How to I animate two joints simultaneously?

[mgianzero]

As you can see in my model.  I have two motion joints and one rigid joint.  I'd like to animate my model with the first two joints - i.e. slide my two objects (pullbow and support) in the track while revolving the pullbow (raising the arm) in relation to the support.  

I think this has something to do with motion links but when I do this, it doesn't animate correctly.  

How do I do this?

I've attached my file to demonstrate my exact problem.

Thanks for helping!

[davebYYPCU · Accepted solution]

Nothing is grounded.  (Track is Grounded now)

Revolve has a limit of 10 degrees, and the slider has no limit.

What is the Pin for?

Motion Link will coordinate at a Fixed ratio of 10 degrees to ?? length, 

and you didn't say how far to slide.  (I used 10 mm - reasonable values work)

So open the Slide joint - select Drive Joint, and slide the Blue move handle.....

Edit the Motion Link, to change the settings for the Slide Joint.

Might help....

[mgianzero]

Dave,

Thank you so much for responding.

I have a few problems and questions here.  

1)  I can't seem to successfully import your F360 file.  It seems that when I try to open it from my drive after downloading it, F360 uploads copies of files that I already have in the F360 cloud and then it doesn't open your file.  So I can't see what changes you made to the model.  I tried emptying the cache and even re-installing F360 with no luck.  This is what I see   ...

2) Also, I was successful in linking both motions together using a motion link like you described.  However, the motion is a bit backwards.  The pullbow needs to start at a 0 degree (flat) with zero rotation compared to the support, but as it moves backward (- x direction), it needs to rotate pullbow up to about 10 degrees.  Instead, the motion is opposite, where the pullbow rotates up to 10 degrees as it moves forward (+ x direction) in the track.  How do I switch the motion relationship?

3) The pin serves to actually lift the pullbow so that it rotates upwards in a second slotted guide as pullbow slides backward in the pullbow support.  Unfortunately I haven't gotten around to do that yet.  The slotted guide is also non-linear and lifts the bow at roughly 1/2 the way down the slide track about 10mm and then stays there for remainder of the run.

[davebYYPCU]

Did nothing strange with the file, 

This is the motion link I did, to change slide direction, add a minus sign to the value - 10.

Cam slot Joints are not available in Fusion (- promised but don't hold your breath.)

Might help.....

[jeff_strater]

@davebYYPCU - we are making progress on a cam follower solution.  We are not quite to the "hold your breath for it" stage yet, but we are getting dang close.  I can't say any more...

[davebYYPCU]

Yep, I had known about that, was meant to be encouraging, (- Aussie slang gets me in strife at times)

[mgianzero]

Sorry it's taking me so long to reply again to your latest comments (davebYYPCU) but, although I've gotten my model to animate roughly the way I want it (see my latest F360 file attached), I'm still having some problems.

First off, I wanted to hide the joint labels in my model while animating (don't want a flag for revolute, a pic for rigid joint or pic for slider joint) to be displayed.  But when I turn them off and then try to animate them by dragging the pullbow, all the moving parts disappear.  What's going on?

Also, what's the best way to auto animate a model?  I've been right-clicking on my joints->Rev18 joint and selecting "animate model".  That seems a bit awkward.  Is this the best or only way to auto animate a model?

Hope I'm explaining myself clearly here.

[davebYYPCU]

Just checked the file, turn off all the Joint eyeballs, the joint icons will be gone.

Left click drag the sliding Pullbow Support - no icons are visible.

There is an Animation Workarea, but I have not used that in a while....  It will loop with out and back if that helps.

Might help...

[mgianzero]

Dave,

With all due respect, I think you did that too quickly and do not see my problem.  Perhaps there's some sort of bug in the F360 "animate model" option that causes this but when I unselect all the joint eyeballs, I know I can manually drag the pullbow and it appears to work fine.  But when I select "animate model" under my revolute joint (right-click) to put my model in a loop mode, the entire pullbow assembly disappears.  Could this be a bug in F360?

Marc G.

[davebYYPCU]

Correct - I did not see your problem, 

If it doesn’t happen my end, what can I tell you.

Animate model displays the joint icon despite the eyeball setting - dark blue while running.

Might help....

[mgianzero]

I know I just accepted your answer as a solution, but this brings up another question.

Is there a way to have variable or multiple motion links for the same two parts at two different points in space? In other words, can I have my pull bow rotate up to 10 degrees from horizontal for first 100 mm, but continue to slide along X axis but at this fixed angle for remainder of distance?

[davebYYPCU]

I think you can do that in the Animation workspace, but not in the Modelling workspace, an area I don't know well.

Might help....

[jeff_strater · Accepted solution]

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@mgianzero wrote:
I know I just accepted your answer as a solution, but this brings up another question.

Is there a way to have variable or multiple motion links for the same two parts at two different points in space? In other words, can I have my pull bow rotate up to 10 degrees from horizontal for first 100 mm, but continue to slide along X axis but at this fixed angle for remainder of distance?

---

the only way to do this is with a Motion Study.  This command lets you precisely drive multiple joints at different rates, and with variable values over time:  Motion Study 

[mgianzero]

Yes!  Exactly.  I just started looking into Motion Study and figured this out not knowing this was the best way of doing it.  But it was pretty easy to do.  

I think the "Animation" workspace is just for trialing simple movements, but a motion study is more precise and controlling.

[mgianzero]

Although the joint I am really looking for is a "cam follower" as you called it, I did somewhat succeed in making mostly what I am looking for using contact sets.  Please examine my new model and see if this is what you are describing.  I can even animate this pullbow assembly by manually dragging the components or using the "Slider-Animate Model" option.

I'm also confused by the labeling of this joint as I would call it a "pin-in-slot" type joint but F360 already has this joint and that's not exactly what I'm doing here.