Thread holes made by 3d printer cannot appear

I have a 3d printer. I drawed a M4 thread by drawing a cylinder and helix cutting, and saved it as stl file. And I succeeded to print.
However, when I draw the thread with the Thread function (underneath the Hole function), only cylinder was printed without any threads.
Also the hole function failed for 3d printing.
Who can tell me why?

Re: Thread holes made by 3d printer cannot appear

SeanCresswell 2nd Gear
2nd Gear
Hi there,
Threads for shafts & holes in most all mechanical CAD programs are typically only representative and are specified further by PMI or in drawing sheets....modeling physical threads is notoriously a system performance drain. Only where in your case is it necessary to bother modeling the thread for real, by way of helical cuts, as per the real world.
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Sean Cresswell
Design Manager Streetscape Ltd
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