Flow, Problem and Question.

[HughesTooling]

I've used a similar feature in other CAM software for the problem in the picture below where a fillet or chamfer starts from a flat face.

The problem with Flow in Fusion is it doesn't start matching the corner fillet at the point it finishes the first straight fillet. I tried clicking the red arrows to see if it would revers the direction but it seems to want to machine in an anticlockwise direction.

Another problem is with one way, there's no lead out rad. I know this can't be added tangentially but it would still be nice to have even though it would be at 90° to the toolpath. A linear extension would be useful as well.

And the last question, why no stepover distance, number of stepover doesn't work well for something like this. Files attached.

Thanks Mark

[Steinwerks]

The fun part is that's in the toolpath, but not active yet (and not active in Beta mode like it is in HSMWorks):

Edit: Oh and there is a Tangential Extension Distance pn the Passes tab that should still stop at the model floor surface (obviously this doesn't affect a lead radius and doesn't act on the trimmed end of the passes):

[HughesTooling]

Yes I'd spotted the tangential extension but really need something at the other end, maybe something like the lathe option of turn leads until they fit.

Another option would be the option for across for Morph rather than along the guide curves. Image below shows a morph toolpath for one of the straight fillets but there's no way to go around the corners.

Mark

[Steinwerks]

It's also fun seeing how close you can get just messing with multiple toolpaths!

And then there's the beta version of Blend which just knocks it out of the park (or at least reeeaaal close!)

File attached for the curious.

Edit: actually it does do a few funny things here but at least it seems consistent. I'm going to keep experimenting.

@fonsecr perhaps you'd be curious about this one?

[Steinwerks]

If you plop three of them side by side it actually does a very nice job of keeping things consistent (but of course not as nice as one path):

@fonsecr Perhaps this is a good example of why multiple drive chains would be useful in a single toolpath. Retracting can be both unnecessary and detrimental to final outcome where keeping the tool in contact with the part can be highly optimal.

[MJK_Performance]

You can solve the lead out issue buy staying off the bottom face by the tolerance amount (or any other amount really)

[Steinwerks]

I'm not getting that result, even when I change the pass direction to Both Ways. Also looks like you made a new toolpath, can you share that file?

[BjoernJohnsson]

If its blend acting funny, I'm interested at least. With acting funny, are you referring to the sharper turns at the top of the cutting passes? And the small spikes around the sharp turns?

[fonsecr]

Yes definitely @Steinwerks, want to get to the multiple drive contours feature - just want the basics done first so we can get it out to everybody first.

[Steinwerks]

@BjoernJohnsson thanks for chiming in! I figured if I got René's attention he would direct the appropriate dev here (sorry I forgot this was your project).

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@BjoernJohnsson wrote:

If its blend acting funny, I'm interested at least. With acting funny, are you referring to the sharper turns at the top of the cutting passes? And the small spikes around the sharp turns?

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Actually I was referring to the interesting trend it has to (for lack of a better term) warp along the surface since the guide curves are at a right angle to each other:

I think this will eventually be solved by intermediate guide curves but for now, although the surface would likely not suffer for it with an appropriate stepover, it's a little odd. Breaking up the toolpath into three also works but is suboptimal of course. Ideally the toolpath would follow the surface more like Parallel would until the radius surface and then follow the straight section again.

Edit: I had to look close to see those spikes! Tightening the tolerance also seems to make them worse which is behavior I would have not expected.

[HughesTooling]

I think Moph gives a better toolpath but it needs and option for between\across rather than just along the guide curves. @fonsecr are there any plans for this or should I put it on the idea station?

Blend doesn't work well with an end mill because you get a flat section at the top the same as the radius of the cutter.

You can see here against a Moph toolpath.

Morph following the guides gives good control as you can offset the guides to give an overlap on the flat surfaces, it just needs the option for the paths to be between the guides.

This is almost there selecting guides that are at right angles but it doesn't go around the corner.

File's attached with these toolpaths.

Mark

[Steinwerks]

Perhaps the addition of a Contact Only option for Blend would be in order? Certainly an Avoid Surface option would mitigate this issue.

Edit: see Radial with avoid surfaces (all but the floor, inner limit to 5mm and 270°-360° angles) and zero clearance:

[fonsecr]

Contact only option should really not be required since we internal use contact curves for Blend - so toolpath should always go exactly to the edge of the surfaces to machine everything.

[HughesTooling]

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@Steinwerks wrote:

Perhaps the addition of a Contact Only option for Blend would be in order? Certainly an Avoid Surface option would mitigate this issue.

Edit: see Radial with avoid surfaces (all but the floor, inner limit to 5mm and 270°-360° angles) and zero clearance:

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Thanks for the workaround but I've still not got any answers about options for across the guide curves instead of just along, would be useful with Flow and Morph. The workarounds are more work and not going to help if the edge is from a spline or something like an intersection that's no a line or arc.

Thanks Mark

[Steinwerks]

Oh I didn't even mean for this to be a workaround, just for examples of better ways to improve Blend and/or Flow - possibly Morph as well. There have to be limits adjustable by the programmer otherwise they will become niche toolpaths and not workable for all preferable situations.

Think of it as attempting to add to the conversation with more contextual input. I agree with the point of the thread entirely!

Edit:

@fonsecr @BjoernJohnsson

But it seems that there must be some sort of limitation to the toolpath extents if the toolpath places the centerline of the tool at the tangent edge of the radius and top face when this is undesirable. Contact Point Boundary would be more applicable, not Contact Only (got them mixed up a bit).

[HughesTooling]

@Steinwerks No problem, thread just seems to be going a bit off course!

Here's an example from SprutCAM using Flow. It has an option for guide curves and sync lines.

And here one way with leadout on bottom face.

Mark

[HughesTooling]

As I've got no answer about across as an option I thought I'd put it on the Ideastation here.

Thanks Mark