Help with axles in inventor

#1

I’ve been learning to use inventor for vex stuff, but something that I keep running into trouble with is using axles, especially through holes that aren’t the same size/shape as the axle.

The way I’ve been doing it for a c-channel hole is that I just do mate constraints to the straight edges with offsets that works well enough, but doesn’t let the axle rotate.

My main issue is with the round holes found on things like nylon spacers, collars, etc. The way I’ve been doing it, which I’m sure is super incorrect based on how badly it works, is 2 tangent constraints between the rounded corner edges of the axle and the inside face of the circle,

If there’s a better way of doing it (I’m sure there is), please help me out.

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#2

Just like in building a real robot, you should use bearings. You can mate a bearing in 4 mate constraints. After that, use an insert constraint on the axle and insert it into the bearing. This should allow it to turn. As a reminder when constraining the piece, there should be a dotted line going through the axle you want the constrain which will make sure the axle can rotate. Then you constrain locking collars and spacers using the same method : just put an insert constraint on them and offset them as desired.

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#3

Well, what I don’t like about the insert constraint is that, once again, unless I’m doing something wrong, the insert constraint locks the part to the end of the axle, there’s no way to insert it in the middle unless you offset which is a pain to do for each thing.

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#4

You have yet to be enlightened by circular holes… let me help you…
Inventor Library

Enjoy!

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#5

If you are using Inventor, you could try offsetting when you make the mate constraints. Try offsetting it by half the length/width of the hole minus half of the thickness of the shaft.

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#6

That’s what I’m doing, but it doesn’t allow for rotation

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#7

Really? Can you show a picture?

Edit: Did not understand, disregard anything I previously said. I would make a point in the center of one of the ends of the shafts and mess mate settings. I did something like that before I think and it worked.

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#8

I just gave you a library that has little circular holes in all the square holes… should solve all your problems and make your life better.

On another note I never use axles, screws, or nuts when I cad.

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#9

It seems like that might actually be the same one i already had with the v5 stuff in it, and it has the circles on some of the things, but not others, i.e. the bigger c-channels.

Even so, how do I attach the axles to the circles?

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#10

You need to edit some of the parts without circles, and make all the hidden linear sketch patterns visible. It has most circles hidden on lots of parts.
For the axle attaching, I actually don’t know. You could draw a line down the center and mate that concentric with a circular hole.

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#11

Thanks for the tip on un-hiding the circles.

If anyone sees this in the future and needs to know, the way i found is that you can add a cylindrical joint with surface 1 being the midpoint of one of the axle’s end’s and surface 2 being the circular hole.

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#12

(obligatory slightly off-topic) Inventor (for me) is cool and all, but I hate trying to merge things. It would be cool to have one of those tony-stark-holotable-thingies. That would be great.

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