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Blueridge Tenor to OM conversion
I purchased a store demo Blueridge BR-40TCE tenor guitar for $280 about 6 weeks ago. A few scuffs and bumps, but still in good condition. I decided to try to convert it to an Octave Mandolin. It has a 23" scale length and 32mm nut (1&17/64").
http://www.sagamusic.com/products/pr...?item=BR-40TCE
Thanks to all of the great folks at the mandolincafe forum, I picked up some great tips on how to proceed.
Here is how it was in original state:
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I removed the open back tuning machines and ferrules. One of the ferrules pulled off some of the finish with it.
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I cut a piece of hardwood to match the headstock so that I could clamp to it, and also use it to help my drill bit from ripping the wood surface as it exited the headstock. I taped the headstock with blue painters tape and then taped the piece of wood to the face of the headstock. That way I would drill from the back of the headstock to make sure the holes are 90° where the new tuning machines would go in.
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I used a $15 Taylor Toolworks Dowel Kit Jig to make sure I was drilling straight (I don't have a drill press)
http://smile.amazon.com/Drill-Guide-.../dp/B0181RB8M2
I started with the existing 5/16" holes. I lined it up using the 5/16" bushing using a 5/16" drill bit, and then clamped it to the headstock. Then I took the 5/16" bushing out and dropped in the 3/8" bushing. I used a 3/8" pilot bit to drill out the existing holes.
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Then I measured and marked the locations for the new tuning machine holes and drilled those with a 3/8" brad point bit.
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FYI - The tuning machines really call for a 10mm hole, and the holes that I enlarged using a 3/8" pilot bit, were a bit snug. The newly drilled holes using the 3/8" brad point bit were fine. If you have a kit that can accommodate a 10mm bit, use it.
More to follow in next post...
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Re: Blueridge Tenor to OM conversion
Here is the heastock after drilling:
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I used some knockoff Grover Medium Tuning machines that I bought for $9 a set:
http://smile.amazon.com/Chrome-Tunin.../dp/B00IYGR316
That are actually very nice quality, surprisingly. The washer for the tuning machines covered most of the finish damage on the front of the headstock, except for the one bit that came off when removing a ferrule (lower left).
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Then I filled the original nut slots with superglue and baking soda and filed the nut clean. Then I cut the nut slots (poorly, unfortunately). I'm using D'addario Chromes Flat Wound (electric) strings in 45, 32, 22, and unwound 12 strings.
I cut the nut (going from low to high in mm) |3-3.5-6-3-5.5-2-5-2-2|
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I cut the bass side a bit too deep, so I'll have to go back and fill it and do it again, and the treble side is not in line from the nut to the tuning pegs, so I'll have to do that again too. One place where it isn't ideal is on the inside strings on the G and E courses. Those strings bend over the string windings of their pair's tuning peg.
For the bridge, I had been planning on drilling 4 more endpin holes, however, I ended up cutting in string ramps into the existing 4 holes, so that each could take 2 strings. I just used a file to cut a slot directly down into the holes on either side of the endpin and then rounded the channels off towards the saddle. I had to trim down the endpin on the G and D courses to get it to fit with both strings in there.
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I was going to reinforce the bridge-plate with formica, as was suggested, but I was not able to get my arthritic hands to do the gymnastics that would have taken. So, I took my chances that the existing bridgeplate would withstand the added tension. Since the Blueridge tenor guitars have the same body and bracking as the 6 string Blueridge BR-41 3/4 guitar, I thought there was a decent chance it would be OK as an 8 string. It appears to be doing fine, however there is a tiny bit of a bump just behind the bridge. So slight, that I was not able to photograph it, however. I thinkit would be wise to reinforce the bridgeplate, however that appears to be a skill above my pay-grade at this time.
Truss rod adjustment was about 1/3 of a turn. And it plays and sounds good! I will have to recut the nut for the G course, as they buzz a bit, but I'll leave that for another day.
