Saturday, December 15, 2012

Pleased to Meet you, Mr. Project Trumpet!

As I write this, I am actually just about done working on my project trumpet. We've covered a lot of ground at school this semester, and it is tough to keep up with all the activities we get to work on, so I apologize for not writing about this yet. This post is a quick overview of my project trumpet, showing how it was when I received it, and the first few steps to fix it.

When I first looked over the instrument, a Bach student trumpet, the first thing I noticed was many dents alllll over the instrument. Almost too many, hmm... But, really these horns are our chance to practice a lot of standard repairs and dent work that we learned about in class--things that can happen all the time in real life to people's instruments. So essentially, if the selected horn didn't have the problems we were looking to fix, said problems were (ahem) added on a case-by-case basis.

Here it is!  A lovely shot of the bent mouthpipe and lower-main to 3rd casing knuckle dent.

More knuckle dents on the opposite side of the valve block.
One of the problems we all had to fix was alignment of the mouthpipe, bell stem, and bell bow. Some instruments were a lot easier to adjust than others. My mouthpipe and bell seemed to be in the medium-hard range. As with dent work, we needed to treat these alignments "like butter" to start with. You can always add more force, but it's tough to go back when you've done too much.

Looking down the length of the horn, you can see where the mouthpipe, bell stem, and bow are all bent. Plus some nice dish dents along the bow!
 Before straightening or any other work, we had to first check-in, then disassemble and chem-flush our trumpets.

All pre-cleaned and ready for the chem-room! See the anodized aluminum valve stems? Staying right where they are, on my bench, since they'd turn into little bath-fizzies in the phosphoric acid pickle. Part of cleaning is separating out any reactive parts.
With everything cleaned, and all needed work logged on the repair tag, it was time to do some flexing. First: the bow! I started by hand, as below, but couldn't get it to move enough to straighten completely.


I used some clean buffing gloves to get a more cushioned grip on the bow. The vise holding the bench peg is loose (pivots if turned) to ensure proper bracing while flexing. Also check out the lovely sharp dent in the throat, ow!

To get enough force to move the bow where I wanted, I had to loop a woven belt through the bow, put both belt-ends in a vise, and snap the bow downward against the belt. This was a technique created in a shop that worked on many Yamaha trumpets, which have notoriously thick bells, making them tough to move. I'll post the name of the technique as soon as I get back to my notes, to give credit where credit is due.

Hooray! The belt worked great, and it's all straight again. What a cool idea.

More to come soon on dents and my mouthpipe project. Since the mouthpipe on my project trumpet had a tiny spot of red-rot or dezincification, I got to use this instrument for that project too. Stay tuned!

Tuesday, December 4, 2012

Trumpet Inner Slide Mandrel Project, or More Fun with Lathes

Hello again! Another lathe project post. This time our mission was to turn a piece of brass stock down to a specific diameter and thread the end to fit a bolt. The diameter needed to be within 0.001" of the goal so that we could use it as a mandrel to fit a standard inner slide tube on a trumpet. First I faced the end of a piece of stock, like in our earlier projects. Next I touched off with the tool bit near the end of the stock, and re-set the micrometer scale on the cross slide to zero. This allowed me to control the amount of material to be removed with each pass as I turned it down. Because we have so many different lathes in the shop (yay!) I had to be careful reading the scale on the cross slide. Since the stock is spinning in the chuck and material is removed on both (well...all) sides of the stock, for every 0.001" I advanced the cross slide, the tool bit removed 0.002" of material. 

To check how much material I was actually removing with each pass, I did a test pass first, then checked the new diameter with my caliper before turning the full length of the stock I had measured out. 

The first test-pass! The tape in the chuck helped eliminate chatter, since the stock was extended a bit farther than usual.

Finishing the first full pass...


In total we reduced the diameter by about 0.050" and used multiple passes to accomplish the finished dimension. The finishing pass had to be within 0.005"-0.015" so that the stock would have the cleanest finish and accurate dimensions. Although you can safely remove up to 0.050" of material in a single pass, we did 4-5 passes in total to get more practice with the process.
Action shot of turning!
Next we drilled and tapped the end which would fit a bolt to hold the mandrel...

Using the live center to steady the tap for the first few twists.

Voila! Another new tool:


Again, it was very neat to work on the lathe, and I feel lucky that we have so many to work on at school here.

Monday, November 19, 2012

Mouthpiece: Can we fix it??? Yes we CAN!

I'm in brass lab, now! And have been for about 4 weeks... We have been kept very busy with lots of projects to do. Polishing burnishers, another lathe project, buffing and dent practice to name just a few. So far I'm loving it! My crafty side is thriving on all the cosmetic work we get to do. One of the first things we did was to rehab a mouthpiece. Each of us was handed one at random, either trumpet or trombone, to whip back into shape. Here's how mine turned out, step by step.


Here's the mouthpiece in it's original state! Check out the dented shank, and big ole' cornflake of crud on the inside!



Plenty of tarnish, too. We had the option to scrub it out with a vineagar and soap solution, or to chem clean it. With the scale and crud, I chose chem flush, finishing with silver dip.


