Borescoping a Rotor Valve

Common or not-so-common practices to maintain, modify, or repair your instruments.

Moderator: Bonearzt

Borescoping a Rotor Valve

Postby boneagain » Sun Jul 17, 2016 5:28 pm

PART I

A question came up in TTF about what to look for when borescoping a valve. Pictures were requested. Given TTF's problems with pictures, Trombone Chat seemed a better choice.

The answer to the question is, perhaps obviously, look for edges. I can see the problem with that obvious answer. Someone who has not looked down into a valve probably doesn't know what an edge looks like.

These pictures should help in that situation.

This one is looking from the slide receiver back toward the 1st valve. As indicated in the picture annotation, you can see the bright ring of the edge of the valve knuckle. For the uninitiated, the knuckle is the sharp little bend attached to the shell of the valve. In my ideal world, I would NOT see that edge. My ideal receiver is tapered to fit the slide tenon on one end, and counterbored so that the inner diameter of the knuckle matches exactly with the inner diameter of the socket at the joint. I'd say the counterbore in this instance is about half the depth I'd like, but I'm not taking the horn apart to find out.
1-Approaching receiver.jpg


In this picture I moved the scope about an inch into the socket. It is easier to see the knuckle edge now. The faint crescent in the dark area is the far edge of where the rotor meets the shell.
2-Approaching knuckle.jpg

Not much to see here that can't be seen with eyeball and small flashlight from the open end of the slide receiver. I include it as a reference for the question, "how far in do I put the scope?" This is not far enough :)

This third picture is just about in the knuckle, but not in the valve body.
3-At knuckle,valve in Bb.jpg

You can just barely see the corner of the channel in the rotor core at the top center of the picture. The joint between the rotor core and shell is the bright line below that. These are some of the landmarks I use to figure out if the valve is well centered (aligned) in a given position.

Since these posts have a three picture limit, I'll post the rest in a post a bit later.
Last edited by boneagain on Sun Jul 17, 2016 6:09 pm, edited 1 time in total.
boneagain
 
Posts: 56
Joined: Fri Mar 04, 2016 3:11 pm

Re: Borescoping a Rotor Valve

Postby boneagain » Sun Jul 17, 2016 6:08 pm

PART II

In this view the channel in the rotor becomes clearer, since I have begun to engage the F attachment.
4-At knuckle, valve halway to F.jpg

The corners that are indicated were barely visible in the previous photo. In the background the crescent of the inner wall of the rotor passage contrasts with the very black background of the unlit passage at the other end of the valve. Note the change in color, mostly due to the relocation of the LED and autoadjustments of the camera software.

In this final shot I put the scope just about inside the valve.
5-In knuckle, valve in Bb, lookup up.jpg

Now you can see the far end of the rotor shell, and the edges of the channel in the rotor core.

I can also put the scope right IN the sound passage because of the way the King valve works. The "webbing" (metal remaining in the core between the passages) does NOT cross the receiver end of the valve, so it won't get stuck on the scope. I'm not including one of those pictures because they don't make sense without either: 1) doing it yourself or 2) a LOT of explanation. Better to try it and see.

Also useful to put a right angle mirror on the end of the scope. The picture is not as clear (you have to clean the mirror very carefully, and even then, it takes a VERY expensive mirror to not degrade the image notably) BUT the 90 degree change in viewpoint makes it possible to see things that would otherwise be missed.

As far as "what to look for..." It's still edges. For me, I like to pull slides and look from different vantage points. I compare results from different entry points with the valve in both positions to gauge how symmetrical they are, and how well those positions are supported by the rotor bumpers. On my horn I can't get full symmetry AND what looks like smooth passage from the inner channel to the next knuckle without having the OTHER side of the valve intrude too far into the passage. Your mileage WILL vary.
boneagain
 
