HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

1. ## HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

Hi there I am wondering if anyone knows how to set the machine in metric?? G20 to G21 ?? ? ? I know that's Fanuc but does Okuma work like that too? or do you convert to inches?

I have done several threading jobs with this machine in inches however I am having a hard time writing Metric or converting it in Okuma

so basically I am trying to 9MM x 1.25 pitch

can anyone write a G71 line or tell me what to fill in the blanks in IGF?

major diameter 9mm
minor 7.647mm
pitch 1.25mm
TPI??
X Start .38"
X finish or minor diameter .301"
H[eight of thread]: .0266 I believe ? (or 9 - 7.647 /2 in MM)

that's all I got for now.

thanks

2. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

Convert pitch to Imperial
1.25 / 25.4=0.0492

Calc TPI
1 / 0.0492=20.32

The lead is 0.0492'', the TPI is 20.32

Major dia = 0.354''

0.866 is a constant for metric thread depth
0.866*pitch = 0.866*1.25 = 1.0825mm = 0.0426'' thread depth
0.0426*2 = 0.0852''
0.354-0.0852=0.2687''

Minor dia = 0.2687''

This should give you enough to set it up just like cutting Imperial threads.

3. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

Originally Posted by Jim Dawson
Convert pitch to Imperial
1.25 / 25.4=0.0492

Calc TPI
1 / 0.0492=20.32

The lead is 0.0492'', the TPI is 20.32

Major dia = 0.354''

0.866 is a constant for metric thread depth
0.866*pitch = 0.866*1.25 = 1.0825mm = 0.0426'' thread depth
0.0426*2 = 0.0852''
0.354-0.0852=0.2687''

Minor dia = 0.2687''

This should give you enough to set it up just like cutting Imperial threads.
thanks a lot, Jim. so provided all that
g50s200
T20202
G95
G97S100M3
G90G1X.38Z.1F50.
G71X.2687Z-1. H.0426 (D..005?) F.0492 (U.001?) M73M34
G80
yeah?

do you use M33 or M34? which is better? is it just preference?
I am putting threads on an already hardened 3/8" bolt. I bought a long one so I could cut it off and put threads on the end of it.

sorry if this is confusing

4. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

is everything here radial ?? and no J value I take it since it's Metric ?or J is # of threads per inch
and we figured it's 20.33? does the machine like decimals?

5. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

Does your machine have a G32 threading cycle available? That's what I use.

I normally set up the M33 or M34 in the CAM program and let it sort that out. In Fusion there is an option switch for this.

- - - Updated - - -

Does your machine have a G32 threading cycle available? That's what I use.

I normally set up the M33 or M34 in the CAM program and let it sort that out. In Fusion there is an option switch for this.

6. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

Originally Posted by Jim Dawson
Does your machine have a G32 threading cycle available? That's what I use.

I normally set up the M33 or M34 in the CAM program and let it sort that out. In Fusion there is an option switch for this.

- - - Updated - - -

Does your machine have a G32 threading cycle available? That's what I use.

I normally set up the M33 or M34 in the CAM program and let it sort that out. In Fusion there is an option switch for this.
I think I tired it once but not G32
I tried G33 which is like G92 in faunc correct? I tried G33 but the control doesn't like it. so I have been working with G71 instead.
G33 X Z F J M23
X
X
X
..
seems pretty easy

but anyway where in IGF is M34 or M33 determined? and if you noticed in my picture spinning clockwise is written as M41 .. .
why?

7. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

According to my list, the M41 is Spindle Gear Range 1, but I don't see a M3 (Spindle CW) or M4 (Spindle CCW) on your picture which is a bit odd. But understand I am no expert on Okuma or Fanuc for that matter. G33 (Fixed thread cutting cycle) by the description seems like a G32, but I'm not sure. In the example code below, the idea is to make a pass everytime a G32 is commanded, with a fadeout at the end of the thread. X and Z reposition at the start of the thread for each successive pass. Conversely, G71 combines this all into one line of code using a number of parameters. As near as I can tell, the M33/M34 tells the controller to fadeout the thread at the end (or not), not sure where this is invoked. Fusion 360 has a switch to fadeout or not.

This is a Haas turning post from Fusion 360, 9mm x 1.25 thread, 1 inch long converted to Imperial units. 5 passes with a spring pass. This will run on my lathe, but your lathe might choke on it. If you choose to try this be very careful, turn the feed and rapid way down.

N15 T100
N16 G99
N17 M22
N18 G97 S200 M3
N19 G54
N20 M8
N21 G0 X1.154 Z0.1969
N22 G1 Z0.246 F1.5748
N23 X0.3323
N24 G32 Z-0.9916 F0.0492
N25 X0.3491 Z-1. F0.0492
N26 G1 X1.154 F1.5748
N27 Z0.246
N28 X0.3155
N29 G32 Z-0.9832 F0.0492
N30 X0.3491 Z-1. F0.0492
N31 G1 X1.154 F1.5748
N32 Z0.246
N33 X0.2987
N34 G32 Z-0.9748 F0.0492
N35 X0.3491 Z-1. F0.0492
N36 G1 X1.154 F1.5748
N37 Z0.246
N38 X0.2819
N39 G32 Z-0.9664 F0.0492
N40 X0.3491 Z-1. F0.0492
N41 G1 X1.154 F1.5748
N42 Z0.246
N43 X0.2651
N44 G32 Z-0.958 F0.0492
N45 X0.3491 Z-1. F0.0492
N46 G1 X1.154 F1.5748
N47 Z0.246
N48 X0.2651
N49 G32 Z-0.958 F0.0492
N50 X0.3491 Z-1. F0.0492
N51 G1 X1.154 F1.5748
N52 Z0.1969

8. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

G20 to G21 ?? ? ? I know that's Fanuc but does Okuma work like that too?
SIAS?

