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Single sketch for two close tolerance mating parts
Hello,
What is the best process for sketching two parts - a hole and a shaft - that have a close tolerance fit? Do you really draw two circles basically on top of each other?
I have modeled a number of parts in a sketch that are line to line. This is great in the sketcher but it creates part fit issues upon review for manufacturing.
There must be a better way to address this.
What is the best process for sketching two parts - a hole and a shaft - that have a close tolerance fit? Do you really draw two circles basically on top of each other?
I have modeled a number of parts in a sketch that are line to line. This is great in the sketcher but it creates part fit issues upon review for manufacturing.
There must be a better way to address this.
0
Comments
So, yes, I will often do this with two circles that are slightly different diameters. In Solidworks I was inclined to draw the shaft with a solid line and the hole with dashed lines. Depending on the situation I would dimension the shaft or the hole and then the clearance between them, but in other cases I can see wanting to dimension each diameter independently.
For some types of complex clearances, I will use move face or even boolean with an offset.
However, it seems like this should be a feature that exists in the extrude or revolve function. I would just like to see a better process flow around something that is so common.
@Isoworks what are your thoughts on a better process? I would vote on an improvement request if someone submits a good idea.
- Separate sketch elements at nominal (as @S1mon suggested)
- Separate sketch elements at max (MMC) or min (LMC) material condition
- Single sketch element and line-to-line parts with clearances called out in drawing/MBD
- Single sketch element with offset surface after the fact, usually to show MMC
I personally prefer the last one. Then, in the drawing I'll use either one-sided tolerances or a range. The offset can be adjusted to use symmetric tolerances, depending on the manufacturing method and functional fit you're trying to achieve. The offset method has several notable benefits.