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Tardus et stabilis

Sunday, May 24, 2020

Day 187: A Finished Jack and Actually Listening to Owen

Well, folks, I did it - I actually completed a jack from stem to stern. Cutting, sawing, drilling, assembling...all of it.

I ended up using a .7mm drill bit intended for drilling holes into printed circuit boards with a "pin vise" mounted in the drill press.

While this did bring me to the doorstep of success, I must admit that I'm not 100% onboard with the approach. I had picked up the idea of using a pin vise from Bill Jurgenson's fine website. Naturally, he's probably using a top-of-the-line jeweler's pin vise while I simply ordered mine from eBay hoping it would work. It did not, at least to my complete satisfaction, and here's why.

The drill bit barely fits into the end of the pin vise, so the connection is somewhat tenuous at best. It is also nearly impossible to get a perfectly straight seating of the bit into the vise, which produces a wobble no matter how carefully I try to insert the bit. At these tolerances, even a .1mm wobble results in adding that much to the hole, making it larger than intended. As much as I want it to be, this is not acceptable.

I also learned a few things about the angle of repose of the vise holding the jack body. In this case, I had set it at 10 degrees, which produced a hole that exited the back too soon (i.e., the angle is too acute). What I need is a smoother slope that allows the bit to exit farther down the opposite side of the body - something more along the lines of 7 degrees. This is required because an angle that's too sharp forces me to cut the through hole (for the PEEK filament spring) too high on the body - in some cases into the tongue divet. Also not acceptable.

In the end, I'm forced back to the drawing board and to actually take Owen Daly's advice regarding this matter - advice he gave me over a year ago. I have no idea why I don't just listen to him and do what he says. Call it a character flaw, I don't know. I can only imagine how exasperated he is with me by this time. I've been pulling this sort of thing for years and always end up just doing what he told me to do in the first place and finding success. Maybe someday I'll learn.

By taking Owen's advice, I mean that I'm now designing and building a slider with a horizontal orientation. It requires a surface mounted to roller bearings that traverse two metal rods to provide the to-and-fro motion of an equally mounted Dremel tool. Said Dremel holds the .7mm drill bit perfectly straight, providing a more stable and accurate cut. I'll be posting more about this device because I ordered the parts tonight and they won't arrive for another week (or two under present extenuating circumstances).

This whole process has been exhausting, but I must keep at it until I can produce jacks reliably and in great number. Then, I will celebrate my success and order all of my jacks from Norm Purdy in Eugene.

Until next time...

Tuesday, April 14, 2020

Day 186: Ideas, Viruses, and Jack Tongues

After my brief explanation for my absence, it's time to get back to the jacks. So far, I've managed to cut pretty reliable body blanks and slot them using the custom table saw blade (the one with 5mm wide carbide teeth). I drilled the tongue axle holes into the bodies using a tiny, little (.7mm) drill bit and also cut the tongues on the CNC (sorry, Owen, it's just easier and more accurate that way). All of the tongues were cut from the side, so I was able to not only cut them, but to drill the complementary axle holes using the .7mm bit there, as well. In the future, I'll also flatten the beech material to 5mm on the CNC before cutting the tongues.

Now, jack tongues are like ideas and viruses - astonishingly small while holding enormous influence. In this case, I will put as much time into making a set of jacks and their parts and pieces as I do the case and soundboard of the instrument. I've been working solely on the tongues the last few days, punching the plectrum holes and sawing in the slot for the PEEK spring filament.

First, the punch process. I used a punch on loan from Owen Daly that I inserted into the Jet mortising machine. Owen had ground down from a spade bit the business end of the punch many moons ago - before he worked exclusively with Norm Purdy in Eugene for all of his jacks. It's probable I'll be making my own punch that is, as Owen has suggested, a little thicker on the initial punch and sloping up. I also made a jig to hold the tongues. In the end, I was able to punch through, but was not entirely happy with the results.

The bottom photo above is the reverse side of the tongue. As you can see, it's got a little pucker that's not appropriate in this circumstance (to be sure, circumstances do enter the imagination in which a pucker is entirely appropriate, this just ain't one of them). After much careful thought over some Tullamore Dew and a large, square ice cube, I realized I could simply hit the reverse side with some high-grade sandpaper to remove said pucker and use the punch to clear the hole from that side.

The result, as you can see, was A-OK. What is not apparent is how the jig slot into which the tongue slides is sloped at 10 degrees to create a 10-degree hole that slopes down from front to back. This supplies a slight upward tilt to the plectrum (when we get to that point) once installed.

