How do I cut a sphere in shape manager?

[Jason Gooch]

Hey folks - I'm trying to cut a simple sphere to use as a ball end on a post. I'm rusty/new at the shape manager and profile cutting operations, and I'm having trouble. My assumption is that I would take a display cube into part editor, cut it into a cylinder, then run a big cove profile around the circumference on the top and bottom. Theoretically this would result in a sphere, right?

I'm at the profiling part, and I'm getting a variety of errors:
"This operation not possible"
"Internal algorithmic failure in performing this action"
"Sweep operation not possible"

I've tried running the path in different directions, compensating left right center, plunging different depths.... something tells me there's either A) a better way to do this, or B) no way to do this.

Help!?!?

Thanks - Jason

[Jason Gooch]

Ok, I hit on this "solution" - instead of a chain path, I went with a single path, which divides the circle into two sections (one 3/4 arc, one 1/4 arc). After much headbashing, I ended up with the sphere shown (the left/right compensation settings make no sense when cutting around a circle, at least to my brain. If someone can explain it, I'll buy them a donut). You can see the problem with the sphere - there's slivers of leftovers where the two paths meet. How do I avoid this?

Also, I'm bashing my head against placing this thing now - it seems to have locked onto one of the posts somehow, so that when I move the sphere it moves everything else. Or something. My sphere hurts....

I'm attaching the assembly and a jpg here, hopefully that will work.

Help please - this "simple" operation is taking me hours.

Thanks - Jason

[DanEpps]

Try these steps Jason (this is for a 4 inch ball):

1. Create a 4x4x4 Display Cube
2. In Contour Mode of the Part Editor, draw a circle at 2,2 with a 2 inch radius
3. Exit Contour Mode and Create Part
4. With the resulting cylinder, select the Profile Edge icon
5. Choose Chain and click Next
6. Select your tool (notice the geometry of the tool--open on the LEFT). This tool started with a 2 inch radius circle centered at 0,0. Leave Tool Diameter blank when you create the tool.
7. Enter a LEFT OFFSET of 1.9999 inches and a plunge of -2 inches. Notice that the material is represented as the BLUE area with this orientation of the tool. If the open side of the tool were on the right, then the material would be yellow.
8. Click OK.

1.jpg (54.53 KiB) Viewed 27913 times

2.jpg (23.72 KiB) Viewed 27913 times

[Georgi Baltov]

Hi Jason,

for the limited time I spnet playing I made a sphere with 6" diameter. I started display cube 6"x6"x6" then I took it to part editor, go to contour, draw a circle with center 3,3 with 3" radious. Go back to contour and create a part using the curcle as closed contour. At this point you should have a cylinder with 6" height. Now you need to make a couple of tools. I have included them as attachments. Basically a tool to cut the top part of the sphere and a tool to cut the bottom. Go go part editor again and then contour. Draw another circle with center x,y at 3,3 with 0,005" radious or less might also work depends how fussy you are. go abck to part editor select profile edge and select the first tool and then the second tool on the same 0.005" radious circle. At the end you should have a decent shaped sphere.

I am not sure if you understand what i mean but I am attaching all of the files so you can get a better idea. Hope I helped

[Georgi Baltov]

Well,

Dann got you before me. His method is simpler as he uses one tool only. I was getting an error message when I used that tool but I know why. Anyways both methods work just fine.

Dann is still the wizard so I would go with his.

[Jason Gooch]

Thanks Dan the Answerman - I'm trying it now. Thus far it's seized up once - I discovered a new fun feature. When entering the offset value, if you accidentally put it as a negative, you get a "please enter a positive number" window, which you can merrily click "ok" until the enter button dissolves under your finger. However you cannot return to work on the program. I couldn't even close ecabs, had to use task manager to shut it down. Irritating to say the least.

More as it develops. Thanks for your input, btw, it looks like an elegant solution.

[Jason Gooch]

Argh. Well gentlemen, thanks for your suggestions and help but I'm getting nowhere. I've recreated your directions, tools and all, and I keep getting "operation not possible" or some kinda algorithmawhatsis issue. This has now eaten my frickin Friday, as happens often when I touch this software. Don't get me wrong, I love it and am dedicated to it, but for pete's sake it's effin' tiresome to stare at a glitch all day.

Programming gods, can you please step up and tell me what's happening?

Thanks.

[DanEpps]

Make sure your left offset is very slightly less than the size of the radius...in my example, I used a 2 inch radius and a 1.9999 inch offset.

Here is the tool I used.

...Thus far it's seized up once...I couldn't even close ecabs, had to use task manager to shut it down...

It took a few minutes to complete cutting the part, so you might want to just wait it out for a while.

[Jason Gooch]

Thanks Dan - unfortunately I did reduce the offset by a teensy. Plus I tried it in metric, which is how I usually work (don't hate me), and standard. Neither one is behaving.

And the seizing up issue was not a processing-time thing - there was an actual error window with an ok button, every time I press the button it pops up another window. Over and over, like I'm caught in a time loop. Like I'm caught in a time loop. Time loop. Time loop. Loop. Loop. Loop-loop-loop-loop-loop.... You get the picture.

[DanEpps]

...there was an actual error window with an ok button, every time I press the button it pops up another window.

Was that only after entering a negative offset? Offsets have to be positive. Post the tool (or geometry) you are using and the dimensions of the ball you are trying to make and I'll have a go of it in the morning.

Over and over, like I'm caught in a time loop. Like I'm caught in a time loop. Time loop. Time loop. Loop. Loop. Loop-loop-loop-loop-loop.... You get the picture.

You've been watching Lost on ABC, eh? (my favorite show...haven't missed a single second on the 5 seasons its been running )

[Jason Gooch]

Hey Dan - here's the .tol files. I'm trying to make a sphere 70mm diameter - or 2-3/4", either one works for me. I've tried them all.....

And I actually haven't been watching Lost... it's just a way of life for me.

Thanks, and have a great weekend!

[DanEpps]

Try this tool and see how it works for you. Use Chain, set left offset to 34.9999mm and plunge to -35mm (the tool is centered at 0,0 and is 35mm radius).

I started with a 4x4x4 Display Cube and made a 70mm cylinder from it (35mm radius circle centered at 2,2).

70mm ball.jpg (9.67 KiB) Viewed 28035 times

[DanEpps]

Oops...I didn't make the Display Cube short enough and it left a stump on the end. Just make your cube 70mm x 70mm x 70mm and you should be okay.

[DanEpps]

Okay, I finally saw the original problem you were having with Chain being two different segments. This was caused by starting with a 70mm x 70mm x 70mm Display Cube and placing a 35mm radius circle at 35mm, 35mm. Apparently this leaves a small flat (that you can't see) just large enough to interrupt the circle.

I went back and made the cube 71mm x 71mm x 70mm (note: depth is 70mm, other dims are 71mm) then made my 35mm radius cylinder.

Using the tool I posted earlier with left offset at 34.9999mm and plunge at -35mm, it works great.

70mm ball.jpg (7.02 KiB) Viewed 28028 times

[Will Williamson]

So now that you have the file how are you going to cut it?