How to make a sweep become solid


I am trying to make a helical spiral line become solid so I can boolean it into a cylinder to create something like threads on a bolt. This “bolt” is 9" diameter and 4" long. This is really for a cable drum, so a cable can wrap around the drum like on rollup doors and stay in the grooves of a certain diameter to fit the cable. There is no rollup door drum this size. So I tried to make the grooves by creating a 4.5" radius spiral then create an circle .125 radius as a reference for Sweep. Sweep creates the appearance of what I want, but the end result is a hollow tube and it will not boolean substract from the solid cylinder. If I create a torus with the same diameter, the torus works perfectly but obviously I need a spiral. Is there any way to make the hollow sweep result become solid so it will subtract? The red in the photo is the hollow tube created from sweep wrapping the outside of a cylinder. This would be perfect to create the exact diameter of helical grooves but it will not subtract being hollow. The blue is just an example to show you that the sweep does produce a hollow result. I have V26 and V32. Both do the same result.

Because this is a cable drum and not a bolt, I need a precise radius for the cable to ride in. This will be made on a 3d printer with polycarb.


Helical Test Boolean 2

I have tried to make a similar part but was unsuccessful. I’m interested in the feedback receivved.

If you create a planar surface to cap the ends you can use the Create 3D > Stitch Surfaces To Solid option to do just that. I cannot tell from your images if the “coils” touch each other. If they do it may cause you some issues.



But the hollow tube is not a solid. You cant stich to a hollow tube created by Sweep. I tried it.

Try “Utilities”, “Extract edges, Single”. On a different layer using a darker color pick the very ends of your hollow tube. Turn off your hollow tube layer and make the tube end circles into planer surfaces. Turn your hollow tube back on and “Stich surface to Solid” or use “Solid boolean add”. If you click on the hollow tube 1st then the planer surface the planer surface will change to the tube color and should now highlight when you select the tube. Do the same for the other end and your tube should now act as a solid. You may want to save a copy of the solid tube to another layer, just in case.

OK thanks for the suggestion Jeff. I tested on V26 and got it to work, not exactly as you said but it will work. I created the spiral. Added the sweep. Extracted all edges single( solid worked just the same) and all extract edges does it add the circles at the end. Then take the 2 circles, and do Planar. Then stich the end caps(both) just made to the hollow tube. I did not change colors, or make layers. Then create the cylinder with the same exact radius as the spiral so that the sweeped spiral hollow tube now overlaps the cylinder by 50% of the tubes thickness. I then did Boolean subtract, select the cylinder first and hollow tube second. The result was wierd, not what should have happended. The cylinder went way and what was left was as if the only parts touching from the tube to the cylinder which is more like Intersect, like the tube cut down the middle Very odd. BUT I then created a new cylinder for which my " half tube" was fitting flush with, not sticking out. I then did subtract again starting with the cylinder then select the half tube and the result was perfect. Now you can create threads on the outside of some object like a cylinder. You can select the shape of the “grooves”. Very neat stuff!

Here you can see the result of subtracting the tube from the cylinder. Odd why this happened but its simple to make another cylinder and subtract it from again.