Pneumatic Circle Clamp

Today some friend were visiting the shop and I had just finished clamping veneer lines onto the inner edge of the soundhole with a balloon. This technique is so simple, but it's also totally ideal for this situation. The pressure is finely adjustable, the "clamp" is extremely lightweight, the rubber is soft, it won't mar the veneer or distort the shape, the pressure is perfectly distributed around the circle, the clamp is almost free and disposable. I get a kick out of this technique every time I use it. But today I didn't get the last laugh. While my friends were in the shop I stepped out for a few minutes, but it was long enough for them to get into some mischief while I was gone. And that's what worried me. I never keep soundboards clamped in the open air like this when someone else is in the shop (or even when I'm in the shop, for that matter), so naturally I was thinking about the safety of the soundboard for those few moments, especially with half a dozen people milling around. So as I step back into the shop, I hear "what's happening with this balloon setup" followed by a loud pop and shreds of yellow rubber flying through the air. My heart skipped a beat, and an entire day of carefully fitting the rosette flashed in my mind. Once the raucous laughter settled down, I realized I'd been fooled, and then I started cracking up too. I'm still trying to figure out how they found another yellow balloon so fast.

Assymetrical Oud Bowls

Finishing the construction of an oud bowl is a milestone. For me, the bowl is the most technically demanding aspect of oud construction. After my second instrument I decided that I wanted to duplicate the bowl shape of older ouds, specifically the shape most commonly used by the Nahat dyanasty of luthiers. My first two bowls were symmetrically shaped. In other words, I took half of the face profile and rotated it 180 degrees around the centerline of the face. Theoretically, this meant that each rib was exactly the same size and shape.



Like slicing a perfect orange in half, then separating the sections. All the sections would be identical.



My second oud had a symmetrical shape. The bowl profile at the apex was taken directly from the face profile.


The shape of Nahat bowls have two distinct differences over symmetrical bowls. The first is the shape of the tail end. It doesn't terminate (meet the face) at the apex of the curve, but rather continues back a bit past the apex to meet the face at a greater than 90 degree angle. This makes for a more aesthetically pleasing look, and more importantly it softens the bottom corner of the face.



This makes the oud more comfortable to hold, as the players arm curves around the bottom of the bowl.

The other difference occurs towards the neck end of the bowl, at the apex of the bowl. The bowl is made deeper in this area. This also gives the bowl a nicely curved shape, but the real effect here is the increase of the air volume of the bowl, and combined with the position of the deeper section itself (which is directly behind the main soundhole) the projection (volume) of the oud is increased. The greater air volume probably affects the openess and fullness of the sound as well.

There have been a lot comparisons between the shape of the oud and the shape of the human body. The closest natural shape I've found that mimics the Nahat shape is actually a kalamata olive. Can you spot the oud in the following picture?



Departing from a symmetrical shape presents all kinds of challenges. Each rib is now a different shape, and with the curved tail end, the ribs closer to the face must twist at each end. No longer is the rib simply bent in one plane, but it is now a bent and twisted rib. In order for the ribs to join at their edges seamlessly, one must accurately accomplish three tasks. 1. Bend and twist the rib to match the profile of the bowl (while matching as closely as possible the curve of the previous rib) and land flatly on the the tail end and neck end gluing blocks. 2. Joint the curved and twisted rib to the previous rib (I shoot for a light-tight joint) without altering the way the rib lands on the mould. 3. Joint the opposite edge of the rib in preparation for the next rib. For me, this involves a stepped approach of gradually tweaking the bend and twist of a square-sectioned rib until I'm close, sawing the taper in one side, jointing the edge on an inverted jointer plane, further tweaking the bend and twist, final fitting of the edge, and finally, sawing and jointing the opposite edge.



Sometimes during this process, the taper of the rib itself will be off, causing the widest part of the rib to depart from the mould, instead of hugging the shape. More material must be removed from the ends of the rib in order to pivot the rib into correct position. Of course, this can drastically change the twist of the rib, which must then be corrected on the hot bending iron.



