sorearm - Posted - 12/20/2009:  07:32:38

Are all cones pressed from a sheet of metal and then finished on a lathe? What do advertisers mean when they boast having a "spun" cone?

jaykellogg - Posted - 12/20/2009:  09:13:33

I doubt that they are pressed, I think they start with a round disc blank. en.wikipedia.org/wiki/Metal_spinning . If they do it cold, the metal gets wok hardened which would be an advantage in a cone.

On Paul Beard's set up DVD, he taps a cone and taps one of his. His rings considerable clearer. The other makes a "tunk".

Slideman1939 - Posted - 12/20/2009:  09:58:58

The spun cone starts as flat sheet metal of a specific thickness and alloy.Suppliers sell 12 in squares off a roll.The spinner cuts this to a 12 in. circle. Dead center is determined, a small hole is drilled and the round disc is attached to the center of the form with a screw. The form is a moulded wooden disc made of smooth hardwood that has been spun to the shape and ridges of the cone.This wooden form acts as a backing plate. The spinner (craftsman) gently presses the spinning disc with various shape forming tools ( typically wooden) that are lubricated ( tallow or soap or light grease) to offset the friction and prevent tearing the thin aluminum. The craft requires a light touch.Either a wood or metal lathe could be used. In the Phila. Pa. suburbs there is a British person who teaches spinning, and has a website, and sells 4 D.V.D.'s of metal spinning instruction (general objects, finials, aircraft nose cones etc.--not necessarily Dobro cones). The spun cone is more within the capability of the small builder. A stamped cone obviously would require a a male and female die and a press with great pressure to slam out a wrinkle free stamping. The cost of the tooling and dies would be 500 times the cost of a spinning lathe and one would have to sell an awful lot of "stamped" cones to justify the equipment cost.

Steevarino - Posted - 12/20/2009:  13:43:30

As far as I know, two kinds of cones exist: stamped and spun. It is easy to tell one from the other, spun cones have spiral lines, like a vinyl record, for us older folks. Stamped cones do not have these lines, but look more like a pie plate. From what I can tell, spun cones are the only way to go, tone-wise. Some Old-Old-Old-School guys might disagree, but, for the most part, current builders are only using spun cones. Maybe some imports still use stamped cones. As with most things, you get what you pay for.

Slideman got it about right, except all of the spinners I have known or heard about spin against steel molds (which they seem to call "chucks") and use steel tools. I have a set of thes spinning tools, made for me by one of the best cone spinners yet, but I have not yet built my own chucks, or converted my bigger metal lathe to do this.

Maybe next year....

Steve Smith
RedLineResophonics.com

Trapper - Posted - 12/21/2009:  09:41:36

C'mon Steve .. are we gonna have Redline cones available in 2010? Merry Christmas, my friend.

GeoBar - Posted - 12/21/2009:  10:37:12

Hello,

Here are some pics: tweedsblues.net/trader/spin.html

and a video: youtube.com/watch?v=xfT-DkLeb8o.

Steevarino - Posted - 01/01/2010:  09:30:55

Trapper, Don't tempt me! Actually, I had planned on getting into the cone spinning business several years ago, and selling them through the Cumberland Acoustic side of our business, but I got sort of screwed out of a deal I had made with a prominent, yet virtually unknown cone spinner who was ready to retire. That business has moved on at least once or twice since then, from what I can tell. Lots of secrets in the Cone Spinning World, you know...

As it turns out, I have a friend visiting me right now, and he is almost a wizard at figuring out mechanical stuff. I think I have him prettty stoked to dig into this project, now that he as fixed just about everything in the shop that was broken! I have a lathe that will work for cone spinning, and a set of spinning tools made for me by the afore-mentioned spinner. Sort of a consolation prize, if you will. Anyway, while my friend is here, we are looking into taking this on as a project, and maybe trying our hand at cone spinning. He's only here for another 10 days, so we may not see it through to completion. However, I think we can get far enough along to see if it something that I would like to go forward with, or not.

Steve Smith
RedLineResophonics.com
CumberlandAcoustic.com