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Post by blueshome1 on Nov 9, 2023 19:07:54 GMT
I think there is something about a cast T or spider that is lost when it it machined from a block. Are there any mettalagists ( not a word on my spellcheck) out there?) Is it something to do with the crystal structure? The only upgrade I can think of that would be interesting is a T made of titanium, which would be stiffer than originals and end up a similar weight? Pete I don't think titanium would work - it is a "dead" metal, it doesn't ring. I saw this demmonstrated years ago as a strip of titanium was "twanged" (like you did with a ruler" and it moved as if in slow motion. With regard to Mule guitars they have a unique sound closely related to a tin can. According to the one's I've heard. |
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Post by mikeholland on Nov 10, 2023 13:10:46 GMT
Having given this topic a little thought and also not being an expert but have had some experience with industrial metals and processing. I would like to make the following observations. Firstly when the initial National Tricones were being developed and manufactured they would have had the use of metal cutting and forming machines, ie lathes, milling machines, shapers etc. The shape of the T-Bar would involve a lot of machine changes and operations with highly skilled operatives and I imagine would involve a fair bit of time to produce. Add to this the amount of material waste. The shape of the T-Bar would mean that you have so much material to cut away and be wasted. I am guessing but I would think that you will be cutting away 75% of the aluminium material that you started with. I think on economics alone at the time of development you would have chosen the cast option.
As Hokojim correctly informed us, when machining any materials the process of cutting and shaping will induce stresses within the material that will have an impact in the strength and properties of the finished item. To improve the material after manufacturing the item will need to undergo some form of heat treating. To improve the internal structure of aluminium it would go through a process called annealing and possibly others also. So it is my assumption the choice of the cast component would have been driven be economics.
In todays world we have far more choice in how materials are manufactured and processed. The use of cnc machines would produce this item very accurately. But you will still have the problems of waste and heat treating. Also the cast option will produce items quicker and more consistently than any machine made part as complex as the T-bar.
The initial cost of producing the patterns and moulds would of course have to be factored into the costs but still today on the basis of economics you would almost certainly go down the cast route.
Best of luck to the people who are manufacturing the machined T-bar but unless there is something in the design that improves the sound I can’t see the point.
Having said all of that I am still lusting after an original National Tricone Square-Neck……. I suspect I am not alone!
Mike
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Post by bonzo on Nov 10, 2023 13:50:01 GMT
Nicely summed up Mike. All makes sense practically and economically and the casting would have been done by people at the top of their game I imagine. 👍🎸🙂
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Post by mitchfit on Nov 10, 2023 17:30:50 GMT
agree with mikeholland but would note that the lost wax method only requires one good pattern to make however many castings are desired. any mistakes resulting from sand movement can easily be recycled. still seems a heat treatment and anodizing would be needed afterward for best results.
with the exception of EDM, any means of mechanically removing unwanted metal will leave stresses in the product, but subsequent heat treating would remove same. the EDM process is painfully slow but able to give precision WELL BEYOND what is needed for this part.
for very long run production investment casting would be ideal. would it be cost effetive for such a low production number product? probably not. it is mostly a choice for mass produced products requiring more precision than what is needed here.
IMO, the lost wax method easily wins as the best choice here. also, the old school sand casting method would work just fine to this day.
mitchfit
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Post by Pickers Ditch on Nov 10, 2023 17:53:36 GMT
The people at National, Dobro and their contracted metal workers certainly knew their onions. They produced these from cast aluminium too:   |
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Post by Michael Messer on Nov 10, 2023 22:42:55 GMT
The people at National, Dobro and their contracted metal workers certainly knew their onions. They produced these from cast aluminium too: View AttachmentView AttachmentI set that photo up back in 2000. It was quite a balancing act, but worth doing! Shine On Michael |
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Post by pete1951 on Nov 11, 2023 10:03:05 GMT
The only upgrade I can think of that would be interesting is a T made of titanium, which would be stiffer than originals and end up a similar weight? Pete I don't think titanium would work - it is a "dead" metal, it doesn't ring. I saw this demmonstrated years ago as a strip of titanium was "twanged" (like you did with a ruler" and it moved as if in slow motion. With regard to Mule guitars they have a unique sound closely related to a tin can. According to the one's I've heard. I still am intrigued by titanium, flat samples ( as used in the ‘ ruler’ test) will be rolled(?) It’s possible that the cast version will ‘ring’ . Though not as light as aluminium it is much stronger, so a much thinner T could be made. Then of coarse, there could be some magic in the mass of the aluminium, and a skinny but strong titanium might give more volume ( a lighter bridge should allow greater cone movement???) but the tone and sustain may suffer?? Pete |
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Post by blueshome1 on Nov 11, 2023 11:35:55 GMT
Pete, Titaniun isincredibly diffult to cast as it. Oxidises so readily so the cost would be high. Wat about carbon fibre with a thin metal ore?
