Taper The Neck? - Or Not.

[richard37066]

Burt and Ross -

Thank you both. I've seen those things - several times - and have done my share of drooling. I guess it's my fascination with all things mechanical that drew me to them in the first place. Should mention that I consider the looks of the machine excellent "eye-candy" as well.

Basil posted a bunch on that thread by Hankey on the SGF regarding changer design. Georg focused on the "knife-edge" characteristic. When I saw the pics that Bas posted I was stoned by the simplicity of the changer fingers. One thing of interest is the fact that there appears to be a part number indented into the side of the finger. Upon closer look it appears that the parts have been "cast". More "pot metal" in the day? Could be.

Regardless, I can't let go of the elegance in that simple design. I'm working on trying to incorporate that basic idea into an all-pull changer and without all of that sheet metal in the undercarriage! Don't hold your breath waiting on results. You all know - very well - that innovations sometimes take an unconscionable amount of time before a reasonable degree of success is seen. I'm being very patient in the path that I take. It can't be any other way.

Besides - whoulda thunk that I'd get all wrapped up in a design that's 37 years old? No matter - the chase is exciting and will be worth it come rain or come shine.

And that's the name of a great ole tune.

Respectfully,

Richard

[Bent]

Anyone else have some input on the "tapered" versus "parallel" string question? I'd welcome any comment.

Respectfully,

Richard

Pardon me you all for not hardly writing...I am in heaven these days, putting in as much time as possible acquainting myself with the mill. I chose a keyhead as my first test project and am glad I did. It is all hand work, no using the power feed, and it really tests my sense for accuracy or lack thereof! I tell you, my second khd is a lot better than the first one. More on that later...

Richard, to the tapered question:
These are my opinions only. I have the feeling that from the word go, it was decided that a 10-string steel guitar should be a certain width and the maker decided that all things had to be fitted into a certain space. Ditto with the key head width for example. The common string spacing at the picking end was to be 11/32. If that same width had been applied at the nut end, the keyhead would have to be made about 15/16" wider and would be overhanging the 5 1/4"(or so) width of the deck that was allotted to each neck.
So therefor it was decided to make the string spacing 1/4" at the nut end - to save space!

One thing was not given much thought however... straight string runs.

Excellent builder/restorer/ Emmons factory repair person since 1987, Mike Cass, told us on the SGF that in order to tune a steel to its fullest potential for tone and sustain is to make sure that the string run is as straight as possible. I hope it is alright to quote Mike here:
"make sure that the string path from tuning gear through the roller, over the magnets and attaching to the finger is a straight as possible. This will help the guitar breathe and resonate, as any angle on that path will produce a pinching of the rollers in their milled slots thus throwing off excessive string vibrations into the keyhead which wont be then transmitted through the body at the changer as well. "

Makes sense, doesn't it? Exaggerate this scenario in your mind: at the changer end, pull those strings sideways and imagine the rubbing against the side of the V-groove.

Maybe we can say that this as very insignificant to enhance sustain...but every little bit helps said the mouse when she peed in the ocean.

I have been thinking of ways to get around this issue. Say I turned a much shallower v-groove in the roller, without concern for getting the strings to the same level height wise. That way there would be minimal stress against the side of the groove. Instead, I would make my rollers height adjustable. That way I would get the strings to the exact desired height.
Just a thought I've been toying with.

[richard37066]

Bent -

Congrats on the Miller! Yer like a kid with a new toy, I bet!

When I don't have my head into the zillion design features to be considered, I wander off into la-la land and try to imagine where I'm gonna spend my few pennies on machinery. A miller would - I think - be a logical first choice. But "vertical" or "horizontal"? Doing my homework on that one. It would have to be used as I don't have the finances to buy brand new.

I think that your thinking on the rollers is on the money but requires a bunch more lathe time than if you made the rollers the same diameter and then "guaged" the grooves as you went. Maybe not.

Your comments on how the configuration of the PSG came about are interesting. Seems as though some folks payed more attention to the aesthetics (their version) than in the functionality of the end result. I tend to agree with Mike Cass. Make those suckers straight as an arrow! The only way to achieve that goal is with parallel strings. That also begs a question - in my mind - as to the minimum distance between strings before picking becomes an issue. We'd all agree that we'd like to keep the neck width as narrow as is practicable and that minimum distance then becomes the determining factor. Gotta think on that one, too.

