Howa 1500 barrel threading

[GenePoole]

Lucky if you can get thru a thread without an awwwshiiiiiiiitttttttt moment with that much slop in a tool that really needs to be rigid.

Agreed. A not-so-clever solution looking for a problem. How does the half-nut disengage?

 

[Sniperhandle]

Maybe this will help explain the whole metric setup better.
Your lathe..........should have some form of chart/cheat sheet
which details what gear to use for a particular metric thread pitch.
Not just what to set the dials and controls to but an additional simple Algebraic formula
that you cross multiply.
Pic 1 shows in the top row, the number of toothed gear to use for a certain metric thread that corresponds to whatever your dials and controls are set to.
(if anyone struggled at 3rd grade fractions they should not be machining, because you need to be able to do simple algebra also), and prefereably some Trig thrown in for fun.
Calculus will be used later when you start shooting and figuring your Standard Deviation "longhand" and calculating trajectories. (the very reason Sir Isaac Newton invented calculus in the first place.)
anyways, this chart tells you what change gears to change out to
and you must have a set of these to be able to set up the correct feed rate "Ratio"
your gears should also be stamped or marked in some way, if not ....mark them yourself
I simple dremel with a carbide tip makes for an easy and quick, engraver.
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Second pic is the gear to change out, 3rd pic is a set of these different gears

The top gear is not going to get you there, The bottom small gear has to be flipped around to engage the outer 120 tooth gear in the 2 large gears that are sandwiched together, This is how you achieve the second gear ratio to adapt to an inch leadscrew, Changing the top gear in your pic will only change the range of inch threads you can do, With the exception of 1 or 2 metric threads, Still have to flip the bottom gear.

So in other words, The smaller of the 2 Large intermediate gears (120 Tooth) has to be turning the lower gear that is turning the leadscrew. The larger gear (127 tooth) will be mated with the top gear as it shown in your pic.

Look at this pic where it says "Pitch" which shows a metric chart, Look where the circle representing the small bottom gear is shown to mate the the 120 tooth gear, And the top gear is mating with the 127 tooth gear.

If you study enough of these charts, It will be like a light bulb comes on and all of the sudden you get it.

 

[ELR LVR]

The top gear is not going to get you there, The bottom small gear has to be flipped around to engage the outer 120 tooth gear in the 2 large gears that are sandwiched together,

On my lathe, the top gear must be changed out or I cannot do metric threads
And yes, good point I failed to mention the bottom gear below the intermediate gear must be flipped around to engage the 120 T, you are correct Sir, I guess that should have been mentioned.
I have that side marked to remind myself when I do metric.
But ---- I kind of figured that since the lathe itself has what it needs to do metric, even the gear that needs to be flipped yes is a good point, but theres also levers that need to be flipped which we don't bring up.
So I figure that since the lathe itself has everything it needs to do metric
the operator should be able to figure that out
except for the one important must have (extra)
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The main point in my last post was that,
--- without those change gears to be able to change out the top gear
There would be no way of doing metric. (at least not in the pitches I would need to)