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Topic: new crossrod design for new steels |
chris ivey
From:
california (deceased)
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Posted 20 Apr 2014 9:22 am |
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reading the thread about the fine tuning of the new rittenbury prestige model, it made me think. they say they experimented with square aluminum crossrods, hexagonal (?) rods and stainless round rods to assess the tone of each. i think they went with the stainless.
my question is if anyone has considered a square (or hex)stainless crossrod in a noticeably smaller thickness than the normal ...whatever that is...1/4" or 3/8 or...?
what about, say 3/16. would the strength of the stainless support that concept without undue flexing?
if it would it would mean you could have a smaller bellcrank attatchment area allowing for much more room around the pull rods, less clutter.....or for that matter, room for 'more' crap under there.
....more room, lighter weight, easier access working tight spaces. would the rigidity of the stainless allow for this possibility?
any thoughts?
perhaps some other super strong alloy? |
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Bill Ladd
From:
Wilmington, NC, USA
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Posted 20 Apr 2014 10:03 am
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Titanium is super strong and super stiff. Kinda pricey and difficult to work though.
Oh, also, super light...
Last edited by Bill Ladd on 20 Apr 2014 3:21 pm; edited 1 time in total |
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John Billings
From:
Ohio, USA
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Posted 20 Apr 2014 12:19 pm
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I must say that I'm a bit skeptical about tone benefits from crossrod material. That said, it takes a lot of parts to make the whole, and perhaps a percent here, and a percent there, will add up? They're not part of the cabinet's real integral construction. They are a little bit loose, or they wouldn't operate freely. They tighten up to the cabinet/changer/etc. only when a pedal or lever is engaged Does the material actually add to the tone? I wish I could have been there for the experiment, and hopefully it was all done on the same guitar!
I'm certainly curious about it, though I remain somewhat skeptical,
Last edited by John Billings on 20 Apr 2014 1:18 pm; edited 1 time in total |
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Rich Peterson
From:
Moorhead, MN
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Posted 20 Apr 2014 1:16 pm
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| Add another to the list of skeptics. But now I am wondering whether titanium would be a good choice for the changer axle. |
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Tom Wolverton
From:
Carpinteria, CA
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Posted 20 Apr 2014 7:00 pm
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If you compare the Young's modulus for al, ti and steel, you will see that steel is the stiffest, hands down. I think steel is the winner. Unless you want to go with berylium. : )
_________________
To write with a broken pencil is pointless. |
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chris ivey
From:
california (deceased)
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Posted 20 Apr 2014 7:13 pm
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| so could a scaled down thickness of steel crossrods still do the job? |
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Emmett Roch
From:
Texas Hill Country
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Posted 20 Apr 2014 8:16 pm
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I got fed up with round cross-rods when the bell cranks on my old MSA started slipping. I ground flat places on the rods for the tightening screw on the bell cranks.
_________________
On Earth, as it is in Texas |
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Bill Ladd
From:
Wilmington, NC, USA
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Posted 20 Apr 2014 8:21 pm
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| Tom Wolverton wrote: |
| If you compare the Young's modulus for al, ti and steel, you will see that steel is the stiffest, hands down. I think steel is the winner. Unless you want to go with berylium. : ) |
Yes, but Ti is about half the weight of steel. Tom, I'm sure you know this, but for others who may not, Ti is used in aerospace applications (among many others - F1 racing, etc) where strength and light weight are demanded.
Again, deep pockets required. A Ti-kitted D10 would be massively expensive.
A Berylium mechanism for a steel guitar? 1/2" diameter Berylium rod will run you about $260 an inch. Be an awesome experiment though! Maybe we could talk Chris Lucker into financing it?  |
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Bill Ladd
From:
Wilmington, NC, USA
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Posted 20 Apr 2014 8:37 pm
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Back to Chris's query - yes, as Tom points out, a strong lightweight steel such as 4130 chromoly really can't be beat for the application.
I'd be willing to bet most builders are using a mild steel for crossrods. If so, 4130 could be specified in either standard sizes for overall weight savings or a smaller cross section for overall reduction in size. |
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Bill Ladd
From:
Wilmington, NC, USA
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Posted 20 Apr 2014 8:41 pm
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| Or, if you're looking to save weight, how about chromoly tubing? I used to handbuild high-end bicycle frames. The chromoly tubing I used was pretty remarkable stuff. |
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John Billings
From:
Ohio, USA
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Posted 20 Apr 2014 10:35 pm
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| At Performance, I think our crossroads were 3/8" square tubing. A handful of them didn't really weigh squat. |
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Bob Hickish
From:
Port Ludlow, Washington, USA, R.I.P.
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Posted 21 Apr 2014 5:55 am
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John
( IMO ) your right on - and made out of 4130 chromoly tubing like Bill suggested - it could be heat treated to be as hard as glass - it would shatter before it give way - |
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Ross Shafer
From:
Petaluma, California
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Posted 21 Apr 2014 6:06 am
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| There's no appreciable difference in the stiffness of mild steel and cro-moly. Yup, much stronger, but strength and stiffness do not necessarily go hand in hand. Nor does heat treating of cro-moly change it's stiffness. If one were using the cross rod material itself as the pivot, heat treatment could be used to improve the durability of the bearing surface. |
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Bill Moran
From:
Virginia, USA
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Posted 21 Apr 2014 6:29 am
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The market will set the standard. Does a player want old school heavy weight, ShoBud, MSA, Push Pull, with great tone. Or, light weight with not as great tone ?