The next challenge was figuring out how to get a slot cut vertically into the back of the tongue that would hold the PEEK filament that acts as a tongue spring. Owen was kind enough to give me some example jacks and the spring slots are things of beauty. Owen told me how guys like Norm have jigs that hold a Dremel tool with a v-bit into which they slide the tongue and...voila!...the most gorgeous slot you've ever seen.

I've also seen makers who simply cut a slot with a small table or band saw. I decided to give this approach a shot and, while I appreciate the expediency of power tools, I also don't like working with amazingly small parts while a blade is running at 1720 rpm. So, I grabbed my good, old gent's saw, nestled a tongue lovingly in my upgraded vise jaws and went to work.

In cutting these slots, the tongues, the punch holes, and everything else about these gadgets, I've come to agree with Malcolm Gladwell that it takes about 10,000 repetitions to achieve mastery. While I clearly didn't take that many hours or pieces to start creating acceptable tongues, I did end up with quite a few on the shop floor. The good news is I can cut hundreds upon hundreds of these in a day using the CNC, so no harm, no foul.

The last step is to cut a couple of holes into the jack body tongue slot that will hold the PEEK spring to keep the tongue in place. This will require one more jig that I'll make adjustable (still have that Zuckerman Flemish XIV needing three sets) to accommodate other jacks in the future. I will bolt it to the drill press table and it will provide a 10 degree tilt for the .7mm bit to do its dirty work. More on this story as it develops.

Until next time...

Sunday, March 22, 2020

Project Update: Where has the Tortuga been?

As you know, it's been far too long since I've posted here. I've been, in a word, sidetracked with another project and have kept my commitment to neither the instrument nor you, my dear reader. Please accept my apology. Now...an explanation.

Two events occurred over the past year that have mitigated my progress on the instrument. The first involves the jacks. I had been deliberating about whether to make them or purchase them from Norm Purdy, a world-class jack maker who lives about three hours south of me in Eugene, Oregon. First, I attempted to make them. When I realized it took a lot more focus than I had been giving it, I decided to simply purchase them from Norm at $5 per jack, which would cost me something on the order of $625. I consider this a great investment, even though the client paying for the instrument is me.

Then, I had an extended conversation with master builder, Owen Daly, who convinced me it would be in my long term best interest to make a set so I would, in Owen's words, "know what to look for when purchasing them in the future." So, it was back to making jacks, which involved using a tongue punching jig Owen had loaned me, figuring out how to line things up, making miniscule cuts with chisels, etc. It was overwhelming and, frankly, still is. But I continue to learn something new every day while I finish that elusive first set.

The second event was a business decision centered on making a high quality MIDI keyboard that provides a pluck/tracker touch that can be, for lack of a better term, turned on and off by moving the keyboard. This keyboard can control any music software that accepts MIDI ON/OFF signals. I had written the MIDI encoder software, designed the printed circuit boards, completed multiple three-dimensional CAD drawings over the course of the last year, and started making the first prototype when I hit a crossroads.

Like you, dear reader, I have experienced several watershed moments in my life. Moments in which a binary set of options were presented and I, in my infinite wisdom, chose the wrong one. I have many examples I will not bore you with here. As I was in the shop trying to figure out where to store wood and parts and pieces and keyboards, I realized my heart was just not in the MIDI work as much as I thought it would be. Sure, it's fun discovering new ways to do things and to create a dedicated microcontroller and to work with PCB design software, but, ultimately, it's not what I want to do. Maybe someday, but not right now.

So, the MIDI work goes on the shelf indefinitely and I'm back to making harpsichords full time. Of course, by "full time," I mean when I'm not completely exhausted from the day job and distracted by honey-dos and the exigencies of everyday life (this crazy virus-that-shall-not-be-named thing notwithstanding). It's harpsichords or bust at Tortuga Early Instruments Worldwide Headquarters moving forward. Watch for more posts here as I reengage in what I truly love and what started me down this path in the first place.

Another event that is heavily influencing how I approach work in the shop is the recent acquisition of a 1985 Zuckerman XIV single manual harpsichord kit. Holy cow, I didn't see this one coming. I received an email from Owen a couple of weeks ago that read something along the lines of "Hey, I know a guy who's been talking with a guy who has a Zuckerman kit I think you might want to take a look at." He was right. I ended up purchasing the kit from a nice gentleman who was managing liquidation of his stepmother's estate and it now sits in the shop taking up more room than the Ruckers because it came with all parts, including the stand (yeah, I said that in one breath).