If the rib continues to need twisting, I'll heat the rib in the area I want to twist, place the rib on the mould, then gently but firmly twist the rib by hand while it's still pliable. Alternating jointing the edge and bending/twisting is necessary to avoid overcompensation of either tasks. I prefer to fit all ribs with oversized (by at least 1cm) square sectioned blanks in order to leave the most room for fitting. On good days, I can fit a rib in a little over an hour. On bad days, I just chuck the problematic rib across the shop and call it a day.





When things go well, I end up with a bowl of the intended shape and size, and a feeling of relief after accomplishing the most difficult part of oud construction. My latest oud bowl is taken directly from the shape of the old Nahats.

The Benchcrafted Tail Vise-Now Available

I'm excited to announce that the Benchcrafted Tail Vise is now available!

Introductory pricing is only $315 for the complete vise. All you have to provide is the wooden dog block to fit your bench.

Details can be found at the Benchcrafted Website. Click on the Ordering tab to place an order.

Vises are built on a made-to-order basis, and turnaround time should only be 2-3 weeks. Eventually the vises will be a stock item, and shipment time will only be a day or two.

As always, email with any questions.

The Benchcrafted Tail Vise

I've received numerous inquiries about this tail vise (also called a wagon vise), and whether or not it will be available for purchase. I'm glad to say that this vise will be available for sale soon.

This vise is extremely robust, precise, and operates smoothly and effortlessly thanks to a precision acme screw and nut. The precision 1-1/4" diameter left-hand screw features a pitch of 4 tpi, which strikes a balance between fairly rapid movement and controlled, gradual clamping pressure.The vise moves the same distance per turn as typical tail vise hardware. The 5" dia. handwheel is chromed cast iron, polished to a high luster. The rim is comfortable to grip when approaching final position or realeasing the vise. The cold-rolled steel outer flange is blued for a subtle look and rust protection. A coat of paste wax will further protect the parts. All other parts are cold-rolled steel. Moving parts and surfaces are machined for smooth and precise action.

The vise is designed around a Roubo-style bench (it can be retro-fit to some benches) with a top thickness of 4" or greater, although it could be used in thinner benches with wider aprons. All hardware is included. The wooden dog block will be customer-made to conform to individual dog hole row and bench thickness. The vise is set up for a maximum dog block width of 1-3/4", although wider blocks could be used. Vise capacity is variable depending on installation. On my bench there is about 7-1/2" max. between the jaws, but this can be increased by lengthening the slot and/or decreasing the width of the end cap. Maximum travel with a 2-3/4" wide end cap is 10-1/4". Instructions and templates will be included. This vise will be produced on a made-to-order basis, although turn around time shouldn't be longer than a week or two. Introductory price for the vise will be $325, not including shipping. The vise will be available with two options. A larger turned handle (in various woods) to replace the handwheel's steel handle will be available for an added cost of $25. Substituting the handwheel for a traditional iron T-handle (seen below) will be an extra $15. Please feel free to drop me an email if you are interested in ordering a vise, or have any questions.









Handwheel knob in cocobolo.



Iron T-handle (wood not included)

Getting To Know Roubo-Part 3

After a few more weeks of one-on-one time with the Roubo bench, one thing that I didn't catch in the design phase is rearing its ugly head. The parallel guide on the sliding vise renders the shelf completely useless for all but the thinnest "stuff". Right now I have a sticking board, a sanding board (for fitting oud ribs) and shooting board living down there. Anything thicker and the sliding vise doesn't do much sliding. It becomes a couch-potato vise. I can fix this problem quite easily by simply removing the shelf. The up side is it won't end up being a giant tool tray (in other words a junk collector). The downside is I loose some handy storage space for bench accessories, and the shelf really is the best place for those. So as I suspected I would, I'm now in the planning stages for retrofitting a St. Peter's Cross on the sliding vise. I'm going to build a prototype before I start retrofitting the sliding vise.

Getting to Know Roubo - Part 2 - Tail Vise Update

Just a quick mention here of the fantastic capabilities of the sliding leg vise. Holding longish workpieces is a snap. This is a 56" long pair of shelves for a wall hung unit I'm building for the shop. Jointing them in tandem using both vises makes for effortless workholding.