Builders could look into both and have options when a guitar is ordered. I think light weight will win out. Most of the players now are older, like me, and want light weight. The younger generation have no idea what a push pull might be. If they do they have no idea why they sound so good.
Could be like Fender amps. Everyone owned one years ago and traded them off for solid state. Now many are moving back to tubes because of great tone.
If I had all the answers I would run for office. My state sure needs a couple senator's.
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Bill |
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Roger Francis
From:
kokomo,Indiana, USA
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Posted 21 Apr 2014 8:39 am
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I think they mentioned tone and resonance by using stainless and no Delrin for pedal stops
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Rittenberry SD10, 2 nashville 112s with telonics speaker, behringer EPQ450 power amp, 705 pups, Telonics FP-100, live steel strings, mogami cords, wet reverb |
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chris ivey
From:
california (deceased)
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Posted 22 Apr 2014 5:16 pm
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| no one's answering my question. |
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Bill Ladd
From:
Wilmington, NC, USA
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Posted 22 Apr 2014 5:49 pm
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| chris ivey wrote: |
| no one's answering my question. |
Sorry chris. On this particular Young's chart, it shows that chromoly steels are stiffest, then milder steels, then monel (stainless), then ti, then aluminum, among other metals listed.
So, if you want to reduce crossrod diameter or width, chromoly steel would be best for strength and stiffness.
That being said, my Magnum D-10 has 1/4" aluminum crossrods (at least they appear to be alu., haven't put a magnet up to them) and has no more appreciable hysteresis than any other pedal steels I've played.
So, I'm guessing if 1/4" alu. does the trick, then perhaps even thinner chromo bar might be adequate? |
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Bill Ladd
From:
Wilmington, NC, USA
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Posted 22 Apr 2014 6:01 pm
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More specific to your question about stainless.
1. Using the chart above we see that stainless (nickel alloys - Monel 400) is a good bit stiffer than aluminum.
2. My guitar does just fine with 1/4" aluminum.
3. 3/16" stainless? My out-of-the-keester guess is yes - but only testing will tell. |
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Chris Lucker
From:
Los Angeles, California USA
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Posted 22 Apr 2014 6:47 pm
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| chris ivey wrote: |
| no one's answering my question. |
Chris, when you get the tubing down to 3/16ths you do not have as much surface for holding bellcranks in place. Another issue is you will have smaller diameter hole through the center of the tubing for dowel pins, if you wish to use the old MCI/EMCI way of turning square tubing into a spinning cross shaft.
I don't know if the smaller diameter dowel pin is better or worse, but the set screws locking the dowel pins in place may not have enough wall thickness for thread grab in a 3/16ths square tube. I do not know.
_________________
Chris Lucker
Red Bellies, Bigsbys and a lot of other guitars. |
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chris ivey
From:
california (deceased)
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Posted 22 Apr 2014 7:18 pm
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thanks guys...
i was just picturing a clean undercarriage with more room to breathe.
it's hard to even see through my jungles with 9+8 and 9+7.
but what with the fine machining capable these days it gave me ideas for some 'redecorating'. |
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Ross Shafer
From:
Petaluma, California
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Posted 23 Apr 2014 6:10 am
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Yo Bill,
I don't want to be a pest or make you think I'm challenging you on anything, but a 1/4" seems mighty small....for any material. Have you actually measured them? Thanks for the info. |
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Jim Palenscar
From:
Oceanside, Calif, USA
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Posted 23 Apr 2014 6:17 am
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| The typical diameter is 5/16"-3/8" of a cross shaft and what the bellcrank hooks to does not influence the side/side room- the determining factor there is the string spacing (typically .343"),the diameter of the pull rod (the smallest currently in use is .093" to the best of my knowledge), and how the pull rod fastens to the bellcrank. |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 23 Apr 2014 7:46 am
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| Quote: |
| new crossrod design for new steels |
My old MSA is a D10 8+8, and there's plenty of room. My new MSA is also a D10, but smaller, and with 8+7, but it's still pretty "roomy", even with 43 total pulls. I think you reach a point where you try to squeeze in more and more pedals (under the guise of it improving your playing) and it really doesn't. That's why my new steel didn't have more (or even as many) pedals as my older one.  |
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Bill Ladd
From:
Wilmington, NC, USA
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Posted 23 Apr 2014 11:58 am
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| Ross Shafer wrote: |
Yo Bill,
I don't want to be a pest or make you think I'm challenging you on anything, but a 1/4" seems mighty small....for any material. Have you actually measured them? Thanks for the info. |
Held a measure against one, bent over, reading upside down. Didn't mic it though. But yeah, looked like 1/4" or pretty dang close. Might be 5/16" though. When I get a chance I'll put a micrometer up to it and report back. |
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Bill Ladd
From:
Wilmington, NC, USA
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Posted 24 Apr 2014 7:26 pm
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Yep. 5/16"
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