Issues exploding a group

I am trying to make a thread rod but every time I explode one of the spiral group some of the cylinder face disappears. I have tried to follow a few youtube videos but no one else seems to have the same issue. I’m at a loss. I am an extreme amateur when it comes to Sketchup, any pointers would be greatly appreciated.

M6.skp (205.2 KB)

What video are you following?

Maybe try modeling it at a larger scale. You’re running into the tiny face issue.

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That was the issue, I was trying to make it to scale instead of making it big and shrinking it. Thank you, doubt I would have figured it out without your advice.

I’m glad you got it sorted out. Do you have a plan for this screw? Is this something you’ll be printing? Does it need to be accurately modeled?

When I need to model screw threads I general work in meters as if they were millimeters. And for most 3D printing I have done there’s no need to scale the model down for exporting the .stl.

This is a 6mm shoulder screw I modeled a while back.


Those look fantastic! Yes it is something I’ll be 3D printing. I’m trying to make an adapter so I can mount a timing disc on the crankshaft of a ‘57 Triumph motorcycle I’ rebuilding. My next job is to some how “cut” a couple of slots up the sides as a relief so I can tighten a nut on the threads to snug it in place. Will also have to make a nut to fit! It’s all learning and sometimes frustrating lol
M24 v2.skp (633.7 KB)

First, I expect you’ll find the thread profile you’ve modeled isn’t quite right. At least it doesn’t match standard threads.

It won’t be printable as uploaded due to missing faces at the top and bottom as well as other issues. Solid Inspector 2 can help you identify issues.
Screenshot - 2_17_2022 , 8_32_45 PM

If you do as I suggested and model with units set to meters and if your slicer will allow you to choose the import units you should probably be able to leave the thing at the larger size when you export the .stl file and you won’t loose the faces.

One you get the screw to be solid you should be able to model cutters as solid shapes (imagine the path a slitting saw or similar would have to pass through to create the slots) then use Subtract from the Solid Tools to cut the slots.

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Okay thanks, stuff to work at. I’ll give it a try

Thanks for your help, now to work on making a nut that fits my wacky threads!
M24m v3.skp (677.3 KB)

I use a pretty lazy way of making nuts for 3d printing. You get a feel for the tolerance needed for your specific printer after a few tries.
Lazy nut


You have just blown my mind with your video! I will be studying it and trying to replicate. You make it look so easy, thank you very much, consider me impressed!

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Just remember this is the lazy way, the threads are basically not accurate, but they work well enough for 3d printing. And by the sounds of your use case as long as they work together that’s what you need. Dave’s your man for accurate threads.

And be aware that small threads and 3d printing are not a marriage made in heaven. If you need a threaded hole in a print it is best to print a blank hole and then tap it.


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