Help please. We are using iventor 2012 at my school and have recently purchased a makerbot 3D printer abd having lots of fun. Howver i recently created a model that has an M40 Thread as part of the model. However when i try to 3D print it, it doesn't recognise the thread and it isn't printed. I seethre thread on the ipt but once it is saved as an stl it seems to disappear. Any ideas?
This has been posted and answered earlier this week.
You either need to model the threads (as Inventor uses a graphic to represent them) or install this add-in to generate the threads. But even that still needs checking as 1 forum user says it may not be correct. Also this shows as compatible for 2013 and 2014, but I remember using it in 2011. Maybe search for an earlier version elsewhere.
Seems like some instructors aren't covering the basics
http://forums.autodesk.com/t5/Autodesk-Inventor/Screw-threads-exported-as-STL-files/td-p/4294591
or maybe the students aren't paying attention.
3D printing of an M40 thread with a machine having a 0.1mm resolution (highest quality) is going to be a severe challenge. Expect it not to fit at all well or, if you chose to accommodate the tolerance and roughness problem, fit together more like a baby rattle than a nut & bolt - doable, not useable.
We routinely print 3D threads on a machine with about .25mm resolution without trouble.
The trick is to print out a sample and adjust model from actual results.
From just a few trials I know how much allowance I need to get pretty smoothly fitting threads.
Just have to remember that it isn't a close tolerance machining process and make adjustments based on experience.
My students are always amazed when I tell them exactly the allowance to make and it works.
Yep, I hear ya. I've actually printed out an "inverse" acme thread - dovetail, if you prefer - and managed to get the clearance in the model just right on the first shot. There was a cearance (face to face) of 0.005" on the model and the printed parts were just barely a slide fit.
Experience is a damned fine teacher. lol