Home made caliper

a real dial caliper is not that expensive

http://www.amazon.com/Oshlun-MTDCF-..._2?s=industrial&ie=UTF8&qid=1297717192&sr=1-2

 

I do - I used a simple rubber band to return the needle back to "0.0". There are many ways to do this, but the biggest problem I found is: the jaws of the whole thing flexed too much to be accurate. I made the "U" from 3/4" plywood, and that wasn't strong enough. At the time I made my bass I didn't care too much, because I knew that the final scraping will be done based on feel, flexing, etc, and the specific measurements were just a starting point.

But if I wanted to make a similar thickness gauge now, I would probably look at steel frame, or something that flexes the least.

George

 

A real caliper with jaw capacity of up to 15" or so is gonna cost you a few hundred at least

http://www.internationalviolin.com/item_detail.aspx?ItemCode=T28

George

 

ah...now i see

 

I don't think the string-and-pulley concept will work well. Too much slop and flexibility. You're trying to measure thousandths of an inch.

If I were building one, I would start with a cheap dial indicator and mount it on a sturdy wood frame like the one in rgarcia26's post.

http://www.harborfreight.com/1-inch-travel-machinists-dial-indicator-623.html

 

Like this. Hope it uploaded.

 

watch the sales at Harbor freight and you can pick up a digital head with a full inch of opeing so it is easy to slip over the edge of the plate. they are also bi lingual metric and sae

 

That looks terrific. The only thing I might change would be to orient the dial indicator so that when you are holding the frame by the middle of the 'C' frame. the dial is facing you.

 

If I was to make another one (I probably will) I'd use one of these http://cgi.ebay.com.au/Digital-Prob...09?pt=LH_DefaultDomain_15&hash=item1e6181e635

and make sure the frame is light and stiff.

The problem with the dial indicators is that the measurement you want is given on the SMALL dial. On a bass you're only going to need the closest mm or .5mm.

 

I think the analog jobs would be workable, but if you wanted digital, Harbor Freight has those for cheaps too -- though not as cheap as the mechanical ones.

http://www.harborfreight.com/1-inch-sae-metric-digital-indicator-93295.html

 

Yes it is MDF. Works fine. I made it for Mandolin tops and backs. Its not deep enough for a bass.