Making a metric thread dial indicator (TDI) easier to use

[Alans Home Workshop]

[metric_taper]

I've never seen a lathe with 3 gears for the Threading Dial Indicator. Is that typical for a metric lathe?
Both of my lathes have imperial threading screws. The newer one, I can select metric threads with the change gears, but I can't disengage the half nut. That's a major PITA. I had read about making a new gear for the TDI that would enable doing metric threads and allow the half nut to be disengaged. But I'm not sure if that's true.

[Alans Home Workshop]

I think you might find these 2 videos interesting:

Metric Threading with an Inch Lead Screw

Threading Dial Indicator for Metric AND Imperial Threads

Cheers, Alan

[DIYer]

Thanks Alans Home Workshop! We've added your Thread Dial Indicator Modification to our Measuring and Marking category,
as well as to your builder page: Alans Home Workshop's Homemade Tools. Your receipt:

Thread Dial Indicator Modification by Alans Home Workshop

tags: dial indicator, modification

[metric_taper]

Alan, thank you. I had seen OxTool video before, but it does not solve the issue of reversing the lathe, only disengaging when forward threading towards the chuck. I typically cut threads in reverse to feed away from the chuck, to prevent crashing.
The second video by An Engineers Findings, explains why metric lathes require 3 thread dial gears. But in my case going from imperial lathe making metric threads, he shows the same problem of needing multiple gears on the thread dial.
I'm thinking of some sort of electronic means, using a spindle encoder along with a lead screw encoder, and have some sort of synchronizing display to indicate when to engage. But I bet that still results in long delays to get the right engagement to the lead screw.
It's not all the big of a problem, as I don't make many single point threads on the lathes. Most of the time I use a tap and die, as I stock both systems of tools. Except, there are some bastard metric threads in the finer pitches that come up every so often. Just the other day I had M12x1.25, which is not included in any sets.

[Alans Home Workshop]

I also cut most smaller ie < 1/2" or 12mm threads with taps and dies. I started as a young bloke with a small metric set (6,8,10 fine and coarse) but relentlessly bought extras whenever I encountered the thread. 40 years later I have everything covered from 2 - 20mm plus similar sizes in Whitworth and SAE. I have always bought good quality HSS items and hate to think how much it would cost to replace this lot at today's prices...