round vs square cross-shafts?

Karlis Abolins · Post by **Karlis Abolins** » 7 Aug 2007 5:34 am

I am at the point in my guitar building where I need to decide whether to use round or square cross-shafts. I realize that I face a similar issue with bellcranks. My experiences are with the MSA style cross-shafts and the bellcranks with brass bushings compared to the Fessenden style square cross-shafts and the bellcranks with grooves rather than holes.
While I like the Fessenden style of setup for its ease of changing pulls, I have always preferred the MSA style for its smoothness and accuracy.
I guess another way of looking at it is weighing the short-term ease of changing pulls against the daily pleasure of smooth and accurate playing.
What have your experiences been with the two systems?

Karlis

Mike Wheeler · Post by **Mike Wheeler** » 7 Aug 2007 5:44 am

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.

Tom Campbell · Post by **Tom Campbell** » 7 Aug 2007 5:48 am

Square shafts with bell cranks that have round holes are best.
Fulawka, GFI, Pedal Master and some others use this method. The round hole with the brass pivot bushing give smooth operation. If you experiment with setups a lot, then square shafts are a must...if not, round are OK. If you use round shafts, keep greas/oil off the shafts as much as possible to prevent slipping of the bell crank when tightening them to the shaft.

Mike Wheeler · Post by **Mike Wheeler** » 7 Aug 2007 5:50 am

Another thought....I agree that the MSA system is very accurate and solid...a very big plus...and smooth playing. With the straight rods, moving a rod doesn't require removing the tuning nut...I always hate that. MSA rods just slide out of the changer! Just something else to consider.

Bill Hatcher · Post by **Bill Hatcher** » 7 Aug 2007 6:47 am

I would never consider building a modern PSG with round shafts UNLESS you devise a system where making changes is as easy as making changes on square shafts. Changing and adjusting a guitar with square shafts and cranks that slip on and off is the norm with virtually all PSG builders now. There is a reason for that.

Mike Wheeler · Post by **Mike Wheeler** » 7 Aug 2007 6:57 am

I agree with Bill's comment. The only potentially good aspect of using round shafts is that the bellcrank angle on the cross shaft is infinitely adjustable. This can be helpful in adjusting the pull to get a very "snappy", or quick, action on the pull. Granted that's a minor issue, and not a good reason to go with round shafts, but thought it worth mentioning.

Michael Johnstone · Post by **Michael Johnstone** » 7 Aug 2007 7:37 am

Excel Guitars have hex cross shafts so that's another option. There are several advantages to that shape. One of them is that altho square shafts are the easiest to make bellcranks for and move them around easily,they offer the least resistance to flexing under pressure because of the large flat sides. Round shafts flex least because of the inherent surface tension of the round shape and hex shafts are very close to round ones in that respect.Bellcranks for hex shafts are a little trickier to make but Excel bellcranks slide on and off just as easily as Fessenden 'cranks while having the same non-slip attributes as well as all those little flats for set screws and several in-between angled positions if needed.

Casey Lowmiller · Post by **Casey Lowmiller** » 7 Aug 2007 11:16 am

Gary Rittenberry has been using hex-shafts and they work perfectly!!! He also has been using quick-change bellcranks. With one screw you can tank the bellcrank off of the hex-shaft & move it where you want to.

To me, that is the way to go. It provides ease of maitenance/changing and an extremely stable undercarriage. It is very modern & very reliable.

Casey

Karlis Abolins · Post by **Karlis Abolins** » 8 Aug 2007 5:46 am

Thank you all for your experiences. The MSA style bellcranks look like the way to go. The square cross-shafts have an advantage for builders because they allow the builders to easily setup and/or change an instrument's copedant. For an amateur builder like me, the ease of making an MSA style bellcrank for a round cross-shaft outweighs the benefits of being able to change copedants quickly.

Karlis

Dan Beller-McKenna · Post by **Dan Beller-McKenna** » 8 Aug 2007 7:04 am

FWIW,

having gone from a Dekley (with MSA-like shaft and crank) to a Fessenden last year, I did not find the round bushing to give any smoother feel than the "toothed" hook up of Jerry's bellcranks. If anything, the Fessenden is smoother.