Owen thought it would be a great idea for me to build a kit AFTER I finish the Ruckers. The thing is, the previous owner did not assemble a lot of the instrument, so there is a ton of work left to do on it. Sure, all parts are cut, yet it's in pretty rough shape from sitting on a living room floor for 35 years with several parts stored on the top, which has bowed a bit. I may not be able to salvage the keyboard and I will need to make new upper and lower registers, as well as three sets of jacks - it's an 8'/8'/4'! I'm fine with this because soon I will be a jackmeister. But first...where to put it?

IKEA sells harpsichord kits?!?

Roubo supports Zuckerman

When I picked up the kit, I was feeling a little under the weather and have not felt entirely well for the better part of the last three weeks. No, it's not the virus-that-shall-not-be-named, but I still feel a little squiggy even today. At this point, I'm simply taking stock of what I brought home. I must say, as a former archaeologist, I do feel a combined sense of trepidation/hesitancy/sadness/horror that I will be putting the thing together. I feel as if I've entered the back rooms of a museum and found all the artifacts of the kit intact. It has, at least to me, enormous historical significance, so what better way to honor the Zuckerman organization and what it has meant to so many people over the years, right?

When I do begin building it, I will start up another blog to track my progress, which I assume will be significantly faster than what I've demonstrated here. I'm still learning lessons on a nearly daily basis, but I've been pleased to see that I understand more of what Owen talks with me about and that I can now look at a harpsichord more critically (not in the sense I'm criticizing the builder, but, rather, with a more informed eye) and I like how that feels.

In the meantime, it's back to jack production for the Ruckers. I'll be posting on a much more regular basis here, so please come back early and often.

Until next time...

Thursday, August 1, 2019

Day 185: Jacks Yet Again

It's been a long while since I've updated you here. My apologies. Things have been hectic and I've been awaiting a new custom made table saw blade with 5 mm teeth from Snooks Saw Service in Salem, Oregon (recommended by Owen Daly, of course). Well, the monster finally arrived, so I went to work on the jack blanks I had cut a few weeks before.

Rather than run them through barehanded, I grabbed some walnut from the stash and made what I think is a nice, little jig that will keep my hands safe. I used the CNC for maximum accuracy, as well.

I'm quite happy with it, though there is some tearout that happens based on the flatness of the teeth and the lack of support as the blanks meet the blade. Some loss is unavoidable, but nothing I can't live with. As you can see, the tongue slots came off nicely.

Because I had cut the tongues on the CNC, including setting the axle holes there, I could drill the axle holes into the bodies of the jacks using a .7 mm drill bit with great precision. These bits are typically used to drill holes into printed circuit boards and work quite nicely for this purpose.

As you can also see, I made a placement jig for these, too. It works. I was able to drill 99 without breaking a single bit.

I then inserted the pins I will be using into a hole and through a tongue and...it worked!

Now, to make jigs for the PEEK spring holes and to cut spring reliefs into the backs of the tongues. Just today, I located a 9" band saw for $15 on the Facebook Marketplace for this very purpose that I'm picking up tonight. I'm sure you'll see it in action in the near future.

On a couple of tangentially related notes, I came across an amazing sale of tools and wood downtown Portland a couple of months ago. I ended up grabbing about 3 gallons of Natural Danish Oil, a Fein shop vac for the CNC, and a couple of hundred board feet of poplar.

I won't need to purchase poplar for a very long time.

I also recently added a wonderful new book to the library.

The only other two books that have had as much impact on me are Hubbard's Three Centuries and O'Brien's Ruckers book. The analyses and articles are just amazing and I can't wait to apply some of what I've learned to the instrument.

Until next time...

Thursday, April 25, 2019

Day 184: More Jack Work and Other Stuff

As you can imagine from past posts, the jack work continues, as do the diversions. Lately, I've been concentrating on making the jack tongues using the CNC. After laying them out in Autodesk Fusion 360, I first drilled .7 mm holes for the axles using a tiny, little bit I purchased for printed circuit board work.

Completing these cuts required a tool change to a 1/8" (3.2mm) bit so I could shape the bodies.

When cutting with a CNC, you always want to leave "tabs" between the items you're cutting so the spinning router doesn't send material flying across the room if the endmill touches it. In this case, I didn't cut quite all the way through the material, so I had to clear some of it using a razor knife.

It all worked remarkably well. The only thing I'm worried about is how to line up the axle holes with the mounting holes in the jack bodies at a later date. Owen Daly's voice is running on a loop in the back of my mind admonishing me to drill the holes with the tongue wedged into the jack tongue slot. I guess we'll see if I can pull it off.

