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barrykingwill

Senior Member
Im using Alibre Pro, and have not been too active on it lately (have other non modelling functions), and today noticed that the icon that allows one to move parts in an assembly, such that they move or rotate subject to their respective contraints, (ie a simple manual animation of motion) seems to be gone. :roll:

I then checked the help, and it seems the EXPERT Version has a substantial MOTION capability.

Please confirm whether this basic motion (ie that icon) has been removed from PRO?
 
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MilesH

Alibre Super User
Hi Barry,

The specific state that the icon controlled is no longer needed. Dragging Parts in Assembly is something which has seen huge improvements....
 
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drof34

Member
In the motion add on(expert), Is there a speed limit with the software or is this a function of the graphic card?
I meshed two gears in (Kinetic) and if I tried to go above 20 RPM it actually looked slower.

I later tried 3 bevel gears in mesh at 20 rpm and it looked right. At 30 rpm the teeth didn't turn at all but the bore was turning. At 25 rpm the teeth and the bore was turning but in opposite directions from each other. That is one odd sight to see the teeth turning in one direction and the bore turning in the opposite direction.

If this is a graphics card problem, what would you suggest? I presently have ATI 3600 with 250 ram. This is the weakest link on my computer.

Thanks
Jim
 
NateLiquidGravity

NateLiquidGravity

Alibre Super User
Miles is right ( unless you have something set up wrong). I don't have Alibre Motion but is there a way to set the number of frames per second higher? This would reduce the frequency of it occurring. Also I'm assuming your gears have the same tooth repeated around the entire gear. If there is no distinguishing features on the gear it will happen more often. Adding a dot, small text, or other mark would help in that case.
 
Max

Max

Administrator
Staff member
It's just an optical illusion. Remember the wagon wheels in early films.........? :)
Click to expand...

Actually, you are correct. :)

Try changing the simulation step value. If it's too large, you will miss relatively large chunks of the visual movement between steps. Increasing the speed at which things move worsens the problem.

Example:

A car is going 5 mph and your simulation step value is .1 - let's say over 5 seconds you get 10 frames. Your car hasn't gone that far at 5mph so there isn't much difference between the frames = smooth.

Now let's say your car is going at 100 mph with the same simulation step value. Over 5 seconds you get 10 frames. But in this case your car has gone a tremendous amount per frame since it's moving so fast. You need to increase the amount of frames to see a smoother motion. To do so, lower the Simulation Step value.
 
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drof34

Member
I'm having a little problem with my head. To begin with Miles told me my hallucination was an optical illusion. :mrgreen:

I understand the concept of increasing the frames for smoother higher speeds, but what does the simulation value do? Is this something that happens within a frame or does it act on the frame?

In playing around with this simulation, it seems you have three factors influencing speed; the accelerator pedals on the motors, the frames/sec and the simulation value. It's hard to tell which has the most influence, but it does leave me wondering just fast it is turning.

Jim
 
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MilesH

Alibre Super User
Yes. It's not easy to work out what's happening..... :mrgreen:

Simulation speed (Actuator value).

Target playback speed (Frames per sec.)

Simulation frame interval.

System resources ceiling.

POV/strobe effect. (affects perceived speed).

I think I'll leave it to Max.... :p
 
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