topic Re: Motion Link problem in Fusion Support Forum

Motion Link problem

hans2taverne — Sun, 13 May 2018 08:33:38 GMT

Hello,

I encounter problems with motion Links.

I have a gear train with 6 gears with bearings, axles a.s.o.

All works fine when I make the links and save the design.

But when I open the design again only three of the gears keeps working fine and the motion links to the other 3 don't work any more.

Tried al kind of things to overcome this problem but can't get it working.

I shared the design as a public link:

https://a360.co/2K8WVcf with password: MLP001

Re: Motion Link problem

TrippyLighting — Sun, 13 May 2018 12:20:24 GMT

I downloaded your design and the motion links work fine.

Re: Motion Link problem

Anonymous — Sun, 13 May 2018 14:36:34 GMT

@hans2taverne

@TrippyLighting

strange behaviour here - sometimes it works, sometimes it does not work.

Re: Motion Link problem

hans2taverne — Mon, 14 May 2018 13:15:34 GMT

Thank you for your reply,
The problem is that one day it works fine the other day only the motion
links 86 & 90 between the 3 biggest gears (rev. 83, 85 & 89) keeps working
and the rev. joints 82, 87 & 92 from the other gears revolute but the
motion links 84, 88 & 93 between rev. joints 82-83, 85-87 & 89-92 are not
working any more.

regards,

Hans Taverne

Re: Motion Link problem

Anonymous — Mon, 14 May 2018 14:32:43 GMT

@hans2taverne

May I make some suggestions regarding your model?

Fusion 360 does not force you to use linked components. Use them only when you really have to.
use joints (in most cases "rigid") to position components. Avoid "move" -> "capture position" to position components.

regards,

Re: Motion Link problem

hans2taverne — Mon, 14 May 2018 16:22:34 GMT

Thank you for your reply,

As I want to be able to spin the gears I need to use revolute joints and
motion links.
When I insert components in my model I have to align them and use capture
position as far as I know or is there a command to insert AND align a
component at the same time?

regards
Hans Taverne

Re: Motion Link problem

TrippyLighting — Mon, 14 May 2018 16:50:16 GMT

After insertion, use the manipulator to pre-position your inserted component in a convenient location. With convenient I mean so that these elements on your geometry that you want to join are easily accessible and are not obstructed any other geometry.

Then simply use an appropriate assembly joint. NO need for the move tool, or the position capture feature. Sometimes it might be necessary because otherwise you cannot select the geometry you want to join. In those cases aftercreating the joint you can delete the position capture feature.

I have to look at this in a little more depth but the structure of some your linked components is also suboptimal and likely what results in these somewhat intemittent problems.

Re: Motion Link problem

Anonymous — Mon, 14 May 2018 16:55:43 GMT

ooops - @TrippyLighting was faster....parallel answer......whatever..

@hans2taverne

"Move" or "Align" - it does not matter in this case. Joints should be your choice if you want to get a "clean" parametric model.

The Autodesk Help/Learning page gives a good introduction.

Fusion 360 Learning/Help Page

Here is a screenshot:

Example: there are parametric 3D-CAD systems where you have to add three planar/plane-mates to fix a component (remove all degrees-of-freedom). In Fusion 360 you do this with applying just one rigid-joint.

Re: Motion Link problem

hans2taverne — Mon, 14 May 2018 17:13:34 GMT

Thanks, I'll try that
Regards Hans

Re: Motion Link problem

hans2taverne — Thu, 31 May 2018 16:14:17 GMT

Manfred, thanks for your help.

I inserted the necessairy gear components and put them in place using the move/copy point to point command in one action and in that way I didn't have to use the capture position command any more.

However to align the gears teeth between the gears I didn't find a way to avoid the capture position command.

The included version worked fine after saving, but after closing Fusion and reopening my design again all the revolution links are ok but the motion links are broken or so.

https://a360.co/2H9aZAC

password: MLP002