Live Tooling Modified 3/8-10 Threads

[rack runner]

Maybe just overthinking it. But, when you live tool threads for the modified 3/8-10 in the shaft, are you: 1 center drilling, 2 drilling a hole small enough for the live tooling to go into with a little clearance on the sides, 3 using the live tooling to mach to .308, 4 threading the regular 3/8 10 thread pitch? Hopefully this question hasnt been answered anywhere else, been looking for a minute.

 

[Kim Bye]

1. Center drill
2. Drill a 17/64" hole do your desired depth
3. Bore the hole to a thou undersize
4. Make a nice chamfer
5. Ream with your final diameter reamer
6. Thread your shaft about 60% of the thread depth
7. Take one more threading pass to final thread depth.

 

[JC]

1. Center drill
2. Drill a 17/64" hole do your desired depth
3. Bore the hole to a thou undersize
4. Make a nice chamfer
5. Ream with your final diameter reamer
6. Thread your shaft about 60% of the thread depth
7. Take one more threading pass to final thread depth.

Nice work flow

Try a three flute solid carbide drill bit @7.8mm to consolidate steps 2 and 3.

7.8mm=.307"

 

[BarenbruggeCues]

Maybe just overthinking it. But, when you live tool threads for the modified 3/8-10 in the shaft, are you: 1 center drilling, 2 drilling a hole small enough for the live tooling to go into with a little clearance on the sides, 3 using the live tooling to mach to .308, 4 threading the regular 3/8 10 thread pitch? Hopefully this question hasnt been answered anywhere else, been looking for a minute.

You're probably overthinking it.........
Minor diameter of the bore....match it within a thou of the minor of the pin.
Touch off your spinning live cutter to get a starting number inside the bore.
I take multiple passes increasing the depth of the cut coming out of the blind hole until I get the desired fit on the pin.
Write down or remember those numbers for multiple shafts if needed.
I can't give you specific numbers for your setup. Too many variables between you and me. But I already know when doing threads for my shafts, I'm going .042 deep with my cutter for the desired fit on my pin.
After acquiring my numbers on the first shaft I can do the rest of the shafts in 2 passes per setup.
One pass for the depth...one free depth pass after.

 

[JC]

You're probably overthinking it.........
Minor diameter of the bore....match it within a thou of the minor of the pin.
Touch off your spinning live cutter to get a starting number inside the bore.
I take multiple passes increasing the depth of the cut coming out of the blind hole until I get the desired fit on the pin.
Write down or remember those numbers for multiple shafts if needed.
I can't give you specific numbers for your setup. Too many variables between you and me. But I already know when doing threads for my shafts, I'm going .042 deep with my cutter for the desired fit on my pin.
After acquiring my numbers on the first shaft I can do the rest of the shafts in 2 passes per setup.
One pass for the depth...one free depth pass after.

I have a question about the cutters. The ones that are small enough to fit in the bore are not listed as being suitable for 10tpi. The last pitch listed for them is considerably finer threads. Yet they seem to work ok at least for wood. What is the skinny on this? Is that for cutting threads in metal and with wood the pin just pushes through the small clearance issues?

Thanks

 

[cueman]

I have a question about the cutters. The ones that are small enough to fit in the bore are not listed as being suitable for 10tpi. The last pitch listed for them is considerably finer threads. Yet they seem to work ok at least for wood. What is the skinny on this? Is that for cutting threads in metal and with wood the pin just pushes through the small clearance issues?

Thanks

The cutter I carry will cut internal 10 thread but you need another bit to cut 10 external.

 

[JoeyInCali]

Maybe just overthinking it. But, when you live tool threads for the modified 3/8-10 in the shaft, are you: 1 center drilling, 2 drilling a hole small enough for the live tooling to go into with a little clearance on the sides, 3 using the live tooling to mach to .308, 4 threading the regular 3/8 10 thread pitch? Hopefully this question hasnt been answered anywhere else, been looking for a minute.

You're UNDERTHINKING.
Use a 1/4 end mill to bore the hole.
That will have the same size as the cutter of the thread mill.
OMG!
Drill a 1/4 hole .
Live bore a .308 hole by you figure out how deep.
Replace end mill with the threader.
OMG, what, I'm at zero of the wall already ?
How deep is the thread?
Two passes.
Clean with the tap as needed.

Please, maple is CHEAP. Do several mock-ups.
1/4 flute carbide end mills are like $25.
They last a long time .