# cutting a circle wider on top than the bottom

I want to recreate something I did at college, namely, a circular plug which I can replace with a different wood. I cannot work out how to get the angle of the saw to make the plug wedge shaped to fit the hole. Hope someone can help. Pickles.

• What is the diameter of the plug you wish to create? How steep the angle? Apr 3 '16 at 17:53
• Are the sides of this plug to be flat then? You are trying to make a plug that matches the angle of the hole? To rephrase... The hole is not cut straight and the plug has to match that shape. Is this something like a grommet on a desk? What is this used for?
– Matt
Apr 3 '16 at 20:09
• Please see woodworking.stackexchange.com/questions/814/…, it may be of help. You are trying to make a truncated cone (i.e. one with its tip cut off), which is addressed there. If that answer doesn't help, please tell us more about your problem as well as the tools you have available. Apr 4 '16 at 0:51
• There are solutions ranging from lathe to tilted saber saw to tilted sander to tilted bandsaw.. Probably others too. Which make sense will depend on size and materials and what you have available. Apr 4 '16 at 1:19

If you have a matched set of a reamer and a tenon cutter this is easy (folks like Lee Valley sell such sets). You can create pair as well; searching for Windsor chair-making tools will lead you to a few approaches. A lathe can also make a taper and hole can be drilled straight and widen by diagonally drilling or by filing with a rat hole file.

http://www.popularwoodworking.com/techniques/joinery/chair-joinery-tapered-tenons-tapered-mortises shows Chris Schwartz wielding a reamer and tenon cutter to fit legs

If you are taking a dowel of some sort and want to make it, for example, 1/2" at the top but more like 3/8" at the bottom then this is how i would do it.Using a bit (like in the picture) to make a plug like i was talking about. I would use a table router. You would need to put a board on the guide of the router table to make it easy. The way i described would work it is just the setup you need to be worried about, and play it safe! I would take a dowel and run it by and then cut it off at the top with the table saw. Hopefully this helps!

• You're suggesting holding a dowel vertically against the fence then routing around it, or, more accurately, spinning the dowel so the bit comes in contact with all 360° of it to make a cone? That sounds incredibly dangerous - nothing like having the 20,000 RPM router grab that dowel out of your hands and fling it across the shop until it lands in something soft and fleshy. If that's not what you're describing, I'm not sure what you're after - your (unattributed) pictures aren't helping me out. Apr 5 '16 at 17:43
• this is indeed what mean. I have done it before. just have to do little by little. I did not ave bad luck but I do understand where you are coming from. This seemed like the only way besides the table saw Apr 5 '16 at 17:58
• you are a braver man than I! Apr 5 '16 at 22:08

You didn't say how large your plug was, but I'm thinking 2" or larger in diameter. This is something wooden boat builders do every day. This is no different in cutting out a transom for the back of a wooden boat.

In this wooden boat the rear of the boat starts to narrow at the transom (that flat board at the rear of the boat. That means the front surface of the transom is larger than the aft surface of the transom. (Hint, same as your plug...)

The key lesson here is: To make woodworking easier take the time to mark up ALL CUTS on all visible surfaces of your workpiece.

Again, you carefully mark the edge line of BOTH surfaces, top and bottom of the work. Obviously for your plug, one circle will be a smaller diameter than circle on the other side of the workpiece. Cut out your 'plug' to the larger diameter. Now place the workpiece on your bench, with the smaller diameter facing up. Use a hold down to keep the work from moving. Use a sharp chisel to pare off the edge to the top line, leaving the bottom edge untouched. Much easier than leaving blood on a power tool.

Good for plugs from 2" to 8' in diameter!

Do note, on that transom shown in this photo, the bevel angle varies huge around the workpiece... you've got it easy with a 'plug'.

One more comment... with this method, you are not limited to circles.. you can draw any shape you want... rectangles, square, butterfly dovetail insert, etc....

• This is a good Answer, but this could be done simply and quickly with a router, using one template and no marking out :-) Apr 6 '16 at 10:46
• Er. no... what if you wanted a 2 degree bevel on your plug, or a 4 degree or a 5.5 degree bevel. If you were a machinist you could make that router bit out of tool steel. The rest of us, I don't think so. Additionally lets pretend you are going to cut a 2" diameter plug your way with a commonly available router bit angle. How do you do the set up SAFELY? Set the 2" disk on biscuits? What does the router alignment bearing set against? I suggest this way is a cheaper investment, and much more flexible. How would you do a butterfly dovetail plug with a router? Apr 6 '16 at 16:15
• What do you mean er, no? You buy the router bits, obviously. Your 2" plug example (which isn't necessarily what the OP is looking for but anyway): obviously the ideal setup there is move the work, not the router as handily was covered just the other day in this Q&A. What does the bearing set against? The sole template I mentioned ;-) Apr 7 '16 at 7:09