# Yuasa Rotary table - rusty



## kb58 (Mar 17, 2021)

Model number is 550-046.

Do you guys think that this is worth $100? The rust looks fairly significant and I don't have much experience with how well that much could be removed, or its importance to proper operation. Can't tell whether the damage goes deeper without it in-hand.


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## matthewsx (Mar 17, 2021)

I’d take it for a Benjamin.


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## macardoso (Mar 17, 2021)

Agreed. I don't have RT capabilities and that would clean up OK. Kiss it on a surface grinder or scrape it with the end of a file and surface plate if needed to get under the rust.

Only real worry would be if the worm itself was rusted, in which case it will eat the worm gear quickly.


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## macardoso (Mar 17, 2021)

I'm also a fan of those anti gravity allen wrenches. Those might be worth millions to spacecraft developers.


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## DavidR8 (Mar 17, 2021)

Definitely worth it!


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## kb58 (Mar 17, 2021)

macardoso said:


> I'm also a fan of those anti gravity allen wrenches. Those might be worth millions to spacecraft developers.


Hah, yeah, even if he loaded the picture rotated, it still doesn't explain its anti-grav quality.


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## Suzuki4evr (Mar 17, 2021)

Put the rusty bits in vinegar for a day or two if needed and then access the damage. I would take it if I were you. You can always ask someone around of they have a surface grinder to help if needed. Look at it this way,right now you DON'T have one. If I convert $100 to SA worthless rand,it is still a bargain.  Go for it.


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## keeena (Mar 17, 2021)

100% would buy. Based on what I can see of from the other parts: I'd think that the table only rusted vs. internals.


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## mikey (Mar 17, 2021)

That is a brand new 6" Yuasa rotary table for $100! Grab it before he comes to his senses. 

If I were you, I would grab it, take it apart, put all the non-painted parts in an electrolytic bath and get the rust off. The surface will be pitted and cannot be helped but when it comes out of the bath it will be free of rust. Hit it with some Dawn and a maroon scotchbrite pad to get the black residue off, then use extra-fine gray scotchbrite to shine it up. 

The table will still be as accurate as it was when it left the factory; no need to surface grind it unless you're looking to uber-accurize it, in which case you have to also scrape the mounting surfaces square and flat. Just as it comes from the factory, this table is very, very good.

I own this table and it is as smooth as silk. Almost no backlash and it is accurate. Yuasa made some of the finest tools and this one cost over $1200 when new. The internals should still be unused and is well worth the money.


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## DavidR8 (Mar 17, 2021)

If you manage to snag it @kb58 be sure to post pics of its return to glory!


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## brino (Mar 17, 2021)

Definitely worth $100.
-brino


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## mikey (Mar 17, 2021)

Just in case you are in your right mind and bought this table, I am attaching the factory listing for the 500 series tables and the manual that you'll need to get it apart.


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## hman (Mar 17, 2021)

macardoso said:


> I'm also a fan of those anti gravity allen wrenches. Those might be worth millions to spacecraft developers.


Sorry to rain on your parade ... but you have a misspelling in your post.  That's "Alien" wrenches, not "Allen."


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## vocatexas (Mar 17, 2021)

Evaporust will fix that right up. If there's no pitting it will look new in 24 hours.


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## Shootymacshootface (Mar 18, 2021)

I want it for $100!
Disassemble, soak in Evaporust, lap top of it, reassemble, make cool stuff.


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## kb58 (Mar 18, 2021)

I picked it up. Having never handled one in person, I expected the table to slowly turn as the crank is turned, but it doesn’t. The crank turns with reassuring resistance but the table isn’t moving. Either there’s a clutch thing going on that I’m not aware of, or there’s something going on between the worm and ring gear. Won’t know until I get it apart.

I’d  think that these things are fairly robust and hard to break, but we’ll see.


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## kb58 (Mar 18, 2021)

mikey said:


> Just in case you are in your right mind and bought this table, I am attaching the factory listing for the 500 series tables and the manual that you'll need to get it apart.


Thank you very much for this!


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## DAT510 (Mar 18, 2021)

Typically there a lever near the Crank, which "cams" the worm gear in and out to adjust backlash and allow the table to rotate freely before engaging the crank.  It may be in the "out" position.

Btw, some use a ring vs a lever.

Just looking the manual "mikey" provided.... Looks like yours uses a ring to move the worm gear in and out, and a t-bolt (#11) to lock the ring.


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## mikey (Mar 18, 2021)

kb58 said:


> I picked it up. Having never handled one in person, I expected the table to slowly turn as the crank is turned, but it doesn’t. The crank turns with reassuring resistance but the table isn’t moving. Either there’s a clutch thing going on that I’m not aware of, or there’s something going on between the worm and ring gear. Won’t know until I get it apart.
> 
> I’d  think that these things are fairly robust and hard to break, but we’ll see.



I took some notes when I disassembled and reassembled my table. If you're interested, I'll dig them up and post them here. Let me know.


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## Choiliefan (Mar 19, 2021)

Did you get those misc items shown with it in the pic as well?