Cheers
Roger

9. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

hi, you don't need to re-set the machine, to be able to deliver a metric or inch thread; you need a bit of infos about :
... threading cycles ( pls find attached pdf )
... metric threads profile iso sizes ( there are tables all over the internet )

do you use M33 or M34? which is better?
please look inside attached pdf, for infeed patterns; some like to use M33 M74, whatever works usually i don't bother with such patterns, unless i have a nasty thread with calls for specific attention

is everything here radial ?? and no J value I take it since it's Metric ?or J is # of threads per inch
you may run some trials, to figure out the answer : program something in igf, inspect the code, and see how the machine performs ( inspect coordinates ) : these should give you an answer

also, check definition of F & J in attached doc, at page 15

does the machine like decimals?
about threading arguments, some programmers consider that they have to be integers ... but this is not true, at least on osp300

I tried G33 but the control doesn't like it.
maybe is an option for your machine, or maybe you did not write it ok ... i don't know, but i can say that i use g33 a lot

but anyway where in IGF is M34 or M33 determined?
i don't know for your machine ... normally, there should be a cnc parameter, or a igf parameter, but i don't know it's location for your machine

and if you noticed in my picture spinning clockwise is written as M41 .. . why?
since rpm is 111, with m41, 1st gear, spindle will output more torque

but I don't see a M3 (Spindle CW) or M4 (Spindle CCW) on your picture which is a bit odd.
it may be possible that a previous operation allready used M03, and igf 'optimizations' occur

can anyone write a G71 line or tell me what to fill in the blanks in IGF?
i am not near a machine right now, and even if i would, machine is in metric, so i won't be able to guarantee my code but, if you wish, i could show you how i program a 7tpi thread : G33 X Z F+25.4/7 G95

you know, if you have futher questions, or curious about how others are doing things, there is an okuma forum, and it is pretty good : https://www.cnczone.com/forums/okuma/

kindly

10. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

ah the good ol days

what a PIECE OF S**

11. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

Originally Posted by RCaffin
G20 to G21 ?? ? ? I know that's Fanuc but does Okuma work like that too?
SIAS?

Cheers
Roger
OKUMA is like learning a different English or Australian English lol
and "programming" is extremely boring too.
tight machines though. probably the best for lathe.

12. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

"programming" is extremely boring too.
Been programming at all levels since about 1969. I quite enjoy it.

I also enjoy using computer programming techniques to replace a 100,000 line CAM program with a 100 line hand-written one.

Cheers
Roger

13. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

Originally Posted by RCaffin
"programming" is extremely boring too.
Been programming at all levels since about 1969. I quite enjoy it.

I also enjoy using computer programming techniques to replace a 100,000 line CAM program with a 100 line hand-written one.

Cheers
Roger
programming with okuma. that's what i meant.
this is not debatable i don't think
as much as i hate Haas machines but man there is that control with easy typing, deleting, altering, COPYING vs

TORTURE

14. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

but when i had my LB15 and IGF and it never really bothered me much.
the only thing i would change or add here is the "F" value. always keep it at 1.

15. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

Ah, OK.
I use Mach3 on a PC. There is NONE of that archaic big front panel with hundreds of keys stuff. That stuff is obsolete, but like dinosaurs it takes a while for the message to reach the head.
Plus I get to sit down while programming!

Cheers
Roger
Dons helmet.

16. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

Originally Posted by RCaffin
Ah, OK.
I use Mach3 on a PC. There is NONE of that archaic big front panel with hundreds of keys stuff. That stuff is obsolete, but like dinosaurs it takes a while for the message to reach the head.
Plus I get to sit down while programming!

Cheers
Roger
Dons helmet.
you probably used tapes yeah? are we talking 1970s?

17. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

..the good old days

18. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

I started with punched cards on an IBM7044 (I think!).
Then paper tape on an Argus 500 in the UK, then PPT on DG Nova, then on DEC PDP-8, then on a glass teletype (ie VDT) on a DEC PDP-9L, then ... PDP-11s, then VMS, then ...
The Flexowriter was a bit bigger than a Teletype though.
Such fun.

Cheers
Roger

19. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

hy, okuma's are pretty high, controller has ease-of-use & other , at least compared to other actual brands, or with older okuma generations

but true comparison, is not relative to other machines, but about how you feel when you work on it

there are persons that really like okuma's, so much, that don't take it easy to work on other machines, and perhaps they wish for something more

i understand when you say you are bored with programming ... sometimes i am also bored, especially for those parts that i know how to machine, but i simply hate that i have to spent time to create the program & setup & proof the machine

if you have any ideas how to speed things up, just say; i have a list of those kindly

20. ## Re: HOW DO YOU METRIC THREAD WITH OKUMA LATHE OSP

lol no, borING
not bored. but can you imagine if there weren't IGF?for somebody like me from Siemnse / Fanuc background. i persoanlly would've never been able to keep a job.
in point of fact i found this and it will be useful to whomever is trying to do metric threading with Okuma

M10 x 1.5 p
F=1
J=16
N=1
all you need is minor diameter.

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