Normally banjo's have a skin stretched over a wooden pot, but the zither banjo has a skin suspended on metal brackets within the wooden pot which acts as a resonator. The 'zither' part of the name comes from sounding similar to a zither apparently -the stringed instrument not the African wooden thing of the same name you rubbed with a stick at primary school.
On this instrument two of the metal brackets appear to have been replaced with brackets from another instrument which didn't really fit and seem to have contributed to warping the pot. When I removed the head I could see some of the brackets were slightly bent and the replacement two were thicker than the rest. The two replacement brackets were going to need replacing.
It looks like Zither Banjos like this haven't been made for about 70 years, having fallen out of favour as with a budget instruments like this one the strings can pull up the lower edge of the pot ruining the instrument. To get a couple of replacement brackets my choice was to either find another instrument with the same size brackets to cannibalise or make them myself. The chances of locating an identical 120ish year old instrument are a bit slim, and unless it was wrecked I wouldn't want to ruin it by taking parts from it anyway so I decided to make some brackets from scratch.
I popped to B&Q and picket up a metre of 10x2mm steel rod and a Dremmel. Measuring the brackets roughly they're length was about 55mm but have two bends in so I cut some 70mm lengths from the rod as I wasn't sure how they right angles would affect the length. Thanks to the early sunset I was working by torchlight, made things a bit awkward but the Dremmel sparks looked impressive :)
The brackets are 7mm across so I needed to trim the width too. I measured it all by sight instead of marking measurements as my pen wouldn't mark the metal and the Dremmel made quite a wide cut anyway. Each bracket used up one cutting disc completely, I also used a cylinder shaped sanding bit to finish the cut edges
With the pieces more or less cut to size I clamped the metal in a vice and bent it to as near to a right angle as I could manage before giving it a wallop with a little 3lb sledgehammer. Seemed to do the trick. The important thing was the distance between the two bends which I measured by holding an existing bracket to the one I was making when figuring out where to bend it. Once bent I trimmed the ends to the right length, again gauging the length by holding an existing bracket to the new one.
I got the brackets pretty close to the size of the originals. The thickness wasn't spot on but I'm learning as I go. The picture below shows my two new brackets needing to be drilled and one of the original brackets which is a little buckled.
The top hole is just a hole straight though for a countersunk screw but the lower one is threaded for the bolt. I'll need to find out how to cut a thread and identify the thread of the bolts at some point too.
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