Posts: 56
Joined: Fri Mar 04, 2016 3:11 pm

Re: Borescoping a Rotor Valve

Postby Terraplane8Bob » Mon Jul 18, 2016 11:11 am

WOW ! What a spectacular job of photographing the valve and labeling the components ! It is what I would have hoped to do when I wrote the first post on the subject, but the double whammy of "Geezerdom" & lack of computer smarts conspired against my doing so. I think there will be a mixed bag of responses to all your hard work ---- exhilaration & frustration both. But --- the end result can be spectacular !
NOW ---- If someone [is George McCracken listening ?] would just make a bumper holder that has a screw- adjustable bumper with a lock-nut provision ! If the bumper had a round profile it could be turned in its seat in fine increments to achieve the desired position, tighten the lock-nut and we could all throw away our single-edge razor blades ! It is the same principle in play when I adjust the valves on my old BMW R-60 motorcycle. If I can draw what I'm proposing I'll post it later. Pretty simple, actually. Why such adjustable bumpers were not a standard feature on every rotary valve is a mystery to me. Cost ? The Cost / Benefit calculation would certainly come out on the "Thumbs-Up" side ! OK --- That's my 2 cents worth ! Let's hear from some happy beneficiaries of this technique ! Cheers to all !!
Terraplane8Bob
 
Posts: 27
Joined: Sun Mar 06, 2016 1:21 pm

Re: Borescoping a Rotor Valve

Postby Bonearzt » Mon Jul 18, 2016 11:41 am

Terraplane8Bob wrote:WOW ! What a spectacular job of photographing the valve and labeling the components ! It is what I would have hoped to do when I wrote the first post on the subject, but the double whammy of "Geezerdom" & lack of computer smarts conspired against my doing so. I think there will be a mixed bag of responses to all your hard work ---- exhilaration & frustration both. But --- the end result can be spectacular !
NOW ---- If someone [is George McCracken listening ?] would just make a bumper holder that has a screw- adjustable bumper with a lock-nut provision ! If the bumper had a round profile it could be turned in its seat in fine increments to achieve the desired position, tighten the lock-nut and we could all throw away our single-edge razor blades ! It is the same principle in play when I adjust the valves on my old BMW R-60 motorcycle. If I can draw what I'm proposing I'll post it later. Pretty simple, actually. Why such adjustable bumpers were not a standard feature on every rotary valve is a mystery to me. Cost ? The Cost / Benefit calculation would certainly come out on the "Thumbs-Up" side ! OK --- That's my 2 cents worth ! Let's hear from some happy beneficiaries of this technique ! Cheers to all !!


Interesting idea of the screw adjustment. But that brings to mind the old Bach "clank"ages that we all SO love!

Not too difficult to file the cork/bumper/stop plate holes to make them oblong and then sliding that around to adjust the stops.

I agree with the great job on the bore pics!!! Gotta get me one of them thangs!!


Eric
Eric
Edwards

"The bitterness of poor quality remains long after the sweetness of low price has faded!"
"If you're doing something a certain way ONLY because it's always been done that way, you're probably doing it wrong!"
User avatar
Bonearzt
 
Posts: 146
Joined: Tue Mar 01, 2016 5:42 pm
Location: Dallas/Ft.Worth Texas

Re: Borescoping a Rotor Valve

Postby Terraplane8Bob » Mon Jul 18, 2016 12:14 pm

Terrific idea to move the actual bumper stop plate instead of my far more complicated idea of screw-adjustable bumpers ! It just goes to show that if you put a bunch of trombone players in a room together that something other than rude noises can be the result ! NOW --- Let's see a prototype ! Cheers !!
Terraplane8Bob
 
Posts: 27
Joined: Sun Mar 06, 2016 1:21 pm

Re: Borescoping a Rotor Valve

Postby Bonearzt » Mon Jul 18, 2016 1:52 pm

I think Holton/LeBlanc had this on their rotary valves, don't think anyone else thought of it at the factory level.

Not really much to prototype, just use a thin, round file & elongate the hole opposite the direction you want to move plate.

I'll try to find/take some pics.

Eric
Eric
Edwards

"The bitterness of poor quality remains long after the sweetness of low price has faded!"
"If you're doing something a certain way ONLY because it's always been done that way, you're probably doing it wrong!"
User avatar
Bonearzt
 
Posts: 146
Joined: Tue Mar 01, 2016 5:42 pm
Location: Dallas/Ft.Worth Texas

Re: Borescoping a Rotor Valve

Postby tbathras » Mon Jul 18, 2016 2:28 pm

Did you mention what scope you're using? Model number or link to where you bought it? There are so many out there and with things like this, it's usually a crap shoot on quality. Would be really nice to know what actually works.
Bass Trombone
tbathras
 