As a means of diversion, I recently made a bookcase (a honeydo model). I only post it to partly explain the holdup in jack production. Because the Tennessee red cedar was in a pretty raw state when I purchased it from Crosscut Hardwoods in Portland, it took days longer than it should have to complete the project because I basically had to mill my own lumber to dimension.

It's a nice, little bookcase, but I'd really rather make instruments.

In a few tangentially related shop matters, I recently replaced the old radial drill press with a newer, larger, version. I must admit it was hard letting the old fella go, but I persisted.

Old Fella

New Fella

After wrestling the Tennessee red through the table saw and having visions of a horrible mishap, I replaced the crappy Grizzly aluminum table saw fence with a Delta T3. It has made all the difference and the blade now goes through wood like a hot knife through butter.

I also picked up a dial gauge to use for setting jointer blades, checking CNC wasteboards for flatness, etc. It was time I stepped up the level of accuracy at Tortuga Early Instruments Worldwide Headquarters.

Finally, as I was working on the Tennesse red, I ran across this fellow:

He surprised the heck out of me, but I went with it and he ended up part of the bookcase. Feel free to help me name him - I'm thinking something like Tennessee Red would work.

Until next time...

Thursday, March 14, 2019

Day 183: Jack Blanks the Traditional Way

Well, hello there! It's been a while since we last spoke. As you may recall, in my last post about jack blanks, I was executing on a hair-brained scheme to cut them on the CNC. Unfortunately, that's just not the way to go with these complex, little fellas. Sometimes, returning to first principles is the best way to go. Okay, using table and band saws is not exactly doing it like the Old Guys, but you know what I mean.

Since we last met up, I've gotten rid of some stuff and acquired some stuff. Before updating you on instrument progress, I thought I'd give a quick introduction to a few of the changes that have taken place at Tortuga Early Instruments Worldwide Headquarters over the last six or so months. First, I upgraded the CNC bed. While I won't be using it for much of this instrument, I will be cutting jack tongues with it later this month. The new CNC bed is composed of four aluminum (aluminium for my friends in the UK) t-track plates that will make it easier to clamp materials for cutting and carving.

Next, I purchased a Craftsman 6 1/8" jointer with a nice, long bed from Cool Craigslist Guy. The price was right because he had let it fall into a state of disrepair. He had lost the safety button for the power switch, cut the ground prong off the power plug, had the outfeed bed so out of level it sniped about 1/4" on the end of every cut, the adjustment wheels were hanging on by a thread and, as you can see below, he let it rust terribly. I can only imagine: "This thing is a piece of crap. I'm going to put it on Craigslist tomorrow and get it the hell out of my garage for good." His loss, my gain.

I broke out the WD-40 and a Scotch-Brite pad and went to town.

The rust practically melted off, resulting in this:

I know, I'm committed to hand tools and have owned four previous jointers, but it was time, especially with the MIDI keyboard project coming to fruition.

In the interest of keeping things on the straight and narrow, I also recently purchased a shiny new DeWalt 735 planer.

The thing is absolutely amazing (too many nifty features to mention here) and I now feel spoiled. Don't worry...I'll get over it.

Okay, back to the instrument. Once I had completed the design of the MIDI keyboard, I could confidently, and without distraction, jump back onto making the jacks. After an abortive attempt or five with the CNC, I decided to just cut them on the table saw and use a couple of jigs Owen Daly was kind enough to loan me. The first step in this process was to cut some 1" beech down to a more reasonable thickness (closer to 1/2").

I resawed the board and did a finishing pass or two on the new planer. The result? Material that was as smooth as glass and ready for the table saw.

Once I got the little pieces squared up, I went to town.

One pile became two piles in short order.

Though I need 104 jacks, I cut 120 blanks to accommodate the inevitable screwups I will introduce into the process.

The next step will be to cut the tongue slots and drill some minute (.4-.6mm) holes in the things using Owen's jigs and some astonishingly small PCB drill bits I acquired for the MIDI keyboard project. It's good to be back in the shop doing what I love: building a harpsichord. I can't wait to share my progress with you as I complete this mini-project.

Until next time...

Tuesday, November 6, 2018

Project Update: Keyboards and Stuff

You're probably wondering why I've not posted anything here in several fortnights. Well, I'm working on creating a MIDI keyboard using some of the same principles I've described here. The keys will be weighted, capped in African blackwood and bone or, more likely, casein, and have a bit of a tracker action feel to them. I'm not going to divulge too much more here. Suffice it to say the design and coding work is coming to an end and I can jump back onto jack production for the instrument very soon.

Thanks for hanging in there with me. Until next time...