Wednesday, May 23, 2018

Day 174: Making Room and Holding Space

As I mentioned in previous posts, I recently acquired a CNC (Computer Numerical Control) cutter/router. It's an amazing tool that I've already used to great effect. I made space for it when I knew it was coming to Tortuga Early Instruments Worldwide Headquarters, but I failed to completely understand just how big the thing would be. It's big. Like 48" x 48" big. I had it sitting on the assembly table for the better part of two months and, when it came time to get back to working on the instrument soundboard, found myself in this predicament:

You can see my dilemma. Now, my good friend and building mentor, Owen Daly, was about ready to break a foot off in my ass because he had asked for string speaking lengths for all Cs and Fs between the eight foot nut and bridge and it appeared I was making excuses for not sending him the data. I had not sent it because I was fed up with the lack of space. The shop is already small enough, you know? So, I did what I always do - I engaged Cheapest Guy Alive Mode and jumped onto Craigslist.

Within minutes, I found what I was seeking: large pallets I could take apart and use to build a stand for the CNC. And they were right up the street. And they were yuuge, like three feet by six feet with 2 x 8s running their lengths. This was a major score and I was able to fit them all into my beloved KIA Soul with the help of my lovely wife. After nearly an entire day of cutting, cutting, cutting, fitting, and screwing, I managed to create this:

It's a little tight between the new stand and the end of the Roubo, but you make do with what you've got, right? Besides, I can just swivel the seat around and use the drill press table to my left as a computer stand when running the machine. So, mission accomplished. And I reclaimed my entire assembly table.

I feel like I'm working on a football field and I like it. Now, back to the soundboard.

The first thing I did with the soundboard was to fit the plan to it using the parameters supplied by Mr. Miller in his eBook Most Excellent. Once that was completed, I spoke with both Mr. Miller and Owen about fitting the bridges. I'm going to end up drilling holes near the Cs and Fs between strings and use these as alignment points with small nails. Yep - I'm drilling through the bridges into the sounboard and nailing them all to the assembly table.

I'm currently taking my time getting things lined up properly because, honestly, the thought of doing this makes my poor, old stomach hurt. But it must be done. I'm hoping to have everything solid within a couple of days.

As I thought about gluing the bridges to the soundboard, I realized I would need cauls for the glue-up procedure. A caul is simply a fitted piece of wood that sits between the subject of the glue-up and whatever you're using for clamping (in my case, it will be go bars) and spreads the clamping pressure across more of the subject piece. So, I started to make cauls in two pieces given the fact that one side would need to be cut at a 30-degree angle to fit on the bridges properly.

I'll have enough to clamp and glue both the eight and four foot bridges.

On a couple of tangentially-related notes, I was able to attend the Western Early Keyboard Association (WEKA) Spring Soiree this past weekend. Several performers, including Owen Daly, entertained us on instruments made by Owen and Paul Irvin, both master builders. It was a wonderful time with like-minded people and I look forward to the next gathering.

Owen is playing his Vaudry copy while Paul looks on

And, finally, I must give honorable mention to another shop improvement: Roubo bench tenon plugs. I know what you're thinking: "Whada?" Well, when I cut the mortises for the bench, I did a pretty horrible job until I discovered a way to cut them that resulted in minimal tearout, which happens a lot with a laminated spruce beam. Naturally, I discovered this on the last mortise, so the other three were pretty rough.

One day not long ago, my friend, John Finn, said, "Hey, why don't we just plug those tenons?" The voice of experience always rules the day at Tortuga Early Instruments, so I took him up on the offer to help. A couple of days ago, he showed up with a template, a plunge router, and clamps - I made and served breakfast. A couple of hours later, all four tenons looked like this:

An amazing transformation. Two or three coats of Watco Clear Danish Oil and all will be well. Did I really need to do this? Heck no. But, sometimes, the better part of valor is attending to appearances. Thank you, John. I couldn't have done it without your help and guidance.

Until next time...

Monday, May 14, 2018

Day 173: Pulling Out the Big Gun

I've gotten quite a lot accomplished since my last post; unfortunately, most of it has been related to climbing the learning curve on some CAD/CAM design software I'll be presenting in the next few weeks. In the meantime, I ended up finishing the eight foot bridge. I did not use a band saw, which I know would have been quicker, but I really did enjoy the process I chose: Drawknife and spokeshave work. Initially, I started with the spokeshave.

