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Lathe thread tool setting
- Thread starter Yingxi
- Start date
- Replies 104
- Views 10,340
angelw
Diamond
- Joined
- Sep 10, 2010
- Location
- Victoria Australia
Hello Yingxi,
Because threads will be often be cut to end very close to a shoulder, its an advantage to know where the very leading surface of the tool is when the program is run. Accordingly, I set, and advise my clients to set the leading edge of the tool in Z. Accordingly, if a shoulder that the Thread is being run up to is, say, at Z-40.0(mm), then you can be confident that a Z coordinate specified in the program of Z-39.9 is not going to hit.
Regards,
Bill
deadlykitten
Banned
- Joined
- Aug 5, 2016
it is a little risky to use only 0.1 clearance ...
... tool before threading may go at-40+0.03
... threading tool may go at -39.9-0.03
... and there is syncro precision
that 0.1 is a risky move, even on a calibrated lathe with quick reaction time
... tool before threading may go at-40+0.03
... threading tool may go at -39.9-0.03
... and there is syncro precision
that 0.1 is a risky move, even on a calibrated lathe with quick reaction time
angelw
Diamond
- Joined
- Sep 10, 2010
- Location
- Victoria Australia
it is a little risky to use only 0.1 clearance ...
... tool before threading may go at-40+0.03
... threading tool may go at -39.9-0.03
... and there is syncro precision
that 0.1 is a risky move, even on a calibrated lathe with quick reaction time
Well, you can wish in one hand and shit in the other and see which fills up the quickest.
Mine was an example of why you would set the leading edge of the tool. Reaction time has Zero to do with the actual finish point relative to a command move, given that the machine is operating correctly. Motion control decelerates to the terminal point, not start the deceleration at the command terminal point. Only an ALAND ISLANDER would be fucked in the head enough to run a machine where the servo system was not tuned and the motion control system not operating correctly.
The majority of experienced programmers would take into account the tolerance of a shoulder feature when specifying the end point of a Threading Op.
IronReb
Stainless
- Joined
- May 26, 2011
- Location
- Shreveport/Louisiana USA
it is a little risky to use only 0.1 clearance ...
... tool before threading may go at-40+0.03
... threading tool may go at -39.9-0.03
... and there is syncro precision
that 0.1 is a risky move, even on a calibrated lathe with quick reaction time
This has not been the case in my experience at all in 20 years.
I routinely thread to .100mm of a shoulder, if a CNC machine tool cant do this without 100% confidence it's time for a new CNC or major repair.
We turn and bore a shoulder with a turning tool and don't sweat it at all holding +-.0005" on Z location, why would it be different with a thread tool?
OP
Take Anglew advice bro, the man knows his shit trust me.
As he has already said, setup off the leading edge of the thread tool and NOT the thread tool point.
That way you can always program to numbers on the print and not have to remember to compensate and end up smacking a shoulder.
When thread a shaft were there is no shoulder and you need to hold a length on the thread...
Lets say the thread is 40mm long.
Your thread tool is 1.574 from edge to thread point.
Your Z move will be Z-41.574mm
One trick I use on just about every setup...
Once all tools are set, Z0 is set and program is loaded.
I MDI or handle jog my tooling to programmed dimensions to check that nothing is gonna crash.
I have often ran the part and stop before thread or partoff cycle, then move the tool down where the control is going to move it to so I KNOW when I hit cyce start nothing is gonna crash. That way I don't strain muscles in my butthole.