Posts: 82
Joined: Fri Mar 04, 2016 3:12 pm
Location: Southern Maine

Re: Borescoping a Rotor Valve

Postby Terraplane8Bob » Mon Jul 18, 2016 3:15 pm

I bought mine on EBay from a company called "greenenv" for the astronomical sum of $8.79 including shipping. They sell everything from welding helmets to manicure sets ! I looked for one that was compatible with Windows XP to suit my computer. If anyone else plans to buy, be sure to make sure of the compatibility of the camera with your computer or cell phone. It has 6 LEDs around the circumference of the 5Millimeter camera with a rheostat to regulate the brightness of the LEDs. It came with a small CD with other programs, but it worked for me as a "plug & play". No labels or model numbers were on the unit so I can't be more specific. Sorry ! Lottsa fun !!
Terraplane8Bob
 
Posts: 27
Joined: Sun Mar 06, 2016 1:21 pm

Re: Borescoping a Rotor Valve

Postby boneagain » Mon Jul 18, 2016 4:58 pm

Terraplane8Bob wrote:I bought mine on EBay from a company called "greenenv" for the astronomical sum of $8.79 including shipping. They sell everything from welding helmets to manicure sets ! I looked for one that was compatible with Windows XP to suit my computer. If anyone else plans to buy, be sure to make sure of the compatibility of the camera with your computer or cell phone. It has 6 LEDs around the circumference of the 5Millimeter camera with a rheostat to regulate the brightness of the LEDs. It came with a small CD with other programs, but it worked for me as a "plug & play". No labels or model numbers were on the unit so I can't be more specific. Sorry ! Lottsa fun !!


I paid a little more but bought from "greenenv" also: http://www.ebay.com/itm/3-5-2-1-5-1M-5-5mm-Android-Endoscope-Waterproof-Borescope-Inspection-Camera-6LED-/252433847220?var=&hash=item3ac63ad3b4:m:m6WDGfNsGuSXGNCL9qVqm6Q

Did your kit have the right angle mirror?

Oh, thanks for the kind words on my effort. Good practice before I bring George the one I got for him :) I'll mention the bumper idea to him, but that would make for a very expensive part. Even if I take the time it takes ME to mill up something that finich and cut it in half, that would be quite a bit of time in the shop. An even bigger reservation for me is the ongoing effect of usage cycles. BMW and others make these sorts of things out of a bit beefier steel. Unless the plate were made out of steel, I can't imagine it holding the adjustment as well as the "cork" does. Then again, it might just be fun to see what some scrap brass can turn into....
boneagain
 
Posts: 56
Joined: Fri Mar 04, 2016 3:11 pm

Re: Borescoping a Rotor Valve

Postby boneagain » Mon Jul 18, 2016 5:15 pm

Bonearzt wrote:
I agree with the great job on the bore pics!!!



Thanks!

Bonearzt wrote:
Gotta get me one of them thangs!!



So you can take a shot like this?
waterkey.jpg

You know what this is, but for the rest of the thread readers, it's the INSIDE hole in the hand slide bow that the water key fits over. The one I got states on the eBay page that it is rated to IP67, so I'm not worried about schmutz on the inner slide causing later problems with the scope. Could make it very handy for checking finish when doing inside boring, like making receiver tapers and such. Just a though :D
boneagain
 
Posts: 56
Joined: Fri Mar 04, 2016 3:11 pm

Re: Borescoping a Rotor Valve

Postby Terraplane8Bob » Mon Jul 18, 2016 8:20 pm

These photographs are probably as interesting to trombonists as the photos from our various inter-stellar satellites are to astro-physisists ! We ALL know we will never get out there to experience space ---- but we CAN look inside our instruments to see stuff which, in many ways, is much more meaningful to the moment. I recall a "spit key" [get over it --- "water key" just doesn't cut it] on the Doc Severinsen Model Trumpet from Getzen that had a "SPIT KEY" that was contoured to the inner tubing of the instrument and presented NO impedance to air flow because the inner contour of the "SPIT KEY" matched the inner contour of the tubing into which it was placed. There is a proprietary name for this valve but it escapes me at the moment. Was it a "Glanz" key [tech guys, please chime in] ? Instead of opening an orifice in the tubing which created a turbulant point in the airflow, it worked in a horizontal fashion to change the inner contours, dump the water and then restore them. In any case, the incremental improvements from these changes are what makes progress. Let's GO !! Cheers !! Bob
Terraplane8Bob
 
Posts: 27
Joined: Sun Mar 06, 2016 1:21 pm

Re: Borescoping a Rotor Valve

Postby Bonearzt » Mon Jul 18, 2016 9:08 pm

You might be talking about the Amado water key. Good idea in theory & OK for smaller horns like trumpets & french horns, but just not quite large enough for trombones, etc.

