Zeta tonearm strip down and bearing change.

[karma67]

So ive been busy over the last week,there has always been a slight bearing rattle since i bought the zeta in the lateral top bearing.

you can here it in this video.


https://youtu.be/YJYUkEy6o3o

so what to do??
After further adjustment to the top bearing i became clear that it was either to loose or too tight,there was no in between sweet spot.
After a call to a fellow Zeta owner,Roger at TPA it seemed the best course of action was to strip the arm completely and check all the bearings.:eek::mental:

As there was no manual it was in at the deep end time!
Each bearing has its own cover disc,to access the bearings each one has to be removed,i made a tool up at work to do this.

https://s26.postimg.cc/5g2zdhto9/IMG_2122_1.jpg

Top lateral bearing cup cover disc.

https://s26.postimg.cc/qnbbfalfd/IMG_2108.jpg


With the bearing cover discs removed we can see 1 of the 4 bearing cups which hold the bearings in place.

Here's a photo of the top lateral bearing cup,the cover disc has been removed.

https://s26.postimg.cc/d8tn52ue1/IMG_2011_1.jpg

To remove the arm tube the 2 vertical bearings have to be removed first,they are held in place with grubs screws so i first removed them.
Once the bearing cups are unscrewed using my special tool :) you can withdraw the arm tube out from the back,whoops the finger lift wont go through the square arm tube block???
Apply some heat,i used hot air pant stripper and let physics to the rest,once there's enough heat the finger lift just pulls out,bingo! you can now remove the arm tube!

Now that the arm tubes out of the way you have to remove the bearing cones before the arm tube block can be removed.These are a push fit and again held in place with grub screws,some heat here gets them out .

Here's the underside of the arm tube block showing the bottom lateral bearing cone.

https://s26.postimg.cc/ur7ou1zpl/IMG_2097_1.jpg

With both top and bottom cones removed the arm tube block comes away leaving the main c shaped block/arm pillar.

So here's all the parts.

https://s26.postimg.cc/6d9elykhl/IMG_2096.jpg

Someones been here before!
The tonearm uses 3, 2.5mm ball bearings to each bearing cup,except my bottom lateral bearing has 4 much smaller bearings which dont even fully cover the diameter of the cup they run in??
Thats not right,i think ive found my problem!!

In this pic you can just see the smaller bearings to the right of the top bearing cup.

https://s26.postimg.cc/xmks0pdxl/IMG_2095_1.jpg

Feeling rather happy that id found the problem i ordered some new Silicon Nitride bearings,my thanks to angus for the advice :cool:

After work yesterday i started the rebuild.
All parts well cleaned with alcohol,basically its the strip down in reverse.
The bearing cones are put back in the arm tube block,then the bottom lateral bearings go in,then the top ones,a good tip here is to use Vaseline to hold the bearings in their cups,the cups have a small hole so once the arm is fully assembled the Vaseline can be cleaned away using wd40 squirted through the hole.

https://s26.postimg.cc/fp01wv4h5/IMG_2099.jpg

Lateral bearings ready for action!
https://s26.postimg.cc/vahdgr3jt/IMG_2100.jpg

Now comes the tricky bit,getting everything centered correctly,i used feeler gauges here,and got the arm tube in the right ball park,the final truing up i did when the arm was completely back together.

https://s26.postimg.cc/5rp13y221/IMG_2101.jpg

Here the arm tube is back in place and new tonearm wire inserted,

https://s26.postimg.cc/st5m9swll/IMG_2105.jpg

Anyone still following??:D

Right next i had to put the arm tube assembly back into the c shaped arm pillar,again final alignment is done when complete.

With everything back in place i set about getting everything totally true,careful loosening of one arm tube bearing and tightening of the other moves the arm tube left or right depending on where you need to be.Be very careful here as if you loosen 1 too much the cone slips out and you have to take the whole thing apart and re sit the bearings again,ask me how i know!!!

With everything all nicely squared up i had a lovely view from behind,ooh matron!

https://s26.postimg.cc/knnkbqg3d/IMG_2113.jpg

https://s26.postimg.cc/y74ehbz6h/IMG_2114.jpg

Nows the time to give all the bearings a good soaking in wd40 to remove the vaseline,i did this periodically about 5 times,wiping with kitchen roll.
With that done i called it a day.