On the ease of making changes it's a wash: the toothed crank is quicker and easier to take of the shaft and move around, but the MSA systrem doesn't require taking the tuning collar off at the changer end.

Dan

Bill Moore · Post by **Bill Moore** » 8 Aug 2007 2:26 pm

I am working on a project right now, and I'm using round crossshafts. The main reason is that a lot of the parts are from a Marrs guitar. The bellcranks are single bladed, the rods have a 90 degree bend. These are the simplest kind to make. I'm just about ready to put on the strings and rods. Here is a couple of pictures.

John McClung · Post by **John McClung** » 8 Aug 2007 9:41 pm

I've come to appreciate the superiority of Mullen hex shafts and the single blade bell cranks. I bought a Carter, thought I'd revamp the setup myself, but could not for the life of me get a bell crank set screw tight without it wiggling out of position, not perfectly lined up with the changer finger.

On my Mullen, the set screw holds it tight and also as it tightens makes the bell crank stay in one solid place.

And the single bladed bell cranks are MUCH better than any twin-blade bell cranks; on my MSA, there were many pull rods bent to go around bell cranks because there was no room left to go over or under other pull rods in bell cranks closer to the changer. There are zero bent pull rods on my Mullen, it's a much more elegant solution, very easy to work on.

Ulf Edlund · Post by **Ulf Edlund** » 9 Aug 2007 2:22 am

Square.

Mike Wheeler · Post by **Mike Wheeler** » 9 Aug 2007 6:43 am

John, not being familiar with the Mullen mechanics...how are the pull rods attached to the bellcranks?

John McClung · Post by **John McClung** » 9 Aug 2007 7:15 am

Mike Wheeler:

small 90 degree bend of the pull rod tip, slips into one of 5 bell crank holes, held in place with a teeny cotter pin. That's the only drawback, the rods would be very hard to make yourself, so when you need more, you order them for the exact length of whichever pedal/kl position you're adding a change to. But they aren't terribly expensive, either, so it's liveable, and the precision is very worthwhile.

Del's guitars are extremely well-engineered, right up there with Zums and GFI's, imho.

Mike Wheeler · Post by **Mike Wheeler** » 9 Aug 2007 8:20 am

Thanks, John. I appreciate the info.

I agree the old MSA style bellcranks can cause a good bit of congestion down by the changer...especially on a U12...been there, and it's not pretty!...but every design seems to have it's downside. I guess it's a matter of what's tolerable, eh? I don't mind that congestion because of the ease of making new rods and the ability to switch things around on a whim (which I tend to do $:\$ )

Paul Redmond · Post by **Paul Redmond** » 10 Aug 2007 10:57 pm

On the Whitney's I've built, I used round shafts, but designed the cranks so that the #6-32 SHCS that held each of them in place also acted as a key to prevent them from slipping or spinning on the shaft. It also made it easier to re-install a shaft without guessing where the crank was before you took it off. BTW I had also pre-drilled/tapped the cross-shafts on location so that all cranks would be in line. This is cost-prohibitive and labor-intensive, but it DOES work well. I used the single-blade cranks, rod bent to 3 degrees past 90 to make it pull toward the blade of the crank rather than away from it.
Zane Beck had a great idea using rectangular shafts where the cranks screwed to the tops of the shafts. There are advantages to this, but they weigh more. Joe Kline used hex shafts and they worked fine, but those pulls on a Kline bottomed at the endplate. If you had too much 'over-ride' on a pull, the set screw would work loose and the crank would flop around a lot. Fessy clips on a square shaft are by far the easiest to position without interference and they do stay put well. There are pros and cons to them all. If you are a player who is always changing setups, you must find one method that will allow for easy changes. If you're a 'set-it-once-and-forget-it' player, they'll all do just fine and hold their own. While I designed and built the Whitney's, I admit that they are the most miserable guitars on earth to work on/change. They weren't designed to be changed!!! Almost all of the pulls on my 2 prototypes have been set up that way since 1984 and 1985!!!
Thanks to guys like Bud Carter, Roy Thomas, Gene Fields, Bill Rudolph, and scores of others, changing setups today is usually a snap. . .changes can be done in minutes instead of hours. It's all in what you want in the final analysis. Fender's have been around for 6 decades and they can be changed in 15 seconds flat.
PRR

