• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join freeLog in
    Want zero display ads or expanded classifieds tools? Compare plans.

Double Bass measuring tools

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?
 
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. And...it's a two handed operation with that magnet on one side and the gauge on the other.
 
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.
 
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.
 
Originally posted by Marcus Johnson
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.

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...