Dial indicator vs Dial test indicator

[FastKat]

I have a work piece that I am setting up on my vertical mill's table. I want to square up the work piece with the X and Y axis travel. In the past I have used an edge finder to make sure my work piece is parallel with the X axis travel. I haven't done anything precise yet and that seems to work fine. However, I have seen people also use a dial test indicator for this purpose. I do not have a dial test indicator but only a dial indicator... an old B&S No. 196. On the face, it says that it measures to .001". Will this dial indicator be okay or do I need to buy a dial test indicator?

BTW, I am not very experienced with this so I might not be using the correct terminology!

 

[kkroger]

Should be fine... the Dial indicator will just have more travel than the Test indicator..
Possibly more difficult to fix in the chuck...

 

[dr_clyde]

What do you have for a base? This is important, because it is easier to indicate features if you can clamp the dial in more places.

For indicating things along the X, you can mag right onto the knee and traverse the part without taking the tool out of the spindle or getting out the indicol.

Assuming your mill has a quill, you can use the V on the base to grip as well.

 

[longlivepunk]

Depends on the precision you need I guess, if you need to be precise to within .0001" then it won't work of course. Otherwise it should be alright.

Use your mag-base to fix your indicator to the body of the mill and have it touching on a flat area of the part, then just run the part back and forth and adjust the part/vise/fixture until the dial isn't moving.

What are you milling? If it's a part that only allows for squaring on a very small flat surface you might need a more precise indicator since a part that is A* out of square will show a lot more difference if you run your indicator over 5" of it than it will if you run it over .5".

 

[A_Pmech]

Yes, it will do the job for thousandths - range accuracy. It's just awkward. A modern test indicator is much smaller and easier to use for things like indicating in parts and vises.

 

[aggierailroad]

Just stumbled on this the other day :Tool Talk: What is a Test indicator ??????:

 

[zkling]

Yes, it will do the job for thousandths - range accuracy. It's just awkward. A modern test indicator is much smaller and easier to use for things like indicating in parts and vises.

Then keep an eye out or spring for a nice 1/2 thou (0.0005") DTI. Very handy for the milling machine.

 

[FastKat]

I know this is late but thanks for all the info. I wound up getting an inexpensive dial test indicator!

 

[Jim Johnstone]

Good move getting the test indicator, totally worth it. I don't even have a conventional plunge indicator in my box at work. I do everything with test indicators.

 

[Techie1961]

Probably known by many but a dial test indicator will not measure distances accurately unless the probe is parallel to the surface that is being indicated or in the case of a round object for runout, it has to be coincident to a tangent line with the diameter of the part and the probe point at the tangent point. It is not intended to actually measure anything other than deviations or finding the same point in space. A dial indicator is used to measure things linearly.

 

[exmaxima1]

It is not intended to actually measure anything other than deviations or finding the same point in space. A dial indicator is used to measure things linearly.

Yep.

 

[Jim Johnstone]

Probably known by many but a dial test indicator will not measure distances accurately unless the probe is parallel to the surface that is being indicated or in the case of a round object for runout, it has to be coincident to a tangent line with the diameter of the part and the probe point at the tangent point. It is not intended to actually measure anything other than deviations or finding the same point in space. A dial indicator is used to measure things linearly.

Very good point. Test indicators are comparison measurement equipment.