The Saturn keys are GREAT!!! A bit pricy, but MUCH better than the Amado's, IMO..

Oops, got off on a tangent from the OP.

Yes, it will be cool to check out the interior of certain parts of the horns I work on. Water keys & valve section tubing for sure!
Although I can usually sight through the tubing to align rotors, it would be cool to see up close like this!
Also to see & record the typical Bach solder blobs inside the 42BO F tuning slides!!

Last thought, on the stop plate, not an expensive or difficult process at all!! Just take the original plate & file the holes slightly to give it some sliding room on the screws. Takes about 5 minutes!

Unless, of course, you WANTED to machine a complete part from scratch..... Not me!!


Thanks again!!

Eric
Eric
Edwards

"The bitterness of poor quality remains long after the sweetness of low price has faded!"
"If you're doing something a certain way ONLY because it's always been done that way, you're probably doing it wrong!"
User avatar
Bonearzt
 
Posts: 146
Joined: Tue Mar 01, 2016 5:42 pm
Location: Dallas/Ft.Worth Texas

Re: Borescoping a Rotor Valve

Postby boneagain » Tue Jul 19, 2016 7:17 am

Bonearzt wrote:Last thought, on the stop plate, not an expensive or difficult process at all!! Just take the original plate & file the holes slightly to give it some sliding room on the screws. Takes about 5 minutes!

Unless, of course, you WANTED to machine a complete part from scratch..... Not me!!


Thanks again!!

Eric


As far as machining from scratch... keep in mind, I've been doing this kind of thing MUCH less extensively and less time than you (pretty much since retiring.) Machining is still very new and quite a switch from hobby woodworking (for the most part, except for building jigs and... I digress.)

The problem I would have with the entire stop plate being adjustable is that pulling one side into adjustment would pull the other side as well. I suppose we could do a two-piece stop plate, but I think that would require four screws in the rotor casing. Or, maybe the pivot screw could be a pin soldered to the casing instead. That would free up real estate for the screw head on the screw over the adusting slot on each side. Hmmm...

Not for my Duo Gravis, though. I put cap screws into the stop plates, and use those as oil plugs, putting body oil straight where it does the most good, rather than down the tuning slide. Bearing oil goes into the channel in the bearing shaft (a feature George borrowed from the french horn and tuba worlds) so overall oiling is VERY effective. I'd rather fuss with the corks once in a blue moon than the oiling every week.

But I could still get inspired... may have to start another thread.
boneagain
 
Posts: 56
Joined: Fri Mar 04, 2016 3:11 pm

Re: Borescoping a Rotor Valve

Postby Bonearzt » Tue Jul 19, 2016 12:12 pm

Hi Dave, when I adjust the stop plate in the manner I'm referring to, there is usually very little movement needed and my method for elongating the holes makes it so that I can adjust each side as needed without disturbing the other.
I know it doesn't make sense in writing, but it works, and that's all I need to worry about.

I've tried repairing broken stop plates by brazing piece of brass rod in place of the broken piece, but the difficult part is forming the proper shape on the inside of the rod to hold the rubber bumper.

But, we've broken off of the main topic here. Maybe start a new thread if there's interest.

Thanks!

Eric
Eric
Edwards

"The bitterness of poor quality remains long after the sweetness of low price has faded!"
"If you're doing something a certain way ONLY because it's always been done that way, you're probably doing it wrong!"
User avatar
Bonearzt
 
Posts: 146
Joined: Tue Mar 01, 2016 5:42 pm
Location: Dallas/Ft.Worth Texas

Re: Borescoping a Rotor Valve

Postby Terraplane8Bob » Wed Jul 20, 2016 9:28 pm

After some consideration, I had the same concerns as "boneagain" about moving the bumper plate independently on each side to achieve the perfect clearances for which we are looking. As they say,"The proof is in the pudding" --- so if "boneartz" says it works, I eagerly await the first example. Not being a production engineer, I wonder how difficult it would be to make such a bumper plate standard on every rotary valve equipped instrument. I know that the auto industry debates every change that costs a cent or two because they typically pump out several hundred thousand cars that add up to a bunch O' change ---- but just how many rotary valve instruments are manufactured each year ? Is it THAT big a deal ? If Schagerl can crank out the outrageous instruments that they do, is an adjustable plate such a great expense to incorporate into normal production instruments ? That's a lot of questions ----- anybody have any answers ?
Terraplane8Bob
 
