Continuously Adjustable Bellcrank - REVISON

[Les Ford]

This is another revision of the bell crank to make it easier to run the rods in the available space. I don't know if this will cause as many problems as it solves but I'm going to find out.

[Bobby D. Jones]

Neat pull adjustment belle crank.

If you cut a grove in the end of the adjusting screw, And used an E clip type of locking clip, Would narrow the present nut slot, Would allow moving the pull rod closer to the cross rod pivot point. May only need a few for certain pulls.

Where the bell crank attaches to the cross rod, The design only has a set screw holding all the pressure of the pull on the bell crank.
You may want to consider moving the set screw down to become a pass through bolt. With the bolt closing the square, For a encircling grip on the cross rod.

Good Luck in this project.

[Fred]

You could also put the locking nut at the top and end the screw in a blind hole.You would lose travel at the other end but could make the whole assembly longer if needed.

[Les Ford]

You could also put the locking nut at the top and end the screw in a blind hole.You would lose travel at the other end but could make the whole assembly longer if needed.

Thanks, A few people have suggested this. I'm going to try this solution today.

[Chris Lucker]

Jerry Blanton's first version -- I think he told me 1960 -- was quarter inch All-Thread rod welded to a cross shaft with a pair of nuts that could be adjusted for height on the threads. The purpose of the second nut was to jamb the nuts in place. One of the nuts had a groove machined around its circumference. A piece of piano wire was twisted until it tightened itself to stay in the groove but could still spin around the nut's circumference. The other end of the twisted wire had a loop that connected to a pull rod. The pull rod went to the changer finger, that was again, quarter inch All-Thread.

[Les Ford]

Sounds a bit complicated Chris.
I think that by the time I have implemented these changes it will be, aside from bending the rod through the travelling block, basically a home shop version of what Ross Shafer is doing on the new Sierras.

[Ross Shafer]

Hi Les, Looks like you and I were working on the same thing at the same time!

[Les Ford]

Hi Les, Looks like you and I were working on the same thing at the same time!

Now THAT'S how it's done!

I see that you have solved for getting as close to the center of rotation as possible, while also enclosing the cross-shaft completely. My setup spreads slightly at the gap for the shaft because of the screw pressure.

It's fun to figure this stuff out but I must admit that it might be cheaper, easier and better to just buy a Sierra!

[John McClung]

Do these bell cranks allow other pull rods to pass through to reach pedal and lever bell cranks closer to the keyhead?

[Les Ford]

Do these bell cranks allow other pull rods to pass through to reach pedal and lever bell cranks closer to the keyhead?

Yes, The rods do not pass through but rather beside the bell cranks.

[Donny Hinson]

These continuously-adjustable pullers are very well made and designed, and I can really honestly appreciate the work and thought that went into them. But with that said, I just don't see them as a "necessary item". (And evidently, most pros don't either.) They're added parts expense and added weight where it's simply not required. Yes, I know some players feel that every set of pulls has to start exactly at the same time, and end at exactly the same time. But my experience and over 50 years of playing and listening shows me that that simply is not the case. You cannot hear those slight discrepancies of pulls not in "perfect" time when you're playing in a real-time situation. So why worry about them?

Continuously-adjustable pullers have been around since the '70s, and maybe even before that, (the Linkon? slotted pullers), and I have no problem with having them available as an extra-cost option. But I hope we don't start expecting them on every new guitar because we can't go on griping about the price of new instruments rising when we're gaga about over-engineering and adding complexity where it's not needed. I even commented here over the years about the necessity or advantage of the Emmons 14-hole pullers vs. pullers with only 4 or 5 holes. But to their credit, at least all the extra holes didn't add extra weight and parts.

[Les Ford]

These continuously-adjustable pullers are very well made and designed, and I can really honestly appreciate the work and thought that went into them. But with that said, I just don't see them as a "necessary item". (And evidently, most pros don't either.) They're added parts expense and added weight where it's simply not required.

You might be right there but I'm just keeping myself entertained. The total weight of a set of 24 for a U12 is about a pound.

I have ben trying different copedants and every time I move the rods around on my Fessy I knacker my fingers. I'm hoping this will solve that problem but I'm guessing it might create others.

In the case of Ross Shafer, His goal is clearly to engineer the S#@t out of it and make a complete Ferrari of a guitar. His guitars are 25 pounds soaking wet from what I understand.

[John Hyland]

These continuously-adjustable pullers are very well made and designed, and I can really honestly appreciate the work and thought that went into them. But with that said, I just don't see them as a "necessary item". (And evidently, most pros don't either.) They're added parts expense and added weight where it's simply not required.

You might be right there but I'm just keeping myself entertained. The total weight of a set of 24 for a U12 is about a pound.

I have ben trying different copedants and every time I move the rods around on my Fessy I knacker my fingers. I'm hoping this will solve that problem but I'm guessing it might create others.