deadlykitten
Banned
- Joined
- Aug 5, 2016
the nut generally has enough chamfer, so there is no need to go that close to the shoulder
on a long setup, the tool before the thread insert may get damaged, leading to a crash on the threading tool, that will be more expensive than replacing the insert on the previous tool
also going that close, means that there is no groove at the end of the thread, so the thread insert finished cutting inside the material; in such a case, when clerance is 0.1, there is no room for lead-out movements, and as a result, insert life spam is reduced
i am not saying that 0.1 clearance is impossible; but is not common practice to go that close to a shoulder
on a long setup, the tool before the thread insert may get damaged, leading to a crash on the threading tool, that will be more expensive than replacing the insert on the previous tool
also going that close, means that there is no groove at the end of the thread, so the thread insert finished cutting inside the material; in such a case, when clerance is 0.1, there is no room for lead-out movements, and as a result, insert life spam is reduced
i am not saying that 0.1 clearance is impossible; but is not common practice to go that close to a shoulder
angelw
Diamond
- Joined
- Sep 10, 2010
- Location
- Victoria Australia
the nut generally has enough chamfer, so there is no need to go that close to the shoulder
on a long setup, the tool before the thread insert may get damaged, leading to a crash on the threading tool, that will be more expensive than replacing the insert on the previous tool
also going that close, means that there is no groove at the end of the thread, so the thread insert finished cutting inside the material; in such a case, when clerance is 0.1, there is no room for lead-out movements, and as a result, insert life spam is reduced
i am not saying that 0.1 clearance is impossible; but is not common practice to go that close to a shoulder
Clearly you're not the sharpest tool in the box; that's evident from your mostly inane Posts. There exists Thread Lead error at the start and end of the Thread Pass due to Acceleration/Deceleration respectively. The error at the start is general able to be taken up in fresh air by starting the tool an appropriate distance from the Start of the Thread. The error at the end is more difficult to deal with and should be considered in the design of the part. If the Thread is a close tolerance class and the assembly enforces the the Thread Lead to be accurate reasonably close to a shoulder feature, then the tool needs to finish as close as possible to that feature in an attempt to circumvent the affects of the Thread Lead error.
One also needs to understand that the Thread Groove is going to end, at best, half the width of the Thread Form of the Threading Insert away from a shoulder feature. Accordingly, the leading edge of the tool has to finish very close to a shoulder for the Thread to end half the Thread Form from the shoulder.
In my world and it would seem that of IronReb's, it is common practice to go that close to a shoulder.
deadlykitten
Banned
- Joined
- Aug 5, 2016
is different cinematic between turning and threading ...
once an inner tool finished, it dwells and/or retreats a bit in feed, and after contact with material is disengaged, it rapids out
a thread tool will disengage in rapid; it is more aggresive
try to thread M27x2 at 1800 rpm, with 0.1 clearance, on thousands of parts
do you think this is stable ?deadlykitten
Banned
- Joined
- Aug 5, 2016
share some examples
and share why it is necesary to go that close ... and not because the drawing is like that also share how you control the assembly ...
angelw
Diamond
- Joined
- Sep 10, 2010
- Location
- Victoria Australia
is different cinematic between turning and threading ...
once an inner tool finished, it dwells and/or retreats a bit in feed, and after contact with material is disengaged, it rapids out
a thread tool will disengage in rapid
try to thread M28x2 at 2000 rpm, with 0.1 clearance, on thousands of parts
Just like Johnny Larue, the more you Post the more your lack of knowledge become apparent.
Before the Threading Tool moves in Rapid in X to disengage from the Thread, it Stops in Z at the specified point, or if anything, it starts the X acceleration during the end of the Z deceleratio; but in practical terms, the Z axis doesn't end past the specified Z point. Its irrelevant as to whether it is a Turning, or Threading tool; the common link is Motion Control.
deadlykitten said:
"Because the drawing is like that" is the reason, even if its unreasonable. I and my clients never have rejected work because the drawing instructions were not followed. And as for the necessity to go that close, I've explained that in my previous Post.
angelw
Diamond
- Joined
- Sep 10, 2010
- Location
- Victoria Australia
Hello Yingxi,
You will need to specify the make and model of the machine and controller to have any chance of getting an answer to your question. The operation of the machine and its equipment is normally explained in the machine's Operator's Manual.
As your original Post was specifically related to a Threading Tool and not "how does one set a tool (any tool) in Z", can it be presumed that you know how to set other tools, such as an OD Turning Tool? If so, then use the same method for a Threading Tool, but set the Leading Edge of the Threading Tool holder.
