# How do I use an Indicol to indicate a hole?



## HMF (Dec 28, 2011)

*Indicol question* 
                                                    Do I clamp it to the spindle of a milling machine? Then what?


Any photos would be a great help!


Thanks,


Nelson


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## Tony Wells (Dec 28, 2011)

Well, I don't own one, so someone else will have to do the photos, but I have used one a time or two. After you clamp it to the spindle nose where it can rotate with the spindle, put a DTI on the dovetail and manipulate the arms to get the indicator just above the hole. Position it near the edge of the hole and turn the spindle by hand so that the indicator point swings in a circle just above the hole. Move the table and adjust the swept diameter until it is close to fitting into the hole. When you think it will fit, lower the quill until the indicator is just inside the hole, then continue turning the spindle and observing the readings. Move the table until you get the same readings all around. If the hole isn't round, you have to settle for the same readings diametrically opposed.


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## Highpower (Dec 28, 2011)

I've got one, but it's a little too late for me to set up and take pics tonight. If no one else posts before tomorrow I'll take some then.


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## Highpower (Dec 29, 2011)

Ok, here are a couple of (poor quality) pictures of a couple of different set-ups. Sorry, but I'm obviously not a photographer and my camera was outdated years ago.  
One with the usual spindle "clamp on" mount - and one with a stud adapter that can be used in a collet or drill chuck.

Tony already described the process above. One thing to keep in mind is that works on _outside_ diameters as well, for centering round stock under the spindle. I also threw in a picture of a co-ax indicator as well for comparison. It works basically the same way _but_ it works while the spindle is _under power_. You *don't* run the mill when using a DTI!!! Turn the spindle by hand only.

I prefer to use a vertical DTI whenever possible using an Indicol. It makes it easier to read the dial while rotating the spindle. You *can* use a horizonal DTI but you will need to stretch your head around to the back of the spindle to read the dial as it goes around - or use a mirror.
When using a co-ax indicator the dial stay stationary while the stylus rotates - making it the easiest to read of all.


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## HMF (Dec 30, 2011)

The tram of a mill is being checked here using an .0005" indicator in an indacol by sweeping table. It is found to be out .002" side to side. This was corrected and rechecked.


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## HMF (Dec 30, 2011)

Here is a photo of an indicol being used to find the center of a horn bell prior to machining.
You never have to remove the cutter to indicate center on a part.


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## Tony Wells (Dec 30, 2011)

To me, that's the big selling point to the indicol. You don't have to remove the tool every time. Just the ones that are really big, like shell mills or larger inserted cutters. Drill chucks and end mills pose no problem.


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## Tom Griffin (Jan 21, 2012)

Another quick and dirty way to "indicate" a hole is to use an edge finder. Just pick up opposite sides of the hole and use the center function on your digital readout to center it up. It's surprisingly accurate and very quick.

Highpower: I also have one of those axial indicators and they work very well, but I feel guilty every time I use it. It just seems so excessive. ;

Tom


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## Tony Wells (Jan 21, 2012)

Tom,
 I know people who use those axial indicators who don't trust them within 0.002". What is your experience with them?


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## Tom Griffin (Jan 21, 2012)

Tony,

Mine is the original Blake brand and it works great. It's probably the knock-offs that people are complaining about. The market is literally flooded with cheap, low quality imitations of just about every successful U.S. made product. I've been on a serious buy U.S. made product push lately. It's getting downright alarming how much made in China garbage there is on the market these days.

Sorry about the rant. 

Tom


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## McRuff (Jan 22, 2012)

Two thing  that should be pointed out. 
1 - When using an Interapid indicator, put the stem in the hole on the end of the Indicol clamp where your dovetail is, thats one of the reasons people buy and use Interapids.
2 - Never tram a mill by running the indicator directly on the table, place it up off the table and swing it over a hardened 1-2-3 block or such, move the block around to the 4 corners as needed, this helps take the error out of the tram reading from dings or scraping marks on the table, it basically averages them out.


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## ddickey (Oct 5, 2017)

Can you use an Indicol to tram the head of a mill? Since you don't clamp it into the spindle there can be errors,no?
I just tried an Indicol and got .004" difference.
Then I used a .250" rod that I bent a little for DTI clearance in an R8 collet  and got .0002" over ~ the same distance. The only difference was that the table was higher with the Indicol.

Edit: I thought I better try again as I was thinking possibly my Indicol wasn't tight enough. Sure enough it came out perfect. So lesson learned I guess. You really need to bear down on the Indicol screws for a rigid setup.


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## Billh50 (Oct 5, 2017)

Another thing to check on older indicators is if the little ball on the end has a flat from wear. They do wear.


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## bobl (Oct 5, 2017)

Tom Griffin said:


> Tony,
> 
> Mine is the original Blake brand and it works great. It's probably the knock-offs that people are complaining about. The market is literally flooded with cheap, low quality imitations of just about every successful U.S. made product. I've been on a serious buy U.S. made product push lately. It's getting downright alarming how much made in China garbage there is on the market these days.
> 
> ...



I still use a length of 1/4 drill rod bent at 90 degrees have for 50or so years and works for me


Sent from my iPod touch using Tapatalk


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## Firestopper (Oct 5, 2017)

I trust my Blake Co-Ax indicator 100% . Indicol works too but you have to chase the dial.


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