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## kb58 (Mar 19, 2021)

So I disassembled it as far as I can, leaving only the table in-place. Even with the worm gear shaft removed (which is in great condition), the table itself is still frozen in place.

My question: How do I remove the table? It looks like there are two pressed-in sections in the center hole, a short section toward the bottom and a longer slender section toward the top. I don't want to start applying a lot of force to it until I know the right way to get it apart.

Table top side:




Back side / bottom:




On the subject of the rust, I have the Evapo-Rust on the way and hope that it can save this:


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## Janderso (Mar 19, 2021)

kb58 said:


> So I disassembled it as far as I can, leaving only the table in-place. Even with the worm gear shaft removed (which is in great condition), the table itself is still frozen in place.
> 
> My question: How do I remove the table? It looks like there are two pressed-in sections in the center hole, a short section toward the bottom and a longer slender section toward the top. I don't want to start applying a lot of force to it until I know the right way to get it apart.
> 
> ...


Does this mean you bought it?
If you paid $100 ---wait for it-----You Suck


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## DAT510 (Mar 19, 2021)

Stefan Gotteswinter takes his apart during his "upgrade" of it.  Looks similar to yours.





  Around the 7:45s mark.

Looks like it should slip apart, from where you have it now.  Might be worth dropping the whole thing in evaporust or soaking the frozen spindle in penetrating oil to loosen it up.

If you have access to a big ultrasonic cleaner with evaporust, that could be a way to go.


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## kb58 (Mar 19, 2021)

Choiliefan said:


> Did you get those misc items shown with it in the pic as well?


Yes.


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## kb58 (Mar 19, 2021)

DAT510 said:


> Stefan Gotteswinter takes his apart during his "upgrade" of it.  Looks similar to yours.
> 
> 
> 
> ...


Thanks for that video. Even though it's about a Vertex, it's very similar to the Yuasa from what I can see. I'll put some penetrating oil on the center column, now that I know that it's supposed to simply lift out from the top.


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## Janderso (Mar 19, 2021)

Aren’t the Yuasa’s made in Japan?


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## kb58 (Mar 19, 2021)

Yes


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## MrWhoopee (Mar 19, 2021)

You definitely SUCK! Even in it's current condition it is worth at least twice what you paid. It will be a fine piece once you've finished.


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## mikey (Mar 19, 2021)

kb58 said:


> So I disassembled it as far as I can, leaving only the table in-place. Even with the worm gear shaft removed (which is in great condition), the table itself is still frozen in place.
> 
> My question: How do I remove the table? It looks like there are two pressed-in sections in the center hole, a short section toward the bottom and a longer slender section toward the top. I don't want to start applying a lot of force to it until I know the right way to get it apart.



Yes, once the worm shaft and collar assembly is out, you should just be able to lift the table off the body. Penetrating oil and a few taps with a dead blow should get it off.


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## kb58 (Mar 20, 2021)

Ah, now I understand... and it's apart.

For anyone else with this Yuasa table, the trick is knowing that the table shaft is tapered. Tighten the bottom plate enough and it jams up solid like a Morse taper. I'm a little surprised, a tapered bore being used as a (non-ball) bearing. On the other hand, unlike the Vertex brand, it's absolutely guarantees that there won't be any looseness of fit.

The overly tight fit aside (I know now not to over-tighten the bottom retention plate), the bore and gear are in excellent condition. Things are looking good. All that's left is de-rusting it and reassembly.

And as far as me sucking goes (I know it's in jest), I'm _always _seeing others walk off with the deals. This one only worked out because I had a Craigslist filter for "rotary table" running for about six months. Also, because I'm working from home, unlike usual, I could instantly take some time off and go check it out, midday during work week, so I could get there before the "weekend warriors". Lastly, the seller was selling off her dad's stuff, as he'd recently passed away. That always hits me because I've gone through the same thing myself. In this case, I paid the asking price, though being unsure at the time whether I was getting a deal or a boat anchor (due to the jammed table).


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## DavidR8 (Mar 20, 2021)

Wow, that looks pristine inside!


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## mikey (Mar 20, 2021)

Reassembly is a bit fiddly. Shout out if you get stuck.


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## kb58 (Mar 20, 2021)

Will do!

What kind of oil is used in something like this, way oil, or regular oil like is used in a mill? With grease on the gear faces I assume.


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## MrWhoopee (Mar 20, 2021)

That's beautiful! I was guessing that was the case based on the condition of the paint.


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## Choiliefan (Mar 20, 2021)

I see now that it's horizontal and vertical.  Wow...  even better.
Please describe the other items you got along with this deal.


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## mikey (Mar 20, 2021)

kb58 said:


> Will do!
> 
> What kind of oil is used in something like this, way oil, or regular oil like is used in a mill? With grease on the gear faces I assume.



Grease on the gear and worm, hydraulic oil on everything else. I prefer Super Lube grease because it is synthetic and will not cake and harden over time. I use regular hydraulic oil elsewhere. There is an oiling cup just to the left of the hand wheel; that gets oil under the table. Another oiling port is located just in front of the hand wheel; this oils the worm shaft. It's a good idea to oil both ports before and after use; you don't need to use a lot of oil here.

