Trying to close a mobius square profile solid

I’ve created a mobius coil by tweening and rotating square curves, lofting and then flowing the object along a curve. I chose stretch to make the object flow the complete length of the circle but it’s showing as a valid but open polysurface. I can’t boolean it and can’t work out how to close it. Does it need to be closed to be printed? If so, any suggestions as to how to do it?

ShowEdges can be used to check for naked edges.

Can you upload a .3dm file with the geometry?

Thank you and yes, ShowEdges shows me an edge but I don’t know how to join it.mobius template.3dm (2.9 MB) please excuse the notes, I’m still learning and find this the best way to keep track of how I’m doing things.

Attached is a file with a similar shape I created. MoebiusSquareCircle.3dm (179.9 KB)

I created a box 20 x 20 x 200 and used ExtractSrf to remove the ends. Line through the middle of the box. Twist command to twist the box 90 degrees around the center line. Created circle. Flow with Stretch=Yes to flow the twisted box around the circle. The result had naked edges at the end of the flowed, twisted box. Explode the flowed, twisted box, Select the exploded surfaces. Join command after selection. The order of selecting the surfaces and Join is important. Start Join and then then only two objects can be selected to be joined. Select first and multiple objects can be selected and then joined. I used Beta version of Rhino 7 but saved file as Rhino 6.

Opened your file in Rhino 6. ShowEdges shows naked edges in the same location my object had them. I tried exploding and joining your shape but it refused to join. Don’t know why. Possibly Rhino 6 vs 7 difference… Update - opened your file in Rhino 7 Beta and it still would not join.

Thanks David, I got as far as exploding the flowed twisted box but it won’t join after that. I tried selecting all surfaces and joining “unable to join” and then tried the command first and choosing 2 adjacent surfaces and it still says “unable to join”? Might it have something to do with curve seams?

I just tried again and it worked! I was confused by

I was only selecting two surfaces! doh! Thank you so much