Bellcranks

[Bent]

In the Inlays thread, Ross wrote:
Thanks Bent...no where near so sweet as that blue dream you just finished!

I think what you're suggesting can be done, but I don't think it has anything to do with how straight a pull rod run is. without digging further into your idea, I can't be absolutely sure, but I'm pretty sure it would also add manufacturing steps (cutting the slot if nothing else). Show Pro, GFI, Fessenden, Emmons, Rittenberry, Lamar, Mullins, Williams, etc. all use bell cranks that do not support the rod from both sides with little of no ill effect.

In a perfect world, I too would prefer to pull the rod symmetrically....But in the real world, using normal pull rod materials and diameters, the string pulling forces we're talking about on the vast bulk of the steel guitars don't really require the extra support.

The full assembly width of the crank you see is .375", the main body is .220", but the next round will probably be a bit thinner. My goal is a .340-.355" total width...essentially in the same range of string spacing norms.

Hopefully that's all clear...and that I understood your question to begin with.

bestest,
Ross

Thanks for your kind words about "Blue".
I only envisioned straight pulls and other rods running thru the bell crank as a means to avoid bending too many rods. I am fine with pulling from one side. With the way I have it on Blue is just like Ritt, Rains etc and no ill effects. I think that making the bell crank as thin as possible is a big step towards avoiding rod bending,
Your goal of 340-355 is a good one. The body part that actually holds the rod could be machined down to .250 to .280 if using a 3/32" rod. That would be thin enough to let other rods pass by without having to bend them to fit. The problematic ones would be rods that go to the same string (as always).

Well...maybe some test cuts would be in order

[Ross Shafer]

Hi Bent,

I guess I'm being dense, 'cuz I'm not following you. Using the protos I've made, the rods going to different cranks from the same string stack above and below each other and run parallel to the front and rear aprons of the guitar. The only bending necessary would occur if one had to get a rod over or under another rod's bell crank position to achieve the desired timing, or to have the rods run parallel to the top of the guitar (as far as I can tell this is for aesthetics only and serves no functional purpose, Justice Guitars are done like this and it does have a nice, neat look)

Again, I may be missing something...I consider myself pretty new to all this.

On your latest beauty how wide is your bellcrank/rod assembly at the rod? I'm not referring to the width of the bell crank clamping area.

[Bent]

Russ...and I suck at explaining sometimes. Maybe it's the Norwegian left in me
Ok say you are rodding sting 4 raise for pedal 3. So you place a bell crank in line with 4th string changer finger and attach rod to bellcrank. Done.
Now you are rodding 4th string raise on LKL. You push the rod thru another raise hole on the 4th string raise finger. You already have this bell crank lined up with 4th string. Push the rod thru and it hits the bell crank for pedal 3. To get around this obstacle, you bend the rod to avoid that bell crank and then bend it back in order to re-align itself with LKL bellcrank.

The width of my bellcrank/rod assembly including wire thickness of retaining spring is .400" You should be able to see what I am talking about if you look at the left in the pic where rods for strings 2 and 9 are hooked up.

With my hook-up procedure AND yours, we can run the rods on either side of the crank. With the original Blanton hookup AND the way I would like to do it, the rod can only be placed in the middle thereby eliminating the "either side" possibility.

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[richard37066]

Bent and Ross -

You guys are doing a great job of beating this thing over the head so maybe an observation and suggestion on my part may not be all that informative or enlightening but here goes: -

IF - IF - we accept a more-or-less "standard" spacing of 11/32nds between strings, then Ross need only shave the width of his crank by a smidgen. 11/32nds is 0.34375" - not far from where Ross is at present. It concerns me that the clamping portion of the crank - around the crossrod - is not that "beefy" but increasing a dimension or two could very well afford the necessary strength. In doing so, two cranks could be stacked side-by-side in order to access adjacent strings in straight-line pulls. In addition, there is the obvious room for a couple of rods passing by the vertical member of the crank. A tight squeeze, no doubt, but manageable.

