60 degree cone baffles.

[pistolpeta]

I have acess to a lathe but was wondering if anyoneknew where one could find a 1" 60 degree zero flute deburring tool? It would make it so much easier to get that inside angle just right. Form 1 budget information.

[partsguy22]

You would probably have better luck with a single flute

but if you want a Zero flute https://www.mscdirect.com/product/details/45117421

[fishman]

that inside angle just right

you dont need that inside angle to be "just right". 60 degrees is entirely arbitrary. as long as its even somewhat close it'll be fine.

[pistolpeta]

So this would work better?
https://www.amazon.com/gp/aw/d/B00OTX3I ... ref=plSrch

And yeah its mainly to cut weight more than anything I think.

[policetruck]

Pistolpeta

I hogged mine out with a zero flute but finished with boring bar on the compound. I mainly did that for time and saving my wrist on the compound. You can use CAD or a little trig and just figure out how deep to cut then leave yourself a couple of passes to clean up any chatter or irregularities.

[yondering]

So this would work better?
https://www.amazon.com/gp/aw/d/B00OTX3I ... ref=plSrch

And yeah its mainly to cut weight more than anything I think.

Yeah, that works a lot better. If you can find one though, go with the M.A. FORD brand, it'll hold up longer, and actually be useful as a normal countersink tool too. I've got a pair of them that I've been using in the shop for ~ 6 years now, and have sharpened them once in that time.

For a one-off tool, especially if you're just cutting aluminum, you can make a D-reamer to cut the inside of cones; I did that for making 22 K baffles. Cut the shape you want from O-1 tool steel on the lathe, mill it in half, then harden and temper it before final sharpening. I made mine with a lip to act as a stop, so I didn't have to measure the depth every time.

[CMV]

If you're cutting the cones on a lathe you really don't want to do it this way. Leave the compound angle once set (just leave at 29.5° if that's where it is) alone & then you can't make the outside and inside cuts at different angles.

Doing the inside as you describe and then cutting the outside will lead to a varying degree of thickness in the wall at one end or the other unless the compund angle is dialed in perfectly. This might not matter if it is a small variation but if you are going for min thickness necessary as it is and then you are measuring on what happens to be the "fat" end you'll be undersize at the other end and won't know it until you finish the cone, part it off, and measure.

Best way I've found is to just grind a small tool (I typically use a 1/4" brazed carbide bit like you'd want for a minilathe) with enough clearance to get all the way inside. It takes a lot of passes with such a small tool, but it's a very easy operation and it's not a race.