I quickly realized I would need to take off more meat with every stroke, so I pulled out the Big Gun.

With a little support from Mssr. Roubo.

Things went swimmingly until...

I was done.

Just look at that hook.

While I found cherry much harder to work with than beech, I can see how it might help produce a more pleasant, ringing tone. The physics behind tonewoods and how they can amplify (or dampen!) the acoustical output of an instrument are well know, so I won't belabor them here. Suffice it to say, a wood that's more "plastic" without some brittleness (for lack of a better term) might not be the best choice for a soundboard. In this case, cherry is the better choice for the bridges.

While working on the eight-footer, I managed to also mostly complete the four foot hitchpin rail, just need to finish sanding the sides to even things up a bit.

This piece will be glued to the reverse as opposed to the obverse, which will get the bridges, of the soundboard, as will the cutoff bar and ribs. I'm preparing the blanks for those in the photos below and will continue to work on them throughout the week.

Until next time...

Tuesday, May 1, 2018

Day 172: Getting the Eight-Footer Locked Down

The four foot bridge has been steamed, bent, spokeshaved, and otherwise prepared for installation (still need to cut to length, but I'm not a detail guy). The eight foot is another matter entirely. When comparing it against the plan, the angle was not as acute as it needed to be. As I was testing it against the form, I heard a loud CRACK and you'll never guess what happened. Yep, this:

Just a scratch, right? So, it was back to the drawing, or steaming, board as it were. One thing I should call out is how to read wood. In this case, I had bent the thing with the flat sawn part of the piece on top. This created an akward bend that resulted in the break. Granted, I probably could have made it work, but I paid closer attention on the second bend and faced the quarter sawn side face up. Though I did this, I still didn't achieve the angle required by the plan, so it was back into the steamer and form. Again.

Only this time, I used the four foot part of the bending form because it would allow me to overbend the stick to account for springback, something that's pretty common when bending wood, especially material that's been kiln dried; it just wants to go back to its original shape when removed from the form.

As you can see, the bend is sharper. A little TOO sharp, perhaps?

Nope, it fit the plan spectacularly well. Time for a celebratory adult beverage. Oh, wait, what's that? Why, it's a pitch pocket in the worst possible location.

Given the fact this side will get a small bevel, I knew I would be spokeshaving most, if not all, of the pocket away, but decided to check with master builder Owen Daly just to be sure. Fortunately, Owen said it's not a show-stopper and that there are a couple of ways to handle it if and when necessary. Based on this information, two things then occurred: 1) Happy dance and 2) Preparation for tacking on the bass hook I had cut a little earlier.

I taped the pieces together, drew a slanted line, and cut them on the band saw. When I checked the joint, it was good enough for government work, so I glued it up.

And now we wait until tomorrow to trim things down. In the meantime, I turn my attention to the four foot hitchpin rail that will be mounted to the underside of the soundboard. This one is made from poplar and will be cut to size - no bending involved (thank the Good Lord Above).

Until next time...

Thursday, April 26, 2018

Day 171: From Beech to Cherry, the Bridge Saga Continues

After completely destroying the last set of bridges on the band saw and with the spokeshave, I had a short conversation with Kevin Spindler, a builder who resides on the East Coast. We talked about materials and techniques and he reminded me how the Old Guys used cherry for their bridges and that he had used it for an eight foot bridge and he was quite happy with the tonal result. Rather than split the new ones between beech and cherry, I just used cherry for both.

But first, let me explain how I ruined the last ones. When I was cutting them on the band saw, I had forgotten to reset the blade tension when I switched from a 3/8" to a newer, sharper 1/4" blade. This resulted in a blade that swam around in the wood, which is never a good thing. The outcome was particularly bad for the four foot and I ended up crossing a cut line and could not save the poor, little guy. I destroyed the eight foot by spokeshaving to the wrong cut line, resulting in a 1/8" top, rather than 1/4".

Both of these mistakes speak to preparation and careful consideration before engaging in anything in the shop. In the case of the band saw blade, it was thoroughness that got me. The spokeshaving came about during a lunch break in which I dove in with abandon without first triple-checking my cut. Granted, it happens, but both of these instances were preventable with a little more preparation and circumspection. You gotta have goals, right?

