Question on BesTest indicators

[jden]

For all you mathematical gurus out there. I have a Brown&Sharp model 7033-5 .00005 horizontal
indicator with a 1/2" stylus. If I replace the stylus with a 1.75" Ruby tipped (.080 dia) stylus what change would their be in the accuracy range from the 1/2: stylus? Would it be .0005 or worse?

 

[geo.ulrich]

For all you mathematical gurus out there. I have a Brown&Sharp model 7033-5 .00005 horizontal
indicator with a 1/2" stylus. If I replace the stylus with a 1.75" Ruby tipped (.080 dia) stylus what change would their be in the accuracy range from the 1/2: stylus? Would it be .0005 or worse?

The Browne & Sharpes are fairly easy the stylus length is close to pivot length so figure .500 stylus into 1.75 stylus readings should roughly triple from what it is now. if you have gage blocks and surface plate you can get an exact reading...a word of warning the .00005 B&S indicators have a pretty crappy backlash spring its the weak link don't be surprised if you have problems getting it to repeat to " zero".....just calculated for you each graduation would equal .000175

 

[jden]

Thanks George. The backlash is noticeable but its a plus when indicating bore over the lands. I've had 2 of these for about 20 years until I sold my lathe a few years back and I'm in the process of obtaining a new lathe.

 

[geo.ulrich]

Thanks George. The backlash is noticeable but its a plus when indicating bore over the lands. I've had 2 of these for about 20 years until I sold my lathe a few years back and I'm in the process of obtaining a new lathe.

guess I reposted at same time grad. = .000175

 

[ab_bentley]

You're looking for indication, not measurement. As long as the needle stops could be metric for the value.

 

[vmaxpro]

You're looking for indication, not measurement. As long as the needle stops could be metric for the value.

Exactly. Unless your using it to measure a linear I wouldnt sweat it. .00005 is almost useless anyway. Ive always favored 5 tenths indicators over 1 tenth or 50 millionths. Especially on a machine, its much easier to find " zero".

 

[geo.ulrich]

You're looking for indication, not measurement. As long as the needle stops could be metric for the value.

after 45 yrs. as a gage maker and working in a gage lab I have never seen an indicator where the needle stops or doesn't move, unless it's broke or resolution isn't fine enough.

 

[ab_bentley]

after 45 yrs. as a gage maker and working in a gage lab I have never seen an indicator where the needle stops or doesn't move, unless it's broke or resolution isn't fine enough.

Touche', but the moral of the story is the same.

Adam

 

[geo.ulrich]

Exactly. Unless your using it to measure a linear I wouldnt sweat it. .00005 is almost useless anyway. Ive always favored 5 tenths indicators over 1 tenth or 50 millionths. Especially on a machine, its much easier to find " zero".

I agree .0005 is easier on a machine what happens when you need .0001 t.i.r. and yes .00005 is way overkill for chamber work.

 

[geo.ulrich]

Touche', but the moral of the story is the same.

Adam

Adam, there was a well known gunsmith that made all kind of claims all his work was under .00005 t.i.r. so I'm your huckleberry, I say I'll have a barrel done but I need to inspect with my equipment at his shop. never heard back imagine that.....

 

[hdskip]

I also have 45 yrs. in the precision business. .00005 is unimaginably small! Some of the claims I've heard in the gun business are absurd.

 

[Cool Tool]

I also have 45 yrs. in the precision business. .00005 is unimaginably small! Some of the claims I've heard in the gun business are absurd.

I DONT THINK IT AMOUNTS TO A HILL OF BEANS ALL THIS INDICATING ON GUN BARRELS.

 

[shortgrass]

Just "eye-ball it" george,,,,, it'll be OK!

 

[ridgeway]

Just "eye-ball it" george,,,,, it'll be OK!

You be surprised how many eye ball it, lol. And some set ups and methods...might as well eye ball it anyhow, lol

 

[vmaxpro]

I also have 45 yrs. in the precision business. .00005 is unimaginably small! Some of the claims I've heard in the gun business are absurd.

I do alot of precision grind. And I gaurentee not one gunsmith can afford to actually measure 50 millionths.

 

[shortgrass]

I do alot of precision grind. And I gaurentee not one gunsmith can afford to actually measure 50 millionths.

Relax,vmaxpro,,, this is the interdnet. Somebody's always tryin' to blow smoke up your butt.... Got 'key board ecpets' everywhere, one tryin' to out do the other, repeating what was posted somewhere that they gobbled up as fact.

 

[vmaxpro]

Yea sorry that was a little harsh!

 

[338 Mollett]

I do alot of precision grind. And I gaurentee not one gunsmith can afford to actually measure 50 millionths.

I agree or work anywhere near that!

 

[ireload2]

Can you even use a 4 jaw George?
It is as simple as that. If you can use a 4 jaw you can dial in a bore with an indicator.
I once work with a decrepit old alky who was too lazy to change chucks so he dialed in every part he worked on for 4 or 5 years.

I DONT THINK IT AMOUNTS TO A HILL OF BEANS ALL THIS INDICATING ON GUN BARRELS.

 

[geo.ulrich]

I guess it would to be what his standards are if he doesn't mind a crooked chamber or throat out of line then I guess like he said it doesn't amount to a hill of beans. If he's shooting any type of competition than i'm just smiling..