I was looking at the threading guide and have no idea how to thread a barrel with no thread relief on my lathe (Grizzly G4003G)...
Unless I am missing something I'd have to disengage the half nut and back out the cross slide at the same time which I don't think would be very repeatable and seems like a good way to chip a tool. Is there a good way to do this on my lathe?
How to thread with no thread relief
Re: How to thread with no thread relief
Never tried it but I think you'd need to use a RH threading tool (flat on the left side so it can get against a shoulder) and run the feed in reverse. Not the spindle rotation just the feed direction. Would still need a little relief to get started in. Anyway, that's how I'd try to do it but I'm sure there's a "right way".
--------------------------------------
"Sorry but you cannot use search at this time. Please try again in a few minutes"
"This board is currently disabled"
These things make me
"Sorry but you cannot use search at this time. Please try again in a few minutes"
"This board is currently disabled"
These things make me
-
- Silent But Deadly
- Posts: 707
- Joined: Thu Apr 15, 2010 7:20 pm
- Location: The South
Re: How to thread with no thread relief
Whats wrong with putting in a relief?
O.D. Grooving tool usually .060-.080" wide . . . whatever the width of the tool is, then back it up towards the muzzle end a full width and cut a 45* into the barrel and back towards the breech on the backside of the major diameter of the threads.
O.D. Grooving tool usually .060-.080" wide . . . whatever the width of the tool is, then back it up towards the muzzle end a full width and cut a 45* into the barrel and back towards the breech on the backside of the major diameter of the threads.
Re: How to thread with no thread relief
As above use a right hand tool ... chips reel off to the right as it moves left.Griz wrote:I was looking at the threading guide and have no idea how to thread a barrel with no thread relief on my lathe (Grizzly G4003G)...
Unless I am missing something I'd have to disengage the half nut and back out the cross slide at the same time which I don't think would be very repeatable and seems like a good way to chip a tool. Is there a good way to do this on my lathe?
As an exercise, on my Atlas 618, I tried it for kicks and the only way to do it was to disconnect
the motor/belt and turn the screw with a hand crank in the back of the head stock. No disconnecting necessary.
<< http://www.youtube.com/watch?v=XMUY6ip14sM >>
<< http://www.toolsandmods.com/docs/ralph_ ... rank_3.pdf >>
Best.
- Capt. Link.
- Silent But Deadly
- Posts: 2829
- Joined: Wed Oct 17, 2007 9:05 pm
- Location: USA.
Re: How to thread with no thread relief
Either the barrel or the can will have a relief if the two will ever meet.Threading to a hard shoulder should be practiced.Disengaging the split nut and retracting the cross slide is the way its done.I like to do this at high speed when a novice is present just for the reaction.You have a option of starting at the shoulder with the tool upside down and run it in reverse out to the muzzle.The relief can be cut in advance or after.
Click on photo for larger view.
Click on photo for larger view.
Last edited by Capt. Link. on Mon Dec 31, 2012 12:35 pm, edited 1 time in total.
The only reason after 243 years the government now wants to disarm you is they intend to do something you would shoot them for!
http://www.silencertalk.com/forum/viewtopic.php?f=10&t=79895
http://www.silencertalk.com/forum/viewtopic.php?f=10&t=79895
-
- Member
- Posts: 15
- Joined: Sun Nov 07, 2010 3:09 pm
Re: How to thread with no thread relief
What's wrong with having a relief? Its better IMO to have the pieces that are being connected to mate on square faces
-
- New Member
- Posts: 1
- Joined: Sun Dec 30, 2012 7:45 pm
Re: How to thread with no thread relief
I'm not a gunsmith, but I am a machinist. Its tricky (I run very slow rpm's when doing this) but you can zero an indicator on the way of the lathe where you want the thread to stop, start thread normally, when it hits zero on the indicator, quickly back the tool away from the part while shifting machine into reverse. Never dis-engage half nut and allow lathe carrige to return to its starting point. This way is a must on some lathes ecspecially metric threads.
Re: How to thread with no thread relief
If I did that, I'd crash. Moving the feed lever directly from forward to reverse without coming to a stop will keep the machine running forward. Do bigger geared machines do this? I'd imagine that would be hell on the gears shifting the feed or direction lever into reverse while moving forward.superstriker90 wrote:I'm not a gunsmith, but I am a machinist. Its tricky (I run very slow rpm's when doing this) but you can zero an indicator on the way of the lathe where you want the thread to stop, start thread normally, when it hits zero on the indicator, quickly back the tool away from the part while shifting machine into reverse. Never dis-engage half nut and allow lathe carrige to return to its starting point. This way is a must on some lathes ecspecially metric threads.
Would take forever but you can turn the headstock by hand with the feed & half nut engaged. Could get wherever you wanted and stop without risking crashing anything. Set for a higher gear or it will be hard turning the headstock. At least mine works that way - if everything is engaged, turning the chuck turns the leadscrew & moves everything along. You could feed in that way, stop at your desired spot, back off the cross slide, run in reverse under power w/o disengaging half nut, stop, feed in cross slide & compound, manually start spinning the chuck for the next pass. Rinse, repeat, until you have what you want.
--------------------------------------
"Sorry but you cannot use search at this time. Please try again in a few minutes"
"This board is currently disabled"
These things make me
"Sorry but you cannot use search at this time. Please try again in a few minutes"
"This board is currently disabled"
These things make me
Re: How to thread with no thread relief
Also, why no relief? Do you start your female threads with a little chamfer in the hole to ease mating? If you do, that chamfer where there aren't full threads anyway would be over the relief so you aren't losing anything.
--------------------------------------
"Sorry but you cannot use search at this time. Please try again in a few minutes"
"This board is currently disabled"
These things make me
"Sorry but you cannot use search at this time. Please try again in a few minutes"
"This board is currently disabled"
These things make me
Re: How to thread with no thread relief
I have been threading in reverse with an upside down carbide insert at high speeds. I get beautiful threads when I'm spinning at 1400 rpm or so, but I have to have a relief to start in and do it in reverse so I don't crash into the shoulder.
I can't quickly reverse my lathe as suggested, I'd probably pop a breaker if I tried that. I don't have any problems with picking up the thread again when re-engaging the half nut using the threading dial though.
My question was prompted because the AAC threading guide shows no thread relief on most rifle threads. I guess that's so that a peel washer will be centered if you were mounting a flash hider, but I like to just time the flash hider with the lathe and not use a washer. Is there any other reason why the threading guide shows no thread relief?
I can't quickly reverse my lathe as suggested, I'd probably pop a breaker if I tried that. I don't have any problems with picking up the thread again when re-engaging the half nut using the threading dial though.
My question was prompted because the AAC threading guide shows no thread relief on most rifle threads. I guess that's so that a peel washer will be centered if you were mounting a flash hider, but I like to just time the flash hider with the lathe and not use a washer. Is there any other reason why the threading guide shows no thread relief?