Rigid Tapping Question

[cncsnw]

The "G Code Tutor" reference applies to some controls in some configurations, but it is not universal, and in this detail it does not apply to Centroid.

When you get into the finer details of canned cycles, there is a lot of variation between control manufacturers, and even between different controls from the same manufacturer.

Centroid's cycle, using Q to specify thread lead, was modeled after prevailing Fanuc behavior in the 1990's. Whether that is still prevailing behavior on Fanuc or any other control now, perhaps others can say.

I do not have time to verify it myself, but I think there is a better than even chance that if you omit Q and instead provide an F value with inches per minute based on programmed RPM, it will work just fine. Centroid's manual could afford to be more clear on this point.

[RJS100]

Thanks for the explanation, very helpful.

Yes. I agree. The manual says you "may" use a Q value, however I could not make it work without one.

A very nice dude on the Fusion CAM forum from New Zealand (Andrew Laas) who has helped me many times with Fusion, was nice enough to modify the Post Processor so that it outputs the "Q" value that Centroid is looking for.

Here is the modified Post Processor:
https://www.dropbox.com/scl/fi/pdhko0o4 ... hu7fd&dl=0

I tested it and it made some real nice, tapped holes in wax tonight. I had one issue when I set the tapped depth to be less than the hole depth so I will need to look into this a bit further.

Here is the link to the Fusion CAM post: https://forums.autodesk.com/t5/fusion-m ... se#M158704

Thanks... Richard

[suntravel]

I have build the Q mod from Andrew Laas in Swissis PP, so you can use it with the features from swissi.

( I am good with copy and paste )

Uwe

[RJS100]

Thank you! I believe that Andrew added the code to the post I was using (Centroid_MillRev-40783-swissi-005.cps). Did you copy the code to a new version?'

Richard

[suntravel]

No, he used the default Centroid PP. Mine is an edit of swissis last one.

Uwe

[RJS100]

You the best! Thanks again. I will be testing it out today.

[RJS100]

Quick update. I tried tapping a different test part and the tapping depth was once again not working properly. I added a 2 second dwell, and suddenly it worked correctly. I don't understand why the dwell has anything to do with how deep the hole is tapped. In some cases, you could see it actually dwell for 2 seconds. In others, even though it was set for 2 seconds, it dwelled for less time, but still appeared to tap properly.

I tapped a few 1/4 x 20 holes in wax and then in aluminum. Both looked good, but when I tested them with a screw, most of the holes would not work at all, and one allowed me to thread the screw about halfway. I am using simple hand taps and don't think I am tapping deep enough. Currently it is set to go to the bottom of the hole. I drove the tap deeper by hand and it worked fine, so I will try again with the tap going deeper.

I used all of the stock rigid tapping parameters. I will try again later. If anything looks strange here. Please let me know.

Fusion Test File Used: https://www.dropbox.com/scl/fi/15jzd62x ... 9esso&dl=0

Richard

[suntravel]

Hand taps are not for machine tapping, use good quality machine taps, if it is a trough hole, one for trough holes.

Default parameters are too slow for a spindle servo.

Uwe

[RJS100]

Thanks. I will order some machining taps before proceeding. I believe you posted some other default parameters for rigid tapping.

Are these settings better suited for the servo:

Richard

[suntravel]

My settings with Servo set to 0.2 s acceleration.

Try 0.5s Spindle Accel/Decel Time first in the Wizard

You can do some air tapping to watch if it seems to work.

Uwe