Rotational Balance

[bigguy136]

I've been working with NX 7.5 for about a 9 months (15 years with SW). I'm designing a two stroke 90° twin (150cc) engine and I want to know if NX has anything in motion simulation to help me with my design.

 

[looslib]

NX Motion Simulation should do what you need.


"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli

 

[bigguy136]

I haven't use NX simulation. What are a couple of steps (what sim type ect) to help me get started in the right direction.

Thanks so much, BG

 

[JonSelby]

I've had some training in NX6 from one of our CAE guys but I don't think its appropriate to post their hardwork without there consent.

The basic principle is ...
1. Create your LINKs (each 'link' is a part or a group-of-parts that can be treated as one rigid entity)
2. Add JOINTs between LINKs (a joint defines the permited movement between links (i.e. sliding / revolving etc))
3. Add DRIVERs to provide motion (this can be done within a joint or as a seperate motion)
4. Define your SOLUTION (i.e. is it constant movement, hamonic motion or just a moving a part a particular distance. I'd start with 'Articulation')
5. Then SOLVE your solution (this is where you see the results)

Then there are also options such as 'Interference' that will highlight where you have collisions.
If NX7.5 follows NX6 then start on the left-hand-side of the motion simulation toolbar and work your way across systematically. A lot you don't need at the start but just work out what the capabilities for each one are.
Oh and read the help file - it really is useful!!!

 

[bigguy136]

You've been very helpful. It looks like I will have a big winter project of learning.

Thank You!

 

[Toost]

A little tip on mechanism simulations,
- build it step by step... : - )
Stupid i know, but:
if you are to simulate an engine, pistons and crankshaft etc, the engine block itself is NOT a link, just leave it as it is. ( unless you want to analyse side accelerations of the engine block but then you also have to decide how to attach the block to the "world".- select and define the joints that hold the block in place.)
I.e, the crank is a link, the revolute joint that the crank spins about should be "fixed", since the block isn't part of the simulation.
This way you can build your simulation step by step and you don't have to make all joints work at once. As soon as you have 1 link connected to a fixed joint you can run the first simulation and see if it works as expected. Then create the next link and connect to the previous , run sim again etc.
And if you later want to simulate the accelerations of the block you can then edit the first fixed link and connect that to the block instead.
Regards,
Tomas

 

[JonSelby]

Good shout Tomas - as they say "KISS"!