Making the Pear Bass

Discussion in 'Basses [DB]' started by Ken McKay, May 16, 2005.

  1. :help: As some of you know I am in the process of building a a pear shaped bass. I mailed the plan to Paul Warburton who approved of the design and signed off :) As many of you know this shape is seen in many of the finest orchestras in the world... or so I am told. I really liked the shape and idea of building a bass of this type. I am making it as an orchestra bass with some solo characteristics. The emphasis will be on a dark, full sound with some brightness. I don't know what size to call it but the string length is 42.5 inches and it will have a wide lower bout and a narrow upper. I tried to hang up the full sized plan and photograph it but it didn't turn out too clear. So take a look at the rib bending form to get an idea of its shape.

    I really don't know how it will turn out but I am just going to plug away and build the thing as best I can.

    I thought it might be interesting for some of you to follow along a bit as I construct the Pear Bass. And since there is a serious contingent of bass luthiers here, I though I would just ask them right here instead of privately as I have in the past.

    I haven't got too far but do have the wood chosen and aclimating to my shop for a month or so. I keep it 45% relative humidity in there.

    I sawed the rib stock from 4/4 Red Maple that is very nicely figured. I resawed the back from 8/4 RM with a little better figure than the back. The top has been bookmatched in half. It is Engelmann Spruce that I got from Fred Lyman about 13 years ago in a trade. He got the old crappy church bass, I got as much wood as I could carry in my stationwagon. BTW if anyone knows how Fred is doing I would love to know. I hope he is well.

    First question for the luthiers: Arnold, Jeff and Nick...

    I have the blocks made, connected to the "false back" which is ramped like the back will be, ready to accept the sides. The sides are thicknessed, bent and cut to profile ready to glue.

    I am planning on putting rib cross braces at the places on the "false back" mold where the upright supports are located (see photo). Is this sufficient to prevent crack spreads or should I space them closer with more? What dimensions should they be. Flat wide ( 3mm thick and about 25mm wide or thin narrow (5mm wide 12 mm thick)? I am using spruce.
  2. I, for one, will be interested to watch this project progress.

    Practicality question:
    How does one carry a pear shaped bass? Normally I would carry a bass by turning it so the G side rib is toward me then grabbing it under the top corner of the E side C bout. Obviously that won't be possible with a bass with no C bout.
  3. Ed Fuqua

    Ed Fuqua

    Dec 13, 1999
    Chuck Sher publishes my book, WALKING BASSICS:The Fundamentals of Jazz Bass Playing.
    Forgive my ignorance, but don't they call that "guitar shaped"?
  4. nicklloyd

    nicklloyd Supporting Member/Luthier

    Jan 27, 2002
    Cincinnati, Ohio
    so you aren't using an inside mold. neat. the pictures are a little fuzzy, but it looks like you have a neck block and a bottom block, and then these "rib cross braces" in lieu of corner blocks (because you have no corners)... how many of these rib-braces will you end up with?

    my thoughts would be to make them 5 mm thick x 25 mm wide. how thick are the ribs? cracks seem to occur first in the weakest part of the rib: the flatter areas with very little curve. have you thought about using linen, as well as spruce?

    just curious- is this your first bass?
  5. I have heard this type of instrument called guitarshaped and cornerless but I think it looks like a pear. I make guitars too and the upper bout is so much wider in proportion than this pear shaped instrument. So ... guitarshaped is probably more correct.

    I will try to keep the potos comming, it is difficult to size these. Sorry for the small photos. The next should be better.

    Nick, I have made a bass violin before that was violin shaped with a carved back. I do not repair basses but I have in the past done some restoration and repair. This does leave me at a disadvantage in longevity issues. I prefer to make new instruments. The ribs are 2.7mm now and will finish about 2.5mm. In the photo you see the upright supports where I am going to place the rib cross braces. The are part of the "false back" and are not part of the rib. I was wondering if I should place a cross brace at each of these supports.

    The Pear Bass will be built on a false back, no inside mold. I have studied how Gamba instruments were made and a false back was seen in some iconography. The false back is rapmed to allow shaping of the ribs. I made mine with a hinge so I can bend the flat back on it. Wait till you see that, it shoud be interesting. The false back is also scooped out a little to help press the back braces into a domed shape.

    Here are some photos of the way I bend the ribs. You can see the red silicone bending blanket. It gets 500 degrees and allows me to bend the flat ribstock around the form. Then when placed on the false back I use the silicone blanket to heat while I press the clamping form into the exact shape of the neck block.
  6. Jeff Bollbach

    Jeff Bollbach Jeff Bollbach Luthier, Inc.

    Dec 12, 2001
    freeport, ny
    Very cool, Ken. That is definately a guitar shaped bass, not a pear. There are a few basses that are truly pear-shaped. Coincidentally I am currently restoring a guitar bass made by V. Lucharini in 1830 or so. I'll try and post some pics. BTW that maker installed little blocks for reinforcement in leiu of full blocks. Imagine a wooden egg then cut it in fourths lengthwise. He has eight or so of those glued to the back and inlaid into the inside lining on the rib.
  7. That is great Jeff, send the photos if you can. What kind of repairs has it had over the years? So, those egg braces are interesting... what the heck?

    I am still trying to get the photos better and still be able to post them in a collage format. I may only to be get away with 4 at a time or they get pretty small.
  8. me a favor and re-post at least a couple pictures of your Q bass with a little explanation of the name...I just wanted the guys to see it. You could just post a link to the other pictures...I can't seem to find those posts.
    I agree with the linen idea.
    Eric, i've actually seen wood handles on some guitar shaped basses.
  9. \

    Hey Paul,

    Are you going to ISB?

    I built this bass for my son Quinn who is now playing in the 7 grade orchestra. He was a Cellist and took to the bass right away. I taught him how to finger correctly and a few pointers and he was off to the races. I just heard his concert the other night an I could really hear this bass projecting above the plywood school basses! are a few photos And here is a link to the discussion here on TBDB.
  10. godoze


    Oct 21, 2002
    I am liking it !
  11. M_A_T_T


    Mar 4, 2004
    Very cool! I'm building a violin right now (in my sig) and would love to do an upright, probably a flat-back, in something similar to a Panormo body shape. :cool:
  12. Hi Matt,

    The first instrument I made 16 years ago was a violin. I wanted to make a bass but thought it would be best to start with something smaller and easier to handle. Then I got interested in making classical and fingerstyle guitars and now I'm back to bass violins.

    I looked at your photos and it looks like you are moving along great.