This is exactly what I wrote about in my post 5488 about synchronizing two cartridges.
But Carlo did not consider this a problem (5489).
Let's see what solution he has.
I have my own solution.
I would be delighted and intrigued to see your solutions Andrey, and any others out there.
I consider this forum as the place where you offer up your good thoughts and advice as early as possible to help others.
Sometimes i am wrong, quite often in fact, but that's OK! - i learn.
Lots of people have helped me enormously that way and i hope if you join in that way you will find it a very constructive and respectful place!
What do you think will help in Carlo's development please?
M
I consider this forum as the place where you offer up your good thoughts and advice as early as possible to help others.
Sometimes i am wrong, quite often in fact, but that's OK! - i learn.
Lots of people have helped me enormously that way and i hope if you join in that way you will find it a very constructive and respectful place!
What do you think will help in Carlo's development please?
M
Thanks for the reply, Mike.
For the rails, do you mean something like these?
Linear Motion Shaft: Ceramic coated 6061 Aluminum
My first prototype, though I'm not even sure I'd call it that, more like an investigation of concept is pictured below. It uses a glass tube and these bearings:
3/16x3/8 ceramic ball bearing
Is that the sort of bearing you're talking about? If not, could you please elaborate (link, picture or description)?
It seems to me that there are 2 material (as opposed to design) upgrades from my current prototype. The first would be a tungsten carbide rod. I'm not sure where I'd buy this or if it would require machining I cannot perform. The second would be a jewel bearing design. What I've seen off the shelf is a bespoke design based on parts from a vendor like this:
Swiss Jewel
Is this the sort of thing we're talking about? These parts seem very small and fragile. Am I wrong about that? I'm also not clear which parts I would use and I don't know what I'd use as a disc or wheel.
Initial "investigation of concept"
BS TwinArm
The angular difference (always referred to their own pivots, not reciprocal) between two tips on the same groove can be reasonably managed, imo, as indicated in the answer to Alighiszem.
Even in the case of a considerable distance between the two (view the attachment of a "wrong" situation), the "timing difference" becomes just the matter of where you place the starting point on the first pulley of the "proper ratio connection"
What instead imposes the minimum distance of the two tips is the possibility of eccentrics on disc, which would lead to serious problems, up to skipping. This is the "small detail", "the elephant in the room" I mentioned from start.
This strange hypothesis is certainly complex and difficult to understand; and the more I go on, the more I realize how large is the "elephant family", and how concentrate must i be on real priorities. (Eg - i was calculating the relative motions basing on torque, while i've now realized to take care the overall work, instead.
Therefore, there is no point in wasting your time.
Thanks to all for precious help and interest. I will let you know
ciao - carlo
The angular difference (always referred to their own pivots, not reciprocal) between two tips on the same groove can be reasonably managed, imo, as indicated in the answer to Alighiszem.
Even in the case of a considerable distance between the two (view the attachment of a "wrong" situation), the "timing difference" becomes just the matter of where you place the starting point on the first pulley of the "proper ratio connection"
What instead imposes the minimum distance of the two tips is the possibility of eccentrics on disc, which would lead to serious problems, up to skipping. This is the "small detail", "the elephant in the room" I mentioned from start.
This strange hypothesis is certainly complex and difficult to understand; and the more I go on, the more I realize how large is the "elephant family", and how concentrate must i be on real priorities. (Eg - i was calculating the relative motions basing on torque, while i've now realized to take care the overall work, instead.
Therefore, there is no point in wasting your time.
Thanks to all for precious help and interest. I will let you know
ciao - carlo
Attachments
Hello Carlo,
Interesting idea. But maybe the elephant in the room isn't an elephant at all, but an ANT, an ELEPH ANT, no?
Ralf (likes to play with words)
Interesting idea. But maybe the elephant in the room isn't an elephant at all, but an ANT, an ELEPH ANT, no?
Ralf (likes to play with words)
Thanks Ralph, we "gadget builders" understand each other right away.
This road is full of stumbles and pitfalls, I don't know if I can get to something.
So better to be careful of the dangerous holes, the small ants can be crushed without remorse; otherwise while looking at the ant you'll fall into the hole.
c (likes to play with words too, but in italian unluckily, so often at risk to offend someone)
This road is full of stumbles and pitfalls, I don't know if I can get to something.
So better to be careful of the dangerous holes, the small ants can be crushed without remorse; otherwise while looking at the ant you'll fall into the hole.
c (likes to play with words too, but in italian unluckily, so often at risk to offend someone)
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Might you also offset the angular difference of the eccentrics through the drive train, is it possible to lag the drive to the RTA by the correct angle through the pulley mechanism (so coincident styli is not an elephant) as well as cope with the arc to straight line effect?
M
I wrote this after a glass of Shiraz, so may be complete rubbish, in fact same as before the glass!
Paul, i didn't wish to leave you out there with no answers too long, but its the golf season, not the tonearm season here.
I admire that you have put something together and put your hands on it to get a feel of things.
I found that was the way i understood a few of the critical matters.
Many folk on the thread gave me great ideas and encouragement, not least Carlo, Warren, Niffy and Karsten, please excuse me, those i left out!
Then i was encouraged to measure the results. initially i resisted that idea..........
Every time i listened to something which took a lot of hard work it always sounded better, but measurements didn't always support that perception.
So lots of kit went in the old parts bin!
Frequently strongly advocated ideas, carefully developed, measured poorly, so i learnt a bit about my process.
There are many different routes to achieve some quite good sound.
What lights your fire?
I quite like the idea that i made it and it cost little so i don't use expensive materials like carbide etc.
I cannot build a cartridge so i use a quite expensive old MM cartridge and my silly old arm sounds and measures quite well with it
I happen to have a quite well respected conventional proprietary TT/arm combination which sounds fine and has attracted good reviews.
My home made set up sounds as good and measures significantly better.
That generates a certain satisfaction.
What ambition do you have?
You can go and buy two good tonearms for you and your son, but what would you like to achieve instead?
M
Now i will seek out some pictures etc to answer the questions you asked me, and welcome to the forum from me where i hope you will enjoy the welcome and constructive responses that some folk will and can give you! - there is some great thinking out there.....