Hi,

I finally managed to buy me a glass gage for measuring the facing curves. It was the Theo Wanne traditional model.
I was surprised how inaccurate it is. The lines are thick like 1/4mm and there are lines only for even numbers on the scale.
It's pretty easy to read almost 2 units (1mm) wrong on it because it's hard to judge the mcp placement accurately behind the thick 0 mark and as mentioned the measurement lines are thick.

I used to use a thick short steel ruler form a Starrett adjustable straight angle. It was quite cumbersome to use and I was afraid the steel wasn't totally flat. Still it had 1/2mm markings and thin sharp lines. The biggest downside was it was practically useless for accurately measuring both rails.

So what do you people use? Is the Theo Wanne gage accurate enough for practical purposes or should I get a another one with sharp thin lines and 1/2 mm markings?

Get the one that Lawry made. Keith- Mojo sells them in the US.
They are NICE.


On Thu, Aug 19, 2010 at 5:17 PM, artmutan <artmutan@...> wrote:

>
>
> Hi,
>
> I finally managed to buy me a glass gage for measuring the facing curves.
> It was the Theo Wanne traditional model.
> I was surprised how inaccurate it is. The lines are thick like 1/4mm and
> there are lines only for even numbers on the scale.
> It's pretty easy to read almost 2 units (1mm) wrong on it because it's hard
> to judge the mcp placement accurately behind the thick 0 mark and as
> mentioned the measurement lines are thick.
>
> I used to use a thick short steel ruler form a Starrett adjustable straight
> angle. It was quite cumbersome to use and I was afraid the steel wasn't
> totally flat. Still it had 1/2mm markings and thin sharp lines. The biggest
> downside was it was practically useless for accurately measuring both rails.
>
> So what do you people use? Is the Theo Wanne gage accurate enough for
> practical purposes or should I get a another one with sharp thin lines and
> 1/2 mm markings?
>
>  
>



-- 
Sakshama

Yes, I agree with Sakshama, the ones that Lawry makes are called the "LAW" glass gauges and Mojo sells them on his site for like 25 bucks. They are great, and they're extremely easy to line up with the mouthpiece tip. They are not zeroed at the edge of the glass, (they are set-back from the edge at the "0" mark slightly), but I have not found this to be an issue at all. They're great gauges.

--- In MouthpieceWork@yahoogroups.com, Sakshama Koloski <sakshama1@...> wrote:
>
> Get the one that Lawry made. Keith- Mojo sells them in the US.
> They are NICE.
> 
> 
> On Thu, Aug 19, 2010 at 5:17 PM, artmutan <artmutan@...> wrote:
> 
> >
> >
> > Hi,
> >
> > I finally managed to buy me a glass gage for measuring the facing curves.
> > It was the Theo Wanne traditional model.
> > I was surprised how inaccurate it is. The lines are thick like 1/4mm and
> > there are lines only for even numbers on the scale.
> > It's pretty easy to read almost 2 units (1mm) wrong on it because it's hard
> > to judge the mcp placement accurately behind the thick 0 mark and as
> > mentioned the measurement lines are thick.
> >
> > I used to use a thick short steel ruler form a Starrett adjustable straight
> > angle. It was quite cumbersome to use and I was afraid the steel wasn't
> > totally flat. Still it had 1/2mm markings and thin sharp lines. The biggest
> > downside was it was practically useless for accurately measuring both rails.
> >
> > So what do you people use? Is the Theo Wanne gage accurate enough for
> > practical purposes or should I get a another one with sharp thin lines and
> > 1/2 mm markings?
> >
> >  
> >
> 
> 
> 
> -- 
> Sakshama
>

Making a good glass gage is no easy task.  I sold my own "MOJO" gage a few years ago but I had a lot of trouble finding an etcher that could make thin lines.  The processes available are sand blasting, printed design transfer and chemical etching, hand scribing with chemical etching, and laser etching. 

I think the Babbitt gages are hand scribed and they have nice thin lines.  But the line lengths are irregular.  Not a big deal, but sloppy.

The MOJO gages were sand blasted.  But it required a tuned up machine and a fine grit sand to produce medium thin lines.  

Some gages have a scale that is just silk screened on the glass surface.  These have inferior thick lines.

There are also a couple of glass gages made of plastic that are laser etched.  These work OK but I'm not a big fan of the concept.  The lines are not real thin and the plastic is not totally flat.  But measurements I have taken of them compared well to other gages.

The LAW gages are laser-etched.  But not any laser etcher can produce thin lines. The machine has to be in good shape (new) and you need to play with the settings to get the best balance between thinness and depth.  For my MOJO gages, I could not find a laser etcher that was better than the sand etcher I used.  But Laury did!

The LAW gages also have the advantage of vertical centering lines that are angled slightly like most windows and side rails are angled.  This makes centering the gage easier on the mouthpiece.

The only issue I have had with the LAW gage is the glass seems to chip on the edges more than others over its usage life.  The glass blank probably could have been annealed better.  But by the time my edges have multiple chips, the measuring surface is pretty scratched up and I need a new gage anyway.  I go through one every 2 years or so of heavy usage.

--- In MouthpieceWork@yahoogroups.com, Sakshama Koloski <sakshama1@...> wrote:
>
> Get the one that Lawry made. Keith- Mojo sells them in the US.
> They are NICE.

Thanks all,

I'll try the LAW gage from Mojo.

--- In MouthpieceWork@yahoogroups.com, "artmutan" <artmutan@...> wrote:
>
> Thanks all,
> 
> I'll try the LAW gage from Mojo.
>
 I recommend the Mojo gauge and still use it though the under surface seems to wear, with continuous rubbing against humped tables. 
Before that, I had some success with home made ones using 1/16" picture glass off cuts, with acrylic ruler edge strips, glued to the glass along the edges with cyanoacrylate.
Two strips, with the markings facing each other in the centre.
This means that the markings are slightly remote from the mouthpiece surface but it works well if looking directly downwards.
I have not tried microscope slide glass, which is thinner.
 A cheap and cheerful solution if nothing else is readily available.