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Mullen Bent Cross Rods
Posted: 28 Aug 2010 7:41 am
by Mike Mantey
Well after reading the tone post, well the first page, then it turned into a physics class. So to not hijack the post, here is a new one to demolish.
I will first start off by saying thank you for all the attention.
Next I will say, watch what you say about our company and my Grandfather (Del), that is not a bridge you really want to go down. With that being said.
I would also like to thank Mickey, Boo and all the others that realize it works.
For the others doubters, try one, just because you can't wrap your head around it, doesn't mean it isn't possible. I am sure you are smart guys, but we are too. We spent 5 years developing your elephant. Then we slapped a G2 sticker on it, and what do you know it works, and sounds amazing. Contrary to everything you all said, the few that have a problem, it does work. I personally setup the machines and run the parts and to let you know the front bearing on the crossshaft has no play and the back bushing is within a tolerance of .0002" So if you think that is play or slop, then your crazy. Come find me personally and we can hash it out in person with the guitar, would enjoy it.
This is a post I had from a little while ago and I'll repost it for all you that think we are just trying to save money, quite the contrary. This is not a cheap inovation, you try making the perfect tooling at a decent price.
The design was in no way associated with production costs, absolute inaccurate statement.
Ever since the Royal Precision came out in '99 it incorporated 2 changers of the same size, which could be used on either neck. The endplates where changed to allow for the 1/4" difference of the 2 necks. So with that, you have 2 changers, same changer, but one (the E9th) is set further towards the top of the guitar than the c6th, there is 1/4" difference. The cross rods however do not follow this 1/4" offset. The cross rod is straight. So that means a rod on the C6th in the same hole in the changer and bellcrank would be straight, now the same rod in the same locations on the E9th, the rod angles towards the top of the guitar due to the difference in the mounting location.
Now on the G2, the design or question was how do we get the rods straight on both necks without going back to manufacturing 2 different changers (such as the original or HWP Mullen). The answer was we needed a crossrod that would bring the E9th side closer to the top of the guitar. Therefore the bent idea was formed. It did not start out as the way it ended up, it was at one time going to be 2 pieces that bolted together, after long hard work by Del he found a way to bend a cross rod and still make it operate for the function needed. It was perfect and there are some other advantages to this design that I won't get into now.
So is it cheaper than the Royal Precision way? No. Is it cheaper than 2 different changers? Not really, but this is the design that best suited the G2 and it is here to stay.
Defense
Posted: 28 Aug 2010 7:54 am
by Mickey Adams
uh huh.....yep...
With respect
Posted: 28 Aug 2010 8:15 am
by Michael Robertson
Mike you are a class act without doubt.
Rather than grace the contemptuous thread you reference, you address the issue in a professional manor here.
I saw the other thread turning into an ugly “I’m right and you’re wrong” forum.
I was advised that conversation is the intent of that thread.
Conversation would be great but that was getting personal and far away from any constructive statements or conversation.
Best regards to you and your family.
Respectfully
Michael
Posted: 28 Aug 2010 10:17 am
by Jim Smith
Mike, are you really able to machine your cross shafts to a tolerance of .0002" (two ten thousandths of an inch) or did you mean .002" ? (two thousandths of an inch)?
Posted: 28 Aug 2010 10:31 am
by Mike Mantey
Thank You Michael
Yes, Jim the cross rods are machined to a tolerance of .0002-.0005
Now to clarify that is the tolerance held on the cross rod, the bushing does have .002 difference so they do not lock up and turn. So yes the crossrods are that accurate and the bushing is 2 thousands of play to they do not drag at all.
Posted: 28 Aug 2010 10:44 am
by Storm Rosson

Anyone who thinks .0022" of play is "sloppy" is just plain goofy (I think that is what the shaft run-out and the bushing clearance add up to)in my, and prolly anyone with any mechanical savvy,opinion.And the "bent" cross rod borders on genius innovation IMHO

Mullen guitar
Posted: 28 Aug 2010 10:57 am
by Billy Carr
My next guitar will be a Mullen. Just hadn't decided which one yet. G2 or RP.
Posted: 28 Aug 2010 11:36 am
by Bent Romnes
Storm Rosson wrote:
Anyone who thinks .0022" of play is "sloppy" is just plain goofy (I think that is what the shaft run-out and the bushing clearance add up to)in my, and prolly anyone with any mechanical savvy,opinion.And the "bent" cross rod borders on genius innovation IMHO

Storm I am with you. Just a wee correction. Mike says it is .002 and 0002, not 0022"
It takes no rocket scientist to realize that this works. It is such a big stretch, a wild exaggeration.
edited to read: by the naysayers
Let me take the opportunity to say this to Del, Mike and the whole Mullen crew: You build a fine steel guitar whether it me a RP or any other kind. You have proven yourself through the ages. Keep building in the same vein and you will always be one of the top manufacturers!
Posted: 28 Aug 2010 12:50 pm
by Rick Collins
For me, the key phrase here would be practical tolerance:
The design of the cross shafts of the G2 would not be practical, if they had to make a complete revolution or oscillate rapidly, but it isn't necessary that they do. They must only rotate in a small arc; therefore, I must conclude that they are practical.
I might draw two parallel lines, 2" apart and 18" long. For practical purposes I could call them parallel. They would be in practical tolerance for me.
If I extended the lines for two miles and they are farther apart or closer togethter, they would not be parallel.
Parallel lines are either parallel, or they are not.
Do the cross shafts of the G2 work? They do.
Are they practical? They are.
Is rotation at opposite ends of the shaft precise? It is not.
Are they in practical tolerance? They are.
Posted: 28 Aug 2010 1:09 pm
by Chris Lang
Mike warns:
I will first start off by saying thank you for all the attention.
Next I will say, watch what you say about our company and my Grandfather (Del), that is not a bridge you really want to go down. With that being said.
I would also like to thank Mickey, Boo and all the others that realize it works.
What is that supposed to mean?
No one has slandered you, your grandfather, or your company so get over it.
I merely point out the physically incorrect design of the Mullen crossrods.
Do not threaten me, or others in any way. I have a right to my opinion just as you do. I don't care if you are the president of the United States. Right is right, and wrong is wrong. I have not called anyone names or made slanderous statements.
Rick:
Do the cross shafts of the G2 work? They do.
Are they practical? They are.
Is rotation at opposite ends of the shaft precise? It is not.
Are they in practical tolerance? They are.
Are they physically correct? No, they are not.

