Continuously Adjustable Bellcrank - REVISON

[Les Ford]

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?

The extrusion would be actually the least of it. In my version it is just a rail with two cuts running the length of it. The tedious part is drilling all of the matching holes. I would hate to do it without a DRO on my mill. Once I have the holes in it is just a matter of slicing them off on the table saw.

[John Hyland]

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

Yes making good progress. Stress testing in the wild anD have improved the pedal / lever stop. One
I think I’m getting close to finishing the undercarriage and will update the top next.

Andy did you mean the weight o& the alum extrusion? The battery is dead on my scales so will have to get back. That said it is very light.

Also thanks for you kind comment.

[John Hyland]

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?

Once the cross rod is in place the bell crank snaps on/off from the top. The screw is unfixed but goes into a ‘t’ nut that also drops in from the top. So all is adjustable without pulling everything apart. It is very secure.

And yes the adjustment is right up on this one. At some stage I will cycle back to the fingers to modify. But trying to keep the pedal travel short.

[Ross Shafer]

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

The bell cranks are tumbled after machining, this deburrs and breaks the sharp edges a bit while creating a matte finish that will be black anodized.

I've no idea how long it takes to make 24 pcs.

[Andy DePaule]

Hi John,
Yes it was the extrusion I was asking about. From what you said it's not very much to be concerned with.
Thanks,
Andy

[John Hyland]

Hi John,
Yes it was the extrusion I was asking about. From what you said it's not very much to be concerned with.
Thanks,
Andy

Andy the extrusion weights 56g (2oz) for 135mm length

[J D Sauser]

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.

CARTER's bell cranks and many other parts (actually, even the changer block) were custom extrusion. Sure, Carter got to a point where they produced over 300 guitars a year. But like everybody, they started with considerably lower numbers which however rose very quickly by design and marketing strategy, which brought them closer to realistic minimum ordering requirements early on. Still I remember that I found it to be extraordinarily low in those days.
The die, for their bell crank which only needed to chopped, sliced and drilled'n'tapped cost, if I remember right $2500.oo (Made in the USA!) in the early 90's! It was a no-brainer!

... J-D.