DIY Shamisen Bachi (for Tsugaru Shamisen)

Plastic, DIY (left to right)

Note: This is more of a report, not a DIY guide. Chung is currently a piano technician apprentice.

A few months ago, I experimented on making a Shamisen bachi myself. Due to the minimum tools I had at the piano shop (technically it wouldn’t even qualify as a shop, but we did restore pianos in there), the process was quite painful. For example, I had to saw a piece of hardwood at an angle by hand without a stationary clamp. The faux bekko is another tricky material to work with, when I have access so few tools. The shop does have a hand drill and a small belt sander; the belt sander is an incredible tool, when it’s all you’ve got, it becomes very versatile.

I have showed this DIY bachi to friends online, they are all quite impressed. Then I was advised to practice with it and see if the material held up with the striking. After making this DIY bachi, I actually got a bekko bachi, which I prefer… just better shaped anyway. Still, I’d prefer my DIY bachi so much more than the plastic one. At the time writing this post, the material is still strong.

Since it was quite a hassle to make this bachi, I don’t feel like making anymore until I have access to more tools.

Back to the topic.

The materials I used were:

• a piece of random hardwood I bought for 50 cents
• a piece of cellulose acetate for plucking material
Dr.Mike’s Model-n’ Crafter’s Glue (high quality thin super glue to bond plucking piece to wood)
• a piece of 1/4″ piano wire (about 3″) – for weight. Lead is even better.

Summary from web research: About Cellulose Acetate

Cellulose acetate is considered a higher grade of plastic. It is densely made from wool fiber, and is very durable and safe (non-flammable). Unlike celluloid which is highly flammable, cellulose acetate was an alternative material; a popular material for eye glasses frame.
The term “celluloid” is commonly misused, it could just means plastic that has the same look. Very often, it’s the the tortoise shell pattern that we all like.
It’s hard to tell sometimes, whether those eBay sellers are really selling this highly flammable stuff, such as electric guitar guard.
Cellulose acetate is also a popular material for guitar pick, which is why I felt it worth a try. Since one sheet of tortoise shell pattern with shipping is $30, it took me a long time to decide. There are cheaper plain color options, but the tortoise shell one looks fancier.

This seller on eBay (http://stores.ebay.com/Spring-Cleaning-Midwest) has a lot of old Mazzucchelli stock from Italy. Turns out this company has moved its manufacturing to China, and the products are now different (less quality?). Who knows how old “old stocks”are? Cellulose acetate is malleable under with low heat or hot water, it soften enough to bend then stay in shape when it cools down.
When I received my sheet of cellulose acetate, they were crooked! I attempted flatten it with a lot of boiling water. Again, without appropriate tools to safely handle boiling temperature by hand, I made it flatter, but not perfect.

Another problem here: cellulose acetate is known to not glue well with anything including itself. Then it does make sense for its popularity for glasses, no gluing needed! But how am I going to attach it to the the wood handle?

About the Glue

I came across a forum response mentioning Dr.Mike’s glue, which claims to bond Delrin (another heavy plastic I was considering) with other material. Delrin, also a popular guitar pick material, suffers the same fate of being hard to bond with others. McMaster-Carr (online contractor supplies) sells one very expensive product that would work for Delrin. So a $10 bottle of super glue is nothing. On the other hand, as advertised, it doesn’t dry up like the cheap super glue and is thin enough for piano maintenance work.
Before I purchased, I was actually able to get in touch with someone at the company, who then confirmed with the company scientist that this glue would bond cellulose acetate to wood.

Measurement & Method

Aside from researching for material, I was also trying very hard to obtain measurements of a proper bachi. I had an acrylic one, but I was hoping to make one with another style (hard to describe, refer to the photo above). This style seems easier to produce with the tools I have. Unfortunately there’s very little information on the web. I don’t read Japanese very well, so all I found was a few pictures. So I still ended up modeling the overall curviness from the plastic bachi, then alter the thickness.

Hogaku-navi has a web page that briefly explained how the top part of bekko bachi was made. It might be difficult to find a 3mm thick bekko piece, but since the cellulose acetate sheet is 4mm thick, it’s just easier to make the plucking part in one piece.

I have found nothing about how to make the handle! And then I forgot to take pictures as well. It is quite difficult because there is no parallel surfaces, which makes using power tools particularly challenging.

Rough cut with hacksaw.

Sanded with small belt sander. Edge is not clean because of heat produced.

Smaller saw with #2 Xacto handle.

Alcohol lamp produces low and clean heat to soften the cellulose acetate.

I forgot to take picture. I used straight edge razor blade to shave the cellulose acetate into shape. At first, I tried to use belt sander, but the part started to melt and turned white due to the heat from rapid sanding. Therefore I had to shave by hand. The shaving residues are small white flakes. The amount of flakes shows how dense this material is. It must have taken me at least an hour to shave.

This should probably be done before gluing the plucking piece. A 1/4″ hole was carefully drilled. I had the choice to pour lead or insert a steel wire. I went the easier route, to insert a steel wire.

Smoothed out by belt sander.

It’d flex and is very durable.

If I dare, I could shave it even thinner.

Chung Wan Choi