I need to repair an Oracle TT bearing

[240z4u]

This bearing uses two oillite or bronze bushings and a thrust plate. I need to replace the bronze bushings. The bottom one is worn.

Does anyone know who I could possibly have do this for me?

Thanks - Evan

This is for an oracle alexandria that I plan on stripping and mounting on a higher quality plinth. I have actually already made a "prototype" and have been using it. I can't go any further until this bearing issue is fixed though.

 

[Zen Mod]

This bearing uses two oillite or bronze bushings and a thrust plate. I need to replace the bronze bushings. The bottom one is worn.

Does anyone know who I could possibly have do this for me?

Thanks - Evan

This is for an oracle alexandria that I plan on stripping and mounting on a higher quality plinth. I have actually already made a "prototype" and have been using it. I can't go any further until this bearing issue is fixed though.

besides asking manufacturer for price,try nearest machine shop with good lathe ; can be much cheaper

 

[240z4u]

I called oracle, they basically said "your crazy" and that was about it. I will never buy anything from oracle after that experience.

I will try looking locally, but was not sure if anyone else had this issue, or any suggestions on where to get it done.

Evan

 

[Zen Mod]

I called oracle, they basically said "your crazy" and that was about it. I will never buy anything from oracle after that experience.

I will try looking locally, but was not sure if anyone else had this issue, or any suggestions on where to get it done.

Evan

look at this this way :
that part is made on some lathe ;
why can't be made again on same tool ,even if locally ?

besides- mebbe you can have it for price of few sixpacks ,and make friends for future crazy parts making ....
been there........ except that I have own lathe now......

(few sixpacks more to me )

 

[240z4u]

No, I definitely agree with you.

I will start looking for a precision machinist. Luckily I do live in a state capital so it should be available.

Thanks - Evan

 

[Vinyl-Addict]

look at this this way :
that part is made on some lathe ;
why can't be made again on same tool ,even if locally ?

besides- mebbe you can have it for price of few sixpacks ,and make friends for future crazy parts making ....
been there........ except that I have own lathe now......

(few sixpacks more to me )

Unless you've actually removed and replaced oilite bushings you would know that it is somewhat of a challenge to achieve a precision fit. Oilite bushings are not the most precision bushing because they have to be fitted with a specific tool, depending on the shaft diameter. Anyone can do this job but be careful what you end up with. If you want a precision fit, better ask if they have done this sort of work before. Oilite bushings are prone to "clogging" if machined after pressing in. I've installed these bushings in bearings that I have built and obtained a very nice fit without machining afterward but I took the time to machine a proper insertion tool. Make sure the machinist uses a dead sharp boring tool if he machines the bushings after installing, otherwise the pores will be closed up and the bushing(s) rendered useless. Good luck!

 

[240z4u]

I spoke to a supplier about oilites and they told me absolutely cannot lap the bushings to fit because of the clogging issue.

I have installed these with an arbor press before, what type of tool do I need? A spindle to keep the hole round?

Evan

 

[Vinyl-Addict]

I spoke to a supplier about oilites and they told me absolutely cannot lap the bushings to fit because of the clogging issue.

I have installed these with an arbor press before, what type of tool do I need? A spindle to keep the hole round?

Evan

You need measure the O.D. of the bearing shaft with a micrometer that reads in 0.0001 tenths of a thousand.
You also have to measure the O.D. of the bushings. The bushing I'D. is oversize and designed to compress, how far it compresses depends on the size of the insertion tool you make. It's actually not that hard but it's hard to explain without knowing all of the critical dimensions. If you can offer the "accurate" dimension of the bearing shaft, the ID and OD of the bushings, I can probably tell you the proper OD of the insertion tool you need, unless you already know how to figure that out.

 

[240z4u]

I actually have an oldschool full set of starret machinist calipers that may be that accurate. Ill have to check.

I guess, regardless of that, whats the odds that I will be able to find the correct size oillite?

Anybody know of anyone specific to do this job, im worried some hack machine shop could screw up the job and render the table worthless.

Thanks - Evan

 

[Vinyl-Addict]

I actually have an oldschool full set of starret machinist calipers that may be that accurate. Ill have to check.

I guess, regardless of that, whats the odds that I will be able to find the correct size oillite?

Anybody know of anyone specific to do this job, im worried some hack machine shop could screw up the job and render the table worthless.

Thanks - Evan

Calipers are not really accurate enough to measure the OD of the bearing shaft but they will work. Measure the ID of the bore that the bushings are pressed into with your calipers. Measure the OD of the bearing shaft. Look for a bushing that is of that "nominal size".
Most of these Oillite bushings are used in AC motors and don't need the level of precision you need for your TT. Can you press the old bushings out?

 

[240z4u]

I can definitely get the old bushings out, thats no problem. I have an arbor press at work.

I am just really worried about getting in "too deep" and not being able to put it back together.

