is your goal? Do you want the hole or is it the disk that you want?
if it's the disk that you want, then the lathe idea is probably the quickest and easiesst way to go

I want the disc

 

[jozicrum]

Exactly as Jim says. ^
This is like making a hole saw "guide". It will locate the hole and stabilizes the hole saw when you place it in your workpiece. You must clamp them down together for it to work. This will work fine, but you may have to lift out the saw to clean out the teeth occasionally, as you progress downwards.
I would avoid "fly cutters " at all costs. They are one of the most dangerous tools you can use on a drill press.

Thanks. I am going to give this a go.

 

[jozicrum]

I have about 4 of the circle cutters (knuckle busters) and used to use them frequently.
but, with my experience, they REALLY need the center pilot bit to be safe and effective.
if you choose to remove the pilot bit, it will take a lot of practice with the work piece securely clamped to the drill press table. and the drill press itself secured so it won't move.
what is the project that you need a round plug with no center hole ??
I just noticed that you need sixty each of the plugs. wow. what is the project ??
this may be a job for a CNC if you can work the cost into your project.

and a note - the "circle cutter" is really a "hole cutter" it will not cut perfect plugs: but it will cut a perfect hole. the plug will have a lip somewhere on the plug that has to be sanded off.
I can provide a sample photo if you need to see it.

I am also in the process of doing some CNC research and just hiring this part out possibly. My wife and I started a little side business and I am making cocktail smokers. Imagine a little chimney type contraption that goes on top of a whisky glass. You fill the chimney with some wood chips and take a small torch to it to fill your glass with smoke. These 4 inch circles will be used as a cap to cover the chimney once they smoke is in the glass.

 

[shoot summ]

ETA, looks like @BigJim already made this suggestion.

I use this method for drilling holes in stone counters, the diamond hole bits do not have a pilot bit.

Take a piece of stock, drill a 4" hole through it with the hole saw and pilot bit, this piece is now your guide. With your stock firmly clamped in the drill press, no pilot in the hole saw, clamp the guide piece on top of your stock aligned with the hole saw. This piece will guide the saw, you might also slow the press down, starting slow is very key, once the hole is started it will run faster.

 

[John Smith_inFL]

I would imagine these are available on the internet somewhere.
personally, I would not use MDF - that would look so cheap. solid wood of some sort would be my way.
what kind of crowd (age group) wants to drink booze out of a glass that has smoke in it ?????

 

[FrankC]

I would imagine these are available on the internet somewhere.
personally, I would not use MDF - that would look so cheap. solid wood of some sort would be my way.
what kind of crowd (age group) wants to drink booze out of a glass that has smoke in it ?????

Those that can't afford a good Islay Scotch.

 

[Tony B]

Those that can't afford a good Islay Scotch.

Sounds like a bong for non-potheads.

 

[_Ogre]

Cut a hole in a scrap piece of plywood using the pilot. Place the plywood with the hole on top of the piece you want to cut without the pilot and clamp in place. Using the top piece of plywood with the 4 inch hole as a guide, cut your hole in the good material. Using a steel wire brush, clean the teeth on the cutter as you make light cuts, it will save the piece from burning.

This is what I would try. I've used this method to resize the hole for a lockset in a door with a hand held drill. I used a lot smaller hole saw, but it should be fine in a drill press