The good news is that I'm now pretty good at making bridges - at least the cutting to length/width/height, steaming and bending parts. I've grown to love the steaming process. It takes time and patience, both of which I have in minute quantities, so it teaches me to relax into the process every time I steam something. And it's fun to bend wood, so there you go.

The first step to getting the bridges into shape is to cut the planks down to length and width. I don't have a setup that will immediately accommodate cutting long boards to length. Well, not without hauling out the chop saw and setting it up. In this case, it was much easier for me to pull out the new Japanese rip/crosscut (Ryoba) saw and get to work.

Then, I cleaned up the plank sides using the new Veritas jointer plane.

It's really nice when a plan comes together. My intent with the new plane and saw purchases was to use more hand tools, less electricity. In this case, it worked.

Then, I carpet-taped the cherry board to a guide plank and cut the bridges to the required widths/angles. The eight foot runs from 3/4" to 1/2" over 55" and the four footer runs 1/2" to 1/4" over 43".

Into the steambox they went.

And then onto the bending form.

It seems like deja vu all over again, doesn't it? Rather than subject them both to the band saw when they come off the form, I'll be spokeshaving their bevels. I just feel more comfortable doing it this way and the new Veritas spokeshave works through wood like a hot knife through butta.

On a tangentially related note, I recently acquired a miniature Veritas spokeshave that I'll use to bevel the bridges on their high sides (or the bevels facing the player). These bevels will be the platforms for string guide pins and I'll shave them down using the little fella below after I've glued the bridges to the soundboard.

As I said on the Book of the Face, the spokeshave had a wee, little baby. It's tiny, but it's razor-sharp and will work perfectly for its intended use.

Until next time...

Wednesday, March 28, 2018

Day 170: Bending, Rebending and Joining

The bridge saga continues. After I had recut and rebent the 8' and 4' bridges and matched them up to the plans, I realized they would need another steaming session. I finally ended up with a nice Owen-approved curve, but not until steaming and bending them twice. I've been told woods will not take to bending once they've been bent because something magical (which always goes unspecified) happens to the lignin (the complex organic polymer in all woods) once it's been heated and bent. I can say with complete confidence that this is untrue. So, I bent the bridges twice until I got the curves I felt I deserved.

I shot Owen a quick email with the last photo above and he responded with encouragement, so I decided it was time to get the hook tacked onto the bass end of the 8-footer. I went with a half-lap joint because I've used them with some success in the past. Rather than scrape and spokeshave the hook to death, I used the Ridgid oscillating spindle sander to smooth the band saw cut marks down in record time.

I then cut the lap joints on the table and band saws and took to gluing it up late last night.

I should have a stable joint in the next couple of days. Then, I'll cut the bevels (on the correct side this time) and, as Owen would say, "Bob's your uncle." I really have no idea what that means, but it sounds really cool.

Until next time...

Wednesday, March 21, 2018

Day 169: Bridge Bevel Bonanza

UPDATE: Owen just told me I cut the bevels on the wrong side. This was based on the image below in Mr. Miller's eBook Most Excellent that I've surmised illustrates the nuts, not the bridges. Sure, it's a little frustrating, but what the heck, practice is good. Back to the drawing board - literally. Besides, it gives me the chance to tack the hook onto the 8' before cutting the bevel.

Image from The Harpsichord Project E-Book 4.0 by Ernest Miller.

As you know from previous posts, I've been preparing to cut the bevels into the bridges for some time now. Frankly, I was scared sheetless to do it because I couldn't bear the thought of ruining another set, but, hey, it's all good, right? Fortunately, I attended a Western Early Keyboard Association (WEKA) event recently and was able to get a good look at some example instrument bridges. Owen Daly was in attendance and was kind enough to give a short clinic on making bridges, which also helped enormously.

I took photos of the instrument at the event, but it turns out they're not very illustrative. The rub for me in cutting the bridges was related to how wide the top of them should be. While Owen was telling me they should be a consistent size (pretty thin) from the larger to the smaller ends, Mr. Miller's eBook Most Excellent describes a top thickness that is variable from end to end. After viewing the instrument at the WEKA recital, I realized they could (should?) be the same width from one end to the other - no disrespect to Mr. Miller whatsoever. And, as Owen said at the WEKA event, "The bevel angle should be determined by the width of the top of the bridge before the outside bevel is introduced, not by an arbitrary degree measurement."

