motion, etc.

Jan 04, 2005 4 Replies

This is looking pretty far forward for me, since I'm a beginner, but:



Is there a way, in an assembly with moving parts, to capture a text file describing how the assembly moves? As a simple example, for 10 degrees rotation of this crankshaft, how far does the piston move? Ideally, in this case, I would like to receive a text file with user specified step size of the crank rotation and the resulting piston linear motion.



Thanks, Bill


I think COSMOSMotion will do it, but that's not for a beginner.

I can picture a way that you could do it manually. Set the crank position with a degree mate. Then put a driven dimension on the piston. Now change your crank position by the desired increment and read & record the piston dimension.

WT

Extreme Design and Programming used to have free monthly macros, and one of them was an excel-based macro that could make a graph of one component's movement relative to another. You should be able to extract what you want from that.

They don't seem to have a monthly macro site anymore, but I have a copy I'll try to email to you.

Thats kind of what I had in mind for the manual method. All the motions I want to capture are angular rotation motions with linkages and crank-arms, so I pictured a fixed degree wheel and a pointer attached to the part in question. It'd be nice to automate the process, though.

Bill

This is not difficult. It involve a little macro programming and a layout sketch.

Set up an angle mate on the crank. Set up a layout sketch to capture the length of a line with one end fixed and the other attached to the piston top.

Record a macro setting the crank angle and add in the readout of the line length via a driven dimension. Then in the macro open a text file and write the numbers out. Put a for loop in the macro and drive the angle that way.

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