VCarve Desktop Spiral Ramp Pros/Cons

Hi everybody,

I’ve had some success using VCarve Desktop’s spiral ramp feature to clear out pockets where the size of the pocket is less than 2x the diameter of the endmill (ramping only works with profile cuts).

This seems to be quite gentle as there’s no vertical plunging.

Gentle and probably better for endmill life… Are there any downsides to using spiral ramps vs say lead ins?

Time is the downside. I am not a vcarve user. In fusion360, controlling the height of the helical start can minimize the time to plunge. Maybe there is an equivalent control for vcarve

The reason to use spiral/helical are what you said, easier on end mill mostly do to keeping constant, or at least smoothly changing, tool engagement and room for chip evacuation. This in turn leads to better quality cuts and longer tool life. Slotting (plunging then full width cut) are horrible for lots of reasons: chatter, heat, poor chip evacuation.

I think helical start and ramp entry are different things. The ramping I’m talking about ramps continually as it cuts. Say I’m cutting out a circle in 4 passes, the cutter starts at the top of the pass at the beginning; 180 degrees around the circle, we’re now 50% lower than we started (for this pass). By 360 degrees, we’re now at the start height for the next pass.

Does that make sense?

I’m a Vcarve Pro user since I started. I use ramps all the time. Vcarve profile toolpaths have 3 or 4 different kinds of ramps. I use the spiral ramp (starts at top surface and ramps for 1 pass depth and continues until full depth is achieved) all the time, but absolutely for a 1/16"D end mill. It might be a little slower, but who really cares? It isn’t a race, so don’t get hung up on elapsed time.

Leadin ramping (you can control the distance of the ramp) has the same effect but you can get to the pass depth quicker. I use that for larger diameter bits where I’m not concerned with bit breaking.

Pocket cutting has ramping also. You control the distance of a zig-zag ramp. It works fine, and I use it occasionally depending on the wood I’m cutting.

I think I understand the difference. While different in execution, I think the ramp provides the smooth engagement like a helical but over and extended period of time. It should have the same general benefits and slight more time (since I imagine it takes one extra lap around the pocket to reach depth than a plunge first then horizontal cut would require. )

Back to your original question, ramp v lead in, I think it’s still time v tool shock. Lead is still way better than plunge-slotting. There would be some impulse shock ti the tool as it moves laterally into the cut that a ramp eases into.

That said, lead in would be my preference over ramp and both way over plunge-slotting first pass…assuming the pocket has a side that can be entered laterally.

Thank for your replies. I think I’ve got a better picture of ramping now, but I’d welcome any other opinions if anybody is reading :wink:

There is no significant downside really, and since you paid for that feature you should use it :slight_smile:
Me, I have two uses for spiral movements:

  • (very infrequently) finishing a 2D contour when I want to ensure that no horizontal tool marks will be visible (a proper router tramming takes care of most of that, but still). However, in 99% of the cases I use a single finish pass at full depth instead, no spiral needed.
  • (very often) helical ramping entry into the material (which I understand is not what you are talking about). And more specifically, to get the tool to go “deep” and then start a horizontal/2D adaptive clearing toolpath. Kind of like your circular pocket example, but for arbitrarily large pockets: the helical entry can bore a circular pocket larger than the tool diameter, and once it reaches the predefined bottom depth, the tool will move in larger and larger circular motions to “widen” the pocket up to the predefined boundaries. However (as far as I know) adaptive clearing toolpaths are not support in Vectric products, so this is mostly valid for Fusion360.

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