I need to make a wooden cone that is slightly smaller than the smallest traffic cone available commercially. My guess is that it will definitely require a table router. Is that correct and are there any other tools that would be necessary in the process. I would use a roughly 12" piece of 6x6 to carve it out of.
If you don't have access to a lathe, you can cut a series of wedges with a band saw and/or a table saw. connect them all together in an "almost cone" and sand down the edges until it's fairly conical. The narrower your wedges, the more conical you'll get. The angle for each wedge is easily calculated. Where N is your number of wedges, 360/N gives you the inner angle.
From here you have a near-conical blank. You can either sand down the edges or use a router jig like in this video: a spindle in a box with a router sliding on top. To get a cone, you could angle the spindle. Perhaps if you wanted to get fancy, you could make the spindle adjustable to make different angled cones/tapers.
TX Turner's comment has another good reference for a jig meant to go on a lathe which could be modified to do tapers, but I don't think it would be too difficult to fabricate something similar as a standalone contraption.
1: Cut a bunch of wedges from rectangular blocks. If you glued them together at this stage, it would make a near-cylindrical drum.
2: make a diagonal cut into each wedge to make the triangular size of the cone you need.
3: Glue them together into a conical blank.
4: Sand the corners down or use a router jig.
As I mentioned in a comment, I would not recommend trying to make a DIY lathe. To me that seems like an attempt for the Darwin Awards.
Well the obvious choice (see my username) would be a lathe. :)
Similar to what is done to make fluted columns, you could mount stock between revolving centers and build a trammel to hold a router that makes cuts angled to the stock.
(Except imagine one end of the platform higher than the other to make a cone.
Technically, you wouldn't even need a true lathe, just a couple of sharpened bolts in a frame to create points about which the stock can rotate.
A similar method to Daniel B.'s would be the common scroll saw method for making stacked cones. This could be adapted to a band saw with a sufficiently narrow blade.
- Tilt your saw's table to the angle complementary to the desired angle of your cone (e.g. 30° if you want a 60° slope).
- Make a zero-radius circular cut (i.e. rotate around a fixed point) on the face of a board. (This is why the blade needs to be really narrow.) Because of the angle of the table, this will produce a small cone.
- Using the base of the cone you just created as a template, scribe a circle on the same stock. Without moving the saw's table, cut out the circle. This will create a conical frustrum (yes, I had to look that up).
- Use the new disk to scribe another circle and repeat until you get your full cone.
If you plan on staining the wood, be aware that the color will fade from dark to light between the end grain and face grain.