Problems using Follow-Me when pulling along an arc

I am trying to pull a face around a 180 degree arc using the FollowMe tool. What I am getting is not a 180 degree surface, and it has anomalies.

I have always struggled with thew followMe tool, so I may just be doing it wrong. But I select the face I want to Pull and get the line I want to follow to light up in red. But the end result is always messed up.

Your suggestions are welcome!

The model is attached.

2021-11-21 - Bowl.skp (116.2 KB)

Here is what I get after doing FollowMe:
2021-11-21 - Bowl After FollowMe.skp (204.2 KB)

Follow Me requires that the first segment of the path be perpendicular to the profile. The extrusion will end perpendicular to the last segment. If the first segment of the path is not perpendicular to the profile, the profile gets projected (not rotated) to be perpendicular to the path.

In your case the first segment and last aren’t perpendicular to where you want the profile to be.

That makes sense, but what is a practical solution? I have a semi-circle, and I wish to FollowMe along that arc. Is there a standard easy way of doing this?

Start with your profile along one of the sides. Use Follow Me all the way around. This satisfies the perpendicularity requirement.

Here’s the file.
2021-11-21 - Bowl complete.skp (196.2 KB)

Again, this is helpful. So I pushed back one of the sides so it could start straight, then I followed the path I wanted the curve to form to. That also worked, and it did create the 180 degree radius I was after.

But I am now getting a little “Gingko Leaf” at the bottom of the bowl. I have tried several times and it always forms. Why does it do this, what is it, and how do I eliminate this “Gingko Leaf”?

Here is the model with the “Gingko Leaf Flaw”:
2021-11-21 - Bowl - With Gingko Leaf Flaw.skp (199.5 KB)

Looks like your profile overlaps at the center. Between that and the relatively short segments in the semicircular parts of the path, you’ll end up with some flaws that need to be manually dealt with. Remember that Follow Me works both in an additive fashion and a subtractive one.

Your profile is simple enough I would suggest starting over making sure it doesn’t extend beyond the center. There will be a vertical face at the center in the bottom but that can be dealt with by deleting the bottom edge and softening the rest. Also model the entire half cross section, not just the bottom.

Thanks for the suggestion. I will try that. The model at this time s very simple.

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Here I’ve run Follow Me on the version I created and left the vertical face inside. You can see the result again int eh background after the minor cleanup.

Just to illustrate the projection thing I referred to earlier, I copied the arc and the square back along the green axis and then ran Follow Me. You can see the change in the width. The guideline is parallel to the red axis.

I still am getting the Gingko. You are doing something different than me in a subtle way. Hmmm.

Would like to understand, but it is probably a very subtle nuance.

I can manually fill the Gingko and move on, but always want to learn and get better. If you have thoughts of what I am doing wrong, they are welcome. Otherwise I can be a clod and stitch the Gingko closed.

bowl

After Follow Me, erase the unneeded edges at the bottom and soften the edges in the edges in the bottom of the curve. Switching to X-ray makes it easier to see what you need to deal with.

Yes, I get the cleaning up part. But why am I still getting Gingkos and you are not?

I have made certain that everything is straight, parallel, clean, and perfect. Yet, they form.

Make sure your profile is no wider than half the width of the oval. Did you redraw the profile from scratch?

You can get those strange holes if your path radius is the same or smaller than the profile radius. They will usually appears as overlapping flaps unless you are working too small for the faces to form.

So here I have the simplest of all possible models. I have the shape I want to FollowMe and I have the path to follow. O grab the shape (the arc surface) and just pull it around the path. And, I still get the Gingkos:

Here is the before & After model:
2021-11-21 - Bowl Simple Before Gingko 2.skp (82.2 KB)

2021-11-21 - Bowl Simple After Gingko 2.skp (563.1 KB)

Set it up like I showed with the path on the outside of the profile. That’s the difference between what I’m doing and what you are doing.

And I still get the Gingkos…

Here is the model. It is now set up with the path on the outside and I FollowMe pull it along the path. Gingkos result…
2021-11-21 - Bowl Simple Gingko 3.skp (84.7 KB)

Do you get them with the file I uploaded?

No, I recreated them.

I wanted to be certain that I could do it from scratch, rather than depend upon some magic that was in your model.

I deleted everything. I then created the path and the shape to pull…very carefully.

While my goal is to build this, and using your model would accomplish this, it wouldn’t allow me to learn how to avoid this from happening again in the future. This problem has happened endlessly to me, and I would like to understand how to avoid it.

I generally like Sketchup, but it is these obscurities that really cause me to think that another CAD product out there may be a better choice…one that just avoids this type of utter-obscure time-wasting nuance.

Again, I like Sketchup, but these subtleties just gobble up time and patience.