First job today was to check how everything was,movement of the arm in all directions was good so i went on to re solder the tonearm wires.

https://s26.postimg.cc/l48rxrj5l/IMG_2115.jpg


And that's it folks,job done!
What effect has it had? well to start with the movement with the arm at balance is way better than before in all directions,the arm glides smoothly with no hint of sticking.
The head stock lines up with the alignment protractor grid lines at 90 degrees,before it didn't, and lastly here's a vid showing the greatly improved vertical free play.


https://youtu.be/4yVlZlQwQRo

[walpurgis]

Well done Jamie!

[oldius]

A great thread

[Bigman80]

Mate, that's a top job and a really good thread. Congratulations.

Has the arm improved significantly?

[karma67]

Mate, that's a top job and a really good thread. Congratulations.

Has the arm improved significantly?

cheers oli,yes it has,in every aspect,im not sure what difference the ceramic bearings have made if any over chrome steel ones? the focus has improved a lot id say and it seems to be quite in the back ground too.
the music flows a long nicely now.
oh and i forgot to mention earlier the azimuth is spot on now,before it always looked off to the right.
ive learnt a lot in doing this, above all else ive learnt there is no black art to tonearms,if your good with your hands its fairly straight forward as its just a mechanical object at the end of the day.
i was a little shocked to see just 3 ball bearings to be honest,i thought they'd be lots of microscopic tiny ones. lol

[Bigman80]

cheers oli,yes it has,in every aspect,im not sure what difference the ceramic bearings have made if any over chrome steel ones? the focus has improved a lot id say and it seems to be quite in the back ground too.
the music flows a long nicely now.
ive learnt a lot in doing this, above all else ive learnt there is no black art to tonearms,if your good with your hands its fairly straight forward as its just a mechanical object at the end of the day.
i was a little shocked to see just 3 ball bearings to be honest,i thought they'd be lots of microscopic tiny ones. lolLol, yes I agree mate. I think it more a fear of not being able to put it back together that puts people off. The Ceramic bearings are a lot smoother Than the steel ones. Less resistance so better all round. Angus knows his stuff.

Well done mate.

[Ian7633]

Excellent job mate in all departments, it's as good as a magazine article. Now you know the Zeta is just so, no ambiguity when setting up a cartridge. You've done well matey, have a kebab.

[RobbieGong]

Well done Jamie, Never knew you tackled jobs like this, good on ya.

I left mine to top man Angus and the tonearm glides as smooth as silk with the ceramics bearings he fitted which has to be a very good thing in terms of friction :)

[speedracer]

Nice job Jamie well done. If you lose your new tool & need it again, or for others thinking about doing something similar, you can get a watch back remover from ebay for just a couple of quid that does the same thing but has the advantage of being size adjustable.

[karma67]

A small update,
i have read on the web somewhere that early zetas used 3 bearings per cup and that later ones changed to 5 bearings.
Now it is very possible that whoever worked on the tonearm before me for what ever reason used the later 5 smaller bearings,even though he/she would have seen the fact that it uses 3.
Also the bearing cone angle would be different and the bearing cups ID made bigger to suit.It explains why my arm tube mounting block sat lower in the c shaped arm pillar,it now sits higher.

Here's a picture from the web of a later zeta using 5 to illustrate what i mean,i adjusted the photo to make seeing the bearings in their cup clearer.

https://s26.postimg.cc/du5qyztjt/zeta_final.jpg

and mine.

https://s26.postimg.cc/xmks0pdxl/IMG_2095_1.jpg

[brian2957]

Very interesting thread this with plenty of pictures . Well done Jamie :)

[walpurgis]

Yes, the bearing adjustments would certainly be different with five smaller ball bearings.

[Bigman80]

Any benefit to having 5 bearings? Just thinking that now you're well versed it may be worthwhile experimenting.

[karma67]

Any benefit to having 5 bearings? Just thinking that now you're well versed it may be worthwhile experimenting.

probably,after all they changed them for a reason,problems with early sticky bearings from what ive read,id have to have new cups machined as they have a bigger internal diameter along with new cones.
i doubt after all that id notice a difference and the cost would be too much i think and with new bearings in,especially ceramic, sticky bearings is the last thing id have :)

[Bigman80]

probably,after all they changed them for a reason,problems with early sticky bearings from what ive read,id have to have new cups machined as they have a bigger internal diameter along with new cones.
i doubt after all that id notice a difference and the cost would be too much i think and with new bearings in,especially ceramic, sticky bearings is the last thing id have :)Ye I can't imagine those bearing cups would be cheap to make. Too specialist. This is a cracking thread mate. Makes me want to buy something just to fix it!!!

