Hi Andy, so I did a closer examination of these 2 curves here:



When building sweeps for them:



If you zoom in to the top you can see they are not aligned:



The root problem seems to be inaccurate end tangents on one of the curves - instead of having an end tangent going exactly along the z axis direction it is off at a slight angle:






So my first step to clean this up will be to go through and tune up all the curve points to be aligned to axis directions where they should be.

- Michael

Hi,

One big problem with 3D software and boolean operations is on the coincident surface or edges.
So to avoid this problem you can do like Barry with small difference on radius.

My solution is similar as Barry's and I have made The 8 sweeps.
- The first one use two circles with 7.5 and 7.5 mm radius
- the 7 next use two circles 7.5 and 7.45 mm radius to "enter" without be same as biggest.
The boolean union is possible with this construction.

To avoid the problem to do the holes inside, I have moved the top and bottom points of curves 0.1 mm to have non coincident surfaces on main solid and the 8 solids made to have holes (with boolean difference).

Hi Andy, the other thing that's pretty difficult in your original one is even when the curve tangents are tuned up, the way it's set up here has a quite complex intersection between the pieces (here shown during a mesh export done to a very high density using "Divide larger than" to analyze the surface shape interactions):





It would probably help if the rail's curve tangent aligned with the z axis direction a little bit before the end of the curve instead of only right at the very end of the curve. That would probably get the surfaces to be the same shape near the top rather than the different shapes for neighboring surfaces like shown above.

- Michael

Hi Andy,

re:
> Michael - how do I tell the sweep to make sure the surfaces all end on the plane for the end circle?
> It's sweep that created those misalignments.

You've got to make the rail curve to be more accurate - currently some of your rail curves have an end tangent that is out of line with the world z axis (see above screenshot). So that introduces a kind of slant into the sweep.

- Michael

I wrote previously:

> It would probably help if the rail's curve tangent aligned with the z axis direction a little bit before the end
> of the curve instead of only right at the very end of the curve.

This didn't seem to work out very well. It's probably better to hack off a slice off the top of each piece before trimming them against each other, to avoid this complex zone here:





- Michael

Michael - that was my plan, however I went with Barry's approach and that seemed to automatically take care of the problem.

Using a difference in diameters of 0.01mm resulted in a huge improvement in boolean performance.

Andy

Hi Andy, here's the result from tuning up all the curve tangents, then remaking the sweeps, then slicing off the top and trimming surfaces against each other and then patching in the top part separately. Is this going to work for what you need? :



- Michael

Hi Andy,

re:
> Michael - that was my plan, however I went with Barry's approach and that seemed to
> automatically take care of the problem.

That's great, I'm glad you've got it solved! Thanks Barry!

- Michael

Cool result!

Filling 8 beer bottles at a time?

I wish. Lubricating and cooling eight fuel injectors on a test stand. Andy

More Badass!

Hi Andy, that's pretty awesome!

re:
> I wish. Lubricating and cooling eight fuel injectors on a test stand. Andy

It would be cool to see a pic of it in action there too!

Thanks, - Michael

Designed a second version with a barbed hose fitting. Andy

Nice tool! Good application