# Building a thread chaser dial for a metric lathe



## rljones (Feb 8, 2014)

Hi all,

I have a BV20 lathe with a 3mm leadscrew, so it is a metric machine, and I really only want to cut metric threads, for now....

I have already determined that metric thread cutting does require a range of thread chaser cogs to mesh with the leadscrew.
I have figured a 14T, 16T and 20T will cover the range of pitches published on the lathe's front panel and using the usual 8 point indexing wheel up top.

As the lathe does not have a thread chaser dial, I want to make one to assist with dropping onto the leadscrew correctly.

What are the opinions on if I should build one with all three gears spaced apart and moving the pivot point to mesh appropriately vs just swapping the cog at the end to suit the thread in use?
I somewhat favour option 1 as it means less loose parts to lose.

Where does the pivot point exist on normal dial chasers? (I'm pretty new to all this business)

Thanks, Ray


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