A 99" long bench also doesn't hurt. I can work on long projects quite easily.

Now on to the more interesting topic of this entry. The updated tail vise.



A couple weeks ago I mentioned my dissatisfaction with the operation of the tail vise. I didn't want to let this go, so I was diligent about developing a proper solution in short order. After some recommendations from my machinist, I decided to plunk down the money for a left-hand acme-threaded screw and matching nut. I liked the speed of the German bench screw I used originally, so I picked a thread pitch to match, 4 tpi. Once I received the screw I noticed two things. The tpi was a bit more than the German screw, so I got about 1/32" less travel per revolution. I wasn't too concerned with this, since it would allow a bit more controlled clamping, at the cost of a little speed. The other thing was the quality of the screw. The threads look to be rolled instead of milled or cut into the shank, and they were very smooth and almost polished. This meant that the screw worked much smoother than the German version. Granted, the German screw worked fine, and I was quite happy with it (except for the backwards action), but I was still impressed by the quality of the Acme screw.



Another thing with the German hardware that seemed a bit unnecessary was the handle. The German screw has a typical "T" style sliding handle that one sees on most woodworking vises. For a tail vise, and especially for clamping between dogs, this is overkill. And not good overkill either. Clamping between dogs requires the right touch, lest the workpiece become distorted. So most of the time when I was opening or closing the vise (gross movements) with the T handle, I was spinning it round with my index finger against the wood. And once I got close, I would just grab the short end of the handle, slide it out just a tad and tighten down. I was never cranking down the vise with the long end of the handle, so most of it was useless, and frankly, in the way. Especially when the screw would stop in a position that would cause the long end of the handle to protrude past the front of the bench. Chris Schwarz, when he retrofitted his Roubo bench with a tail vise (he calls it a wagon vise) used a veneer press screw that features a handle that most of us are used to seeing on Jorgensen style bar and pipe clamps. On a clamp this is a functional handle, but for a bench, I wanted something a little more friendly to touch, which is why I ruled out using Chris' press screw idea in favor of the German tail vise hardware. After coming to the above conclusions, I decided that a heavy handwheel would be nice to try. It's no coincidence that handwheels are used to adjust machinery settings, like table saw blade height and tilt. They are ergonomic, compact, and their weight is an advantage when spinning long distances.



The position of the screw dictated the maximum diameter of the wheel I could use, if I didn't want the wheel to extend past the top surface of the bench. This ended up being 5", with about 1/4" to spare. This will allow several flattenings of the bench top before I reach the diameter of the screw. I'm not sure what will happen when I get that far. Maybe I never will. I tried to find an inexpensive wheel, with good ergonomics and a nice finish. I ended up with chrome plated cast iron. The edge is thick enough to grasp easily, and the rotating handle spins freely for rapid adjustment, although this replaceable part could be a little larger. The screw was machined down to 3/4" dia. and the wheel's hub bored out to match. The hub rests against a flange of cold-rolled steel that in turn presses against a washer abutting the shoulder of the screw. My machinist thought the washer would be more functional on this side of the flange given the directional forces of the vise. We thought about painting the collar, or having it powder coated, but we both decided gun bluing would do for now. The screw is fastened to the wheel's hub with a tapered pin.



The German bench screw nut was removed from the angle and the new acme screw nut was screwed to the plate with cap screws. We considered welding the nut in place, but didn't want to commit to a permanent placement before testing the vise.



The nut is 1-7/32" thick.



The vise components.



The new flange bolts to the end cap using the same bolts and holes as the German screw.







The hand wheel is really nice to use. It spins freely, and thanks to the mass of the cast iron has a bit of momentum to keep it going. It's a tad slower than the German screw, but this has an important advantage for all but gross movements.




Here's where the slower movement of the screw really shines. With my leather-lined jaws and dog faces, all I need to do to clamp firmly is crank the vise to contact the workpiece, then give the handwheel another little turn. It holds extremely well with little effort. Opening the vise is just as easy. I don't have to really crank down on the wheel, and I never need more than one hand to tighten or loosen the vise. I think this is a combination of the pitch of the screw, the fine polished finish of the threads, and the leather faces of the jaw and dogs. It's just about perfect.

