13engines
Stainless
- Joined
- Jun 30, 2015
- Location
- Saint Paul, MN
Got my first CNC theading job coming up this week. 60 parts out of 4140 annealed 1 1/4 hex. Roughly 6" long with an ID thread of M22 X 1.5 Left Hand. The customer is looking for at least 2" of usable thread on this ID.
Question 1: What bar to use?
Steel Thru Coolant Bars - (Not enough money in the job to buy a $310 carbide bar.)
Both just make it as far as the 0.81" Minimum Bore requirements go.
1/2" Top Notch insert bar?
5/8" Laydown Insert bar?
Which of these threading bars would you choose? Obviously one has a larger diameter then the other, and a person would think that is the one to use, but I'm unfamiliar with the nature of the two different types of threading inserts and am curious if the nature of the inserts will sway the answer regardless of bar size. My gut tells me the 5/8 lay-down setup, but what do I know?
Question 2: Inserts
Full Profile?
Partial Profile?
No experience with either.
Question 3: Technique:
Thread towards the chuck?
Thread away from the chuck?
I'm kind of liking the threading away from the chuck idea but am wondering if this can be done without a thread relief? This is a 2000 Mori with Fanuc 18i control if that matters. On this ID, can a guy just barge into the stock at the bottom of the bore without a relief cut there? If run in one non stop cycle, will the tool tip start in the same place every time and not inadvertently run a pass into previously uncut stock? Not sure how that plays out.
As an aside - anyone know where to get a M22 X 1.5 Left Hand Spiral Flute Tap at a reasonable price? I'd machine tap this thing if I had half a chance... and could afford it.
Fellow machinists... I beg your wisdom on these matters. Thank you.
Dave
Question 1: What bar to use?
Steel Thru Coolant Bars - (Not enough money in the job to buy a $310 carbide bar.)
Both just make it as far as the 0.81" Minimum Bore requirements go.
1/2" Top Notch insert bar?
5/8" Laydown Insert bar?
Which of these threading bars would you choose? Obviously one has a larger diameter then the other, and a person would think that is the one to use, but I'm unfamiliar with the nature of the two different types of threading inserts and am curious if the nature of the inserts will sway the answer regardless of bar size. My gut tells me the 5/8 lay-down setup, but what do I know?
Question 2: Inserts
Full Profile?
Partial Profile?
No experience with either.
Question 3: Technique:
Thread towards the chuck?
Thread away from the chuck?
I'm kind of liking the threading away from the chuck idea but am wondering if this can be done without a thread relief? This is a 2000 Mori with Fanuc 18i control if that matters. On this ID, can a guy just barge into the stock at the bottom of the bore without a relief cut there? If run in one non stop cycle, will the tool tip start in the same place every time and not inadvertently run a pass into previously uncut stock? Not sure how that plays out.
As an aside - anyone know where to get a M22 X 1.5 Left Hand Spiral Flute Tap at a reasonable price? I'd machine tap this thing if I had half a chance... and could afford it.
Fellow machinists... I beg your wisdom on these matters. Thank you.
Dave
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