My buddy is giving me his kenwood turntable, which I can use for a temp table while this project goes underway.

Evan

Sounds like oillite is not the bushing of choice for this application.

I am really sorry if I am being too timid about this whole project, I am just not the finest machinist LOL. I don't want to ruin anything Haha.

 

[Vinyl-Addict]

I can definitely get the old bushings out, thats no problem. I have an arbor press at work.

I am just really worried about getting in "too deep" and not being able to put it back together.

My buddy is giving me his kenwood turntable, which I can use for a temp table while this project goes underway.

Evan

Sounds like oillite is not the bushing of choice for this application.

I am really sorry if I am being too timid about this whole project, I am just not the finest machinist LOL. I don't want to ruin anything Haha.

Oillite bushings are great. You just have to perform the correct process if a precision fit is important. If you do remove the bushings, make sure you measure how deep they are pressed into the bearing housing. If you can't get someone to do the job I may be able to help but I am swamped right now and wouldn't be able to touch it for a few weeks. Can you post a top and bottom image of the bearing housing when you have time?

 

[240z4u]

No problem on the pictures. I would be willing to wait for months if I knew that someone cared enough to do it right.

Ill snap some photos.

Evan

 

[240z4u]

Here are the pictures. The bearing assembly unbolts from the subassembly. The bottom bearing looks just like the top. Its hidden behind a little plate that has the thrust bearing integrated into it.

Note the MDF, this is the remains of one beatup oracle alexandria.

Evan

 

[240z4u]

Heres the bottom picture.

 

[Nanook]

which version Alex?

if the plinth is mdf, painted , then it is a Mklll. If aluminum , then a Mkll. How did the bushing get beat up? I've owned my Alex for more than 15 years with no problems.

Except the mistake of putting an old SME 3009 on it, and never getting it "right. Finally put a magnesium 309 and magic...

any machinist worthy of his job should be able to make a new bushing for you. Too bad Oracle didn't sell you a new bearing well...

 

[240z4u]

I don't remember which one it is.

The original plinth was a composite plastic. The spring tower mount broke off of the table.

As for the bearing, if you do some reading you will find that most of the bearings in these tables are worn. its very common.

I could never figure out why I wasn't happy with the sound of my table and after the advice of some guys online I took the bearing assy. apart.

The top bearing was absolutely fine, however the bottom one is not as tight as it should be. I took apart the bearing assembly and flipped it over and slid it onto the shaft with just the bottom bearing. Lots of play.

Just for an experiement to see if it was the bearing, I ran a heavier (well tempered silicone) oil in it. The sound quality was dramatically better.

The old plastic plinths in these things sag, and then its impossible to level the table. My solution was to gut the oracle (since its already broken) and build a new plinth. Another common problem is the aluminum subassembly warps/twists. Mine is in good shape.

Also, the genious who had this table filled the whole damn table with lead!!! Thing was rediculously heavy, and it screwed up the suspension. No doubt was the reason the plinth broke.

I just don't want to go any further until I figure out that the bearing is pristine. Does not make too much sense to build a table around damaged goods.

Evan

 

[240z4u]

Oracle was not in the least bit helpful. They didnt offer me parts or anything!

Doubtful I will ever own another.

Evan

BTW, I have a well tempered classic on my table.

 

[Nanook]

too bad ...

your experiences haven't been good with Oracle. Here's a real problem: the company moved from Quebec to New Brunswick for tax purposes (I always question the financial stability of a company that does this if it isn't some large multinational), and back to Quebec.

The worst thing that has happened to Oracle is that the Riendineau brothers (if I recall correctly) had a squabble, and Marcel became Oracle. Oracle has always seemed to struggle (as many high end manufacturers do). ASFAIK, the Mklll bearing is different. I've never had an issue, although perhaps I need to check out the play with a local machinist. I am unsure if I have the same style bearing/bushing set up as your table. I'll take a closer look.

The best thing I can recommend to any with an Oracle is to ditch the "Prelude" arm if they haven't already...it was/is a completely bad arm. If an MDF plinth, then please remake it. I do know some who filled the bottom of the plinth with a mixture of lead shot and epoxy, to good effect, but personally I wouldn't do that. I'd use fun-tack or similar non-hardening putty to fill the plastic. Several I know swear it improves the table--I would just do something that was reversible if I didn't like the results.

 

[240z4u]

I would definitely reccomend checking out the bearing. Yours might be different. I checked mine by feel, its obviously worn. There is a definite rocking motion present in the bottom that its not there on the top side.

I have the plastic plinth, ill have to take pictures, its broken so I really need to make something nice if I am going to go to the trouble of making it work.

IMO the plastic plinth is kinda cheesy, seems like it would warp if you put too much weight in it.

I have a well tempered tonearm, so I am set there. I never knew the prelude was not a good arm though.

Thanks - Evan