Posts: 27
Joined: Sun Mar 06, 2016 1:21 pm

Re: Borescoping a Rotor Valve

Postby boneagain » Thu Jul 21, 2016 7:50 am

Terraplane8Bob wrote:After some consideration, I had the same concerns as "boneagain" about moving the bumper plate independently on each side to achieve the perfect clearances for which we are looking. As they say,"The proof is in the pudding" --- so if "boneartz" says it works, I eagerly await the first example. Not being a production engineer, I wonder how difficult it would be to make such a bumper plate standard on every rotary valve equipped instrument. I know that the auto industry debates every change that costs a cent or two because they typically pump out several hundred thousand cars that add up to a bunch O' change ---- but just how many rotary valve instruments are manufactured each year ? Is it THAT big a deal ? If Schagerl can crank out the outrageous instruments that they do, is an adjustable plate such a great expense to incorporate into normal production instruments ? That's a lot of questions ----- anybody have any answers ?


This truly needs a new thread of its own :)

And thanks to the nice folks on THIS forum, we can include ALL kinds of diagrams/pictures/sketches!

Back on the original topic, I dropped one of this off to Mr. McCracken yesterday. He was quite tickled with it! Of course, I blamed the WHOLE thing on Bob Kraft!

First thing we did was check out valve alignment on very old Kruspe that he had just sleeved the valves on. The original index marks were quite a bit off. I believe the owner will be VERY surprised how much better this horn plays with all the dings out AND the valves in PROPER alignment!

Thanks Bob!
boneagain
 
Posts: 56
Joined: Fri Mar 04, 2016 3:11 pm

Re: Borescoping a Rotor Valve

Postby Bonearzt » Thu Jul 21, 2016 8:50 am

I'll see what I can do.
Eric
Edwards

"The bitterness of poor quality remains long after the sweetness of low price has faded!"
"If you're doing something a certain way ONLY because it's always been done that way, you're probably doing it wrong!"
User avatar
Bonearzt
 
Posts: 146
Joined: Tue Mar 01, 2016 5:42 pm
Location: Dallas/Ft.Worth Texas

Re: Borescoping a Rotor Valve

Postby boneagain » Thu Jul 21, 2016 9:27 am

Bonearzt wrote:I'll see what I can do.


I couldn't resist... I started a thread. I'm up to my neck trying to figure out an alto tuning slide bow and doing GIS work for my yardscaping, but I'm sure I'll have some time to sit with CAD soon. If you don't have time to sketch your idea, I'll PM you when I DO get a CAD sketch of it.

