Lathe Carriage Dial Indicator

[jjr2001]

Some times I just need to know where my carriage is. Took an import 2" travel dial indicator and hack sawed (yep hack sawed) off the mounting flange that was clearly in my way in order to use this indicator as I wanted to. The back was removed for the sawing. Good thing too, the mounting flange was hollow. Filed it smooth and filled the hollow part with epoxy. Made up the clamp from aluminum and a few screws. Clamps to the rear bed of the lathe and is easy to position when the carriage is relocated. Two inches is usually enough travel but it might be nice to obtain a 4 incher!

Cheers, JR

[mklotz]

It's not inconceivable that someday you'll forget it's there and run the carriage into it driving the DI rod into the delicate works inside.

There are (at least) two ways to avoid such a tragedy.

1. Tap a hole into your aluminum holder for a screw and lock nut that can be extended such that the carriage will hit the screw before it destroys the DI.

2. If you have sufficient space, withdraw the body of the DI into the aluminum holder far enough so that when the carriage hits the holder the DI rod hasn't fully bottomed out. This is clearly the easiest but you may not have enough 'grab' on the DI if you do it. Give it a try.

[jjr2001]

Thanks Marv, That is a good idea. I think I will just drill and tap for a stop rod or screw. That should keep things safe.

Cheers, JR

[mklotz]

In the past, I've used my very similar arrangement to move the carriage left and right about some feature of the workpiece that serves as an origin.

When I do this I first set the DI to the middle of its (2") range. To facilitate setting it, I made a setting gage that consists of a 1" long aluminum rod with a deep groove down its entire length. The groove is wide enough to allow the gage to slip over the DI rod.

The procedure goes like this...

Pull DI rod far enough to slip gage over the "back end" of the rod between the rod cap and the top of the DI dial. This holds the DI rod at 1" compression, the middle of its range.

With the carriage positioned at the reference feature, move the DI up until it just touches the carriage.

Remove the setting gage and you're ready to go.


I set the rotating dial so zero is at the 12 o'clock position as seen by the operator. This way the needle tells me which way to move the carriage to return to the reference. If the needle is to the left of zero, I need to move the carriage to the right to get the needle to move right to the zero.

[jjr2001]

Thanks Marv, I never thought to use the DI for measuring both directions at the same time! Excellent tip,
Thanks, JR

[mklotz]

I use one as a precision Z-axis depth gauge on my mill. As such I have to have the freedom to move both up and down and the DI needs to start in about the middle of its range. Hence the idea of a quick way to preset it to mid-range. The arrangement I use is a bit different from what I described but the idea is the same.

One advantage of using a DI in this role is the fact that they have virtually zero backlash due to the spring-loading of the internal gear mechanism.

[jjr2001]

The preset to half range is so handy. I just had a small job to bore out but only .325 deep. Set up the DI with the preset and it was fast and quite easy to do.

Cheers, JR

[DIYer]

Thanks jjr2001! We've added your Lathe Carriage Indicator to our Lathe Accessories category,
as well as to your builder page: jjr2001's Homemade Tools. Your receipt:

Lathe Carriage Indicator by jjr2001

tags: lathe, dial indicator