In the video I'm clamping first between jaws, then between dogs. I really put my entire weight into trying to dislodge the workpiece, and I'm not small. That's 250 pounds wrenching about. Between jaws, the workpiece shifted forward about 1/2"after a couple shakes. Between dogs it didn't budge. And the work piece wasn't distorted. Granted, it's a short piece in the video, but longer pieces hold just as well. I'm putting enough force into the test to visible move the bench, so this obviously a torture test. No woodworking task would ever stress the bench to this extreme.

As I mentioned earlier, one thing that could be possibly improved (and it's a small point) is the size of the handwheel's handle. It could be a little larger. The handwheel itself could also be a tad larger in diameter. This would make the clamping effort even more effortless, but might make gross adjustments a bit more work due to the larger diameter. It's really a toss-up. I'm totally satisfied with the tail vise at this point.

And finally, here's the really interesting part. When I asked my machinist if he was interested in building some of these vises for friends (I've had a few inquiries), he said yes. The complete assemblies, since they are not being mass-produced, will be more expensive than typical tail vise hardware, which runs around $150. But the parts are also of superior quality. If you are interested in buying this vise hardware, please drop me an email and I'll keep you updated on pricing and availability.

Two Masters

Earlier this year I was honored by two living masters of the oud, Mr. John Bilezikjian and Dr. Munir Beken. Both musicians were invited to a small gathering of oud enthusiasts in southern California. I was particularly honored to have them perform at this gathering using two of my instruments. First, a little biographical information on the two oudists.

John Bilezikjian has been performing on the oud for over 40 years. He is a multi-instrumentalist and is an accomplished violinist and kanunist. Besides traditional Armenian music (John is of Armenian background), John has composed music for numerous television shows and feature movies. If you've seen any movie with a Middle-Eastern theme (among others), chances are John has done the music for it.



Movies such as The Prince of Egypt, The Scorpion King, Alladin, The Mummy, and Beowulf are all part of John's resume. His TV credits include Mission Impossible and Three's Company, just to name a couple. The list goes on and on. John has performed with the L.A. Philharmonic and the Boston Pops. John also performs regularly at local venues and restaurants in the southern California area. For more, check out John's resume.



Munir Beken's career spans theory, composition, ethnomusicology, and performance. As a composer, he has written a state-commissioned ballet suite for orchestra, won awards for film music, and scored television documentaries both domestically and internationally. His scholarly work focuses on modal theory; he is also conducting research on musical globalization and the phenomenology of music. He has published in Ethnomusicology, a premier journal in the field, and contributed to The New Grove Dictionary of Music and Musicians. He was one of the founding members of the State Turkish Music Ensemble. As a soloist on the ud, he has performed in venues across the U.S. and has recorded a solo CD with Rounder Records.



The day before the gathering John and his wife Helen were kind enough to host me, Mike Malek and Lee Varis for an enjoyable afternoon of oud playing and conversation about everything oud. John's love of the oud was very evident, and his fatherly character kept us all feeling like awe-inspired children gathered around his knee for a lesson. John was also kind enough to offer some very constructive analysis of the ouds, for which I am indebted to him. This type of feedback, especially from someone who has been playing ouds his entire life, is invaluable. John has excellent taste, and plays instruments from the giants of the oud-making world, long-gone master luthiers like Emmanuel Venios and Onnik Karybian.

I've uploaded a sampling of videos of John and Munir. Follow the links below to download the videos.

John Bilezikjian and Munir Beken
In this clip, the two masters play a composition on two of my ouds. John is playing a Nomex-soundboard oud I completed in 2006, Munir is playing my latest oud, completed earlier this year.

John Bilezikjian Outdoor Cafe
We joined John at a performance at a local cafe one evening. John versatility is evident in this clip. Make sure you wait for the last half for Albeniz's Asturias. It's right after "Tennessee Waltz"!

John Bilezikjian
And here's 0ne for Beatles' fans.