Posted: 28 Aug 2010 1:23 pm
by Rick Collins
Are they physically correct? No, they are not.
You are quoting my third statement as correct __ which it is.
Posted: 28 Aug 2010 1:33 pm
by Storm Rosson
Bent Romnes wrote:Storm Rosson wrote:
Anyone who thinks .0022" of play is "sloppy" is just plain goofy (I think that is what the shaft run-out and the bushing clearance add up to)in my, and prolly anyone with any mechanical savvy,opinion.And the "bent" cross rod borders on genius innovation IMHO

Storm I am with you. Just a wee correction. Mike says it is .002 and 0002, not 0022"
It takes no rocket scientist to realize that this works. It is such a big stretch, a wild exaggeration.
edited to read: by the naysayers
Let me take the opportunity to say this to Del, Mike and the whole Mullen crew: You build a fine steel guitar whether it me a RP or any other kind. You have proven yourself through the ages. Keep building in the same vein and you will always be one of the top manufacturers!
errrrrr Bent ol buddy I think if you add the max rod runout (.0005 and add it to the bushing clearance of 002")I'm pretty sure it adds up to .0025, or if u use the min rod runout of 0002 + .002 bushing clearance you get .0022" ....I ain't no rocket scientist but adding and subtracting is my "forte"...hehehehe....J/K ...buddy but really Bent your math is gotta be better'n mine......maybe.....just funnin ya B ...oh yeah I decided to strip my project and start over (again..lol) ...Stormy

.....lotta great semantics Rick....but in my world if it works and works well then it is correct for the application.

Posted: 28 Aug 2010 1:43 pm
by Bent Romnes
Stormy, you ARE a stickler for details aren't you? Of course you are right.
Man, you tool a big leap by starting allover again on your project. I think what you did here is what signifies a great builder. I'll be keeping tabs on ya!
Posted: 28 Aug 2010 2:17 pm
by Mike Perlowin RIP
Has anybody who owns a G-2 every complained about a problem caused by the bent cross shafts?
Posted: 28 Aug 2010 2:32 pm
by Jimmy Lewis
Mike your family does make a fine guitar and I certainly approve of you taking up for your grandparents I still wish mine were around to stick up for. This is something your should really take pride in in this day and time very great indeed.
Posted: 28 Aug 2010 2:51 pm
by Tony Glassman
"Chris Lang"Are they physically correct? No, they are not.

Are the physics correct for the application? YES!....Why is that simple concept so difficult for you to grasp?
No design is 100% correct or efficient. Amplifiers lose energy as heat, cars must overcome wind resistance and pedal steels are plagued by friction.....so what's a few thousands per inch of elliptical rotation in the grand scheme of things.
Form should follow function....and Mullen guitars function just fine.
Posted: 28 Aug 2010 3:00 pm
by Chris Lang
elliptical rotation
Thats good!

Posted: 28 Aug 2010 3:37 pm
by Earnest Bovine
Erv Niehaus wrote:It violates basic rules of physics.
Which rules does it violate?
Posted: 28 Aug 2010 3:38 pm
by Chris Lang
Form should follow function....and Mullen guitars function just fine.
Then why do you not see other builders jumping on the "bent crossrods" band wagon??
Do you think that Excel, Whitney, Lamar, Anapeg, or GFI would use something like that in their guitars?
No way!
Why?
If the "bent crossrods" are such a great deal, then why don't others follow?
It is not physically correct, that's why.
That matters to some folks.............

Posted: 28 Aug 2010 4:02 pm
by Jimmy Lewis
Mike bent cross shafts or not Mullen si a FINE guitar and you folks are top notch so keep up the good work.
Posted: 28 Aug 2010 4:26 pm
by Jaclyn Jones
I love my G2. I think every one should bent.
Posted: 28 Aug 2010 5:27 pm
by Bent Romnes
Posted: 28 Aug 2010 5:32 pm
by Tony Glassman
Chris Lang wrote:It is not physically correct, that's why.
[1] Who died and and left you Grand Master of Physics?
....and just what is "physically correct"?
Physics is the branch of science concerned with the nature and properties of ALL matter and energy. Last time I checked, Mullen guitars fall under the category of "matter"
[2] re: elliptical rotation
that's good
http://www.idexworks.com/u2u/cycloidal.html
Posted: 28 Aug 2010 5:36 pm
by Storm Rosson
Posted: 28 Aug 2010 5:58 pm
by Chris Lang
Tony says:
Who died and and left you Grand Master of Physics?
No one, as there need be no Grand Master of Physics.
An elementary student can see the obvious flaw in the bent rods.
BWAHAHAHA!