I know this may all be a bit abstract. At the end of the day, Flemish instrument bridges end up being weird variable trapezoids that change in size from one end to the other. The 8' bridge is 3/4" at one end and 1/2" at the other and the 4' is 1/2" to 1/4". I'll be illustrating in greater depth how they work in subsequent posts - it's really too much to fully explain here. Suffice it to say the bridges act as terminal resonance points for the strings between them and the nuts - just like on a guitar. On both instruments, the termination points of the strings (i.e., where they are secured to the instrument) are less important than the location of the nuts and bridges because the distance between those points determine the notes played by the strings.

Whew. Just a second, I need to catch my breath. Okay...we're back. Now, Mr. Miller has devised an ingenious way to cut the bevels into the bridges BEFORE BENDING them. Owen, on the other hand, cautioned me against this approach due to the potential for twisting post-bend. As always, I was willing to give Owen's recommendation(s) a shot and went ahead with the cutting, steaming, and bending of both bridges.

As you may recall, I tried bending the bridges using the bentside form. Not a good plan. This time, I made the 8' bending form, steamed the bridge, got it onto the form for a couple of days, and, viola! - it actually worked. A nice, curvy, uniform bend with little springback was the result.

I was so pleased with the result that I forged ahead with setting up a 4' curve on the same form and got the 4' bridge steamed and bent.

Now, this is where I took a pretty substantial break for fear of screwing up (again). Once I gathered up the requisite fortitude, I went ahead and set the band saw at 30 degrees and ran a test cut.

When I compared the test against the "old" bridges, it was a nearly perfect match, so I went ahead and cut the 8' bridge bevel.

The next step was to clean up the band saw marks. I initially used a spokeshave, but found it to be a bit rough, especially since I had not honed the blade after purchasing it. In the interest of expediency, I switched to the Lie-Nielsen low angle block plane, which made quick work of the cleanup.

I was so pleased with the result, I moved on to cleaning up the 4' bridge, yet I found that a little ebony luthier's plane worked best on that one. The added benefit was that the ebony burnished the wood as I planed it down, resulting in no need to scrap or sand.

Still, there remains the matter of adding the hook to the bass end of the 8' bridge. This part of the bridge curves at too sharp an angle to bend on the form, so we just cut one to angle and tack it onto the bridge at just the right place. In the photos below, I'm tracing it out and preparing to cut it, but, alas, it got too late and I didn't want to suffer from spousecide (she goes to bed much earlier than I).

On a couple of completely unrelated notes, I am now and probably always will be a sucker for swag.

I'll most likely order a few, but with our tag line "Tardus et stabilis..." (Latin for "Slow and steady...") and the web address. The quality of the pen is pretty high, which is nice.

I also got the dust boot installed onto the CNC machine, which is the culmination of an interesting story. When I picked up the machine after driving to Waldport, Oregon from Vancouver, Washington - about a 4 hour trip each way - I asked Cool Craigslist Guy about the dust collection he advertised on the CL ad. He said, "Oh, yeah, here it is," and handed me a Dust Deputy funnel and sawdust bin. I thought, "Well, okay, I guess I'm saving enough it doesn't really matter."

A couple of days later, I received an email from him saying he forgot to give me the Suckit Dust Boot (you know, the dust collection he advertised on CL) and that he would be shipping it to me post haste. All good, right? Well, when I got it, I discovered so many parts were missing it rendered the boot unusable. So, I contacted the Suckit people to see if I could purchase the missing parts. The wonderful person there said, "We love the fact you purchased it on Craigslist. If you send me a photo of what you have, I can send you what's missing."

After emailing Jenn a photo, she let me know they'd be replacing the missing parts and shipping them to me free of charge. Holy cow, I was flabbergasted. In a consumeristic society like ours in which everything has a price, a company exists that cares more about customer satisfaction than making a buck. My hat's off to the Suckit people - you rock.

The assembly was made easier by following a video on their website and I now have a CNC machine that looks an awful lot like an elephant. If it keeps the shop largely free of CNC-created sawdust, I'll take it.

Until next time...