This idea of scouring used furniture outlets for Cabinets and the like is very common, many Vendors are not aware of the Wood Species there is to be found on sale items, due to the unobtanium of certain wood species, some decorative parts found on an item are worth much more than the piece that is for sale, as obtaining the raw materials comes with many hurdles.
https://www.wood-database.com/wood-articles/restricted-and-endangered-wood-species/
https://www.wood-database.com/wood-articles/restricted-and-endangered-wood-species/
I see there is at least one company lignumvitaesolutions.com making LV bearings for various heavy industries like hydropower. These bearings are quite large so they must source
their timber from newly grown timber probably licensed. They would soon run out of material if they had to use old bowling balls !
I also used to do some antique furniture restoration and Ive still got pieces of rare timber I came across though no LV.
their timber from newly grown timber probably licensed. They would soon run out of material if they had to use old bowling balls !
I also used to do some antique furniture restoration and Ive still got pieces of rare timber I came across though no LV.
unfortunately john the sp10 uses a tiny thrust cap thats a tight press fit on the spindle,i think it would be too fragile in LV.
Ah, but the SP10 has a rubber insert in its chassis/sump that could easily be removed, allowing a deeper cap (that could then be secured to the sump, thereby rigidising the bearing). I always wondered about that rubber bit and concluded that Technics must have not really finalised the bearing design (and wanted to leave their options open).
I doubt it; it's just a thin blank covering a hole directly under the bearing. But whether it is or not, it can be removed and the main bearing extended if necessary.
I think a lot of people ignore the rotational damping on the horizontal axis with very low friction systems.Having a bit of artificial controlled drag actually helps regulating the instantaneous accelerations caused by whatever motor you might use while compensating for lower platter weight or innertial mass... A motor drive can get into settlement time trouble if friction is too low.
The magnetic levitation is used I think mainly to decouple the platter from the support structure. Platters are, on high end turntables mostly I would say of the high mass/larger diameter type to gain a flywheel effect, which will as you say reduce the chance of 'cogging' and are dampened with inserts or absorbant mats. Have you seen many high end turntables using low mass platters?
Not many but, i have one...Of course I have 3...3.4 kg platter Duals as well which are about 2kg heavier than the B&O one...
I think we should abandon the habit of thinking out of the box cause everything Santa gets you is usually inside the box!
Interesting point. But friction always adds noise. Perhaps a rotating cylinder in an oil bath?
Hydraulic arms found on excavators usualy use a very dense molibdenum sulphide +lithium blue grease.It may work very well with chromed steel on brass bushings if you have lighter platter as the drag it creates is considerable while thr noise...I have to think of any that you can hear. A magnetic regulator creating infinite poles and continuous decelerating drag like the one found in Garrard and Dual motors is, I think, superior to any other solution.
OK, so I now have two bowling balls, one having relative density of 1.32 and the other 1.35, so I conclude they are lignum vitae. But I'm having trouble deciding which way the grain lies. It would seem sensible for the grain to go along the axis of the spinning ball and they're marked with grooves to tell you what the preferred axis of rotation should be. Does anyone have any thoughts?
as long as its not the Argentinian type its ok 🙂 cut the ball into a cube and you'll see whats end grain and whats not.
After a lot of peering and wondering, I cut one ball in half using a rip saw (my small bandsaw didn't like it and kept jamming). I seem to have got it right and cut along the grain. The cut was very clean - it's a very odd wood. As the descriptions say, it's waxy and I assume that's why it kept clogging. Looks like it will machine nicely, though.
There is not an easy to recommend method to identify which LV Species is which.
There are complications to be met with for the untrained, when carrying out the identification of the commonly discovered LV Species.
There are variants within the Species, and they present a situation where it is quite easy to make an incorrect species identification, as there are similarities that make it difficult to distinguish between them. They all share similar grain pattern, colour/hues and scent.
Those who report on working with these wood types, have made it known they machine quite similar to each other as well.
If not 'hands on experienced' with the various species and having developed the knowledge to distinguish the differences.
The only positive identification would be a Specific Gravity or Cell Structure analysis.
I would assume any entity supplying to LV Wood to a Large Organisation for a specific mechanical application, would be making sure there product supplied is not as per the specified. I would also assume the certificate of authentication through testing and analysis will be supplied with the batches.
The selection of the correct species, I assume will be critical when being chosen to produce a part for a Heavy Duty role in a industrial scale mechanical application.
