Sweep

[jacek0841]

Trying to sweep a circle along the path composed from straight line (the middle portion) with one 1/8 circle (arc) attached to each end of the straight line. Both arc are tanget to the straight line, which I guess "mathematically" means the path is "smooth", that is the first "derivatives" (I think that how it is called) of both joining elements at the joining point are equal.

The OPTIONS are set to: Twist along the path, define by degress , 0 deg

Yet I get the following message:

Sweep operation failed to complete. Smooth path is needed for sweet with twist.

What does it mean ??

 

[jacek0841]

.
I must add sw2006 sp5.0

The part I am making is a Crank Shaft. If I use as the Path the first Segment of the circle and the Straight Line, it works fine (Orientation = Follow Path, Path Alignment Type = None). The trouble starts when I try to use the other end of the arc (which bends the opposite direction, Crank).

This time I get the message:

Sweep resulted in topologically invalid body

I am trying to do those two "bends" in one Sweep - if I do use two sweeps (the other one just for the second arc) then NO problem.

Sigh ...

 

[Theophilus]

I don't think you want to twist a circle along your path--since the geometry you're going after will ultimately resemble a bent piece of round wire. Rotating the round profile along the way (twist option) won't change the geometry, since round is round.

How large is your Profile circle? To make the sweep around the "1/8 circle (arc)" on each end of your straight part, you'll need to make sure the diameter is small enough that it doesn't collide on itself when making the sweep (min radius of your path needs to be larger than the max radius of your profile).

I'm wondering if I'm understanding what you're doing correctly.

By the way, did you sketch your profile on a plane normal to the end of your guide curve (arc on one end of your path)?



Jeff Mowry

http://www.industrialdesignhaus.com

Reason trumps all. And awe trumps reason.

 

[jacek0841]

... (min radius of your path needs to be larger than the max radius of your profile)

Haaaa .... that gave me a hint. The rad of the profile (circle) was 130 mm and the rad of the path was also 130 mm. At one end it worked fine but was getting messed up at the other end (see my second post).

After reading Theophilus answer I decided to cheat a bit - I made the rad of the Path = 130.00001 mm - which in the real life does not matter but gets me around the problem because now the sweep works in one sweep.