Post chem room: much better!



To bring the dented shank back to round, I tapped the end on a tapered drift punch, since the arbors we had weren't quite the right size or taper.

When I tested the shank in a shortened receiver, it was still wobbly. I had made the end of the shank round again, but the side of the shank near the end was a bit uneven. To get rid of the wobble, I tapped a dent ball in to the backbore to bring the end out a bit wider. The receiver prevented any flaring.
Removing the wobble, striking on the small dent ball-holder I made on the lathe.

Besides not fitting the arbors, turns out the mouthpiece was also too big to fit in my bench motor, so I went to the mini lathe to spin-polish.
Oooo, shiny!

 Since my mouthpiece had some dings and scratches in the rim, I burnished it while spinning it on the lathe. Unfortunately, due to improper bracing and the slippery nature of spin-burnishing, I had a minor boo-boo. Or, as a my bench partner put it, "punched the lathe."
Of course, this picture was taken without the lathe on. Safety first! See the band-aid? It pays to be careful when pushing with heavy force against the rim. Lesson learned, set up right and respect your tools! Accidents happen.



Ta-da! The finished product! Trued-up, shiny, clean, and smooth.

Check in again soon for more!

Saturday, October 6, 2012

Project Flute!

After turning in the project clarinets last Friday, we have moved on to flutes! This is mine: A Gemeinhardt 2SP with some apparently troubling pad issues. Upon my inspection, the pad protrusion varied greatly where it should have been much more consistent. According to my instructor, I might run into some challenges when it comes time to re-pad... But I'm looking forward to it! Other than that, just some torn pads, a few scratches and some worn plating. So far...

As with the clarinets, we took note of the existing venting and silencers on the instrument before pulling it apart for cleaning. This time was a bit different, though, as we had to regulate and re-adjust the flute so that one thickness of cork could be used for most of the feet on keys. After scraping off the original foot corks with a razor (except the F key), I used one piece of my Gummi-Kork feeler gauges to find the new venting, and flexed the feet of keys to adjust it to where I wanted.


Tinkering with the venting before disassembly...
So far, I've taken apart all but the upper and lower stack, and trill assembly and sent it through the chem room to be cleaned. Since my flute is silver plated, I had run it through the silver dip after de-greasing and pickling to remove tarnish. We are short on knock-pin removers for the class, so I have been working on clarinet re-pad Part II in the mean time. I will soon post about that project as well as the first clarinet and small tool projects on the lathe! 

Friday, September 21, 2012

Project Clarinet

Hello again, and welcome to my clarinet re-pad slide show! Alright, not really, but since I have so many pictures, I'll confine most of my remarks to a few problems I ran into during the process. An introduction to this assignment: We each received a rental clarinet to do a complete overhaul on. We had just over two weeks to complete the project. New pads, corks, fit keys, and make it work as good as new.

First, before tearing it down for cleaning, I had to straighten out a few keys that had been bent. The alternate F# and side Bb/Eb keys were both a bit wonky. Unfortunately I did not come out with an "after" picture on this one... lesson learned. 
The bent side keys before repair
Before using my duck-billed pliers to flex the bent keys, I needed to apply some protective high-density plastic to keep from scratching the plating on the instrument. Flexing took a couple tries to get right--not enough, not enough, too far, just right! Then once the key itself was straight, the touchpieces had to form a nice table. In the end, I got a feel for it and I was very satisfied with the results.

Cut to fit, the plastic self-adheres to the pliers and they're ready to use!

The next step was to pull all the keys off, and clean all the hinge rods and hinge tubes with valve oil and denatured alcohol.

The hinge rods are also cleaned with crocus cloth to remove corrosion and debris.

We used pipe cleaners to get the hinge tubes all scrubbed out.
 Next we pulled out all the old pads, keeping them for reference during the project.
Heating the Ab key over my handy-dandy acetylene bench torch to soften the pad glue 
The last step before the cleaning was a bit of a bugger--removing the tenon corks. After removing the majority of the cork with some pliers, I gave mine a nice soak in some valve oil to loosen the glue.

before...

after! No more glue and ready for cleaning.
The next step was to degrease the body and scrub it out, and send the keys through the pickle for cleaning. After that, we started key-fitting, then padding.

Padding the inline Bb/Eb. The orange feeler guage in the background is what we used to check for leaks.

I overdid the glue on a few pads, so after installing I used a heated screwdriver to clean up some of the excess.
.
After padding, we started corking. Later, for efficiency's sake we could do both steps at once, but in class we did them separately to make sure we had everything right along the way.

Putting the articulation cork on the F/C key
When I got my instrument I noticed on the post for the Ab/Eb key, there was a little spoke missing where the touchpiece (and silencing material) is supposed to contact when the touchpiece is depressed. It looked like the instrument had likely been dropped, judging from some scratches on the Ab/Eb and other lower joint touchpieces, knocking the spoke off.