I am not so sure if the same critical selection applies, when selecting the wood to be used as an alternative material Bush Part or Thrust Pad in a light duty role within a TT's Vertical Axis Thrust Bearing.
There are complications to be met with for the untrained, when carrying out the identification of the commonly discovered LV Species.
There are variants within the Species, and they present a situation where it is quite easy to make an incorrect species identification, as there are similarities that make it difficult to distinguish between them. They all share similar grain pattern, colour/hues and scent.
Those who report on working with these wood types, have made it known they machine quite similar to each other as well.
If not 'hands on experienced' with the various species and having developed the knowledge to distinguish the differences.
The only positive identification would be a Specific Gravity or Cell Structure analysis.
I would assume any entity supplying to LV Wood to a Large Organisation for a specific mechanical application, would be making sure there product supplied is not as per the specified. I would also assume the certificate of authentication through testing and analysis will be supplied with the batches.
The selection of the correct species, I assume will be critical when being chosen to produce a part for a Heavy Duty role in a industrial scale mechanical application.
I am not so sure if the same critical selection applies, when selecting the wood to be used as an alternative material Bush Part or Thrust Pad in a light duty role within a TT's Vertical Axis Thrust Bearing.
I dont honestly know if there is any difference between genuine LV and the Argentinian substitute that would be detrimental in this application.
When ever i bought a bowling ball from ebay i look under a loupe at the end grain to tell if its genuine LV as described here. https://www.wood-database.com/how-to-tell-genuine-lignum-vitae-from-argentine-lignum-vitae/
On another note im removing my LV thrust pad today to inspect for wear and going back to a Torlon one to see if there are any sonic differences. I will post a few photo's later.
When ever i bought a bowling ball from ebay i look under a loupe at the end grain to tell if its genuine LV as described here. https://www.wood-database.com/how-to-tell-genuine-lignum-vitae-from-argentine-lignum-vitae/
On another note im removing my LV thrust pad today to inspect for wear and going back to a Torlon one to see if there are any sonic differences. I will post a few photo's later.
As it happens, I've already ordered that book (of the website). I've just looked at the end grain of a cut piece under a microscope (my eyesight needs more than a loupe), so one ball at least is the real deal. They were both mounted on rectangles of mahogany. Now, my woodwork isn't up to much, but the mounting and mahogany were awful. The "rectangles" weren't, but I suppose if you cut wood with a bendy bread knife, that's to be expected. The wood was rough sawn - no attempt to tidy it up. I think the frayed end of a bit of rope must have been used to apply the varnish, or perhaps it was just poured on. Made my work look beautiful by comparison. Still, I was after the balls, and I figure they were a pair originally bought together, so the other ball will almost certainly also be lignum vitae and I'm well pleased with my purchase.
Two balls should be able to make lots of bearing sleeves. 4mm and 5mm rod is popular in 5 1/4" floppy drives, and VHS 24 pole 3 phase capstan motors are 3.5mm, so H7 reamers are readily available for these shafts, enabling motors to be made/modified for belt drive turntables. I took up the Altmann http://www.altmann.haan.de/turntable/ suggestion and have a Harley-Davidson valve (5/16" diameter) for platter bearing, plus 3.3kg granite platter (chopping board), or maybe plywood. I've always fancied making a turntable from scratch...
Be interested to see the thrust pad wear. I doubt if it will be much. Long after sawing the lignum vitae I realised that it was like sawing a tough plastic, but much harder. Incidentally, I asked Drakespride (bowl manufacturer) about grain alignment for bowls and they said it was totally random.
Two balls should be able to make lots of bearing sleeves. 4mm and 5mm rod is popular in 5 1/4" floppy drives, and VHS 24 pole 3 phase capstan motors are 3.5mm, so H7 reamers are readily available for these shafts, enabling motors to be made/modified for belt drive turntables. I took up the Altmann http://www.altmann.haan.de/turntable/ suggestion and have a Harley-Davidson valve (5/16" diameter) for platter bearing, plus 3.3kg granite platter (chopping board), or maybe plywood. I've always fancied making a turntable from scratch...
Be interested to see the thrust pad wear. I doubt if it will be much. Long after sawing the lignum vitae I realised that it was like sawing a tough plastic, but much harder. Incidentally, I asked Drakespride (bowl manufacturer) about grain alignment for bowls and they said it was totally random.
so after removing the LV thrust pad here's what i found,to be honest the wear is so small its hard to capture in a photo.
