1 ACCEPTED SOLUTION
Accepted Solutions
Thanks! This is much more specific and very good for getting useful help from the community,
The problem is your analysis is forcing the position outside of the travel limits.
at 600 mm/s you will reach 410mm in 0.683333 seconds, but you ask to go for 1 second with only 10 frames.(0.1s,0.2s,0.3s...)
At 0.6 seconds a frame is made and the travel is 0.6*600 = 360mm. At 0.7*600 = 420 mm >410mm so an error and only the previous frame at 0.6s was successful. If you did 100 frames the last success would be at 0.68 seconds =408mm.
A couple more tips...
Current Position as Initial means wherever you last left the model.
It is better to set your analysis with an initial condition that starts with a snapshot with the configuration at the true beginning. (circled, looks blank to me)
Another way is to control the position rather than the velocity. This way the initial position/condition does not matter and can be left blank.
I would use driven quantity position and function type table and have two lines like so.
time, position
0, 0
1, -410
I would try to change the direction so it travels positive 410 rather than negative. There is a flip direction for the initial connection definition. The slider arrow points in the positive direction and can be flipped. Also in that definition there is a place to change the joint names so they are more readable rather than "Connection_6" In my example "Handle_Pivot"
-regards
I have to simulate the exact sequence of movements of the following assembly to show to a customer. When I try to move using the Drag components functionality, especially on the lower assembly, it's quite impossible to move just a cylinder without move at least two or three other rigid bodies. This is the reason why I thought that a mechanism would be the better way to show how the assembly moves. All the movements have a servomotor already set and each connection has the limits defined.
For example, when the cylinder 1 is lifted, I want to lower the cylinder 2 letting the cylinder 1 completely lifted. Using the Drag components, lowering the cylinder 2 cause the cylinder 1 to lower as well and most of the times the whole assembly rotates aroud axis 3.
Thanks in advance for the help.
Giovanni
I can give some general help.
Based on the number of joints and degrees of freedom shown in your image, this model appears very complex for a beginner. (Like 20 connections from Slider, pin, cyclindrical, and even 3 general 6dof connections, in total somewhere around 30 dof)
You can stop the movement of those joints that are moving but you want fixed by a constraint in the drag box or locked entities in the analysis definition.
Or, change everything but the three moving joints to fixed connections.
The rectangle icon on your part/assembly name in the tree indicates a moving part.
I would probably put a motor or a fixed constraint for all 30ish degrees of freedom, not leave any joint up to chance.
Generally, a beginner should build a model and understand it one joint at a time.
I don't see any reason you need the advanced mechanism dynamics license.
If you have joint limits then of course your servo motors must not force travel past the limits.
Also, I would do kinematic instead of position as the analysis type.
Once the Creo Mechanism animations work, the saved playbacks can be used in Creo Animation to make a more complete demo movie.
thanks Sweetpeahub-old for your reply and your tips.
I tried just one joint as you suggested and I came to the error that yesterday let me think I needed the dynamic mechanism.
The carriage is set to get a stroke of 410 mm and using the Drag it actually works (even in the Mechanism applications).
When I run the Kinematic it doesn't complete the stroke and it stops after 360 mm with the attached warnings .
If I set the time to 0.5s instead of 1s it stops before 360mm and I don't get errors.
Thanks! This is much more specific and very good for getting useful help from the community,
The problem is your analysis is forcing the position outside of the travel limits.
at 600 mm/s you will reach 410mm in 0.683333 seconds, but you ask to go for 1 second with only 10 frames.(0.1s,0.2s,0.3s...)
At 0.6 seconds a frame is made and the travel is 0.6*600 = 360mm. At 0.7*600 = 420 mm >410mm so an error and only the previous frame at 0.6s was successful. If you did 100 frames the last success would be at 0.68 seconds =408mm.
A couple more tips...
Current Position as Initial means wherever you last left the model.
It is better to set your analysis with an initial condition that starts with a snapshot with the configuration at the true beginning. (circled, looks blank to me)
Another way is to control the position rather than the velocity. This way the initial position/condition does not matter and can be left blank.
I would use driven quantity position and function type table and have two lines like so.
time, position
0, 0
1, -410
I would try to change the direction so it travels positive 410 rather than negative. There is a flip direction for the initial connection definition. The slider arrow points in the positive direction and can be flipped. Also in that definition there is a place to change the joint names so they are more readable rather than "Connection_6" In my example "Handle_Pivot"
-regards
Thanks for the further tips.
Now I understand better how it works.
I did some tests and again something happened that I would like to understand.
I set the servomotor using the position and the table to define time and position (I also flipped the direction)
I modified the analysis:
But still when I run it it doesn't arrive to the end of the stroke.
I thought the frame count could be connected to the number of interpolated points of the motor, but again no success.
Increasing the number of frame count it's going closer to the final position, but still doesn't reach it.
I set the time in the motor to 1 and the time in the analysis to 0.5s and it stops exactly at half the stroke.
Then I changed the analysis from Kinematic to Position and all works. Working on the frame count it increases the velocity.
What I don't understand is why it doesn't work with Kinematic analysis.
About the snapshot, it's locked and I cannot use it. Anyway, everytime I click on run it starts from the initial point.
Another question is the return to the initial point.
I was able to define it in the motor settings
In the position analysis it works, although I get the limits error (I measured the position and it is exactly the initial, so I don't understand why I get it)
.In the Kinematic it stops because it doesn't reach the first position at 430mm.
Thanks,
Giovanni