David Mitchell · Post by **David Mitchell** » 15 Oct 2017 8:27 am

This is an old thread but people are still building new steels everyday so here is my thoughts on round vs square cross shafts. For what it's worth just about a month ago I reversed a man's old MSA with round shafts on swivels from an Emmons to a Jimmy Day setup. 6 bellcrank and 6 rod changes in about an hour and I didn't have to remove any bellcranks and the reason why is that when you loosen an MSA round bellcrank they will fall over and duck the pull rods allowing them to slide over. How many times will someone want to completely remove a bellcrank and place it on another cross shaft? Only when adding bellcranks does it become necessary to pull the shaft. If one does that too often then their time would be best spent deciding which setup they really need or just buy a bunch of steels with different setups. I find the old MSA's not any harder to work on than modern square shafts. As someone said earlier removing the nylon nut which is actually metal and part of the pull rod on the old MSA's is not necessary. Only one screw to loosen to remove it whereas on square shafts you need to loosen the bellcrank set screw and remove the nut too UNLESS it is a square shaft bellcrank with floating pivots which are rare and expensive. 6 of one and half dozen of the other in my opinion. One other thing about old MSA's is they had no problem with the pull rod threads dragging on the raise and lower actuators because they have sleeves that prevent that. MSA parts are probably more expensive to make but they sure made life easier in several ways.

admin · Post by **b0b** » 15 Oct 2017 10:29 am

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.

Greg Cutshaw · Post by **Greg Cutshaw** » 15 Oct 2017 11:24 am

Some pics of the Excel hex shafts. Click images below for larger pics

David Mitchell · Post by **David Mitchell** » 15 Oct 2017 11:39 am

The last three I have built have been square shafts. Two were 3/8" one was 5/16" LeGrande size. What I want for bellcranks from now on is removable square bellcranks with the round swivel straight through with locking set screw collars. They will probably cost a fortune. The reason I responded to this post was because round shafts and it's relating bellcranks are not the nightmare a lot of people make them out to be. I can think of some a lot worse like ZB pedal steels.

David Mitchell · Post by **David Mitchell** » 15 Oct 2017 11:48 am

b0b wrote: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 would tend to think round shafts would have to have a flat spot for none slip operation but then if they did I don't suppose you could call them round anymore. I do favor the square shafts and the instantly removable bellcranks. I am so tired of bending rods and sometimes bending one too short or too long. Looking for square bellcranks that doesn't require bending rods. I'm willing to pay extra for locking collars but then I'm back to the round rod problem it's just a smaller rod. lol!

Storm Rosson · Post by **Storm Rosson** » 15 Oct 2017 6:05 pm

Mike Wheeler wrote: but the Fessenden style 3/8ths square crossrod mount.

My Fessenden has 5/16", square, steel crossshafts.

Brint Hannay · Post by **Brint Hannay** » 15 Oct 2017 8:56 pm

Square and hex cross shafts seem to me equivalent in terms of stability. Round, even with a flat spot: Why? Why take any risk of slippage?

The important point to me is being able to put the bell cranks on or take them off the cross shaft without having to detach the cross shaft from the guitar to slide the bell cranks on or off lengthwise, a la Sho-Bud.

BTW, as for bell cranks with the "comb" style attachment of the pull rods, it makes no sense to me to have the rod seat in an open slot in the "back" side of the bell crank without anything to secure it there. I briefly borrowed a friend's (older) Fessenden, which had the rods hooked into slots in the back of the bell crank with nothing to secure them, and because my tuning wrench for the nylons was apparently a slightly different size from the Fessy's nylons ("English" vs. metric?), in attempting to fit the wrench onto the nylon I would end up pushing the rod inward and it would fall out of the slot in the bell crank. Who would necessarily remember which slot the rod was in? This shouldn't be able to happen!

Scott Duckworth · Post by **Scott Duckworth** » 16 Oct 2017 2:06 am

Square or hex with round ends placed in bearings.