And Bent, you're quite right in saying that multiple pulls on the same string can be problematic - a desired adjustment on another crank bringing its' rod in intimate contact with another or the necessity of putting a "Z" in a rod for clearance. Since the Blanton crank, indeed, does the tuning then some contact - interference - may be unavoidable in a given copedant thus requiring the bending of a rod. In Ross' case, however, where the nylon tuners are brought into play, there may be a solution - however wacky. In search of an ideal setup, could not one simply extend the length of the changer fingers and/or the cranks for added clearance with an appropriate increase in the spacing of the holes in the fingers, themselves? One could argue that, if both the fingers and crank were lengthened porportionately, the interference problem would remain. However, a slight maladjustment in either (or both) - in order to achieve clearance - would not signify the end of the world and especially in Ross' case where the tuning is still done with the nylon adjusters. Would a disparity in these adjustments be noticed and objectionable when attempting to coincide start and end times of two pulls? In a TRULY REDICULOUS EXTREME, one can envision a cabinet that is 6" deep with 5" fingers and cranks affording gobs of room for most any configuration. The question then is, how far can this ludicrous depth/length be shrunk to the extent that the ideal is approached and workable? Will we, in some instances, still be left with that damnable and unwanted interference? Yes, I know, it necessitates a redesign of the changer fingers and creates a new set of leverages to contend with. My only defense of this suggestion is that we're spending creative energy and time in an effort to arrive at an optimum configuration. If it means that we deviate from the "norm" in our efforts, then so be it. Does not the end justify the means?

As an aside, I must mention that Georg and I are two who are not locked into the grouping of raises and lowers - that is - all of the raises are at one end of a finger and the lowers at the end of the other. Although we differ in the absolute configuration, we, nonetheless, favor either smaller groups which are staggered or the alternation of raises and lowers in the vertical plane of the changer. This is an option which might very well alleviate the problems associated with the above and modified Blanton idea. Georg is even considering easy, drop-in changeable fingers to accomodate different copedants with attendant different pulls. I'm not quite there, yet, but his idea has merit.

You guys are attempting to grasp the brass ring and corral the holy grail. Don't give up the quest.

There - I've tossed another hair-brained idea into the air. Catch it if you can and crucify it if you must. There's merit there - but how much? Don't know.

Richard

[Ross Shafer]

bell cranks/pull rods are spaced at .344", hard to see without a 3D viewer or multiple views, but there is no contact between any pull rod and the bell crank on on an adjacent string. Are we talking about the same thing? I'm all for being set straight if I'm missing something. Thanks for checking me.

[Bent]

Ross,this works well because it is just part of the whole rodding sequence for E9th.

Just for the sake of the discussion, let's say that the cross shafts from teh top are A ped, B Ped C Ped and the PF ped
I have drawn in 2 items on C ped which is the 4 and 5 string raise. Let's say that the one bell crank and rod that you have there is for raising str 5.
So we need a rod for raising str 4 as well. Two ways to do that Either install a rod clamp on the other side of the existing square lug (if that is possible) or install a bell crank on the other side of the existing one to accommodate the 4th string raise. I wrote in C Ped and "Also raise 4" and Raise 5
Now we have to add another cross shaft and two bell cranks to accommodate LKL raise for str's 4 and 8. Say we put this cross shaft in between shafts 2 and 3.
Now we run into problems for the 4th string raise since there already is a rod in that line from pedC and the bell crank for LKL 4th str raise is right in line with the crank for PedC 4th str raise. Here is where the rod bending might have to be done.

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[Ross Shafer]

hmm, ain't nothin like a little 3d modeling to finger this out...I'll get to it when I can. In the meantime since we're on this subject, here's a pic of Linkon's take on an "ABC" (adjustsble bell crank)

this sucker has a total width of around .680"!

[Bent]

Steel huh? Very thin. Good. adjustable, sure, but hard to fine-adjust - all you do is loosen the screw, lift or lower the rod by hand and re-tighten. Just a tad "mickey mouse". Yes, the shoe is too wide. It should be kept the same or narrower as the string spacing.

I like yours better, with the fine adjustment. I envision a knurled brass nut on the end of the screw. That way, you can reach under and fine-tune on the fly.

[Georg]

I want split-rods and JI-compensator-rods, so regardless of type of bellcranks/adjust-methods they have to allow for a minimum of two rods attached to each.

[Ross Shafer]

didn't need that on my protos Georg, but I've got it covered, very simple