Rotax Valve Maintenance

harrisonreed · by **harrisonreed** » 2018-08-18 11:00 a.m.

I even asked the valve manufacturer, read my Edwards manual, and search on the YouTubes... but I can't find it.

I can disassemble and reassemble a conventional rotor. I can't figure out how to do the same on a Rotax valve. I also don't understand what the adjustable mechanism around the spindle does. The manual says: "adjustable with hex screw", but not what is adjustable about it.

Anyone know? Even better, anyone want to make a video of it?

greenbean · by **greenbean** » 2018-08-18 11:38 a.m.

You contacted Willson and they didn't help you? That would surprise me.

harrisonreed · by **harrisonreed** » 2018-08-18 11:44 a.m.

[quote="greenbean"]You contacted Willson and they didn't help you? That would surprise me.[/quote]

Yeah, they had no manual to give me, and basically wondered why anyone would want to take tge valve apart....

:weep:

BGuttman · by **BGuttman** » 2018-08-18 1:07 p.m.

I wonder if it's like the old joke about boats: If you need to ask how much it costs you can't afford it.

In this case, "if you need to ask how to take the thing apart you aren't qualified."

I'm sorry it probably doesn't have pictures if it exists in our Archive, but I think Trav1s looked into putting one on a Conn 79H.

Matt_K · by **Matt_K** » 2018-08-18 3:45 p.m.

Are the Rotaxes they put on the 396 (I assume that's the one you're talking about) different from the stock ones too? That might explain their recalcitrance as well.

Trav1s · by **Trav1s** » 2018-08-18 3:58 p.m.

I had a Rotax installed on my 79H in 2011. Other than oil it with Hetmann oil I have not done anything to it. I don't play it as much as most people do but it was only sticky once because I had not oiled it in a LONG time. (shaking head in shame)

My install is also slightly different because I wanted to keep a string on the rotor because I like the quiet and quick response.

Now you have me curious...

Trav1s · by **Trav1s** » 2018-08-18 3:59 p.m.

Here are pics of the install Benn H did the work.

<LINK_TEXT text="https://www.facebook.com/media/set/?set ... d9b1e4ee92">https://www.facebook.com/media/set/?set=a.10200104507229318&type=1&l=d9b1e4ee92</LINK_TEXT>

harrisonreed · by **harrisonreed** » 2018-08-18 4:14 p.m.

[quote="Matt K"]Are the Rotaxes they put on the 396 (I assume that's the one you're talking about) different from the stock ones too? That might explain their recalcitrance as well.[/quote]

No clue! I don't think so though.

harrisonreed · by **harrisonreed** » 2018-08-18 4:17 p.m.

[quote="Trav1s"]Here are pics of the install Benn H did the work.

<LINK_TEXT text="https://www.facebook.com/media/set/?set ... d9b1e4ee92">https://www.facebook.com/media/set/?set=a.10200104507229318&type=1&l=d9b1e4ee92</LINK_TEXT>[/quote]

That does look really cool, but I wish it showed more of the "front" of the valve (which is what trombonists think of as the back of the valve). That's usually where the work of popping the valve out is done.

BGuttman · by **BGuttman** » 2018-08-18 4:20 p.m.

Thanks for posting that Trav1s. At least the history is not lost. And nice shots of the stripped down Rotax to boot.

Trav1s · by **Trav1s** » 2018-08-18 4:53 p.m.

I will see what I can do for some additional pics. Just picked up a 32H (dual bore .500/522) and want to play with the 32H slide and the 79H bell section. I hope I can get pics tomorrow and will add them to the album.

Trav1s · by **Trav1s** » 2018-08-19 8:44 a.m.

You can see the valve alone in this album.

<LINK_TEXT text="https://www.facebook.com/media/set/?set ... fd5ca92c4f">https://www.facebook.com/media/set/?set=a.4824227557449&type=1&l=fd5ca92c4f</LINK_TEXT>

Mikebmiller · by **Mikebmiller** » 2018-08-19 3:40 p.m.

FWIW, I have a Rotax valve on my Rath and the support guy at Rath told me they recommend using standard Dennis Wick valve oil on it.

Bonearzt · by **Bonearzt** » 2018-08-19 7:49 p.m.

Cleaning, servicing and oiling is the same as any rotary valve, with the exception of the Olsen valves.

Rotax "might" need a slightly thinner oil that other, and Olsen DEFINITELY thin!!

Spindles still need heavier oil such as the Hetman 13 or other key oil.

Still need to be very careful when disassembling & reassembling ANY valve!!!

Eric

harrisonreed · by **harrisonreed** » 2018-08-19 11:26 p.m.

[quote="Bonearzt"]Cleaning, servicing and oiling is the same as any rotary valve, with the exception of the Olsen valves.

Rotax "might" need a slightly thinner oil that other, and Olsen DEFINITELY thin!!

Spindles still need heavier oil such as the Hetman 13 or other key oil.

Still need to be very careful when disassembling & reassembling ANY valve!!!

Eric[/quote]

But what is the purpose of that adjustable silver metal piece with the hex screw around the spindle screw?

It seems like I shouldn't unscrew the spindle screw and then pop the rotor bearing if I don't know what that piece is doing.

Bonearzt · by **Bonearzt** » 2018-08-20 10:45 a.m.

It secures the stop arm onto the spindle, if we're talking about the same piece. A picture would help if not.

Other than that, they are all similar.

Eric

tctb · by **tctb** » 2019-06-26 8:04 a.m.

Trying to take a Rotax valve apart for cleaning. Does anyone have a video or pictures to help avoid doing any that might cause me a problem later when I try and get it back together again?

Bonearzt · by **Bonearzt** » 2019-06-26 3:14 p.m.

