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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.

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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.

In short:
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. enter image description here

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.

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  • I bet if you were careful about it, you could glue the scrap together too and make a neat vase or something. – Daniel B. Apr 7 '15 at 3:08
  • This is a homemade "lathe" that would earn someone a Darwin Award. This and this do not seem particularly unsafe to me. – lars Apr 7 '15 at 21:07
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    Hm. Yeah, they're probably OK. I still wouldn't want to do it personally, but I suppose most of the energy is in angular momentum. You'd still want to make sure that whatever you use is either very heavy, or bolted to something that is, or that angular momentum will get transferred to linear in unpleasant ways. That first one made me laugh ... that guy is nuts. – Daniel B. Apr 7 '15 at 23:50
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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.

e.g.

lathe trammel

(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.

image via: http://customfurnitureandfab.com/how-to-make-fluted-or-beaded-columns

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    A table router probably wouldn't have the torque necessary. You might be able to hack something together with an electric motor, but you're likely to cause some injury to your person in the process, i wouldn't recommend it. Lathes can be dangerous. Cobbled lathes ... I wouldn't try it. Consider that you're rapidly spinning a piece of wood and then pushing a sharpened blade into it. You could get a mini lathe for around $500. – Daniel B. Apr 6 '15 at 21:08
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    Well, I was thinking not of cobbling a lathe together, but a 6x6 between two fixed centers with some kind of trammel for guiding a router back and forth. Make a pass, rotate the 6x6, then make another pass. When you make a fluted column, the lathe acts more as a rotisserie than anything else- it's the guide structure that holds the router that's important. – TX Turner Apr 6 '15 at 21:19
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    Ah! Yes, that can be done. In fact I recall a decent video ... one moment. (you'll probably want to do something like my response anyway, or at least use a band saw to trim it down just so you're not using the router to remove ALL the wood.) – Daniel B. Apr 6 '15 at 21:47
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    youtube.com/watch?v=TUA3lryix64 Here it is. If you made the guide angled, then you would wind up with a cone. – Daniel B. Apr 6 '15 at 21:50
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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.

  1. 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).
  2. 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.
  3. 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).
  4. 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.

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  • I really hope this makes sense. – saltface Apr 7 '15 at 17:58
  • It took me a minute but I see what you're saying, but yeah: adding parallel segments of the cone until you have a complete cone, i.e. horizontal divisions rather than vertical. This would get you a more perfect cone without a router jig, but would take more work adjusting for each cut. You could do the same on a bandsaw using an angled block and a spindle for your blank. – Daniel B. Apr 7 '15 at 19:08

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