Underground Scoop - animate movement

[SeanFarr]

I am have a model of a scoop that I would like to animate to show motion and check for interference and clearance.

I was told by a friend the best way to create and assembly is to create it as it would be built.

Doing this, I created the cylinders and added to them to the main assembly as an assembly, but I am having trouble controlling movement. I checked off flexible for each cylinder but using the mouse to try and position the scoop bucket and front frame is undesirable. I know I could apply mate constraints to check for clearances and movements, But seeing the scoop move in a regulated motion would be need. Could possibly be used for marketing purposes as well.

Is using dynamic simulation or studio better? I have heard good things about the Wasim Younis Series - book

Does his books get into how a model should be assembled/created before trying simulations?

The boom moves off yellow cylinder and the bucket moves off the red cylinder

A 4 way joystick controls this movement (hydraulically), is it possible to simulate a joystick to control this animation?

The blue cylinder is controlled by a 2 way valve, that steers the front frame.

I know uploading a model is the best way to get fast accurate solutions, however this model is currently over 200 parts, so I figured a .DWF export was the easiest way to give you a visual representation.

Thanks!

[JDMather]

Dynamic Simulation would allow you to add things like gravity, friction.... analyze actuator sizing, lifting capacity...

but from your description I think you are only after the kinematics.  You can do this without DS.

The correct constraints with Limits should give you the motion.

Drive Constraint can give you the contact locations.  (analyze for part Interference before this)

You could then animate this in Inventor Studio.

There is no need for the entire assembly.

Only the parts involved in the motion (and perhaps an anchor part) would be needed.

The control with a joystick would be more difficult to represent and would require some tricks.  (I would use DS for this.)

[SeanFarr]

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@Anonymous wrote:

The correct constraints with Limits should give you the motion.

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if I apply constraints with limits, how do I control these to create motion (drag with mouse?)

Do i create these limit constraints in each cylinder assembly then turn on flexible once they are placed in the main assembly? I tried creating a mate constraint in the main assembly, but I can't because Inventor will not let me constrain to 2 opposite faces of the cylinder assembly. I would have to assemble the cylinder in the main assembly to allow me to mate the faces to control the cylinder motion. 

Thanks!

[GSE_Dan_A]

Sean,
We have done something similar to what you are after by using Driven Constraints (as JD had mentioned).  It can get a little messy depending on how many contraints and driven constraints exist in the model.  Essentially by placing a constraint and giving the said contraint a limit (ie. if mating 2 faces, you can give the faces a minimum offset and maximum offset) and then rght clicking the constraint and click 'Drive' It will annimate the constraint based on the limits specified.  You should see a +/- next to a contraint that has limits.  You can also set a limit as the "Resting Position".

[SeanFarr]

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@GSE_Dan_A wrote:

Sean,
We have done something similar to what you are after by using Driven Constraints (as JD had mentioned).  It can get a little messy depending on how many constraints and driven constraints exist in the model.  Essentially by placing a constraint and...

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This is one of the main issues I am having,

the cylinder is its own assembly, that I placed into the main assembly. The internal part of the cylinder is inaccurately modeled. I modeled it this way so I could easily manipulate it for motion. Basically I would mate face A to Face B and drive it.

But once I place this cylinder assembly into the main assembly, I can not drive that constraint, even when I turn flexible on.  And even when trying to constrain face A and Face B of the cylinder inside the main assembly, Inventor will only allow me to select either Face A or Face B, not both to each other. I would have to mate it to another face or work place inside the main assembly, but this won't work because there is so much movement in the main assembly, nothing is linear to mate to.

The only solution that I can see to drive constraints for each cylinder, is it delete each cylinder assembly, and re-create it in the main assembly.(so that each cylinder is NOT a sub-assembly, but just made up of parts inside the main assembly)

Does this make any sense? haha, I don't really understand why Inventor won't let me drive constraints of a sub-assembly inside another assembly. Unless there is something I am missing, which is why I created this thread. Am I creating bad models, or is there options that I don't see or haven't applied?

Thanks!

[JDMather]

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@SeanFarr wrote:

The only solution that I can see to drive constraints for each cylinder, is it delete each cylinder assembly, and re-create it in the main assembly.(so that each cylinder is NOT a sub-assembly, but just made up of parts inside the main assembly)

Thanks!

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I have a model of a pick-and-place robot using 6 actuators (syringes) that my students use for learning this stuff.
We create limit constraints first and later go into DS environment.

We proceed through several different solutions (with/without subs...) and end up in DS.  I can't recall exactly what we do with Drive Constraint and don't have time to check right now (I will try to check later), but one thing - you don't have to delete sub-assemblies.  Right click on the sub and go to Component>Promote.  (I would do a Save>Copy As on the main assembly first and work from the copy.

Edit:

I was wrong, there are 4 actuators in the assembly and we go through quite a fiew steps to demonstrate what will and what will not work.  I don't know if I have those steps documented. I will have to examine my notes.

[GSE_Dan_A]

I completely understand your issue.  Essentially you need to place the parts or sub-assemblies of the cylinder into your main assembly such that the parts or sub-assemblies get constrained in such a way that they are able to move relative to eachother.  I will take a quick look at what we did, but from my memory, that is what we had to do. In your example, the cylinder with Face A could be one part and the canister with Face B could be another part. Faces are mated with an offset and a Min Max limit is applied. 

[SeanFarr]

Thanks guys,

You both have confirmed that I can't drive a constraint that was created in a sub-assembly, I can only use one 1 selection either Face A or Face B and the 2nd selection of the mate constraint must be outside of the cylinder sub-assembly, either a workplane, axis or face of another part.

JD in your picture, what 2 selections did you use to make that mate constraint, looks an axis and a point?

Thanks!

[JDMather]

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@SeanFarr wrote:
 

JD in your picture, what 2 selections did you use to make that mate constraint, looks an axis and a point?

Thanks!

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I just took a quick screen capture, after looking a bit more - this might have been our trials that don't give intended results.

At this point I just wanted to give encouragement that what you want to do can in fact be done some way or another.

I've got to get back to work - I'll try to come back to this later, but my moto is - try everything.

[SeanFarr]

yea, going back to the cylinder picture i had above, if I mate Face A of all my cylinders to the axis' of the eyelets of the scoop where they mount (with a pin) and use the min and max, with an offset. I can grab the bucket with the mouse or drive the constraints one by one and manipulate the scoop.

I tested it on one cylinder and it worked. I wasn't aware there was a little >> in the bottom of the constraint menu where these little options were hidden.

One more question, what should I use to create an animation to show the the functions of a scoop in a short continuous video. Studio is probably the solution??

Thanks JD and DAN!

[dan_inv09]

I would just constrain the pins in the assembly, or you might be able to create a work plane in the assembly constrained to one of the faces and constrain that to the other (you'd have to try it, it's just a thought).

As far as the joystick: If you have a sketch in the assembly that projects the axis of the stick to dimension the angle as you push it around with the mouse and use that parameter in a formula for the constraint ... again just ideas, you'll have to play with it (and maybe tell me I was wrong).

[JDMather]

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@SeanFarr wrote:
 

One more question, what should I use to create an animation to show the the functions of a scoop in a short continuous video. Studio is probably the solution??

Thanks JD and DAN!

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Animate Constraint or Animate Parameter  in Inventor Studio.
You can animate mutliple constraints/parameters simultaneously.