As I mentioned, it's the same as any standard rotary valve except for the stop arm which is held on with a small allen screw.

Everything else is the same!!

Eric

tctb · by **tctb** » 2019-07-30 11:26 a.m.

When I tried to take my rotax valve apart it would not comply. Once I had removed the mechanism driving the spindle and removed the rubber stop mechanism no amount of tapping the spindle end would persuade the rotor to come out of its casing. It looked to me as if you would need some sort of mechanical puller to get it to come apart without damaging the components . The screw fit circular cap at the spindle end looks like a neat way of hiding the threads for such a puller . I am stuck . Any ideas?

Mikebmiller · by **Mikebmiller** » 2019-07-30 4:24 p.m.

My local tech had a hard time with the Rotax on my Rath. It took 3 trips to him for him to get it working right after a chem clean. And he is generally very good.

Bonearzt · by **Bonearzt** » 2019-07-30 5:22 p.m.

As I mentioned, the Rotax valves are the same as any other rotary valve when disassembling other than the set screw holding the stop arm in place.

You unscrew the cap, remove the stop arm and tap on the spindle to pop the back bearing off, the plate under the cap, of the casing and remove the rotor.

Eric

harrisonreed · by **harrisonreed** » 2019-07-31 1:43 a.m.

The spindle has two screws interacting with it. One is bigger and it's on the end of the spindle. The other is tiny and holds the C-ring onto the spindle.

The instructions say "adjust the stop arm with the screw". Which screw does what? Remove both screws to free the spindle?

brassmedic · by **brassmedic** » 2019-07-31 4:33 a.m.

Never had a problem taking apart a Rotax valve. It's the same as any other rotary valve. If you have trouble, take it to your friendly neighborhood tech.

tctb · by **tctb** » 2019-07-31 4:34 a.m.

[quote="Bonearzt"]As I mentioned, the Rotax valves are the same as any other rotary valve when disassembling other than the set screw holding the stop arm in place.

You unscrew the cap, remove the stop arm and tap on the spindle to pop the back bearing off, the plate under the cap, of the casing and remove the rotor.

Eric[/quote]

I appreciate what you say but having hit it with a rubber mallet and then with a wooded one it will not budge . I am reluctant to hit it any harder for fear of doing some expensive damage .

I think this is one for the professionals!

harrisonreed · by **harrisonreed** » 2019-07-31 5:30 a.m.

The C-ring around the spindle is not like just any other valve. I understand that the rest of it is the same, and talking it out after you get the C-ring off is just like any other valve, but I am frustrated by the instructions regarding the stop arm and that C-ring that come with the horn. "Adjust the stop arm with the screw." How? Does that mean I can loosen the tiny screw that goes through the C-ring (like this " Cl. " where C = the silver piece around the main spindle and bigger screw, and "l" is the tiny screw), rotate the rotor core independently of the stop arm, tighten it back up, and now have the rotor out of alignment? Or does it mean I can move the stop arm /C-ring up and down along the axis that the spindle sits on? Is the section of spindle it goes around square like most rotors, or round (friction fit, thus explaining the tiny screw and strange adjustment control idea)?

I was hoping I could figure out what the purpose of the stop arm screw and C-ring design choice was before taking it off (because it is not the same as a normal rotor), but I'm going to just take it apart and figure it out.

When I do I'll write up something here for the dolts like me who believe that the valve is indeed not quite the same design as a regular valve

Burgerbob · by **Burgerbob** » 2019-07-31 6:01 a.m.

Some pictures might help this topic.

harrisonreed · by **harrisonreed** » 2019-07-31 6:19 a.m.

Yep, when I get time to take it apart I'll take some pics. I have no doubt that it is nothing for an experienced tech to make sense of, but the design choice of that stop arm has me stumped until I get it off and see what it's around.

afugate · by **afugate** » 2019-07-31 8:22 a.m.

This is from the TubeNet tuba forums.

--Andy in OKC

harrisonreed · by **harrisonreed** » 2019-07-31 9:34 p.m.

You can see both screws and the C ring/stop arm in the picture.

tctb · by **tctb** » 2020-05-15 7:39 a.m.

Finally got my Rotax valve apart . The secret ( for me ) turned out to be using a rawhide mallet and hitting it fairly hard . As has been pointed out elsewhere , you need the right amount of resilience in the hammer face to shock the parts into separating . In reply to the post above , the stop arm plate with two rubber stops is just screwed to the backing plate and should be left alone when dismantling . The screw that you might adjust is the large one you can see in the picture above which takes up the slack in the lever mechanism before you tighten the clamping screws ie you use it to regulate the clearance between the arm and the backplate.

To dismantle the valve I removed the cap at the front then at the back I removed the the large screw , slackened and removed the clamp after releasing the F trigger linkage . I then hit the bearing rod with the hammer and it came apart.I would point out that it is wise to take some photos so that you can get it back together again . When reassembing , a tap or two with the rawhide mallet seated the valve nicely . They thoughtfully put notches on the valve unit to help align it when replacing the parts.

I am sure the experts can explain the process more effectively and point out my mistakes , but this is my take on the process.

brassmedic · by **brassmedic** » 2020-05-16 5:32 p.m.

[quote="tctb"]I then hit the bearing rod[/quote]
Just for the sake of nomenclature, that's called the "spindle".

tctb · by **tctb** » 2020-05-17 4:50 a.m.

Thanks Brad . I made up the names as I went along ! I hope you are happy with my description . I am an amateur attempting maintenance during the lockdown.

brassmedic · by **brassmedic** » 2020-05-18 4:18 a.m.

[quote="tctb"]Thanks Brad . I made up the names as I went along ! I hope you are happy with my description . I am an amateur attempting maintenance during the lockdown.[/quote]
Good luck to you. I'm glad you were successful with the valve.

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