measuring tools

Discussion in 'Setup & Repair [DB]' started by toman, Sep 5, 2003.

  1. Here's one for our luthiers... I'm wondering what kind of a tool is usually used to measure the thickness of things like tops, backs and ribs. I know there are special large calipers made specifically for this, but they're quite expensive and I'm sure makers hundreds of years ago didn't have such things. I haven't been able to think of anything else that would work, except calipers like are used in turning bowls. That doesn't seem like it would be very accurate, at least for something as precise as a musical instrument... So what are people using?
  2. arnoldschnitzer

    arnoldschnitzer AES Fine Instruments

    Feb 16, 2002
    Brewster, NY, USA
    Special large calipers made specifically for this purpose...
  3. Jeff Bollbach

    Jeff Bollbach Jeff Bollbach Luthier, Inc.

    Dec 12, 2001
    freeport, ny
    Here's that caliper showing a too thin area under the bassbar.
  4. Marcus Johnson

    Marcus Johnson

    Nov 28, 2001
    If a guy wanted to spend lots more $$$, he could get one of those Hacklinger gauges, with the magnet that goes inside the instrument. A guitar luthier friend bought one after a particularly good year, and loves it.
  5. Jeff Diamondbach-

    Beautiful cleats!
  6. I doubt they had dial indicators in Italy 350 years ago...

    Don't recall where, but I've seen calipers that were a scissor arrangement, with pincer- like points ahead of the pivot and a pointer and scale behind it.
  7. Here is a photo of an old caliper that was given to me by my mentor about 40 years ago. It is mission a small piece of wood that screwed on to a threaded post on the bottom of the little end. The dial caliper on top is the one I've been using for the last 30 years or so. The old one I keep displayed on a wall, the dial caliper gets used every day.

    Marcus - the Hacklinger gauge is great for determining the thickness of a finished (i.e. smooth surfaced) instruments, but for new bass making, it would be virtually useless because it's capacity is so small.'s a two handed operation with that magnet on one side and the gauge on the other.
  8. Hey thanks for the replys folks; since it would seem people like to show off their shop equipment, maybe we should have a "show us your tools' thread... ;)
  9. John Sprague

    John Sprague Sam Shen's US Distributor

    Mar 10, 2003
    Rochester, NY
    Sales Manager, CSC Products Inc.
    That's a good idea Toman, I have a bunch of pics of tools our guys use in China, alot of hand-made stuff that they've come up with for certain jobs. They're pretty creative when it comes to that sort of thing. My favorite is a coping saw for f-holes made out of hand-notched piano wire for the blade, with a bamboo crescent for a handle/tensioner.
  10. Marcus Johnson

    Marcus Johnson

    Nov 28, 2001
    Could you build one from some type of hardwood, and use an inexpensive gauge from, say, Harbor Freight Tools? I'm thinking of a bigger version of the one that Bob Benedetto shows in his archtop guitar making book.
  11. I was thinking the same thing, but would you be able to find a guage? I guess it would be the same thing as a depth guage, exept the exact opposite in measurement.
  12. Harry Wake had plans for a (non-dial indicator) caliper in his bass making book. The problem it had as well as anything you were to make from wood is that the arms flex and throw off the accuracy. Remember you've got to have an opening of about 2" and and a depth of 13-14". You would probably need to laminate a couple of pieces of 3/4" hardwood (without voids) plywood for the frame to minimize the flex. Cheap dial indicators are availble on the internet, but you'll need one that has a capacity of about 1" and a shaft length sufficient to pass through the frame you build.
  13. arnoldschnitzer

    arnoldschnitzer AES Fine Instruments

    Feb 16, 2002
    Brewster, NY, USA
    When I was first starting out, I needed to do some graduation work on a top, and had not yet purchased a thicknessing caliper. So I cut out a long "U" shape out of 3/4" birch plywood, fitted small blocks, drilled a hole, and inserted a movable dowel. The dowel had millimeter and half-millimeter markings on it, and the thing worked pretty accurately. Of course, the pro tools measure in tenths of a millimeter, or even in thousandths of an inch. BTW, can you say "thousandths" and pronounce every consonant? I can't...
  14. mpm


    May 10, 2001
    Los Angeles
    Marcus, I've made one with the Harbor Freight gauge. Like Bob and Arnold said, the hardwood ply is a must as there is flexing of the "U" shape. Half the fun of making that rascal was making the trigger mechanism!