In the case of Ross Shafer, His goal is clearly to engineer the S#@t out of it and make a complete Ferrari of a guitar. His guitars are 25 pounds soaking wet from what I understand.

The real advantage of the continuous bellcrank is you don’t need to mess with the rod - just a few turns of the screw. Also regarding weight don’t forget to take off the weight of the bellcranks you would need otherwise.

[Les Ford]

The real advantage of the continuous bellcrank is you don’t need to mess with the rod - just a few turns of the screw. Also regarding weight don’t forget to take off the weight of the bellcranks you would need otherwise.

The difference in my case is 3 grams or .105 ounces between one of these and a Fessenden bellcrank.
They can also be adjusted while the guitar is standing because of the Robertson screw.

[John Hyland]

The real advantage of the continuous bellcrank is you don’t need to mess with the rod - just a few turns of the screw. Also regarding weight don’t forget to take off the weight of the bellcranks you would need otherwise.

The difference in my case is 3 grams or .105 ounces between one of these and a Fessenden bellcrank.
They can also be adjusted while the guitar is standing because of the Robertson screw.

2.5 ounces isn’t much to worry about. My prototype bellcranks are polycarbonate so the weight is in the screw only.

[Ross Shafer]

Thanks Les for your kind comments about the Sierra's I build.

Any comments about a weight penalty are moot since the Sierras I build are amongst the lightest guitars available. I don't have any other bell cranks here to compare with but at 10 grams, I'm guessing they're not a whole lot heavier (if at all) than most bell cranks out there.

Necessary or not my customers (including some pros) appreciate having them. Most players who spend any time in the driver's seat of a new Sierra comment pretty quickly on how smooth all the pedals and levers feel....this is largely due to the near perfect timing that is achievable with micro-adjust bell cranks.

Are they necessary to make great music....not at all! But neither are pedals or knee levers. Another very common comment I get from owners of the new Sierra's is that their tone and smooth, precise mechanics, simply make their owners want to spend more time playing them...I'm 100% certain that the timing benefits of micro-adjust bell cranks (yup very expensive to produce) are part of the equation.

[Bobby D. Jones]

With all those frames in those boxes, Are you using an extrusion and just slicing off the width of crank to make them. They do look exactly the same.

[Andy DePaule]

Nice work Les.
I may change my plan and do some like that too.
Thanks for the post.
Andy

[Andy DePaule]

With all those frames in those boxes, Are you using an extrusion and just slicing off the width of crank to make them. They do look exactly the same.

Not sure if Ross is working from an extrusion but when I saw this post by Les I also thought it may be a good idea to see if I can find an extrusion to do the same thing?

[Ross Shafer]

It'd sure be bitchin' to work with an extrusion for these parts. It would make them substantially less expensive to make while saving a bunch of material as well.

While extrusions can be really affordable....the minimum quantity necessary to make them so would provide me with more bell cranks than I could use in a couple of life times. Hence these are all machined from aluminum billet. The added benefit of not doing an extrusion is that I can make changes to my design far more easily if needed. And I have done this since I first introduced them.

Here's a link to a video showing how I make them: https://youtu.be/UQ4e7Mn5uko. This is an old video. I wish I had a video from the batch you see in my earlier post. They're now done on a new, faster, awesomer machine. The new machine has a 4th axis that allows me to do the first 3 operations on 72 parts with one push of the go button.

[John Hyland]

Hi Ross thanks for the video. do you polish or otherwise cleanup your bellcranks after the machining and how long does it take to make your 24 items?

[Andy DePaule]

Thanks Ross,
That answers my question except I was thinking of going to the local metals seller to see if they might have an extrusion that would work for the application. I know the chances are thin at best.

I remember back in 1978 when I took my friend John to pick up his Custom Sierra D-10 in Portland. We spent most of a week there and I was astounded at how many of the parts were made from extrusions that must have cost a fortune.
Maybe that's one reason they didn't survive even though they were making what may well have been the best PSG design at that time.

Chuck Wright was an amazing man who had designed every part and the extrusions needed to complete the project.
Danny Shields I think may also have been the first to make the changeable pickups in PSG's though I don't know who had that idea.

[John Hyland]

For those that might be interested this is my 3d printed bellcrank.


Since my rod fixing is a thread, the adjuster can slide (at the top) to maintain the rod angle.

[Andy DePaule]

Nice bell crank John.
Makes me wish I had a 3D printer and also knew how to use it.
Curious, How much do each of those extrusions weigh in the PSG?

Also if you've made any more headway with that PSG project.
It's certainly one of the most innovative designs I've seen.
Best wishes,
Andy

[Chris Lucker]

It looks like the tide is in all the way.

i cannot identify if the bellcranks are slid on at the ends of the extrusion or if they are dropped into place from above?
Is that a screw inside the bottom of the crank body interior that pushes a plate against the cross shaft to lock the crank in place? Or, is the screw supposed to be longer and pull up on a square nut to lock the crank in place?