3D Adaptive - What is the fine step-down parameter?

[Anonymous]

I've been playing around with the fine step down parameter in my 3D adaptives to try and remove some of the extraneous tool paths that generate when the tool works its way back up the model. However, I've not been noticing much success with it - mostly because I don't fully understand the parameter. I'm roughing out a part using a bull-nose and the tool path has the tool cutting ghost passes around the outside contour of the part as it moves back up in z. Can anyone explain what the fine step down actually does and how I could control these unnecessary passes? Cheers. 

[martin.dunschen]

Hi @Anonymous 

Can you share your part with us? (Export as f3d file and attach here)

We have detected a problem with the retract moves (z levels that work their way up the model and are 'fine' stepdown apart) and from your description it sounds like you're encountering this. A fix is on the way and should be available soon, hopefully with the next release. In the meantime you can try changing the optimal engagement; others reported that this can get rid of the air cutting.

Martin

[Anonymous]

Hi Martin, 

I'm using Solidworks 2018, but I've attached the part file if that's any use. 

[martin.dunschen · Accepted solution]

Hi @Anonymous 

Thanks for sharing your part. I assume that the problem you see are passes in the inner radius near the base of your design, I've circled them on this screen shot:



These are difficult to avoid in 3D Adaptive Clearing, this is because the model is triangulated and the vertical faces end up being slightly off their initial vertical-ness. We try to compensate for this is much as possible, but there is no setting that is satisfactory in all cases. I will open a ticket with this issue and see if this can be improved.

In theory you could use two toolpaths; start with a 2D Adaptive toolpath to create the prismic shape first that in effect should be the same as the stock after the 3D Adapive cleared the base. You need to create a couple of sketches to get that to work: Use the base contour and a bigger rectangular sketch to make sure the 2D AC machines the outside of the shape, and also another rectangle to represent the stock contour. Then you could use for example a 3D Adaptive from previous operation(s) and adjust the setting for the lower z. But I agree this is a very convoluted way to achieve this. I've attached my suggestion anyway.

I will let you know the ticket number I will open for this issue.

[Anonymous]

Thank you for getting back to me on that. Great to understand more about how the toolpaths work and to know that I wasn't missing some obvious setting.