We now return you to your borescoping channel...
boneagain
 
Posts: 56
Joined: Fri Mar 04, 2016 3:11 pm

Re: Borescoping a Rotor Valve

Postby Terraplane8Bob » Fri Jul 22, 2016 11:14 pm

I've always wanted to part of a "Revolution" but hadn't been born yet when George Washington led us into the first one, but, by golly, it looks like I'll be able to participate in the "Borescoping Revolution" and that gives me a great deal of satisfaction. To hear that the venerable George McCracken found that a USB Camera could improve upon his long-standing skills in maximizing the efficiency of ANY brass instrument ran a chill up my "Duo Gravis" !! When you hire a lawyer to investigate your legal situation, when you hire a doctor to assess your health problems, when you hire a mechanic to diagnose your automotive problem you always get --- at best --- an opinion as to what the problem really is. But --- for under $10 [American] you get to SEE the problem ! WHAT could be better ? I know that the percentage of trombonists that have a "Valve" or "Trigger" on their horn is not overwhelming, but, nontheless, we DO have to deal with the encumbrances that are part and parcel of hauling this additional machinery along for the ride. The more that we can make them inclusive to the "ride" -- The better we can all enjoy the ride. I shudder to think that I have to accept years of " this is the best that there is" and blew my way through thousands of "Mini-Calculations" as to how THIS note responded, and THAT note responded
only to find out that if the damned valves on my horn had been optimized to what Mr. McCracken had theorized would be the "WAY" , I might not be as traumatized as I am at the present. I sat next to the remarkable Robert Isele for many years in the NSO and always thought that Bob could make music with a broom [ which I've seen him do ] and know that he'd Poo-Poo this idea of the instrument being captive to such chicanery. He could play through anything without any dread because of his incredible talent ---- but for the rest of us ---- we need ALL of the help we can get ! Attempts to make both the open horn and the valved portion respond without a noticeable difference are commendable, but make one wonder ---- if the valves were REALLY properly aligned --- would this even be necessary ? To me ---- making a slightly larger bore for the "trigger" mechanism only pointed out the fact that there was an impedance somewhere in the system that should have been balanced out of the equation long before having to increase bore dimensions to solve the problem. I remember studying with Karl Rucht, who, in his teens was the principal trumpet in The Berlin Philharmonic. He said ----" Robert ! The instrument cannot change ----- YOU must change" ! He was right, of course, but if the instrument were properly designed in the first place, the instrumentalist wouldn't be in the position of having to worry about technical problems and could concentrate on the main aim ---- music. We are so fortunate to have so many fine instrumentalists who have turned their talents to developing and improving the instruments that we all rely on. Would Renold Schilke have produced so many fine brass instruments without having had a performance background on which to ground his theories ? Would George McCracken have done the same without his performance benefit ? Perhaps --- but not likely. The incremental benefits with which these pioneers have blessed us are proof enough for me that if you "Can't Blow It " --- "You Can't Know It" ! Cheers to all !!
Terraplane8Bob
 
Posts: 27
Joined: Sun Mar 06, 2016 1:21 pm

Re: Borescoping a Rotor Valve

Postby afugate » Sat Jul 23, 2016 9:01 am

For those interested in getting one of these... I ordered a DBPower borescope/endoscope from Amazon.com. When I hooked it up to my computers (work macbook and windows 10 at home) I first thought it was DOA. But I checked the USB enumerator and saw that it had recognized that a device had been connected, but I couldn't get it to see the camera.

I started looking around for drivers, but couldn't seem to find any. While researching, I happened to read a comment from someone about being able to make their borescope work by connecting it to a USB hub instead of to the computer directly. I didn't have a USB hub lying around, but it made me curious about what might be going on. So, I grabbed my old macbook and Voila! Immediate success. No drivers. Apps all recognized the device (this is what I expect from the mac - it just works - no fiddling around required. :))

I believe that the issue is that the newer machines have USB 3 ports and the camera I bought is a USB 2 device. (I know that the spec is supposed to be completely backward compatible, but I've read of other situations in which it wasn't.) Thought I'd mention this here, in case anyone else had a similar problem.

So, I'm happily borescoping (is that a word?) now. This is fun and cool!!

--Andy in OKC
afugate
 
Posts: 9
Joined: Thu May 12, 2016 10:08 am

Re: Borescoping a Rotor Valve

Postby Terraplane8Bob » Tue Aug 09, 2016 9:07 pm

Well --- I've waited quite a while for somebody to jump on the train, but I guess we're stuck at the station ! Has there been NO-ONE who has figured out that [if you have a trombone with a change-valve] with a small alteration of the alignment of that valve, you will experience, perhaps not a NEW instrument, but one that has shed a considerable number of negative characteristics ? You can't get a decent hamburger these days for the cost of the USB camera needed to find out whether or not your valve is impeding your progress ! I envision hundreds --- maybe a dozen --- or --------- at least a couple of adventurous souls who might bother to investigate the possibilities of improving the response of their instruments with this simple tool. It might just be that it's more fun to go out and buy a new instrument every time a particular note doesn't quite feel right instead of figuring out why it doesn't. Here I go with the "It Used To Be" routine where I explain just how rough it was with those who were the "early adopters" [usually reserved for cyber equipment] who didn't have the marvelous digital renaissance to help us down the road. But --- here it is ---- and no one seems to be paying attention ! If this didn't work, I'd be the first to say so, but my experience has been so positive that I wanted to share it with the community. Anybody out there ? Crickets --- Crickets ----- [Credit - Bonearzt] --- Cheers to all !!
Terraplane8Bob
 
Posts: 27
Joined: Sun Mar 06, 2016 1:21 pm

Re: Borescoping a Rotor Valve

Postby Bonearzt » Tue Aug 09, 2016 10:52 pm

There are many posts "over there..." about valve alignments and how they affect the horn and also how it made the horn play correctly.

