Indicators

[redvan22]

I recently discovered that there are a plethora of indicator types, test indicators and accessories available so I went to LMS where I was overwhelmed by what I saw; bases, arms, dials and more.

What do I need to perform the following on my mini mill:
Tramming my milling head?
Tramming a vise to the table?
Setting up work?

Not looking to take out a second mortgage but would like something reasonable and accurate and suited to my needs.
Mike

 

[Ulma Doctor]

some folks can go with the standard drop indicator and be fine with it
you'll need some kind of base to attach the indicator to


some folks swear by a DTI
they are used when a drop indicator is either too big, or awkward to use,
OR, when the resolution required is beyond the capabilities of the drop indicator.
they generally are more precise than a drop indicator, with exceptions.
they can generally be easily adapted for use on a small milling machine or small lathe due to smaller size.
they usually have a very limited range of indication, in the neighborhood of .030", so you need to be close to even attempt use




some folks swear by the Starrett Last word indicator



i have one , i don't use it much, but it is in the arsenal!
i find it to work ok, but i have other indicators that i grab first.


if i were to give advise,
i'd get a drop indicator (or 2) of your favorite brand (i'm partial to old, used, indicators - Tesa, Mitutoyu, Brown&Sharpe,Ames, to name a few)
and
a DTI to a .0005" resolution, as well as a .0001"DTI- this is where you must decide whether you are going to spend a lot of money or not.

i bought some higher end DTI's and prefer their action and repeatability,
but there is something to be said for low end gear.
the low end gear will indicate ok, but you don't feel as bad when the floor re-calibrates you indicator after a brain fart

i use both the cheapies and the higher end stuff
-cheapie, when it doesn't really matter
-high end when it does

good luck in whichever road you travel

 

[redvan22]

the low end gear will indicate ok, but you don't feel as bad when the floor re-calibrates you indicator after a brain fart

LOL. I really try to avoid those....

Thanks,
You helped a lot.
I have a crap-o-drop that i've been using and only after recent video viewing did I wonder if I had the right item for what I was using it for.
Mike.

 

[Mitch Alsup]

I tram my head (G0730), tram my vise (4"), and perform most of my setups (G4003G lathe 4-jaw) with a std 0.001 dial indicator 1" travel.

I also place this on the back of the bed (magnetic base) and measure x movements when the dials are not going to be accurate enough.

I occasionally need 3 DIs to correctly setup a part.

ETA: DTIs are for when you need better resolution, or cannot measure "null" with the DI at an angle to the measured surface (cosine error)

 

[mikey]

In my opinion, you need at least one dial indicator and one dial test indicator, both preferably with 0.0005" increments. I won't get into the cheap vs expensive argument but I find that in the long run the cheapest route is usually to buy quality.

 

[bill stupak]

I use a Starrett back button indicator for tramming both mill head and mill vice and a test indicator to do most work set up.

 

[jbobb1]

I have 2 - 1" (.0005" graduation) dial indicators with mag bases for both. I also have several test indicators I've accumulated though the years.
I use a Indicol to tram my mill and vice.

 

[brino]

The only small bit I can add to the above is that a dial indicator with 2" travel comes in handy sometimes.
I use one on the lathe carriage for accurately spacing two shoulders.
I use it on the mill for a double-check of the dials when milling offset features.
-brino

 

[francist]

A few different tips for the run-of-the-mill drop indicator come in handy as well. I have a button style and extended reach flat nose tip that really save the day sometimes without changing indicators. Fairly cheap to come by either new or on eBay, and dead simple to change provided your indicator has the standard thread (I think it’s #4-48)

-frank

 

[Chewy]

From your post, you sound like a Newbie. You will end up getting several indicators and duplicates over a short period of time. Most of mine are Starrett, Mitutoyu & Brown&Sharpe bought used on Ebay. I also have Shars and Igaging and have no trouble with them. It will depend on price and how soon you need it. I can tell you that it hurts to knock a brand new $30 igaging test indicator off the mill and watch it bend.
I started out with the first indicator that Ulma Doctor shows, since I had that for automobile work. You can tram a mill with a piece of 1/2" round stock from a big box store. About 7" long, bend it to 90 degrees. Mill a flat on both sides at one end and drill 1/4" hole to attach indicator. It will be solid, but you will have to go behind machine or use a mirror for the Y reading. For the vise, do the same but drill and tap 1/4" hole in the end.
One of the prominent You Tube people did a video comparing cheap and name brand dial indicators. The difference has been stated above about action and smoothness and is absolutely correct. It seems that the biggest difference is in spring tension. If everything is rock solid, it will read correctly. Have any little give and you may be off a couple of thousands from the heavier spring.
If you are fortunate to have a real several thousand pound Bridgeport, this next part won't apply. If you have a small belt driven machine, make a small thin wedge and gently place under the pulley. This will stop the spindle from rotating/moving and giving false readings when tramming a vise. My first time I had to put a wrench on the drawbar and tie it off to stop false readings.

The hardest part is starting out because what ever you do this time won't work well with the next setup. Get an indicol knockoff from Ebay. When it comes mic the rods and get some drill rod in that size and cut to length as needed. Same with magnetic bases. The drill rod has saved my bacon plenty of times. The advice above is spot on and soon you will have a collection of different indicators and clamps/bases too.

Good luck!!! Charles