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Post by Michael Messer on Nov 11, 2023 13:02:52 GMT
Nothing that we haven't all concluded in different ways, I was talking on the phone with Mike Lewis earlier today and he told me that many years ago he tried this method of making a T-bridge and it doesn't work, it kills the sound.
Shine On
Michael
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Post by hidesert on Jan 7, 2024 22:32:38 GMT
“I'm not sure how the tone, volume & sustain might be affected by using a machined aluminium T-Bar - IF at all !
What do you all think ?”
Hi guys. I am a long time (40 years-plus) National and Dobro owner and player…vintage Duolians, Triolians, Style O’s, wood and metal-bodied vintage Dobros, and a vintage square neck Tricone. I’ve had the same all original 1928 Style 1 square neck Tricone and 1934 12 fret Style O (with rolled f holes and a mahogany neck!) for all that time, and just recently added an original Sears 12 fret Duolian.
I picked up a used 2023 Mule Tricone last year…it had an approval period, so I felt relatively safe despite having never played one. After spending a few days with it, I decided I liked it, so I kept it. It sounds very good and has a fantastic neck, fretwork, and unmatched playability.
So when the machined t bar became available, I figured what the heck as I was already committed to the guitar.
It came just before Christmas and I had my luthier, Fox Fletcher in Albuquerque, NM, install it. While he had it, I did an online search and found this thread.
Well, I picked up the guitar last week. I asked Fox what he thought. “Night and day better”. After spending some time with the Mule, I am in 100% agreement. We re-used the strings, so it’s really a fair comparison. More volume across all strings, a more immediate attack, a much more singing, harmonically complex, and sustained note. Really, everything, sonically speaking, is substantially improved.
I only wish I could put the Mule on a diet and shed a few pounds (or a kilo)!
Anyways, that’s my experience. Perhaps it defies metallurgic science and the laws of physics. But it wouldn’t be the first time that alchemy has sonically triumphed over intellectually founded presumption, now would it?
Happy New Year!
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Post by mitchfit on Jan 8, 2024 18:41:09 GMT
the residual stresses left in aluminum or titanium post machining should be sonically invisible compared to those that were cast.
my guess only.
< zero experimentation done to test this theory.
mitchfit
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Post by snakehips on Jan 9, 2024 8:57:44 GMT
Hi there !
I wonder if anyone has considered 3D-printed aluminium - if that is possible in such a material ??
In my field of work as a Dentist, the labs I use for making Cobalt-Chrome alloy dentures, that were traditionally cast, via the "lost wax process", are now being made by 3D printing the alloy. The denture metal framework is designed virtually, onto virtual models of the patient's mouth - then the metal framework is made via the additive process of 3D printing.
To be honest, I wasn't expecting it to be that good - but when trying the 3D printed models in patients mouths - I have been constantly surprised how well they fit - and they look just the same as traditionally cast CoCr frameworks.
CoCr is quite a light metal alloy - hmmmm - I wonder if my lab could make up a T-bar ? !!!!
Anyone wanna supply a 3d cad file for me ??
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Post by pete1951 on Jan 9, 2024 10:02:46 GMT
Very surprised by hindsert’s result. It could be to do with the quality of the aluminium used? Or possibly the cooling or heating of the T bridge material? It certainly goes against all the received wisdom of many years.
It would be interesting to see it the cast and machined bridges are the same alloy.
Pete
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Post by Michael Messer on Jan 9, 2024 10:34:11 GMT
Each to their own and I respect other people's opinions, but I'm sticking with the original invention of sand-casted T-bridges and spiders. The air that gets trapped and the way the molecules bond together is a whole different thing to something that is machined. I recently played a Mule guitar with a machined T-bridge and it did not make me change my opinion. If John Dopyera had wanted the sound created by machined T-bridges and spiders, he would have manufactured his guitars with them.
As the decades roll by and new inventions, materials, designs and components are used as a so called improvement on the original designs, I just become more convinced that John Dopyera, Rudy Dopyera and their gang, were masters of their creations and that nothing can better what they did. It may have been 100 years ago and we may be able to do all kinds of stuff with manufacturing and design that they couldn't do, but so far I have not seen anything, not one single thing, that is better than those original designs. They are what they are and that is what they are! You can't change that and why would anyone want to.
Shine On
Michael
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Post by Pickers Ditch on Jan 9, 2024 11:04:43 GMT
...and why would anyone want to? Shine On Michael The cynic in me says "To make money from the gullible, my boy!" |
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