1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  

Winter Build Off 2018 - Gemini 2

Discussion in 'Luthier's Corner' started by Jisch, Dec 21, 2017.

  1. I'll update this with more details and pics later today. My build will be a headless four string 34" scale bolt on. I'll use mostly walnut with a few strips of maple here and there for contrast. I'll be building two necks for it, a fretless and a fretted (part one of the Gemini theme) and will be loaded with a Bartolini pickup and Ghost piezo pickups (part two of the Gemini theme) with a Bartolini preamp. The body will be chambered and carved and be made from bookmatched slats on the front and bookmatched lumber for the back.

    Woodpile pic coming soon.
  2. I cut my first wood and changed the wood selection, all in the first fifteen minutes. The wood on the right in the picture below will be the front. I'll do the bookmatched slat thing on the back.

    Here's my pile of wood and basic body shape:
    20171221_080140.jpg 20171221_080211.jpg
  3. Got first sawdust and some stuff glued up. Necks
    20171221_142455.jpg 20171221_144434.jpg
    I'm uncertain about fretboards, I need to get that figured out. Initial thoughts were to do them with walnut, but I don't think that would be wise. I need to think about it overnight.

    The front is this cool piece of walnut, it has some cool grain and figure, though the figuring is light, it's pretty deep.
    20171221_151049.jpg 20171221_160638.jpg
    And lastly the back, which is going to be a pain to glue up, but should look pretty cool, it may be hard to tell, but the slats are bookmatched across the middle, so the overall piece is symmetrical.
  4. There's going to be some really pretty guitars come out of this competition!
    Guiseppe likes this.
  5. Ordered some stripey Macassar Ebony for the fretboards.
    Guiseppe and ctmullins like this.
  6. Are there extra points for first one to finish? I should be done tomorrow at this rate. Not really, but starting tomorrow I will have everything glued up so I could work for a long time before I'd have to stop.

    I counted up my clamps (I recently bought a bunch of them second hand when I bought my table saw) and had enough to do the back wood glue up, wife went out, why not? I got everything set up and it was probably 20 minutes from first glue on wood to clamps tightening. I see good squeeze out everywhere, so I think I'm set. I'll be heading over my dad's tomorrow to run all this through his sanding planer.
  7. I got the wood out of the clamps, 100% good joints, gotta love a sharp table saw blade

    Out of the planer, looking much better.


    The body design is being altered, bigger body, less pointy.

    I guess I'll do truss rod slots then start working on the body cut out. Holiday events will slow this down after today, I suspect.
  8. Beej


    Feb 10, 2007
    Vancouver Island
    Good lord Jon you work fast! I haven't even uploaded my thread yet and you're a quarter way finished... :D lol
  9. I got the truss rods installed (I did a little chambering in the neck heel there :-D) and got the basic body shape cut out, I can see on the lower bout there's more work to do, but it's a start (at least it's not too small!). The route for the bridge is a nightmare (it's the same one I used on the Stumpy last winter). I found my template from the last time I used this bridge and remembered how much thinking went into getting it right. I hope I can repeat!
    20171222_140018.jpg 20171222_144951.jpg
  10. Well this is what happens when I have wood sitting around for months waiting to start cutting it. I had a lot of the first steps planned out, I just needed to execute. It will slow down now, so you can catch up :D. I have all next week off work though, so I plan on getting significant work done before I go back to the grind.
    RBS_Johnson likes this.
  11. Up from the shop for a coffee break.

    I got the route for the bridge done - not as hard as I remembered, but I see on the last one I had to recess the bridge, hopefully I won't have to do that here, that adds a level of complexity. I could have done a square route, but what's the fun in that. It will need some fine tuning a bit further down the road. After that second pic was taken I shortened up the bottom so the knobs clear the body.
    20171223_090807.jpg 20171223_095338.jpg

    For this one I will be replacing the string saddles that came with the bridge with piezo saddles. It will take some engineering as the piezo ones are slightly narrower and the intonation adjustment won't work. I'm not sure what I'm going to do about the intonation yet.

    Ad finally I cut out the back and brought it in with the oscillating drum sander, I could have used a pattern bit in the router, but this is less stressful and zero chance of chip out.
    The edge grains lined up nicely, totally planned (not).

