StewMac tools

Burns Gear-O-Matic Truss Rod

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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Thu Aug 10, 2017 8:40 am

That's good information David. Thanks
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Thu Aug 10, 2017 9:12 am

Discovered new issue. I was taking the nice gold-plated Schaller machine heads off and discovered this. Whoever installed these tuners used a coarse rasp to open up the tuner holes. The machines were only slightly snug in the hole at one point. The fit of the hole to the tuners is very loose at the top and bottom. When I say loose I am talking about over 1/16" of void around the tuner. I am sure this guitar had tuning instability. The proper fix will be reaming away the jagged hole and making a tapered plug out of maple. And then cutting a proper stepped hole.
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Re: Burns Gear-O-Matic Truss Rod

Postby David King » Thu Aug 10, 2017 2:21 pm

If a cello peg plug cutter and reamer are big enough you'd be all set if they were close at hand ;-). I make stacks of boxwood dowels for some violin friends every year. They supply the lumber and seem to go through a gross at a time.
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Thu Aug 10, 2017 7:51 pm

I don't have any cello tools but I do have a stew-mac end pin reamer. I put it in the holes and it did not fit well. The holes had a more angled taper. Using that reamer would have opened up the hole on the front of the peghead excessively. I did find an old 6 degree hardware store reamer in my tool chest that fit the holes better. But I never liked the way it cut. It bounces around and cuts a hex shaped hole. I took a design clue from the stew-mac reamers that only have cutting edges on one half of the reamer. So I took a dremel cut-off wheel and dulled three of the six cutting edges on the reamer. It still bounced around so I dulled the cutting edge in the middle of the three, leaving only two sharp edges that were separated by a dull one. This actually cut fairly well so I smoothed out the holes in the peghead.
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Thu Aug 10, 2017 7:54 pm

I went to my Taig lathe with the taper attachment and cut some matching maple plugs.
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Thu Aug 10, 2017 7:57 pm

I took quite a bit of time cutting the ends at the correct point to keep them from protruding when glued in. By the time I got to the 3rd or 4th peg I was getting it pretty close with less trips to the sander.
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Thu Aug 10, 2017 7:59 pm

While the tapered plug was still on the lathe I used a center drill to start a hole on the end for a drill guide. Pretty pleased with the end result.
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Re: Burns Gear-O-Matic Truss Rod

Postby David King » Thu Aug 10, 2017 11:12 pm

I can't imagine how anyone gets by without a metal lathe. Those do look great and no one will be the wiser once the tuners are back on there. Had the original person who swapped the tuners had a lathe they could have made a stepped pilot reamer to do this job correctly in minutes. Even a $6 Radio Shack tapered reamer would have done this job cleanly instead of hacking at it with a rasp or screwdriver etc.
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Fri Aug 11, 2017 10:12 am

I've had my micro lathe for only a few years and have found many uses for it. I haven't turned any steel yet but I have turned wood, delrin, and a lot of brass parts.
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Tue Aug 22, 2017 8:54 pm

Kind of missed taking photos of a few steps. Routed a wider slot for the Blanchard rod and installed it under a wood spline. Also installed two carbon fiber rods that are 0.1" wide and 0.21" high. Finished the new fretboard and glued it on. I took the unusual step of trimming the sides of the fretboard binding to be flush to the neck before gluing the fretboard on. The reason for this was the desire to have no touchup to the existing finish.

The reason for the new fretboard is the original one blew up during removal. For some reason the ebony was only about 1/8" thick and laminated on top of some basswood. Weird and vexing.

Here is a photo of my 24" long radius beam. It is a homemade MDF plate with a auto-body adjustable plane on top, which has the ability to shape the MDF beam.
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Tue Aug 22, 2017 8:55 pm

Getting there.
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Tue Aug 22, 2017 8:55 pm

Done. By the way, I replaced the original plastic MOT inlays with yellow MOP.
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Re: Burns Gear-O-Matic Truss Rod

Postby Gordon Bellerose » Tue Aug 22, 2017 11:34 pm

Barry,

What kind of jig did you have to use to rout the truss rod channel?
And, how did you rout for the inlay?
Nice work on the tuners by the way.
I need your help. I can't possibly make all the mistakes myself!
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Re: Burns Gear-O-Matic Truss Rod

Postby Bill Raymond » Wed Aug 23, 2017 12:36 am

Nice job on the fretboard; I really like those "Neo-Classic" markers!
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Wed Aug 23, 2017 11:01 am

Thanks guys. I actually pulled the old plastic inlays out of the original board and glued them to the MOP to use as cutting templates. The fretboard recess for the inlays was simply routed by hand using a Stew-Mac base and a dremel.

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Gordon, I made up a quick router template with 3/8" thick plywood. Two pieces with a precise 1/2" gap for the router bushing to follow.

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There are some brackets on the back of the template to hold the neck in the proper position. The rosewood strap was used as a support under the neck at the nut end. When I was routing the slot for the truss rod, I also placed a couple of small wood screws through the template into the neck to hold it tight. For good style, I located the screws so they went into the filler blocks that I had previously placed into the neck to fill the voids left by the old truss rod.

IMG_0584.jpg
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Re: Burns Gear-O-Matic Truss Rod

Postby Bob Francis » Wed Aug 23, 2017 6:59 pm

What a great thread!
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Wed Aug 23, 2017 7:46 pm

I don't usually post much of my work here, but this was such an unusual instrument I thought someone might be interested. Plus, there is kind of a deficit of posts on the forum so maybe I can kickstart something.
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Re: Burns Gear-O-Matic Truss Rod

Postby Mario Proulx » Wed Aug 23, 2017 8:30 pm

Dammit..! I keep looking for the "like" button..... <lol>

Nice work!
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Re: Burns Gear-O-Matic Truss Rod

Postby Barry Daniels » Thu Aug 24, 2017 9:50 pm

I decided to update my fretting methods. Normally, I run a dremel through my fret slots to open them up to about .027" to make fret setting easier, but I realize that is not considered to be the "best practice" these days. Even though I added some set to my fret blade, the fret slots got narrow again after cutting about 3 fretboards. I measured the slots in the board for the Gretsch and they are about .025" wide. I think my frets will be tight, especially in the upper fretboard extension area.

I had heard good things about Stew-Mac's fret barber but didn't want to spring for the cost, so I decided to make my own version. I took a single cut file and broke off a couple of pieces. Then I ground one edge to a radius of about 7.5"

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I made the two pieces to match along at least the working edge.

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Placed a feeler gauge between the files and held them in a wood clamp. It worked pretty well. I took the fret barbs down using consecutive feeler gauges that are .002" thinner than the previous.

IMG_0586.jpg


The only difficulty was getting the tops of the files aligned during clamping. I may have to make an alignment guide.
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Re: Burns Gear-O-Matic Truss Rod

Postby Mario Proulx » Thu Aug 24, 2017 10:33 pm

What kind of fretwire are you using that requires such large slots, or filling-off the barbs???
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