Helix ramping not working correctly in 3d pocket

So somewhere in one of the Fusion updates I started running into a problem with 3d pocket clearing. It defaults to helix when ramping down into the work. I’ve never had a problem with it until about 3 or so months ago. It started getting real jerky and loosing steps (both X and Y, not sure about Z). I switched to ‘spiral’ and it would work fine.

The jerkiness would start just before the bit would touch the wood. With the latest upgrade to Fusion the spiral option is gone. I tried smooth profile but it too does it. I’ve gone through everything on the 1F twice and there’s no problems with it. Once the ramping down is finished my 1F cuts just fine.

After playing around with Fusion I figured out that if I change the helical ramp diameter from .475" to .3" and the minimum from .25" to .1" it works just fine. However I would like to know why it’s doing it.

I’ve included a video. You can’t really see much but at about the 10 second mark you can hear it. The VFD, the dust collector, and the water pump are all powered off so it’s not a noise issue with something else. I don’t have a bit in my spindle so it’s not load related.

My Journeyman is a pro with a stiffy.

https://www.youtube.com/watch?v=fUOlQQKjsjY

Hello Alex,

It would be very helpful to see what settings in Fusion you were using and also to see the NC code you used when it is making that noise.

Here’s a screen shot of the 3d pocket settings.

test.nc (11.7 KB)
It’s just a basic file. A 5" x 5" square 1" thick with a 2" hole .5" deep.

Thanks for the info.

First thing to try is turn off circular interpolation in your post. Repost then run it again. This will remove all arcs from your code.

It appears the clunk is happening at every junction between arcs.
Tomorrow I will test the arcs in the code closer but the video matches the code for arc connection issues.

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Thank you for the help. I’ll test it further later this week with a file that I’ve ran in the past that had the problem. It did fix the issue with that sample program. The next question is why is the default on and how can I change it (or is there a reason not to) so it’s off unless I select it.

Open your .cps post file.
If you are using the Onefinity Community Edition v2022.02.21.1 or some variant of it then the setting will be at the bottom of the file.
Search for:
properties.useCircularInterpolation.value = true
and change it to
properties.useCircularInterpolation.value = false

I can’t see any reason to have circular interpolation on since the controller always converts arcs to line segments anyway. This way you can control the tolerance of how the line segments fit to the arc instead of using the controller default tolerance.

I checked out the accuracy of those arcs that caused the clunking. The start, center and end points were only .0001 mismatched so I am surprised that was enough to cause the clunk.
It may be that the controller is coming to a full stop between the arcs to calculate the next one.
I will run it on my machine tonight to see if it clunks too.

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So I ran your test.nc and, yes, it clunks for me too the same way. Nasty!
I am glad that turning circular interpolation off fixed it.

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