Cutting Circles - Acceleration

[SMITYP116]

Looking for some feedback guys...

I'm test cutting today after switching from DSP. Same hardware. Stepper drives not servo.

All feeds and speeds are the same as used with DSP. Machine cut perfect at these speed (9100 mm/min)

This morning I've tested 100mm circle pockets which are way off perfect when measuring across the diameter. You can see it by eye.

I can cut a perfect circle by changing the following. Reduce the feed rate of 9144mm/min to 30% on the feed rate bar. 40% it starts running out again.

Or by running Exact stop mode. Very jerky.

My CV settings are default and correct for working in metric.

Later in the afternoon managed to achieve the same cut speeds as the dsp system at 9100mm/min by increasing the acceleration to 1500 from 200. Circles were perfect and parts with arcs looked as it did before

Stupid question time, how do I know or test if the machine is losing steps at this speeds?

The reason I ask is because the machine doesn't seem as refined when it was running at an acceleration of 200. By this I mean the speed it approaches the park positions and home switches etc. It seems more abroupt. Before it would deaccelarate nicely to a stop. Hard to explain really.

Any idea or tweaks I can make please guys?

Thanks
Paul

[cncdrive]

Which UCCNC version are you running?

[cncdrive]

To test if the machine is loosing steps is pretty simple.
Drill a hole outside the cutting area and note that XY position or zero XY at that point, then do the cutting.
Move the tool back to that position and see if the tool fits in the hole perfectly.
If not then your machine lost steps or it has a backlash.

[SMITYP116]

Thanks for the quick response. It's v2.2113.

[cncdrive]

Please try 1.2115 to see if it makes any difference.

[SMITYP116]

Thanks I will do. Where do I get that version sorry, I could only see 1.2113 on the cnc drive website.

Also what's the best way to upgrade this and keep system settings as before.

Sorry for the basic questions.

Paul

[SMITYP116]

I managed to swap the sw. Difficult to say but I think I has improved slightly. I've dropped acceleration back to 800 and seem to be able to run at 9100 mm/min for the majority of cuts. Circles still need to be reduced to 80% of that speed to get perfect diameter circles. I can reduce those operations in cam so can live with that. Appreciate the help thanks.

[SMITYP116]

Just on a side note, I've now noticed my UCR 201 is stopping the probe buttom working on my M31 macro. I get a "probe active" message and can't prove.

Having read as much as I can my understanding was this meant to be fixed in the latest version?

[cncdrive]

It was fixed in 1.2115

[SMITYP116]

Apologies....I.didn't realise their are 2 versions of 2115.