Rigid Tapping - not seeing index pulse [solved]

[cut2cut]

[edit: solved. it appears it was one of two issues (or both). A solder joint that was a bit suspect and/or I simultaneously soldered the read head side of the "drain" shield ground wire to the 0v solder tab which reduced noise. I had previously only connected the "drain" shield ground wire to the body of the DB9 connector. So I can't be sure if it was noise, a bad solder joint, or both together but now its working like a charm with the default rigid tapping settings ]

I'm looking for some help with Rigid tapping using an index pulse. I can rigid tap if I set parameter 36 to "3" ( Do not wait for index pulse ) however if I set the parameter bit to "1", only one out of many many attempts results in a normal tapping cycle. If I have Acorn set to wait for the index pulse Z will almost always stop short and do a short tapping cycle, never getting to the stock at all. The resulting motion is very consistent, except for the odd time it goes through and does the routine as it should.
(Its consistent whether I use Intercon tapping cycle or from gcode from Fusion 360 ).

Notes specific to my configuration : I have a large pulley on the spindle motor going to a small pulley on the spindle itself. The spindle has a magnetic encoder ring with index pulse , 1024 ppr line encoder with corresponding pickup ( from RSL ). In order for Acorn to be able to control the spindle motor in a linear scale across the entire speed range ( 0-7000rpm ) in my configuration I have to use mid or low gear, I cannot use high gear or the commanded speed is roughly half what it should be ( unless I set the spindle override to nearly 200% ( nearly maxed out ). I have parameter 65 and 66 set to "0.5085" for the gear ratio of the pulleys.

Enclosed is my report file ( note, the parameter settings for tapping may or may not be accurate in this report file as I have been changing every possible setting to get it to work without much success , so I'm not sure where I last left the settings )

Thanks for any help,

Jake

link to video of the issue :

https://youtu.be/PLtKUHiLkuE

[martyscncgarage]

Is the encoder before or after the reduction?
For the index pulse to work correctly, it must be at 1:1

You do realize you can program CNC12 for gear ratios correct? (for spindle RPM control, not threading)
Marty

[cut2cut]

The encoder is directly connected to the spindle, so its 1:1.

I have parameter 65 and 66 set to .5085 which is the pulley ratio, if thats what you mean, Marty ?

edit: I need to check the PID screen for the asterisk in column 1 row 5 next to the N while rotating the encoder to verify the Acorn is seeing the index signal at all. I had looked but looked at the "motor" tab, but not the PID tab in the config menus, the contents of both the motor and PID tabs look very similar, and someone in another post said to look for the asterisk to appear in the motor tab, which is incorrect !

Jake

[martyscncgarage]

Yes, it's the PID tab, line 5

[cut2cut]

Yes, it's the PID tab, line 5

Thanks Marty, it's solved. Likely just a finicky solder joint but possibly a ground issue too. I edited my first post and subject line to say its solved.
Its working well with the default rigid tapping settings now. Nice tight threads.

[url]
Cheers,

Jake

[martyscncgarage]

Yes, it's the PID tab, line 5

Thanks Marty, it's solved. Likely just a finicky solder joint but possibly a ground issue too. I edited my first post and subject line to say its solved.
Its working well with the default rigid tapping settings now. Nice tight threads.

[url]
Cheers,

Jake

Great! You know, Keith told me early on, start with all the basic settings in the Tech Bulletin, and it would work most of the time. I've set up several machines with it and tapped blocks of machine wax, and it's worked so far for me.