I see it weekly with school tubas & f-horns where the bumpers are deteriorating or missing and the director can't figure out why the horn clanks and doesn't play well!

Honestly, a boroscope isn't totally necessary to sight & align the rotor ports! Just look into the bell side slide receiver as you move the lever and you can clearly see if the rotor is aligned or not. And then adjust as necessary by replacing or simply shaving the bumpers and/or moving the stop plate.

A dependent second valve might be more problematic to sight through a tube, but can be done.

I bought a scope, but haven't had a chance to stuff it into a horn yet.


Eric
Eric
Edwards

"The bitterness of poor quality remains long after the sweetness of low price has faded!"
"If you're doing something a certain way ONLY because it's always been done that way, you're probably doing it wrong!"
User avatar
Bonearzt
 
Posts: 146
Joined: Tue Mar 01, 2016 5:42 pm
Location: Dallas/Ft.Worth Texas

Re: Borescoping a Rotor Valve

Postby boneagain » Wed Aug 10, 2016 7:35 am

Using a bore light I had already lined up all my valves close enough that the difference with a scope was minimal. But I DID help out a friend over the weekend. He had a nice 70H with bumpers that had never been trimmed. I had figured that out without looking at them, just by playing. The scope made the process easier, but the BIG advantage of the scope over the light was being able to point out to my new friend what was going on inside his horn, and show the difference between actual port positions and the index marks.

What is obvious to most, after the fact, is that the index marks are are on a very small radius relative to the outer radius of the core. For easy calculation, think of the index marks being on a 1/4" shaft, with the outer radius around 1 1/4". This translates into a five-to-one difference in what you can see. One degree of index error at the shaft is a turn of about 0.002 inches at the shaft, but about 0.011 inches out at the edge of the rotor.

This is why I set bumpers by looking down the tubes before, and use the scope now. And it really catches a players attention :)
boneagain
 
Posts: 56
Joined: Fri Mar 04, 2016 3:11 pm

Re: Borescoping a Rotor Valve

Postby Bonearzt » Wed Aug 10, 2016 9:15 am

Great job Dave!!!!
Eric
Edwards

"The bitterness of poor quality remains long after the sweetness of low price has faded!"
"If you're doing something a certain way ONLY because it's always been done that way, you're probably doing it wrong!"
User avatar
Bonearzt
 
Posts: 146
Joined: Tue Mar 01, 2016 5:42 pm
Location: Dallas/Ft.Worth Texas

Re: Borescoping a Rotor Valve

Postby cozzagiorgi » Sun Aug 28, 2016 4:50 am

Anybody got pictures of how to align hagmann valves?
cozzagiorgi
 
Posts: 4
Joined: Sat Mar 05, 2016 4:10 am

Re: Borescoping a Rotor Valve

Postby Bonearzt » Mon Aug 29, 2016 11:03 am

cozzagiorgi wrote:Anybody got pictures of how to align hagmann valves?


The end result is the same, the rotor ports line up with the casing ports.

The adjusting process is quite a bit more involved as you have no easy access to the bumpers. You actually have to remove & replace the stop arm ass'y each time to trim the neoprene.



Eric
Eric
Edwards

"The bitterness of poor quality remains long after the sweetness of low price has faded!"
"If you're doing something a certain way ONLY because it's always been done that way, you're probably doing it wrong!"
User avatar
Bonearzt
 
Posts: 146
Joined: Tue Mar 01, 2016 5:42 pm
Location: Dallas/Ft.Worth Texas

Re: Borescoping a Rotor Valve

Postby boneagain » Mon May 29, 2017 8:33 pm

Attempting to replace lost images 1 to 3

1-Approaching receiver.jpg


2-Approaching knuckle.jpg


3-At knuckle,valve in Bb.jpg


Sorry, but no hints of image attachment working anymore :(
boneagain
 
Posts: 56
Joined: Fri Mar 04, 2016 3:11 pm


Return to Maintenance, Modification, & Repair

Who is online

Users browsing this forum: No registered users and 1 guest