Wildfire 3 Mechanism problem

[BertilRogmark]

I am trying to model an old sail ship and am currently trying to make the gun ports movable using Mechanism.

The first picture shows the gun port closed, the fake canon withdrawn and the blue activating lever in its start position.

                                                                                                                                      

The second picture shows the activating lever, after having taken up some necessary slack, pushing the fake canon and the gun port outwards.

The slack is neccessary because other ports moved by the same lever has a larger angle between closed and open positions.

The third picture shows the fake canon in its final horizontal position.

The last picture shows the activating lever returned to its start position but the fake canon remains horizontally.

I would like it to follow the activating lever back to its start position and stay there while the lever continues to its start position (cam follower type allowing lift-off.)

Now, is this possible?

Is there som mechanism connection that would do this?

In reality I would use a rubber band or a spring to return the fake canon and the gun port to where it all started. 

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[gfraulini]

Hi Bertil,

I don't understand where are the problems to model your assembly inside mechanism.

You should tell us if you need a simple position analysis or a dynamic analysis with the research of the forces.

In each cases you can use pins-cylinders or sliders, but if you want a dynamic analysis you have to do attention to the redundancies of constraints that alter the results of the connection reactions.

Bye

[BertilRogmark]

Hello Giulio,

Thanks for your interest.

I believe I have found the problem.

It seems that to introduce "elastic" components you have to have the ProE Mechanica module - I only have Proe Mechanism Design.

But I have another question which you may be able to help me with.

The assembly shown in my pictures have a number of instances.

The angles of some parts vary from one instance to the next.

As a result, the mechanism movement analysis that works on the generic assembly will not work on the instances.

I wonder if it is possible to put the value of an pin connection's angle-limitations in the family table?

kind regards

Bertil

[ChrisKaswer]

Bertil,

You can create the slack you need by using a slot joint for the links connecting the cannon base and the port window. This will allow movement of the actuating device and not move the cannon base until the end of the link reaches the end of the slot to pull the cannon base up toward the window. I hope this makes sense.

Regards,

Chris

[BertilRogmark]

Chris,

I am not quite sure if what I believe you suggest, will give me what I want.

I have managed to solve the mechanism by defining 3 different motors and the attached mpg file shows the result.

Ideally I would have liked to show the flexing spring that makes the canon bracket follow the drive lever part of the way when closing the gun port but as I wrote before, I don't believe I have the necessary software module.

kind regards

Bertil Video Link : 6806