Ruh roh... The missing spoke
My instructor suggested that the easiest way to fix the problem would be to put cork on the underside of the key. I could have soldered a replacement spoke in place, but that would take too much time to be worth it for the instrument I was working on. The cork underneath the touchpiece, contacting the post, would serve the same purpose that the little spoke had: to control the venting of the Ab/Eb key.
I started with a tiny piece, but for cosmetic and practical reasons, it worked better to cover the entire touchpiece.

It took a little more key fitting to get the feel right, but in the end, the action was feeling pretty good. Problem solved, and no soldering required. Next step was regulating!

Flexing to regulate the low E/B and F/C keys
Next was tenon corking. Compared to the rest of the process, this step went very quickly and easily the first time.
Softening the cork before gluing it to the tenon

Completed, tenon cork, sealed with warmed paraffin wax.
After finishing the tenons, my project was all ready to go! Both joints were sealing, and the tenons fit great! Overall a good project experience!

Tuesday, September 18, 2012

Lathe Projects I

Hello again! This installment will focus on some of my first, lovely lathe projects. The very first time we got to use the lathes was when shaping the ends of our large and small Delrin hammers. Out of the packaging the hammers had one flat and one domed end on each hammerhead. In order to make the flat ends more suitable to our purposes we had to slightly round off the flat end and smooth the rounded end. Better for dent work, softening tenon corks, etc.  So we took the hammers apart, chucked the heads in a lathe, and used a file and buffing cloth to shape and polish the ends. Pretty simple and a good introduction to using the machines!

Getting ready to file my small Delrin hammer. A good shot of one of the larger lathes in the common shop.

After getting comfortable operating the lathes, it was time to try some facing! We were each given two pieces of brass stock, cut with a band saw. These little nubs were to become tone hole levelers. 



Because of how they were cut, the ends of each piece were pretty rough. Lots of burrs and saw-marks, as seen below:




 Yep.. probably not too good to put that on someone's clarinet:


Our goal was to clean up the ends and make them perfectly flat and smooth. To do this we used a right-handed cutting tool bit to face the ends of our brass stock. First we had to make sure the lathe was set up and adjusted properly. Especially important was getting the height of the tool bit properly set, otherwise the stock  would be left with a tiny nub in the center after each pass.

Using the dead center to adjust the angle and height of the tool bit.

 When making passes with the cutting tool, it usually took a few tries to get the ends looking right. The ends were rough to start with, so it took a few runs to get past all the saw-marks. On the larger piece of stock, I had to adjust the height of the tool bit a few times to get the end smooth with no nub in the center.

The larger future tone hole leveler after a pass of the cutting tool--still some saw marks here.

We had to tear-down and set-up the lathe between each person using the machine and each leveler being faced. When I went to set it up for my small leveler, I got the tool bit height exactly right on the first try! No adjustments needed! I thought it an appropriate moment to pause for a fist-pump:




After finishing the facing on the lathe, and passing inspection from our instructor, we took the leveler back to our bench and sanded out the machining marks on one end with some sandpaper. This end will be to check how level a tone hole is, while the other will be covered in sandpaper and used to bring down any high spots so that pads will seal better. Here are the finished beauties, all sanded up:



I love working on the lathes, and look forward to doing more projects using them as the year goes on!

Monday, September 10, 2012

First Week and Practice Clarinets

Classes started off with both brass and woodwind groups together, talking about general rules and safety, along with some simple projects. Expectations are really high for everyone, which is motivating to hear. Even on our first tool project where we just cleaned up some dowels and drove needle springs in to make pokers, the sanding and grinding had to be just right. After a few days, we divided into woodwinds and brass for the first half of the semester. I'm starting in woodwinds, and one of the first things we started working on  was practicing trimming cork for use as silencers on keys. It only takes a couple cuts to burn through a razor blade and, boy, was there a lot of learning going on. Thus: the rapid accumulation of blades you see beginning below.

Cork-trimming practice! Those poor razorblades...
One of the nice things about working on woodwinds, is that it's pretty easy to take things home to work. There were certainly a few late nights spent at home or the coffee shop taking apart the practice clarinet. We used the practice clarinets to try out new skills (key-fitting, padding) before getting to our project clarinets. The project instruments came from a big rental company on the East coast, and will be sent out to actual students who will PLAY them! So it is less of a big deal if we make some mistakes to be learned from on the practice clarinets, than on the graded and student-destined projects. 
Studying up on clarinet nomenclature at home
It is really great practice to work on student instruments, as most of our work when we get out in the field will be for student-level instruments. Especially important is that the better and more precise we can get them working, the easier and more enjoyable it will be for the students playing them!

Saturday, September 1, 2012

Introduction

Welcome to my blog for the year! Here I'll be covering my endeavors while studying at Minnesota State College, Southeast Technical (henceforth referred to as SE Tech.) in the Band Instrument Repair (BIR) program. If you wish to learn more about me, where I come from, etc. check out my profile. You may also communicate with me via comments on the blog, or via email. I will do my best to keep my records interesting and updated with lots of exciting band repair action-shots and videos! So, thank you for visiting, come back again soon, and I look forward to posting more about what happens this year.