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Re: Blueridge Tenor to OM conversion
Re: Blueridge Tenor to OM conversion
Al, im curious about the neck width at the nut and where the neck meets the body. With two courses at strains does it require a bigger neck?
Re: Blueridge Tenor to OM conversion
Also, how is the sound different or the same? Nice work by the way
Re: Blueridge Tenor to OM conversion
Nice job. Tuners look good. I've been on the lookout for a tenor to do exactly the same thing. Since you are using flatwound Chromes, I would think the tension would not be that much more, at least on the G and D side. Flatwounds have much less tension than their bronze wound equivelants. I use the Chromes for one of my OM conversions and never had issues. The most recent conversion I did I used a mandolin tailpiece and just ran the strings over the existing guitar bridge and it worked great. I'm using Martin Monel guitar srtings for that.
Re: Blueridge Tenor to OM conversion
Quote:
Originally Posted by
jazzjune18
Al, im curious about the neck width at the nut and where the neck meets the body. With two courses at strains does it require a bigger neck?
Thanks!
I think that these tenors are a bit overbuilt. I'm sure at this price point that they are not spending a lot on trimming down the bracing or removing material to make it sound better, etc. The neck joints seem to be handling it ok. I'll be sure to update if it starts coming apart.
Regarding sound, it has much more volume and sustain now, which is to be expected. Sorry I dont have any sound clips from before. I'll try to post some sound clips soon.
Also, I'd like to caution anyone else who is considering this, you might want to wait a few weeks to see if mine develops any issues. I felt comfortable trying this on my Blueridge tenor, partly because I got it used at a really low price, and partly out of ignorance. If it fails, I'll let you know!
Re: Blueridge Tenor to OM conversion
Good luck with your mods Al, I bet it sounds great!
Re: Blueridge Tenor to OM conversion
Re: Blueridge Tenor to OM conversion
Great stuff Al, seems to work OK :)
Re: Blueridge Tenor to OM conversion
Thanks! Now I need some practice!
Re: Blueridge Tenor to OM conversion
I just happen to have a blueridge tenor (non-cutaway) up at the local music store on consignment. Because It had two very small cracks in it's top that I had professionally repaired it doesnt seem to be selling.
After seeing what you've done here perhaps I will consider such a project. Though I would rather sell it.
Re: Blueridge Tenor to OM conversion
Quote:
Originally Posted by
remellick
I just happen to have a blueridge tenor (non-cutaway) up at the local music store on consignment. Because It had two very small cracks in it's top that I had professionally repaired it doesnt seem to be selling.
After seeing what you've done here perhaps I will consider such a project. Though I would rather sell it.
The Blueridge Tenor that I bought was a shop demo and has a small separation in the top seam. It has been stable, even with the added tension of 8 strings.
Re: Blueridge Tenor to OM conversion
Sad news: the separation in the top seam of my Blueridge Tenor cum Octave Mandolin is getting worse. I think the added tension of the extra strings is having a negative effect. It may be that had it not had the problem before being converted, it would be fine, but not sure.
Re: Blueridge Tenor to OM conversion
Sorry to hear that. It was a really cool project. Perhaps it can be saved.
Re: Blueridge Tenor to OM conversion
Quote:
Originally Posted by
Freddyfingers
Sorry to hear that. It was a really cool project. Perhaps it can be saved.
Thanks. It isn't terrible. I think it might be in need of humidification and can be reglued.
Re: Blueridge Tenor to OM conversion
It was always going to be a bit risky but at least you have had two years fun.
Re: Blueridge Tenor to OM conversion
It is still playable, and sounds fine. I think I'm going to humidify it to see if I can get the gap to close and glue it with a cleat underneath
Re: Blueridge Tenor to OM conversion
Since Ibanez tenor guitars is the only brand I have around my neighbourhood.....how feasible is this kind of conversion in a Ibanez AVT2E tenor guitar?
Re: Blueridge Tenor to OM conversion
Update - I was able to humidify the guitar and glue the seam shut. It appears to be holding steady. Just need to make sure to keep it properly humidified from now on.