Steel Guitar Builder

I'm happy with my 5/8 inch diam on my current guitar. Next one will be also 5/8. I looked around town this morning and I can get 5/8 chromed shafting that will apparently dint if hit with a hammer. I'm wondering if it's worth a try or should I be looking for something else.
Thanks!

I guess we all have our preferences or ideas on what makes a great shaft. I am sure your 5/8" will never bend. I don;t think the chroming is going to make any difference as far as bending goes. Plus, you take a chance on chipping etc. Actually I might want to stay away from it.

I know a builder, Martin Weenick, who found that the 1/2" anodized aluminum does it for him.
Emmons PP arrived at 9/16" drill rod. I believe it was untreated because I saw a 35 yr old Emmons shaft and it was all gouged up from the changer fingers turning on it.

I have arrived at what I will use, which is a 1/2" drill rod that has been hardened to 50-60 Rockwell hardness.

My 2 previous builds have 1/2" 304 stainless in them. Nice and ultra smooth axle. Which is best? Open for discussion.

I also use a 1/2 inch stainless steel rod , 5/8 is fine but you dont really need the chrome on it. Russ

I use 3/8" steel rod.....but I have spacers between each string that butt against a solid plate in the front and back. No chance for bending.
Just my 2 cents worth.

By the way my stacked humbucker I posted about yesterday works pretty good....except I somehow shorted both windings to the 1 and 10 slugs so it doesn't work the best. Back to the drawing board. I've pretty much run out of #42 wire anyway.

My birthday today! 74 this time around

Happy birthday Mac

As for cross shafts, I use 6mm diameter st/st bar which is individually supported (like the Sho-Buds) and each finger is set in a sealed st/st bearing, smooth as silk! A 5/8" (16mm) should really do the trick, but if you think that it may flex a little just put a center strut/support on it.

Dave.

Thanks Guys! That was quick.

HAPPY BIRTHDAY MAC. Gotta love those numbers easily divisible by 2.

Happy Birthday Mac!

Yes, Happy Birthday Mac! You are almost exactly 10 years older than me..this bodes well...I have 10 more fun years to look forward to.
Keep building them, my friend, this is what keeps you young no doubt. Proof: Eddie Fulawka is almost 83 and still cranking them out like no tomorrow!

Happy Birthday Mac!.......Mike

Happy Birthday, Mac! Yer catchin' up to me!

The "egghead" in me sent me chasing for some numbers relevant to the question of adequate shaft diameter. The following is what I came up with.

Notes: - The tensile strength of steels does not vary by much with alloy therefore I used a value of 30 X 10^6 PSI in the calculations for the value of the so-called Modulus of Elasticity. From calculations done elsewhere on this forum we saw that the average tension per string was in the vicinity of 27lbs. I used 30lbs to be on the safe side. The length of my axle shaft is 3.25" between supports. I used this number. In treating the shaft as a beam, one must specify whether it is a simply supported beam - i.e., resting on two knife edges for example - or one which is fixed at both ends. I did the numbers for both conditions although, intuitively, the configuration is closer to the "fixed" model as opposed to the "supported" one. The calculation is done assuming an evenly distributed load. To that end, I calculated an average load per lineal inch and used that in the formulae. The numbers given are the maximum deflection at the center of the beam (shaft).

Diameter: Supported: Fixed:
5/16", .00951", .000585"
3/8", .00461", .000284"
7/16", .00248", .0001528"
1/2", .00146", .0000899"
9/16", .00091", .000056"

It can readily be seen that "fixing" the ends of the shaft reduces the deflection considerably. The calculated total load on the shaft is approximately 300 pounds. (30 pounds/string) If one were to stomp a couple of pedals for whole tone raises then there would be an additional 15-20 pounds added to the total load. Attempting to calculate individual loads located at specific points along the "beam" is hairy and tedious thus I took the liberty of averaging the load along the length of the shaft. However, and by inspection, one can see that the overall effect of this additional loading is somewhat negligible. In terms of "detuning" when one mashes a couple of pedals it is seen that the added loads would not contribute measurably to the overall deflection thus the "scale length" doesn't change by but a tiny smidgen. Just as a comparison, if the shaft were bent by 0.0024" (for a scale length of 24") then this represents a change of scale length of 1/10,000th at the center of the shaft.

This is not meant to be a spot-on analysis of the loads on the shaft and the deflection incurred as a result of those loads. It is only meant to be representative of the deflection that we might realize as a result of shaft diameter. The axle shaft on my GFI is 3/8" in diameter and seems to afford no problem.

Hope all of this helps a bit.

Respectfully,

Richard