Fairly inexpensive compared to Lomax, Theo, etc:

http://www.pmwoodwind.com/instruments.cfm?
c=3&instrumentid=977&morepics=1

Does this type of gauge give more accurate readings than using a digital caliper and a piece of plate glass?

  ----- Original Message ----- 
  From: Keith Bradbury 
  To: MouthpieceWork@yahoogroups.com 
  Sent: Tuesday, February 03, 2009 9:59 AM
  Subject: [MouthpieceWork] Tip opening gage from PM


  Fairly inexpensive compared to Lomax, Theo, etc:

  http://www.pmwoodwind.com/instruments.cfm?
  c=3&instrumentid=977&morepics=1



   

Using calipers works well, but is a more difficult technique to do.  You need to learn to hold 3 things: the mouthpiece, the glass, and the calipers.  Other gages require just the gage and the mouthpiece.
 
With dial gages, you need to be concerned with the tip shape and the spring force.  The gage can actually bend open the tip of softer materials like Delrin mouthpieces.  So you need to be able to grab the lunger at the top of the gage to offset some of the spring force. 
 
I like to use a machinist depth gage with a 6" long base.  It has no spring.
 
How you "zero" your gages is another source of error.  But this may account for just .001"-.002".  Once you zero them, most gages agree with each other.    
 
To really check for accuracy, you need to compare your gages to gage block standards.
 
--- On Tue, 2/3/09, Doug Haining <dhaining@...> wrote:

From: Doug Haining <dhaining@...>
Subject: Re: [MouthpieceWork] Tip opening gage from PM
To: MouthpieceWork@yahoogroups.com
Date: Tuesday, February 3, 2009, 11:18 AM







Does this type of gauge give more accurate readings than using a digital caliper and a piece of plate glass?
 

----- Original Message ----- 
From: Keith Bradbury 
To: MouthpieceWork@ yahoogroups. com 
Sent: Tuesday, February 03, 2009 9:59 AM
Subject: [MouthpieceWork] Tip opening gage from PM



Fairly inexpensive compared to Lomax, Theo, etc:

http://www.pmwoodwi nd.com/instrumen ts.cfm?
c=3&instrumentid= 977&morepics= 1

 














      

The only caveat I can see is that the base is made of some kind of PVC
polymer. Because of the phenomenon of "plastic memory", there is an issue of
dimensional stability, unless he's found some apt material.

on 2/3/09 10:59 AM, Keith Bradbury at kwbradbury@... wrote:

> Fairly inexpensive compared to Lomax, Theo, etc:
> 
> http://www.pmwoodwind.com/instruments.cfm?
> c=3&instrumentid=977&morepics=1
> 
>