Geeeeez! With all this "thinkin" goin' on, will the instrument EVER get built? Can ya "overthink" this thing to the extent that all you have is paperwork and drawings as the end result to all of your work? I would sure hope not.

Even though you're not into the "autofeed" thing yet, post us some pics of your first attempts. You know that we'll not be critical and simply applaud your efforts!

Richard.

[Georg]

I've been pretty silent lately too, and not because I've got a new "toy" but because I've been disconnected for a week while moving. Got cable connected at my own place down south only a few hours ago, so...

Richard, tapering the neck is nonsense, keep those stings perfectly parallel.

For distance between strings: your GFI is a good guide, only it got the changer at the wrong end. So does mine BTW

With the changer at the right end you simply integrate everything and interconnect non-gauged rollers with whatever changer you end up with, and remove all tendencies to stress and "hysteresis" at those rollers in the process. If non-gauged rollers work at the bridge now, they will work at the other end too. Height adjustment for those rollers isn't difficult to add.

[Ross Shafer]

vertical milll hands down Richard...horizontals are cool (we have 4 here along with our 4 verticals), but they don't see nearly the use the verts do. Don't get swayed by the low price into buying a "drill/mill" table top kind of thing....if it doesn't have a movable knee and a rotatable head you don't want it. Bench top "drill mills" are a very common first mill purchase (low price new and used compared to a vertical knee mill) and I've NEVER known anyone who was satisfied. If you find someone who says they are happy with a drill mill, put them in front of a knee mill for an hour and ask them again.

Congrats on getting that beaut running Bent....after owning Lagun's and Taiwan or Chinese Bridgeport copies over the years (all of which have been great machines)...it was the delivery of your mill late last or early this year that got me off my butt to finally get out and sell my way too big Lagun and find myself a fully rebuilt like new Bridgeport....the mill I wanted from the very beginning 30 years ago!

Does your rig have a DRO (digital read out)...if not, get one! They ain't cheap but it makes precision parts that match each other a whole lot easier...a whole lot!! Then of course there's that lather you're gonna have to have....maybe it'll rain money in 2011!

Happy New Year!

[Bent]

Ross, I agree with the vert vs horiz. Also agree with the DRO. Wish I had one with all 3 axis. OTOH I guess it's good for me to learn the old fashioned way and maybe advance to the DRO in a year or so? I'll likely never get satisfied until I get a CNC retrofit on it. But the money! wow!
You know, it looks to me right now that cutting a nice even curve (like a neck) is darn near impossible to do without a CNC. Remarks?
Also, I need to ask santa for a 6" rotary table. With that, I would have a lathe for most of the round work I would need to do, plus plus.

The mill I have is a TOS, built in Czechoslovakia, 3200 pounds and solid as a rock. 675V/3ph.

The guy that gave me the mill also supplied a step-up transformer and rotary phase converter, installed by an employee of his. I mean, where do you find people like that, this day and age? I expect to pay a nominal sum for the purchase of the trans& ph conv. But the mill- he gave me for free, even transported it to my shop, leveled it up and everything. Plus he gave me a vise that would sell for $5 or 600 new. Plus he says he will bring a bunch of tooling with him when he comes to spend a day with me and give me a crash course.

I am still pinching myself...

Yes, Happy New Year to you and all my friends here on Builders!

[richard37066]

Bent -

Ya lucky dog! Now that's what I call a Christmas present and a half! Ya know anyone who wants to deliver a freebie to Gallatin, Tennessee?

Ross -

Thanks for the advice and education. Intuition told me that a scaled-down imitation of the real thing was not the way to go. You've convinced me. Now, where did I stash that old piggy-bank?

Richard

[Georg]

Now, where did I stash that old piggy-bank?

Weather permitting I'll come up and help you look in a couple of weeks time

[Ross Shafer]

Howdy Richard,

let me clarify on the vert mill selection....there are actuality some very nice scaled down (size wise) vertical mills that are dinky and work very well. We've got a little tiny Clausing mill that's only about 3 feet tall, but has a knee that raises/lowers and a tilting head (the drill mills I despise, commonly referred to as "bench top mills" have neither)....good mills can come in small packages and if you're vigilant small prices too.

When you start searching for the heavy metal of your dreams, feel free to contact me if you have questions.

[burt]

When I need to mill a radius, I have to calculate the x and y positions the old fashioned way, as my millers don't have CNC.

When milling a radius (or indeed, when milling at all) the operator must be mindful of backlash and downmilling, as cutters can be easily smashed, and jobs ruined, by not knowing about these two aspects of machining.