The Morin Khuur Part 2



Here's the assembled rim structure.  For reference sake, it's about 12" (300mm) long, and almost as wide. I fashioned the end blocks from Douglas fir and you can see I've drilled them out to reduce weight. It may be difficult to see, but they are also curved slightly to reduce the possibility of standing waves in the finished box. (Caused when sound bounces repeatedly between two parallel surfaces.)
I rarely use my adjustable spherical workboard for guitars, but this seemed a good opportunity to put it to use. It's made from plywood and 1/4" hardboard tensioned with a machine screw. By cranking down the screw the radius is increased.  I went ahead and pushed it to the limit - it's capable of a 10' radius, which would be extreme on a guitar.  I'm thinking of this Morin Khuur as more of a flat-topped viola.
After scribing the contour of the form on the ribs, I went planed it down to an approximate fit.

The fit is perfected by sanding. I marked the surface to be refined with some graphite and spent about ten minutes a side working it down until the joining surfaces were smooth and clean.

Later in the day I glued the bass-bar into position using Go-bars and the spherical form as a caul. The violin makers are laughing and pointing.  No. The photo isn't reversed. The stringing on this instrument is actually opposite to that of a violin with the top string on the left hand side when looking at it from the front. Hence the bass bar is on the "wrong" side.  Seriously. I'm not joking. It's not a mistake!

Using spool clamps seemed the way to go.  Given that this is a flattop, I decided to splay the bar out to cross more grain and resist the downward tension. There will be a soundpost installed as well. The top thickness is 3mm (.0120") 

I decided to attach the neck using machine bolts and inserts and I've predrilled for those holes.





An Eastern Expedition. The Morin Khuur, Part 1

Some time ago I was contacted by a music student who casually asked if I could build an Igil or a Morin Khuur.  It took a second to pull the information out of the dark recesses of my brain's instrument archive.  I knew they were Chinese or Mongolian.  "I don't see why not.", was my reply.

The idea took root. These instruments are associated with the Tuvan culture. Tuvan music is characterized by peculiar modal octave harmonies. You may be familiar with the Mongolian throat-singing tradition  I decided on the Morin Khuur, which loosely translates to "Horse-head fiddle".  It has two strings and is bowed something like a viol, being held between the knees . What's really interesting is that the strings aren't stopped on the surface of the board, but "pinched" against the side of the fingernail or fingertip.  The sound produced is a shimmering raspy tone. It's evocative of wind and wide open spaces.

I've finished the rough work and will undertake assembly this week. As it happens, I managed to find all the materials necessary in my cast-off pile. There's a good stiff Sitka top, bigleaf maple for the sides and back, (rejected as guitar sides due to a knot), some rock maple for the neck and pegbox, and a slice of rosewood for the fingerboard. So far the only thing I've had to purchase was a piece of steel to reinforce the neck. It feels good "salvaging" these woods.

I'll document the assembly in coming days.

Sears Benchtop Jointer Review

Here's a little product review for my new acquisition. I was looking around for a jointer to help make some of my small-batch production schemes easier on the elbows. Hand planing gets tiresome if you're doing eight of the same thing.

Space is always an issue. My shop is as small as some walk-in closets. Machinery has to be compact and portable. This limits me sometimes to "home handyman" items. That being said, I look for good value.

This little jointer is from Sears in the USA. It isn't available in Canadian retail locations, but ordering online was easy - Sears is using an online customs broker which means I don't get hit for duty fees at the time of delivery. That's a nice touch. It arrived within a week.

This model (351.217890) has a 4-1/8" capacity. Small? Yes. But that's wide enough for my purposes. The main feature that drew me to this machine was the lapped granite bed and fence. The major failing with all these little benchtop machines is warped castings. The customer feedback on this one was five stars. I felt safe taking the plunge.

Assembly was quick - just screwing some brackets in place and affixing the fence. The fence pivots to 45 degrees, a feature I'm not likely to use so I screwed things down firmly at right angles. What do you know! - It was both square and flat. The depth adjustment had me scratching me head until I discovered the locking knob on the back side of the machine.

In this price range, there's no hoping for a fence that slides across the bed. If I was edge-jointing 3/4" stock continuously I might devise a plywood arrangement to slip over the fence and move the cut forward to prevent all the wear happening in the same location on the blades.

I took it for a maiden voyage using some Douglas fir scrap. The universal motor whines in the usual fashion but at least the cutter head is belt driven.

There seems to be an onboard impeller that sends the shavings flying . I'll need to buy an adapter to perfect the fit between my shop vac and the dust port.

The lines on the face of the board are from rough planing. The joined edge came out dead straight over 15". I was pleased.


Time for something more challenging. Here's a neck blank about 3-1/2" (88mm) wide. It's Honduran mahogany with some ribbon figure and a twist in the grain.

Two quick passes - I'd set the depth of cut for a shallow bite, using the supplied push blocks for safety....

And voila! Shimmering clean. There are a couple of little burnish marks from where I'd neglected to wipe the shipping oil off the edge of the machine. The 29" board came out nice and flat.

And now the ultimate test. A rough-sawn ebony fingerboard. It too posed no problem. I rushed the feed a little when doing the edge, magnifying the problem inherent in all rotary jointers. That wave can make for less-than optimal glue joints which is why I'll always clean up a joined edge on my shooting board to ensure perfectly smooth glue-friendly surfaces. It's nice to have the machine to do the bulk of the rough work though!

All in all, my first impressions are very favorable. I can't speak for durability, but out of the box this is a tool capable of fine accuracy.