Fixed / Continuous Positioning

[Jake L]

I'm back updating what was originally an MPFAN post for our H.Plus-630 HMC. I've made a lot of updates up to this point and am looking for something to be explained to me. I sifted through this forum for a while but didn't find a good explanation.

My question is, in the "Fixed / Continuous Positioning" box on the machine rotary axis page, what should I have checked? Currently my settings are as shown in the screenshot. I have "force_index" set to yes in the post, but I'm not sure if that's how it should be setup.

On the machine the B-axis is a full rotary which is setup to rollover so it does not need to unwind. Would it make more sense to turn on "Axis positions to fixed angles only" in the MD and have the index increment set to .001? (this is the smallest B move the machine can make) Or should I leave the MD the way it is?

We don't do much 4-axis simultaneous work, but I'd like the MD and post to be setup for it if we need it. I also find myself using the unified toolpath more and more, so I want to make sure the MD and post can handle this as well.

I can post snippets of the post if it's needed. Please let me know if more info is needed. MC2023 working in Code Expert 2023. Thanks in advance for any information.

[cncappsjames]

In the last MP Post I modified for Matsuuras, I used shortest direction, absolute angle. That said, the control does support signed continuous. I just liked seeing numbers between 0 and 360. Purely personal preference.

Keep in mind you are limited to most likely 6 digits to the left of the decimal. That's 2,777 full rotations.

 

HTH

[Jake L]

Thanks for the response James! 

Here's what I figured out:

1. "Axis positions to fixed angles only" this one seems pretty self explanatory. If you want the axis to only ever increment by a fixed amount, this is the right option. For example, 5° 10° 15° etc.

2. "signed continuous" this one is for if you want the rotary axis to be signed (negative or positive) and the output can be greater than 360.

3. "signed direction, absolute angle (0-360 deg)" this one is for if you want the rotary to only output a number between 0 and 360. The rotary gcode will also have a sign on it. For example, B-7 or B190.

4. "shortest direction, absolute angle (0-360 deg)" this one also keeps the rotary output between 0 and 360. instead of a signed output, it will output an M code to tell the rotary which direction to turn for shortest distance.

I don't fully understand the difference between option #2 and #3. Is it just that #3 won't output a number greater than 360? Because I have option #2 selected and I have yet to see a rotary output greater than 360. Please let me know if I got any of this information incorrect, I'm eager to learn. I'm still fairly new to post editing and don't do it nearly often enough.

I appreciate any tips and tricks. I do know I'm supposed to make a post backup, and a backup of my backup, and then back that up. That seems to be the most common tip.