topic Re: bolt and nut interference in Inventor Forum

bolt and nut interference

Anonymous — Thu, 29 Oct 2015 12:30:05 GMT

good day to all!

hello! I'm a beginner in using the Autodesk Inventor and somehow as of now can manage to create 3d's by instinct. As I'd been curious on how to create bolt & nut, I've seen a video how to make it, still get confuse aboutthe interference when mating the twoparts. Is there a better way to reduce or eliminate interference as I know for sure that bolt and nut is designed with certain interference allowed for each used. What I am talking about is when you inspect the two parts together in Autodesk Inventor.

pls educate me, I was an aspirant since the time I'd learned Autocad and Inventor was a new thing to me.

many thanks to all geniuses!

Re: bolt and nut interference

JDMather — Thu, 29 Oct 2015 12:40:59 GMT

Can you attach your Bolt and Nut assembly here?

Usually in Inventor (and other MCAD programs) you do not model the true helical threads, but instead use a cosmetic texture to represent the threads. Calculation of helix geometry is processor intensive, and understood by standard convention - so there us usually no need to have the actual modeled geometry. Because of this - the hole size is the tap-drilled size that would then be cut for the threads (smaller than the diameter of the bolt fastener. Therefore there will be interference as there are no modeled threads.

Sometimes a modeled thread is desired - example, for 3D printing. If it fairly trivial to model threads with the Coil command.

Turn on your sound.

The classic raw, still wet behind the ears, beginner mistake is to make a hole the same size as the fastener - not leaving any material in which to cut the thread.

Re: bolt and nut interference

Anonymous — Thu, 29 Oct 2015 12:49:03 GMT

thank you for your very quick reply.

as things getting right when learning this Autodesk Invetor, I just wonder if having a design of a bolt and nut with an interference (when inspected) would affect the design as a part in a whole assembly when simulate the stress analysis?

Re: bolt and nut interference

mcgyvr — Thu, 29 Oct 2015 12:54:55 GMT

http://blogs.rand.com/manufacturing/2009/10/analyze-interference-tips.html

starts at paragraph #4

Re: bolt and nut interference

JDMather — Thu, 29 Oct 2015 13:33:54 GMT

@Anonymous wrote:

... when simulate the stress analysis?

Including fasteners in stress analysis would usually be "overkill" (especially if the threads were modeled).

Instead of actually including the fasteners you could define the clamping forces or constraints, this way the solver does not have to mesh the fasteners.

Re: bolt and nut interference

Anonymous — Thu, 29 Oct 2015 13:40:39 GMT

in your video that you've showed to me, are you suggesting that when making a 3d bolt & nut, in that way harsh interference in two mating parts would be eliminated? it's pretty obvious what you've shown to me is very helpful...thank you very much. more power to everyone geniuses here!

Re: bolt and nut interference

Anonymous — Thu, 29 Oct 2015 14:14:06 GMT

in the video that you'd shown, i dont want to do that, but i know others were getting into that trouble of seeing interference with bool and nut assembly. what i usually did was to put a thread on the shaft and make a tap drill size on the hole ( same deatail thread of the shaft).