lynx 200 Question

Hi all
brief intro
Live in Australia, Queensland, Goldcoast.
I'm a qualified fitter turner with cnc experience since 1988
Machine controllers used; Haas and Fanuc.
Machine types
Lathes Mill turn with c and y axis.
3,4 axis vertical machining centers
5axis horizontal machining center

I'm hoping the knowledge bank here can help.
I have recently got the use of a Daewoo Lynx 200 with 21tb controller 2 axis lathe.
nicknamed "the nugget"
so far I have changed from workshift to work coordinates aka G54,G55 etc
type 2 turning cycle for plunge profile turning in G71
drill pecking/clearance G83
but cannot get rigid tapping to work.
I have tried all the combinations of m29s*** before G84,in the same line etc
but continue to get the same result
G84 on it's own taps but for floating holder only.
Engage the m29 the tap gets to the position and just does nothing apart from the spindle having some load/Resistance until I reset the spindle rotates freely.
parameters I think are original install from factory, I have backed up the file several stages along the way

My only experience with rigid tapping has been with Haas Machines, it's either on or off kind of feature.

Q can this Nugget actually rigid tap?


Regards
Jorg

Hi Jorg,

In MDI mode, input M29S100, see if it alarms out.
its' one indication that it'll either have or does not have rigid tap.

Best regards,

Wen.

The Doosan documentation is awesome. Print this out:
Download PDF Doosan NC Programming Manual for Turning Centers Fanuc 30 Series Controls - CNC Manual

page 96 of the manual has the G84 cycle. It looks like its optional on 2 axis lathes. My old 2 axis Daewoos don't have it.
If you don't have it then you will have to use a floating tap holder.

https://i.imgur.com/qpBUhvf.png
https://i.imgur.com/ec2nmBE.png

Generally, any Doosan/Daewoo built AFTER 2011 will have rigid tapping as standard. It was optional before that.
The MDI test is valid. If it alarms, you don't have it.
All is not lost. You can tap in IPR mode (G99) and it's pretty close to rigid tapping.
Let me know.

Hi Thanks for the reply.
I'll give it a go with the mdi option.
from memory when m29s200 was programmed it just sat there with no alarm.

I have also found a trouble shooting guide with parameters that are associated with rigid tapping,
however they do not go into detail of how to set them.
It would be good to see a copy of parameters from a 21tb lathe that has rigid enabled.

Thanks avongil for the pdf , very interesting format for the g84 definitely will be testing this.

DouglasR I have ordered a floating tap holder as a backup, fingers crossed it will rot in the cupboard.


regards
Jorg

Very good. Let me know.

Quote:

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Originally Posted by Mr-Li

Hi Jorg,

In MDI mode, input M29S100, see if it alarms out.
its' one indication that it'll either have or does not have rigid tap.

Best regards,

Wen.

---

tried this and no alarm
I see hope....

Quote:

---

Originally Posted by DouglasR

Very good. Let me know.

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"G97S250 M29 P11
G99G84Z-0.625 F0.0625"
I used this format but in metric
again the machine gets to the position and sits

attached is current parameters if anyone could shed some light ?
regards
Jorg

Weird I can't see the attached file from any other pc, nor can I edit the post above...

OK, If no alarms then the machine has the option.

There are some key factors in rigid tapping on Doosan lathes -

1) You always start rigid tap from a DEAD STOPPED spindle. Always.

2) Tapping in Z axis is always done with a G84.

3) Both G84 and M29 are cancelled with a G80.

So your program syntax should look like this -

M5 (Main Spindle Stop)

T0202 (Tap)
G0 G54 G99
G97 S150 M29 (RIGID TAP ON)
X0 Z.25
G84 Z-.75 F.05
G80 Z6.
G28 U0
ETC..

Note that the rigid tap is around 150 rpm. You can tap from 100 up to 2000 but it's not recommended to go too high as the machine will never reach it's designated rpm and the spindle loads will max out into the red. I usually rigid tap from about 100 to 250 rpm. More than adequate.

Note that the machine is in IPR mode and that makes the thread lead 1/#of tpi. So for 1/4-20 threads, the "F" thread lead is 1/20 or F.05!

Note that the tool is starting at .25" in front of the part not .1. This is done deliberately as it gives the machine a chance to get the spindle up to speed/power it needs. Many rigid tap problems occur because the tap is so close to the part, the machine isn't able to accelerate properly before the tool is engaged and the load goes sky high. Giving it a .25 clearance allows the machine to tap properly.

Rigid tap can also be left handed! Insert a M76 (spindle polarity reverse) on a line by itself BEFORE the G97 S150 M29 line. M77 is Spindle polarity normal and that is inserted AFTER the G80 line also by itself.

One more thing. If your machine has only a main spindle, or was built prior to 2011, eliminate the "P11" from the M29 line.

Quote:

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Originally Posted by DouglasR

One more thing. If your machine has only a main spindle, or was built prior to 2011, eliminate the "P11" from the M29 line.

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Hey thanks DouglasR for your reply. It seems email notification isn't working for me either.
Yep she's a 1999 model doosan,
somehow rigid tapping may not be tuned in properly as I followed your eg with the exception of metrification and the program runs until the g97s100m29 command, then it does absolutely nothing like a deer in the headlights.
Pressing cycle start won't pass the line either so a reset is required.
the spindle rotates easy by hand when "stuck"
I was hoping to see someones param list of a similar machine to compare.
thanks anyway .
I'll keep hunting.
regards
Jorg

re upload param list????