Assembly constrain, gripper.

[Callesson]

Hello!

I want to constrain a assembly to work as a gripper. But I can't figure out how.

And I found this Topic that has a solution for it:

http://forums.autodesk.com/t5/Inventor-General/Constraining-a-2-jaw-gripper/m-p/4597337#M487889

But i'm using Inventor 2012 and cannot look at the files. Can someone explain to me how its made?

(mine is attached, img)

/p

[JavaLodge]

There are probably dozens of ways to constrain something like this, depending on how it is constructed. If you want better help you should include more details, or even include your assembly and all associated part files here. Have you attempted any constraints yet? Is there a specific one that's giving you trouble?

[Callesson]

Hey!

I was thinking all info was in the topic i linked. And if there was someone that could open that assembly and see how they did it and explain for me.

But anyway all I want is a very simple function:

The 2 gold parts should not go further out than where the blue main part ends and not more than into the center where they should collide. And that I worked out with the Maximun and Minimun constrain. And works fine i guess.

But what I also would like is to have the 2 gold parts move in sync. If I move one away from the center, the other one should also move away from the center. And if I move 1 back again the other 1 should move in to the center again.

The assembly is just simple. 1 main part with rails for the 2 parts that should be moving like a gripper.

I hope this help you help me! 🙂

[JDMather]

Attach your assembly here.

What book are you using to learn Inventor?

There are 3 or 4 ways to do this depending on your design intent.

[JDMather]

There is an easy trick to this - if your assembly matches the conditions of the original thread you referenced.

[Callesson]

Alright sweet!

im gonna send u the files. But it said I cant upload .rar file?

[JDMather]

I am not interested in rar files (would require me to download software I don't want on my machine).

Use Windows Explorer to zip the folder (right click on the folder in Windows Explorer).

or

attach the individual Inventor files here without compressing.

[johnsonshiue]

I think you can use Joint -> Slider with Limits turned on. Please try it out and see if it works for you.

Thank!

[Callesson]

"

I am not interested in rar files (would require me to download software I don't want on my machine).

Use Windows Explorer to zip the folder (right click on the folder in Windows Explorer).

or

attach the individual Inventor files here without compressing."

Cool (didnt know that you could do that at all.. wierd!) 

I'm sending them right now 🙂

[Callesson]

"I think you can use Joint -> Slider with Limits turned on. Please try it out and see if it works for you.

Thank!"

Can I use joint in Inventor 2012?

Thank you!

[Callesson]

So I just found this thread:

http://forums.autodesk.com/t5/Inventor-General/Inventor-2012-Constraints-Advice/td-p/3843013

And I tried it and it worked. But I also want to be able to move it back and forth, by simply dragging 🙂

Maybe that doesnt work with the solution above doh.

[JDMather]

---

@Callesson wrote:

 But I also want to be able to move it back and forth, by simply dragging 🙂

---

Step 1.  Delete one of the grippers from your assembly.  Right click on the remaining gripper and turn off Adaptivity.  Right click on the assembly XY plane and turn on Visibility.  Right click on assembly Y axis and turn on Visibility.  (I stretched out the Y -axis to make it easy to see in attached screen capture, but technically, it doesn;t even need to be made visible.)

Post back when you are ready for Step2.

[Callesson]

Alright! Done with step 1, thanks 🙂

[JDMather · Accepted solution]

Now add a Mate Constriant with offset distance  between the assembly XY Plane and the clamping face of the jaw as shown.  Expand the dialog box and set the constraint limits as shown.

Click OK and then try click and drag of the jaw.

What happens?

Assuming it works as expected.

Create a Component Pattern - Circular of this part 2 - instances about the assembly Y axis in 180°.

(Note: The Circular option is hidden, select Component Pattern and then you will see the option.)

[Callesson]

Aye! That's one way to do it. Works like a charm 🙂 Thank you very much!

Is it possible to be able to select either of them in order to make them move? Because now I can only drag the firt jaw.

The jaw created by the pattern cant be selected to move. (this is nothing important and if you don't have time you dont have to give me help with that. I just thought it could be nice to know)

And btw, I have no book for learning.

I studied Inventor 2 years ago in school, but only for some months ( and with a bad teacher)

Now I started learning it on my own via internet 4 months ago. And I also use it for proffesional use in my work now. But I still have much to learn!

[Callesson]

This kinda makes a mess for me in the assembly its in doh.

Doesn't work so good when i move other adaptive stuff in it.

Maybe it doesnt work that good using it for adaptive sake? (atteched file)

[JDMather]

Beginners (almost) always use Adaptivity incorreclty.

Flexible might be what you are after

or

Environments>Dynamic Simulation (in Inventor Professional).

[Callesson]

---

@Anonymous wrote:

Beginners (almost) always use Adaptivity incorreclty.

Flexible might be what you are after

or

Environments>Dynamic Simulation (in Inventor Professional).

---

Yea, could be that I am using it wrong 🙂

Thanks!

I want to be able to move the components while im working with the assembly, to see how all functions work together for the machine.

[SBix26]

Before the arrival of the Symmetry constraint (2014, I think), I used the following technique for grippers:

 - Create a part that consists of nothing but a sketch with one line in it, constrained with the center at the projected origin point.  

 - Dimension the length of this line to a little more than the maximum opening of the gripper fingers  

 - Add this part to your gripper assembly, constraining its center to the centerline of the gripper (the midpoint between the gripper fingers).  

 - Constrain the face of each finger to one end of the sketch line.  

 - Turn off the visibility of the sketch part.  

The sketch part can pivot about the center of the gripper, and keeps the two fingers exactly the same distance from the center.  You will also need to constrain one of the fingers with limits so it can't overtravel its stroke.

I don't have an example to attach here at home, but I hope you can understand from my description.

Sam B
Inventor 2012 Certified Professional

Inventor Professional 2014 SP1 U3
Windows 7 Enterprise 64-bit, SP1
HP EliteBook 8770w; 8 GB RAM; Core™ i7-3720QM 2.60 GHz; Quadro K4000M

[Callesson]

Alright!

I'll try it out, thanks Sbixler! 🙂