I finished writing up the write up on the rotab and am attaching it below, but only because there is a sequence to reassembly you need to be aware of. There are two things that you need to pay attention to. One is that you should not mess with the centralizing set screws in the black worm shaft collar unless your worm shaft binds. Second is that the worm shaft collar needs to be in the correct rotational position in order to adjust the set screw that eliminates back lash in the hand wheel. Otherwise, nothing is critical.

Edit: the hyperlink in my word doc doesn't work. It points to a thread I posted on a T-slot clamp set that I confirmed to work well on this table.


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## hman (Mar 20, 2021)

Congratulations on getting the table apart!  Looks like you got a real winner there.


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## 7milesup (Mar 21, 2021)

I use Super Lube also.  Good stuff.   For those that may not know, it is available at Harbor Freight, ironically.


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## kb58 (Mar 21, 2021)

Having never used Evapo-Rust, I have to say that I'm very impressed. The table top turned out perfectly usable, and the graduations on the side turned out even better.  Next up, reassembly.







A couple people asked what else I got with it. It's these two things, which appear to be bases for a rotating vice maybe. Both have graduations on them, and while I have no use for them now, I suspect they could be very useful down the road.


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## DavidR8 (Mar 21, 2021)

That looks fantastic!


Sent from my iPhone using Tapatalk


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## FOMOGO (Mar 22, 2021)

Came out great. I paid almost three times that for my 8" Phase II, and while it does what I need, it is nowhere near the same level of quality as yours. Cheers, Mike


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## Lo-Fi (Mar 22, 2021)

That's turned out even better than I thought it would! Fantastic find. Much fun to be had using it now


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## vocatexas (Mar 22, 2021)

I've used Evaporust on lots of tools I've bought at auctions. That stuff will work miracles sometimes.

I'm glad the rotary table cleaned up that well for you. You got a heck of a deal there.


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## kb58 (Mar 22, 2021)

And it's done, turning out far better than I ever expected, and yes, silky smooth operation. A big thanks to everyone with the very helpful posts!

If there's something more to be done, it's to make locating feet for it to match the mill table slots, which are different in width (10mm vs 14mm off the top of my head).

Thanks again, guys.


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## bollie7 (Mar 25, 2021)

kb58 said:


> Having never used Evapo-Rust, I have to say that I'm very impressed. The table top turned out perfectly usable, and the graduations on the side turned out even better.  Next up, reassembly.
> 
> View attachment 360242
> 
> ...


May be you should go back and ask the seller if she still has the vice that goes with the blue base. If she has it might be good quality as well and might be worth buying for a fair price. (if its for sale of course)


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## pontiac428 (Mar 26, 2021)

Great results!  Usually with marine salvage they use electrolysis, but the evaporust seems to have done well.


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## PaulJ1950 (May 12, 2021)

I have a 6" Yuasa rotary table which was good until the worm wheel gear lost some teeth. The material is soft and crumbles easily (see photo).  Not recommended for milling a curved surface under any heavy load.  Spare gears were not available.
Paul


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## brino (May 12, 2021)

PaulJ1950 said:


> I have a 6" Yuasa rotary table which was good until the worm wheel gear lost some teeth.



I have to wonder if the cam that controls the worm depth was set wrong during that cut.
If the worm and wheel were just barely in contact I could see that happening.

I wonder if it could be repaired by brazing those teeth and re-gashing. ........for regular duty use anyway; the braze material will also be somewhat soft. A Yuasa is worth a try!

-brino


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## Lo-Fi (May 12, 2021)

brino said:


> wonder if it could be repaired by brazing those teeth and re-gashing. ........for regular duty use anyway; the braze material will also be somewhat soft. A Yuasa is worth a try!


It's something I'd try, for sure. Get some silicone bronze on there, gash and free hobb on the lathe. Agreed it looks like the depthing was not right!


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## PaulJ1950 (May 12, 2021)

Not sure what the gear is made from but not steel, more like die casting material. Brazing material would be stronger. The Yuasa RT has been made to good standards but it is an economy model, no main bearing just a bush for the table.
When I contacted Yuasa in Japan about 6 years ago, they told me that the RT was a superceded model and they did not have spare parts and suggested I try their office in USA. _(I live in Australia)_. They said that they had one in stock which cost me about $90 for the gear and postage.
Paid for it and after a month nothing delivered. Contacted them again and was told that the item had been processed but lost somewhere in their postage system and that they would send a replacement. Then I was told that there was no spare parts in stock.  
I asked for a refund but no reply. Only after threatening to take legal action and broadcast on the internet was my money returned.
Since then I have purchased another RT and use the old Yuasa as a turntable with no gear drive.
Paul


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## Janderso (May 12, 2021)

PaulJ1950 said:


> I have a 6" Yuasa rotary table which was good until the worm wheel gear lost some teeth. The material is soft and crumbles easily (see photo).  Not recommended for milling a curved surface under any heavy load.  Spare gears were not available.
> Paul


Soft and crumbly, maybe cast iron and climb milling was responsible??


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