Let's continue from previous post. Now it's time to see our previous calculation for the timing diagram of indexing mill and punch die in 3D Motion Simulation using Unigraphics (UG) NX4. Though we have made motion simulation in excel spreadsheet using excel VBA, it's much better and easier to do it in UG motion. The UG NX4 Assembly model is prepared as shown below.
Timing Diagram (Part 1 - No Overlap Movement)].
New to UG NX4 Motion Simulation? No problem, just follow our guideline in step-by-step, and you will find it easy to use. Let's see how to do...
We can enter into Motion Simulation Environment as shown below.
Then we define the links to use in motion simulation by just following the steps shown in the pictures.
1. Click link command.
2. Select object, for this case select the indexing mill.
3. Enter name of the link, for this case enter Mill.
4. Click Ok to confirm.
Let's starting defining joint of indexing mill. There are a lot of types to define, but for this indexing mill we select "revolute joint". The revolute joint has 1 degree of freedom because it can only rotate in Z-direction and this is what we want for the indexing mill. To set the joint, just follow the following steps:
1. Select Joint command.
2. Select "Revolute joint" icon (default) then select the "link". For this case, select the Mill.
3. If not yet selected, select "Orientation of joint on the first link".
5. Select the top face of the indexing mill.
These steps are to define the direction of the joint. For the revolute joint, we need to define the Z-direction for rotation axis. By selecting the top face of the mill, we define the vector normal to that plane.
6. Change from "Vector" to "Point".
7. Select the center point of the index mill.
8. Rename the joint to "J_Mill". This is for reference and easy to trace back.
9. Click Ok to confirm.
It's still not finished yet for the setting of the revolute joint for indexing mill. Though, the vector and point are fully defined, but there's nothing define how it moves yet. At each instance, the revolute joint can rotate to any degrees. Therefore we need to define the last thing for this revolute joint, Motion Driver.
1. Select "Constant"
2. Enter numerical value at "Velocity" box e.g. 100
3. Click Ok to confirm.
The above process sets the motion driver to have constant velocity of 100 deg/s. You may argue that the motion of this indexing mill as per the previous posts must be "cycloid" not constant velocity. Yes, that's right. But that is for later. For the moment it's enough to define it like this.
Let's take a break for a moment and continue in the next post.