Can you improve the stock techie bearing???

[rmsshipbroker]

Received mine back today after Ian kindly turned it round very quickly over the Easter break.
The engineering looks to be to a very high standard.
The central shaft comes out, which eases experimentation with oils and is not an issue in use.
Sound wise, things have a fair bit more power and snap, holding together better when the going gets tough.
Definition and clarity has improved too, particularly the low level stuff.
One caveat is that I can only compare at the moment with an old worn mark 2 bearing, whereas the modded one is a low mileage mark 5'er.
This will of course account for some of the difference, but I have to say that from memory, I dont thnk it was as big a difference when I took it out.
For the money I'm happy.
Thanks Ian.

[Khom]

This is my realization of Ianmac improved bearing. Ian, many thanks for nice work and for your photos.





All details except of thrust pad are made from brass, bottom cap (i.e. new baseplate) fixed by 3 screws M4. I calculated simplified contacting area and decided {3 * M4} should be better than {4 * M3}. Side threaded hole (sealed by M3 screw) used for oil filling, top ring is the oil bay. Also I made 3 small grooves for oil on the upper end of bearing bush. As I see now, it was not the best solution, but.. 'as is'.




I didn't find here PEEK plastic (e-bay sellers doesn't send it here) and made thrust pad from 'caprolon PA-6' (equivalents are: Ultramid D/BASF, Duretan В/Bayer AG, Maranyl/ICI, Zytel/Du Pont EI etc. etc. - there are a lot of them over the world). I have worked with this material earlier and decided that it is quite good for my purpose. It has low friction coefficient with steel and high rigidity comparing with teflon (Brinell hardness is approx. the same as PEEK and 5..7 times higher than teflon).

Sound difference with stock bearing is evident, bass is more solid and accurate. I think the hard baseplate gives the main contribution to sound. Unfortunately I didn't measured stock bearing but I quite trusted Ianmac's measurements.

Some pictures of manufacturing and finished device attached, all works performed by small lathe C3 (7x14") and drill press (see album http://s1159.photobucket.com/user/US...oved%20bearing). Cutting the 100-mm support ring was one of the difficult operation

[Marco]

Excellent work, Valery, and great pictures! So how's it all sounding - can you hear some sonic improvements since fitting the modified bearing? What about a nice picture of your turntable with the bearing in situ?

Marco.

[Khom]

Thanks, Marco! As I said above, differencies in sound are great, especially in bass register. Bass becomes more solid and tight but without any kind of sharpness or roughness. In general, the sound became more conjoint and in the same time detailed. I compared it in my memory with stock bearing (new one bought on e-bay from Japan) and first version described by Qwin here http://www.jkwynn.co.uk//Projects.html (my old realization of Qwin upgrade was wrong, but I understood it only after mashining this one). My main mistake was soft thrust pad, now I use caprolon and it's what I wanted.

Nothing special in my TT exterior, see asked photos. But inside: fully recapped, transformer moved to the external power supply unit, strobe LED current reduced from 80 to 4..5 mA (I replaced red LEDs to yellow ones), stock tonearm rewired by litz, stock cables replaced with Klotz MC-5000 (twisted pair in double shield) and RCA replaced with balanced Neutrik XLR. AT-440MLa.

Do some experiments with homemade record clamp and platter mat, thinking about big chassis upgrade based in Qwin's idea.

[Marco]

Excellent stuff, Valery!

Pictures just bring the whole project together, as it were, so thanks for that and for showing what the rest of your equipment looks like. Glad that you're getting good benefits from the modified bearing, too. Enjoy the music!

Marco.

[Ianmac]

Khom.
I have been away for the last two weeks and just catching up
Nice to see you have tweaked a bearing in a similar fashion to mine and are getting similar results.
Its well worth the effort.
Thanks for the mention of different plastics one can use for the bearing pad. I found it very difficult to get sheet form of some types, particularly in small quantities. Cutting/ slicing a pad from round bar on my mill didn't give me an accurate enough finish.
I did drill a 1mm vent hole in my bearing to allow for any mechanical/ oil volume change with temperature change in the oil bath. Maybe overkill on my part but it doesmake the insertion of the bearing shaft easier.
My next project is to build a high Q phono amp to replace my existing.
Get the lathe running again and try an under slung counter weight ?
Ianmac

[RickeyM]

My next project is to build a high Q phono amp to replace my existing.
Get the lathe running again and try an under slung counter weight ?
Ianmac

So there are no more Ianmac bearings available?

[Khom]

I did drill a 1mm vent hole in my bearing to allow for any mechanical/ oil volume change with temperature change in the oil bath. Maybe overkill on my part but it doesmake the insertion of the bearing shaft easier.

I think your solution is better than mine. Don't sure about temperature volume changes, but initial oil filling should be more convinient with vertical hole. My design of this hole near to useless.

Get the lathe running again and try an under slung counter weight ?
Ianmac

Never think about counterweight upgrade, do you have some ideas? I equipped my lathe by QCTP and it ready to fight

[Ianmac]

Khom
I'll try and post a picture of my underslung counterweight and Silicon filled Damper. (The latter ideally heeds a milling machine)
If I cant get this to work ill let you know and we can arrange to send one by email. Ive had previous issues trying to download photos due to my keyboard operational skills.

RickeyM
I made as promised 8 set of bearing parts as promised earlier. I have been asked to a make a further 2 two bearings for forum members. I made 4 sets of component parts that can be fitted to donor bearings, after that I do not intend to make any more.

[diviy]

Is Ianmac still around tried to contact him to order bearing

Cheers Gerry