Indicator sensitivity test.

[Ksracer]

The subject of indicators came up in a few other threads and I've seen phrases like "zero runout" and "no movement is zero" used. I've done this test before, but I wanted to repeat it to make sure I wasn't talking out of my A**.

These indicators are all equipped with the factory length stylus. The Mitutoyo with a 2.625 stylus on it takes roughly the same amount of deflection as the Interapid to move the needle, but the graduations are so close it's very hard to read.

The indicators are all clamped as rigid as possible, using them on a mag base with 2 rods and snugs will make them worse.

I couldn't figure out a way to include a Grizzly rod in the video, but I can promise you they aren't much better, and significantly worse if precautions aren't taken with them.

This reflects the sensitivity while checking runout in a smooth bore, such as the FB area, neck, or rear of chamber. Running the stylus over a land forces the needle to overcome the friction in the indicator and it tends to give a more accurate reading when it stops in the following groove.

This is my experience, yours may vary. Just food for thought....

 

[DaveTooley]

You're comparing a .0001" indicator to a .0005" indicator. They do not have the same level of accuracy. Just for the hell of it turn your Interapid 90 degrees and have the ball slightly above the center line. That's how I indicate barrels in as it takes the side play out of it. We can debate tenths but the fact is the reamer is going to the center of the bore unless there is an outside influence applied.

 

[LVLAaron]

Like dave said they're different divisions.

But... It'd be more interesting for you to center up with the interapid as best you can, and then check that work on the Mity and see how far out it is. It's still pretty clear that the interrapid is moving

 

[Dusty Stevens]

I sure like my interapid with the long island stylus. I can get on up in there without drilling and boring. This and a range rod is how i get it closer past .001

Tool Post Indicator 42-000

Reduce set up time with the Tool Post Indicator by Edge Technology. This unit is much faster to install and more rigid than a mag base indicator holder. It is the best way to align a work piece in a 4 jaw chuck.

www.edgetechnologyproducts.com

 

[Ksracer]

Like dave said they're different divisions.

But... It'd be more interesting for you to center up with the interapid as best you can, and then check that work on the Mity and see how far out it is. It's still pretty clear that the interrapid is moving

The different divisions and level of accuracy was my point, specifically splitting the divisions on the Interapid. There's .0004 runout in that pin and the needle on the Interapid isn't even wiggling.

I've checked them back to back in finished chambers several times and the Mity finds stuff the Interapid doesn't. Most notably "runout" from 5r rifling, setups that moved slightly, or reamers that didn't go to the center for whatever reason.

The obvious problem is reaching the areas we want to minimize runout in. I do use the Interapid for that. The stylus riding over the lands seems to "break" the friction of the movement and increases it's accuracy, but on smooth surfaces like the neck and freebore area or the back of the chamber, the tenths indicators kick its butt.

 

[LVLAaron]

I sure like my interapid with the long island stylus. I can get on up in there without drilling and boring. This and a range rod is how i get it closer past .001

Tool Post Indicator 42-000

Reduce set up time with the Tool Post Indicator by Edge Technology. This unit is much faster to install and more rigid than a mag base indicator holder. It is the best way to align a work piece in a 4 jaw chuck.

www.edgetechnologyproducts.com

Edge Tech makes all kinds of handy gadgets.

 

[jackieschmidt]

I have at my shop about every brand and type of indicator made.

For chambering cases 308 length and shorter, I still prefer the Mititoyo 513-504 With the 1/2 inch long stylus.
After I rough drill, I can easily reach in and indicate the throat.

Mitutoyo 513-504-10T Indicator, Pocket Type, .01in, .0001in

Mitutoyo 513-504-10T Indicator, Pocket Type, .01in, .0001in. Great savings PLUS Free Shipping when you order today on GlobalTestSupply.com.

www.globaltestsupply.com

 

[Judd]

Edge Tech makes all kinds of handy gadgets.

I use the heck out of their carriage indicator. I bought the drill chuck but haven’t put it in a tool holder yet.

 

[Dusty Stevens]

The lathe alignment bar works very well for a quick check. It caught one of my feet getting soft.

 

[X Count]

This is a good demonstration of something people don't really want admit.

 

[Ksracer]

This is a good demonstration of something people don't really want admit.

That was pretty much why I did the demonstration.

The conversations seem to go something like this.

Person A. "I get a couple tenths run-out if I do XYZ"
Person B. "I can do XYZ all day long without any problem. There must be something wrong with your setup."
Person A. "How do you check your work?"
Person B. "A range rod and a long stem indicator."

A few days later, person B post a picture of him using a long stem indicator ON the range rod....