Lathey day fun project
- Thread starter IllinoisCoyoteHunter
- Start date
smokeywolf
Well-Known Member
Love machining brass. Easy to get a great finish, pretty good thermal stability, mass/density make it more dead to vibration than most metals (except Pb), looks great brushed, polished or with engine turning.
To single point internal threads and start from a internal relief at the base of your bore and feed out, you have to use a left hand tool and either flip your tool upside down, reverse your spindle and feed out or mount the tool right side up and position it on the far side of the bore, reverse your spindle and feed out.
Run forward, feeding in, right handed tool produces right handed thread. Reverse your spindle and feed, left handed tool produces right handed thread.
Aside from not having worry about crashing your tool into the base of your bore, threading backward also sweeps more of the chips out of the hole.
Nice knurl and great finish on your parts Brad. Also looks like just the right amount of edge-break or chamfer.
To single point internal threads and start from a internal relief at the base of your bore and feed out, you have to use a left hand tool and either flip your tool upside down, reverse your spindle and feed out or mount the tool right side up and position it on the far side of the bore, reverse your spindle and feed out.
Run forward, feeding in, right handed tool produces right handed thread. Reverse your spindle and feed, left handed tool produces right handed thread.
Aside from not having worry about crashing your tool into the base of your bore, threading backward also sweeps more of the chips out of the hole.
Nice knurl and great finish on your parts Brad. Also looks like just the right amount of edge-break or chamfer.
smokeywolf
Well-Known Member
Go ahead and buy her a diamond ring. Just don't get caught when you borrow it to dress your grinding wheels.
IllinoisCoyoteHunter
New Member
Tap follower
Fun project that doesn't require tight tolerances.
Fun project that doesn't require tight tolerances.
Last edited:
IllinoisCoyoteHunter
New Member
Yes, I hardened the pointy one and still need to harden the other one. If anyone else has any tools they made and care to share I am always looking for projects!
Kevin Stenberg
Well-Known Member
I can make whatever I need in wood. But when it comes to metal I am out of my comfort zone.
Pistolero
Well-Known Member
I like that kind of tap driver, but my friend uses one where you thread a full machine
speed. Scared the heck out of me the first time he did it....... tap in a tap holder
on the tailstock, workpiece turning at maybe 250 rpm or so, he is holding the knurled
~1.25" diam handle on the tap holder, and pushes it forward to engage......
Tapped perfectly. He stopped then reversed the lathe, grabbed the knurling again,
tap backed out perfectly - the guide piloted on a ~7/8" diameter smooth inner pin,
very nice fit, smooth finish. Your hand provides the torque, when the tap bottoms
it spins in your hand. Looks like an accident for sure, but works great.
speed. Scared the heck out of me the first time he did it....... tap in a tap holder
on the tailstock, workpiece turning at maybe 250 rpm or so, he is holding the knurled
~1.25" diam handle on the tap holder, and pushes it forward to engage......
Tapped perfectly. He stopped then reversed the lathe, grabbed the knurling again,
tap backed out perfectly - the guide piloted on a ~7/8" diameter smooth inner pin,
very nice fit, smooth finish. Your hand provides the torque, when the tap bottoms
it spins in your hand. Looks like an accident for sure, but works great.
Been threading in forward. Been getting much better at it too. Sharp tools sure help.
I want to screw around some and see how threading in reverse works for me. If I can get it worked out and thread at a higher RPM it might make for even better threads.
I did just finish a tap guide similar to that one. Mine needs a spring before it is functional. My guide pin is a little undersize for what I wanted but will still work pretty well. I can easily enough make a new one.
I can run as slow as 65 rpm. Like watching molasses on a cold day. I have been threading mostly at 100-200 rpm, I think I get a better finish.
Thread pitch makes a difference too. 20 plus TPI is easy, 14 is much harder. Has to do with the distance the carriage moves for each turn of the spindle.
Thread pitch makes a difference too. 20 plus TPI is easy, 14 is much harder. Has to do with the distance the carriage moves for each turn of the spindle.
Pistolero
Well-Known Member
I run at about 70 rpm for threading. Very easy to be sure you catch it at the end
properly. Especially when doing 18 TPI or fewer. I guess newer lathes don't
actually have back gear, just lower speeds. The back gear requires you to flip up
a gate just above the spindle, rotate the spindle until you get to the drive pin,
pull out the drive pin, now the spindle front - which has the chuck on it is free
wheeling, no drive, but has a gear on the outside of the first wheel inside the cover.
Then you throw a handle on the left rear which drops an alternate shaft into engagement,
both gears moving in towards the now two piece main shaft for about a 6 to 1 reduction
with back gear. More torque, lower speed. I guess you just select the lower gear,
not any different than other gears...... more modern.
properly. Especially when doing 18 TPI or fewer. I guess newer lathes don't
actually have back gear, just lower speeds. The back gear requires you to flip up
a gate just above the spindle, rotate the spindle until you get to the drive pin,
pull out the drive pin, now the spindle front - which has the chuck on it is free
wheeling, no drive, but has a gear on the outside of the first wheel inside the cover.
Then you throw a handle on the left rear which drops an alternate shaft into engagement,
both gears moving in towards the now two piece main shaft for about a 6 to 1 reduction
with back gear. More torque, lower speed. I guess you just select the lower gear,
not any different than other gears...... more modern.
Pistolero
Well-Known Member
18 speeds is a lot more than I have, and you can get to them a lot easier, too. I have
a belt drive underneath, takes a bit of fiddling to move the belt to anther set of pulleys.
I see the more modern lathes with handles on the top, just select a couple levers and
get your different speeds. That is a big improvement.
I need to start spending a bit of time studying feeds and speeds and see if I can improve
my cutting. I do like single point threading at lowest speeds, although I CAN do it faster,
there is a lot less margin for error when you reach the shoulder, and it always seems
like there is a shoulder. Since I am not making production runs where time per part
is important, running slowly is fine. I am still at the walking stage, not yet comfortable
"running".
a belt drive underneath, takes a bit of fiddling to move the belt to anther set of pulleys.
I see the more modern lathes with handles on the top, just select a couple levers and
get your different speeds. That is a big improvement.
I need to start spending a bit of time studying feeds and speeds and see if I can improve
my cutting. I do like single point threading at lowest speeds, although I CAN do it faster,
there is a lot less margin for error when you reach the shoulder, and it always seems
like there is a shoulder. Since I am not making production runs where time per part
is important, running slowly is fine. I am still at the walking stage, not yet comfortable
"running".
IllinoisCoyoteHunter
New Member
Yep I normally chuck up the tap in the tailstock and power tap, but there are times I feel more comfortable doing it by hand.
Pistolero
Well-Known Member
That tool used your hand as the clutch, but I haven't made one or tried it
myself. The spring loaded tap alignment tool is a good project, I will make
one, for sure, more comfortable going slow on that. Probably make the power
tapping tool some time too, but I was surprised to see how quickly you could tap
without fracturing the tap. The hand torque control is very cool.
myself. The spring loaded tap alignment tool is a good project, I will make
one, for sure, more comfortable going slow on that. Probably make the power
tapping tool some time too, but I was surprised to see how quickly you could tap
without fracturing the tap. The hand torque control is very cool.
smokeywolf
Well-Known Member
Pistolero, although this is for running O.D. threads with a button die, I think this is what you're talking about... 
IllinoisCoyoteHunter
New Member
Yep. Cool Smokey. You just chucked it up in your drill chuck huh? Knurling to help keep it from slipping? I like it!