    Next up is the chambering and control cavity routes, this will be a carved top, so I will have to be careful about how close the chambers get to the edges.
  12. I got the chambers done, I'll get the cover cut out later today at my dad's shop. I tried to lay out the contours then do the chambers once I had that figured out. I had one slip with the router that will need to be fixed, but nothing too big - it will end up inside the lower horn curve.
    20171223_111426.jpg 20171223_111442.jpg 20171223_114658.jpg
  13. IconBasser

    IconBasser Scuba Viking

    Feb 28, 2007
    Fontana, California
    Coming together nicely so far, Jisch :)
    Jisch likes this.
  14. Beej


    Feb 10, 2007
    Vancouver Island
    Great idea using those piezo saddles. :)

    Can they just be used as compression fit like on lots of inexpensive bridges? The kind where you just push it with your fingers and then tune up. Don't know if that would work here...
  15. That's actually a good idea, if I put wooden spacers along the sides that are wide enough the string saddle should stay in place just from resistance. I'll try that first, the simplest option is usually the best. I have to drill a hole for the wires for each piezo to go through the base plate, my intention is for that hole to be underneath the saddle, so I'll need to figure out the intonation first. I did this on a previous bass, I will use that to determine where the magnetic pickup should go for maximum sound versatility.
  16. I'm getting much better with the scroll saw, the straight line is mostly straight and the other side is a nice arc: 20171223_170816.jpg 20171223_170834.jpg
  17. I've never paired a piezo and magnetic pickup before, so I alligator clipped the Bart pickup (in fact I've never used a Bart pickup before) and found where it sounds good on my other piezo equipped bass. It was a highly non-scientific experiment as there were multiple variables, the bass I tested on has tapewound strings and the one I'm building will be roundwound and the magnetic pickup wasn't going through a preamp like it will be when I finish this bass. Still, it was a good way to find a spot for it (4.5" north of the scale length). I had plexiglas templates for Fender pickups before the fire, I swear I've seen them around here somewhere post fire. It would be nice to find those rather than have to make a template, we'll see.
    RBS_Johnson and mapleglo like this.
  18. I took a couple days off building while the kids were home. While thinking about activities we could do together I thought about making cutting boards, so I ran a cutting board workshop with my two kids and one of their SOs. I pulled out appropriate wood, they each chose a piece, we resawed the wood, planed, then sanded them down and put mineral oil on them. I heard comments like "there's so much sanding, how do you do a whole bass?". The finished pieces look amazing, and 100% walnut!

    Overall it was a great activity, I can probably streamline things a bit, the planing part was a bit boring for those not using the router. I guess it took us about an hour and a half to finish all three.
    20171226_141745.jpg 20171226_162816.jpg
    RBS_Johnson likes this.
  19. I got a few minutes in the shop this morning.

    I got the pickup route done:

    And in something that looks an awful lot like planning, I added a pocket for the battery. I had planned on making two, so I could run as 18v, but there's just not enough real estate considering the carving I'm going to do on the body. I think I can still get a second battery in there, if I want, but it will be tight. There are essentially two preamps in this body, one that acts as a piezo buffer and a second that gives me treble and bass adjustment, so those along with four pots makes for a lot of stuff.

    And after drilling a wire channel for the pickup, it goes into the bag for glue up. It looks like I got good squeeze out everywhere, but it's hard to see inside the bag. The bag comes with this black rubbery sticky stuff on the edge that is supposed to seal the bag, they send you a couple extra to use once this one gets too much stuff on it. This first one passed that point a few glue ups ago, so I just use some spare wood and clamps to ensure it's sealed. I could swap to the next strip of sealer, but I figured I'd use this one until it really dies before I swap it.

    Next up I'll trim up the sides of the neck blank, I don't have the fretboards yet, so that will slow me down soon. I have to get the bridge settled, so I'll probably work on that to kill time until the fretboards get here.
  20. One of the difficult parts of this build will be making both necks exactly the same, the heel has to be exact. I made one and used it as a template to route the edge on the second one. They look pretty good. The more difficult thing to make perfect is going to be the height of the fingerboard on the fretless and the frets on the fretted neck. The idea would be that I wouldn't need to do any string height adjustment when swapping necks, but that's a problem for another day.
  21. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

    Apr 17, 2021

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.