[karma67]

ha ha,its all good fun mate,i reckon i did the zeta just in time as the Japanese monster is in customs at the moment!

[Bigman80]

ha ha,its all good fun mate,i reckon i did the zeta just in time as the Japanese monster is in customs at the moment!Holy shit, I'm really looking forward to seeing that on the 590!!!! They don't come up often do they.

[karma67]

so am i!! very very rare. i hope its not shit.:lol:

[Bigman80]

so am i!! very very rare. i hope its not shit.[emoji38][emoji23][emoji23][emoji23][emoji23]

[karma67]

another update......
after concerned comments about using Vaseline i decided to strip the arm down again to check,yes i know im a glutton for punishment!
and what did i find in the bearings caps? yep traces of Vaseline! and thats after numerous heavy spraying with wd40 followed by ipa :mental:
so as the arm is in bits again i thought id try 5 bearings and see if that improves things,it would seem the only difference is the bearing size and not the cups as i thought earlier,an email from moth marketing confirmed this.

ive also learnt that having a small gap left over in the cup when the bearings are fitted is no bad thing,in fact its better than having them touching for obvious reasons,the general web view is half the bearings diameter is acceptable. so ive ordered some 1.5mm and 1.59mm bearings.

so watch this space chaps :)

[Bigman80]

Good stuff. I'm watching. [emoji6]

[Hammer]

Good stuff. I'm watching. [emoji6]

Me too

[walpurgis]

I wonder if magnetising the cups would hold the balls in place? ......................probably not a good idea :)

[karma67]

im thinking along the lines of a soft shoe polish,it would easily dissolve in white spirit.

[walpurgis]

Actually, the magnet idea may not be so daft. Could you not use a small ring or disc magnet to hold the cups and balls together for installation?

[karma67]

now thats a bloody good idea! i will give it ago!
id have to ditch the silicon nitride balls in that case and go for chromed balls instead.

[walpurgis]

Oh. And another thought. When I'm working on something with small parts. I do it on a large tray with raised edges. Saves hunting around on the floor and under furniture for bits that get dropped. I learnt from experience. :D

[karma67]

been there and got the t-shirt too! regarding the ceramic balls,its all very well having an almost perfect sphere but then the machining on the becomes the weak link. i dont think i need to go all NASA about it,im sure chromed balls are more than acceptable.

[walpurgis]

im sure chromed balls are more than acceptable.

Yeah. They're not exactly enduring the kinds of stresses they might in an engine bearing.

[337alant]

im sure chromed balls are more than acceptable.
Agree, but do get a precision bearing
Geoffs idea of magnetisation is a good one and can easy be demagnetised after installation

On the subject of Vaseline it melts at body temperture 37C so couldn't you use a hair dryer to melt it? or just use grease and remove with meths or alcohol

Alan

[337alant]

im sure chromed balls are more than acceptable.
Agree, but do get a precision bearing
Geoffs idea of magnetisation is a good one and can easy be demagnetised after installation

On the subject of Vaseline it melts at body temperture 37C so couldn't you use a hair dryer to melt it? or just use grease and remove with meths or alcohol

Alan

[DSJR]

Very late reply..

Before anyone else wants to risk messing up or even destroying their rapidly value appreciating Zeta arm, I remember Mike Harris (http://www.britishaudio.co.uk/rewire.htm) as being able to properly help with Zeta bearing rebuilds - the early bearings were troublesome I was told. Mike was also one of the very few people outside of Rega with the special custom torque tools to PROPERLY rebuild and reset reset the RB300 (and upwards) bearings. Worth checking with him if he still offers assistance, as it's many years since I was there and saw Zeta arms there waiting bearing replacements and re-wiring...

[karma67]

yes if you not confident doing it yourself always go to an expert.
i should point out mine went off to a so called expert for a re wire and bearing check,the excessive horizontal play in the bearings was totally missed hence why i did it myself. nothing was destroyed or damaged.

[maxpalat]

Hello there,
I saw your post on Zeta Arm repair but photos were not visible.
Could you gently send them for me?
I have a problem with anti skating control ( wheel? spring?) concerning arm descend to disc: often occurs a kind of arm floating that prevents a correct vinyl lecture.
Any advice for this kind of malfunction?

Best regards
Massimo

[02GF74]

As above, is there any chance you could either send the photos to me or are able to put them on another photo hosting website?

I think the photo hosting website I have used still in the past is working and free so I could redo your first post with photos or compose a Word document ..... goes off to check if photo hosting site is still running ....