Question about feed rates in conversational pocket

[Mooser]

I had to do two quick spotface/counter bores tonight on the ends of an aluminum rod and was wondering why the machine was hardly moving.

Here's the setup. circular counterbore for the head of a socket head cap screw with the part held on a 25 deg. angle, one side of the pocket is about 1/2 deep and the other maybe 1/8 or so.
5/8 hss cutter was being used for some profiling on another area so I used it
Pocket dia was 3/4 so not a lot bigger than the cutter
I was extra conservative on the feed and used a .025 step over, feed of 5, full depth of cut

When the program posted it made a series of pecks in the z down to final depth and then it rapids down to that final depth (I wish that last bit was a feed) but anyway...

Then it started it's "spiral" of very tiny straight moves but the feed rate starts at almost nothing and steps up with each move.

Here's the first few lines of the spiral (I tried it in PP1.9 in virtualbox as well, same basic result)

The initial feed rate is F0.01 and the fastest it gets to is F0.83
I know it's insignificant movements but I wasn't expecting it to give these kinds of results.

Anyone else notice this?
M

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[tmarks11]

The g-code for this was spit out by the conversational tab?

[Mooser]

Yup

[Mooser]

This is 1.9x but same in 2.0
M

[Mooser]

I'll give it a try tonight and see if that fixes it up
Thx
M

[TurboStep]

The initial feed rate is F0.01 and the fastest it gets to is F0.83

This is exactly what I would expect. The feed rate starts at a very low nominal value because F0 isn't too useful, and increases to F0.83333.

F_programmed = F_cut * (hole_diameter - tool_diameter) / hole_diameter
             = 5 * (0.75 - 0.625) / 0.75
             = 0.83333

I tried to reproduce your values and the peck "drilling" went down to -0.5" so I don't find it unreasonable to rapid down to this depth before spiraling out. Perhaps it would actually have been better not to retract after pecking at all.

So this morning I checked out the PPv2 "mill_conversational.pv" routine

Which version of PPv2 are you using? The Beta or the released version?
I don't have a Beta version running any more but my released version sets the naive cam tolerance to Q 0.0000. The H200.txt gcode file you uploaded in your previous thread had this set to Q 0.0010.

G64 P 0.0050 Q 0.0010 (Path Blending)

When I change this value to Q 0.0000 in your H200.txt file the simulation spirals down as expected.
Step