VPI 3D tonearm

I heard a description of this VPI arm at the NYC show in April. Harry explained that there are some complex shapes and sectional changes in the arm tube interior that are not possible to produce by other methods. Apparently this arm tube is very good at controlling/damping vibrations. The lack of joints/seams also was discussed as an advantage.

I don't know how different the VPI 3D is from my SME V-12 arm tube, but the latter is also one piece with a varying cross section, and it is made of magnesium.

I was also told the 3D takes one day to make in the printer.

Dear Henry, You obviously have a vast knowledge of esoteric manufacturing processes. Thanks for the input on that subject. However, I would take issue with your last sentence:

"But casting, welding, machining and gluing do." This was written in reference to what makes a one-piece construct. Welding and gluing do NOT make a one-piece construct, by my strict definition. Welding and gluing can fuse two constructs that are separately one piece each. In both techniques there will be an interface even between two items machined from identical materials, where the foreign material in the joint (glue or weld) could act to reflect energy and create spurious resonances. Casting and machining have their limitations, as well. Could you admit that it is remotely possible that there could be some advantage to the use of 3D printing to make a tonearm that is "more" of a single piece than was heretofore achieved (by technologies with which the rest of us are somewhat familiar)?

I have no idea whether the VPI tonearm is good, bad, or indifferent, but the project seems novel and interesting. It's possible that the 3D printing is ground-breaking but that epoxy sucks for a tonearm. We'll find out.

You might better say that introducing a Classic 4 so soon after the Classic 3 is an example of something not so admirable.

I have no idea if the VPI tonearm is complex or not, or if it sounds good, but I do know that the 3D process allows for much more complex structures than casting or machining would allow. I also know, that after a given production, 3D printing is less economical. That production point depends on the cost of the tooling or molds required for other processes. However, that tooling or mold is required whether you build 10 or 10 thousand and can be prohibatively expensive to prototype, which is really the purpose of 3d printing, not mass production, at least yet. But, when you can tweak a design, and have a working prototype in a day, for little expense relatively, that allows a designer to try various options in something resembling their final form.
I just dont get why anyone would be down on Harry for building and selling turnables and arms when he could just as easily be buying stuff from China or making some other widget for Walmart to sell. Its his money, he takes all the risk, and is entitled to whatever profit he can derive. if you think you can do better, then take your own money, roll the dice and have at it.

+1 Manitunc

Manitunc

That production point depends on the cost of the tooling or molds required for other processes. However, that tooling or mold is required whether you build 10 or 10 thousand and can be prohibatively expensive to prototype, which is really the purpose of 3d printing,

The point here is that you can perhaps use drawings for existing or modified parts to input into the computer, but there is an equivalent to tooling costs in that the more complex the shape the longer it takes to design the part in order to get the information into the computer.

I am familiar with modelling and prototyping techniques, and the advantage of 3D printing (and laser cutting, and CNC machining generally) is that because nowadays almost all products are designed on computer it is possible to extract from the drawings enough information to quickly see what a product will look like with regard to its external dimensions, but to integrate all the various drawings of all the parts is a bigger task.

Peterayer

there are some complex shapes and sectional changes in the arm tube interior that are not possible to produce by other methods.

That would be the advantage - by incorporating webs, coaxial tubes, and varying wall thickness it would be possible to alter dimensions to increase strength and rigidity without adding to effective mass, while reducing resonance. What it appears is that the original drawings have been tweaked, rather than a new concept considered based on the technology. Which is fair enough, and a reasonable starting point.
J

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