round vs square cross-shafts?

[Jack Stoner]

My 81 Franklin has round shafts. I've never had a puller come lose. However, I have had them come loose on a 71 PP Emmons with round shafts with a flat side.

[Richard Sinkler]

Regarding the Fessenden bellcranks, the slotted design is not really a problem. I have reconfigured 2 of them. Unless you have the nylon nut loosened a lot, you shouldn't have problems with rods falling out. This really only happens when moving or installing new rods. If you hold onto the rod under the guitar when putting the nylon nut, you won't have any problems with the rods falling out.

[Storm Rosson]

My home made project psg has round shafts and they don't slip ever.....but that's likely to be a result of using hardened, tempered, 5/16" motor shaft rod with a full length key way for the set screws to seat.

[Brint Hannay]

Regarding the Fessenden bellcranks, the slotted design is not really a problem. I have reconfigured 2 of them. Unless you have the nylon nut loosened a lot, you shouldn't have problems with rods falling out. This really only happens when moving or installing new rods. If you hold onto the rod under the guitar when putting the nylon nut, you won't have any problems with the rods falling out.

The problem I had was in simply trying to tune the nylons, which had no excessive slack. It was caused by a size difference between the nylon nuts on the Fessenden and my tuning wrench (which fits fine on my Sho-Bud, Mullen, GFI, and Williams guitars). It was hard to get the wrench onto the nut, and too much pressure pushed the rod, and with it the finger, inward, and with the rod unsecured in the bell crank, it fell out of the slot. This probably wouldn't happen using the Fessenden's own tuning wrench, but nevertheless I prefer the Williams approach (mine's a 400 Series), which also uses slots but adds a spring clip that holds the rod in the slot. Why take any risk of a problem, perhaps for example in a hurried situation?

[Charley Bond]

I have an old Sierra Olympic. It has round shafts, but I overcame that problem with a drill, a tap & socket head screw.

It was setup Emmons & I like the Day setup, so when I did the change, I drilled my spots on the shafts, drilled out the hole in the bell cranks, tapped them & stuck a socket head set screw in there. Then I located the bell cranks & tightened the screw. I used the medium lock LOCTITE. Done Deal...

[Richard Sinkler]

Regarding the Fessenden bellcranks, the slotted design is not really a problem. I have reconfigured 2 of them. Unless you have the nylon nut loosened a lot, you shouldn't have problems with rods falling out. This really only happens when moving or installing new rods. If you hold onto the rod under the guitar when putting the nylon nut, you won't have any problems with the rods falling out.

The problem I had was in simply trying to tune the nylons, which had no excessive slack. It was caused by a size difference between the nylon nuts on the Fessenden and my tuning wrench (which fits fine on my Sho-Bud, Mullen, GFI, and Williams guitars). It was hard to get the wrench onto the nut, and too much pressure pushed the rod, and with it the finger, inward, and with the rod unsecured in the bell crank, it fell out of the slot. This probably wouldn't happen using the Fessenden's own tuning wrench, but nevertheless I prefer the Williams approach (mine's a 400 Series), which also uses slots but adds a spring clip that holds the rod in the slot. Why take any risk of a problem, perhaps for example in a hurried situation?

Point well taken. I don't understand why there can't matches between the tuners and tuning wrench. I preferred the wrench I got with the Williams I had. Even when I sold the Williams, I kept the wrench as it fit the nuts on my Carter better than the George L wrench.

[Mike Bourque]

I once had a bell crank slip on a round cross shaft, detuning the pedal on stage. Total disaster. Square is the way to go.

I agree with you there bob. Usually the Blanton design is on a round shaft for more time tuning possibilities and the round one do ring better but I do like the square shaft idea implemented with the blanton style crank like over here

[Bill C. Buntin]

[quote="Mike Wheeler"]Karlis, since you're making the parts, I'd go with the MSA style for the pull rod connections (straight rod with round brass bushings), but the Fessenden style 3/8ths square crossrod mount. You'll have the best of both worlds...quick bellcrank position changes, and straight pull rods (very easy to make).

I wish I could find some inexpensive ones like that for my MCI. But the ones I know of are very expensive (I'd need 30 of them). So, I'll have to save up for a while.[/quote] PS

Mike, my thoughts exactly. I made a couple of these bell cranks. Because I too liked the Carter made msa setup. They work perfectly. I would convert my emci to this entirely if I could find 30 bell cranks already made.

To the op...square is the way to go IMO

[Jon Light]

I've come to appreciate the extra bit of finesse that round shafts allow. To be able to adjust the bellcrank's position in the arc of the rotation of the shaft adds one more dimension in fine tuning multiple pulls on one shaft. But I am always nervous about tightening and overtightening the bellcranks.

[J D Sauser]

Round shafts have in my opinion only one draw back: you can't remove the bell-crank unless you remove the shaft.
Slipping has never been an issue on a properly tightened guitar, and the ability to freely angle the bell-cranks is an advantage.

H-style bell cranks are the logical mechanical way to go, as long they are made to pull straight the center of the rod. There are only two ways I've seen this done:
1- the simple mechanical way with lock-barrels which can be somewhat "bulky" and taking space for other rods to pass, or the "Top-Grade" way with pins thru the rod in a comb-style H-bell crank (Franklins and I believe some Zums had that). Everything else with hooks, bend-around will ALWAYS by the unbendable laws of physics applied to mechanics, tend to bend the rods at engagement.

... J-D.