elementary problem

[henrycasson]

I want to join these two objects , so that the three holes on the ring rim correspond to the ones on the gear. In another system this could be done with a couple of mates. If I use a rigid or revolve joint, the components are concentric, but the holes are not aligned

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[TheCADWhisperer]

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

[henrycasson]

Here are the two files, in the format that it allows me to save

[etfrench · Accepted solution]

For some reason the SCWindBack model wasn't created with one of the mounting holes aligned vertically with the origin.  If it had been aligned, then a simple Align or Joint command would put it in the proper position.

One workaround is to align the two components using their centers.  Next create a sketch and project one set of mounting holes. Draw lines from the center to each of the projected mounting holes. Measure the angle. Close the sketch and rotate the SCWindBack model.

Note: See Rule #1 and make each of the parts components.

[g-andresen]

Hi Henry,

this is my way to solve that.

günther

[TheCADWhisperer]

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@henrycasson wrote:

....In another system this could be done with a couple of mates. ....

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I use several CAD programs.

I would not model the parts like this in any other CAD system.

I recommend fully defining your geometry (just like out on the shop floor) and pattern features rather than sketch entities when possible and practical.

[henrycasson]

Thanks for taking the time to help me.

The easiest thing was to go back and edit the original sketch.I would have preferred Guenther Andersen's solution, which is the way I would like Fusion to work. However, when I do exactly what I see, on placing the second join, the first one no longer applies, so the components remain unaligned. If anyone can work out what I am missing it would be helpful as I have other less tractable components to line up.

[henrycasson]

I did finally do what I intended in  a test assembly. The underlying problem was that the radius on which the holes lie in the two parts was different ( at the 4th decimal place).  Possibly an unnoticed drag, since they started out identical. I also turned off joint animation, and the parts did not move into place until I hit J again after I had already specified the two joints. Now I know that it can be done, I can probably make it so that I do not need to.

I think that fusion is utterly superior for sketching, and I will work more to be comfortable with 3 D mates. Most of what I do is DXFs for a laser cutter. The 3d model just for showoff, and to catch component collisions.

[g-andresen]

Hi,

here is the file.

günther

[henrycasson]

Thanks. It looks like my original problem was because I used bottom up design, and the radius on which the holes were was minutely different in the two pieces. I have learned enough, I think wer can lay the topic to rest.