Regards,
Bill
Last edited:
deadlykitten
Banned
- Joined
- Aug 5, 2016
i know how this works
at 0.1 clearance, if the tool before the threading gets a bit of wear, than a crash will occur ...also, with a bit of luck, this crash will occur at 1st part, with new tools, and this is how :
... tool before threading may go at -40+0.03
... threading tool may go at -39.9-0.03
...... so far there is 0.1-0.03*2=0.04
... and there is syncro precision, or you think that cnc will stop at same point when cutting 500rpm*0.5thread, versus 1800rpm*2 ? well, consider at least 0.005
in the end, what you get is 0.035, and that is 35% of the expected 0.1 tolerance
.. and now try to keep that up for thousands of parts if next day thread insert is chaged and the thread tool is measured at the senzor, it may input an aditionally 0.05 : 0.02 from insert precision and 0.03 from tool setter over night deviation
at this moment 0.05 is > 0.035, and bang
well, is not a big crash, but it will scracth the surface of the parton tight things i always try, and so far succeded, to find a common ground with the client
i dont regard the drawing as being prioritary, but only as a form of comunication
some parts have drawings and manuals, covering all the ways arround
deadlykitten
Banned
- Joined
- Aug 5, 2016
hy / just cut a thread, and after that just say what is wrong with it and what you wanna do better
angelw
Diamond
- Joined
- Sep 10, 2010
- Location
- Victoria Australia
i know how this works
also, with a bit of luck, this crash will occur at 1st part, with new tools, and this is how :
... tool before threading may go at -40+0.03
... threading tool may go at -39.9-0.03
...... so far there is 0.1-0.03*2=0.04
... and there is syncro precision, or you think that cnc will stop at same point when cutting 500rpm*0.5thread, versus 1800rpm*2 ? well, consider at least 0.005
in the end, what you get is 0.035, and that is 35% of the expected 0.1 tolerance
if next day thread insert is chaged and the thread tool is measured at the senzor, it may input an aditionally 0.05 : 0.02 from insert precision and 0.03 from tool setter over night deviation
at this moment 0.05 is > 0.035, and bang
on tight things i always try, and so far succeded, to find a common ground with the client
i dont regard the drawing as being prioritary, but only as a form of comunication
some parts have drawings and manuals, covering all the ways arround
BLAH, BLAH, BLAH, Fucking BLAH, more of your nonsense contribution. If this, if that. - If my mum had been a car, I'd have wheels.
deadlykitten said:
Another example of your space wasting contributions. And how does he get to the point of "just cut the thread"? Your answer is about as useful as directions to a destination as being: "just drive in ever increasing circles and you should hit it"
And to expand on you own rhetoric, "also, with a bit of luck, this crash will occur at 1st part", with a bit of luck, the crash may not be too catastrophic when "just cut a thread".
Vancbiker
Diamond
- Joined
- Jan 5, 2014
- Location
- Vancouver, WA. USA
Another thread trashed by the deadly idiot.
twr
Hot Rolled
- Joined
- Mar 18, 2014
- Location
- Kitchener Ont. Canada
damm thats funny vanc and true!!!
IronReb
Stainless
- Joined
- May 26, 2011
- Location
- Shreveport/Louisiana USA
OP
As you see, when asking for information on the web one can widely different answers.
So what is a person to do when your seeking answers but get multiple choices?
Do a forum search on the person posting.
For instance, if you search my name you will see my level of expertise is limited to certain scenarios. When I post something such as in this thread I only post what I know to be true and practiced over time and I am smart enough to realize there is always a better way as often posted here.
If you search one of the others names you may find this person could, and probably has written text books on CNC programming and manufacturing for aerospace.
Good luck.
As you see, when asking for information on the web one can widely different answers.
So what is a person to do when your seeking answers but get multiple choices?
Do a forum search on the person posting.
For instance, if you search my name you will see my level of expertise is limited to certain scenarios. When I post something such as in this thread I only post what I know to be true and practiced over time and I am smart enough to realize there is always a better way as often posted here.
If you search one of the others names you may find this person could, and probably has written text books on CNC programming and manufacturing for aerospace.
Good luck.
angelw
Diamond
- Joined
- Sep 10, 2010
- Location
- Victoria Australia
Too true vanc. Here we have an information seeker that by his own admission, is new on lathe operation and, as you so succinctly put it, the Thread has been fucked over by the idiot.
Of the total Posts up to the previous, just on one third have been by the Idiot NOT addressing the Op's question (100% of the Pussy's Posts). I'm also guilty of consuming one third of the Thread; one third of which was to assist the OP, the other two thirds rebutting the comments of the Idiot from ALAND ISLAND. Would you blame the newbie not coming back? Not really.
Regards,
Bill
twr
Hot Rolled
- Joined
- Mar 18, 2014
- Location
- Kitchener Ont. Canada
I will second that angelw/Bill and Vanc know this stuff!!! Also both forgot more than i will ever know about cnc machines and programing!!!
