Engine Assembly Constraint Conflict- Please Help!

[Anonymous]

Apparently I bit off more than I could chew when I decided to build a small scale engine block for my Inventor Class. I have a connecting rod and piston assembly, a crankshaft assembly, and a block ipt. I have a free range of rotation with my crankshaft assembly. The crankshaft assebly is constrained to the block assembly so that the bearing journals sit in the the correct position. The piston also has a full free range of motion around the crankshaft assembly.

However; I am unable to get my piston/connecting rod assembly to remain inside the cylinder of the block. When I rotate the crankshaft, the piston remains in the current position. thus, the piston does not ride inside the cylinder wall. If I constrain the the piston to the inside of the cylinder wall (insert constraint) it no longer allows me to rotate the crankshaft? Thank you for your help. I have to turn this project in a few days from now and I am struggling to finish it up!

[Anonymous]

I do not have windows 7. Windows Xp does not have a snipping tool.  however, I was able to download one. It would only save as a jpeg. not as a png. (135kb)

[JDMather]

Your latest screen shot shows the Crank subassembly as Flexible, not the Piston subassembly.

I don't think you need the crank as Flexible, but you certainly do need the Piston as Flexible so that it can rotate about the Piston Pin and the Crank.

Right click on the Piston assembly and set to Flexible.

(I'm getting cranky now.)

[Anonymous]

My apologies. Like I have been doing all day, I have been changing around things to see if it effects the outcome. Either way, There is no motion availible. Whether the piston or the crank is flexible doesn't appear to make even the slightest difference. I have 2 different versions of inventor on my computer. One is my copy, and the others is my student copy. I accidentally copied the wrong screencap.

Please do not feel obligated to continue to help me if you are obviously upset and cranky with me.

[JDMather]

The holes in the Connecting Rod and the cap do not have the same center-to-center distance, therefore they will not properly assemble.

The holes in the caps should be clearance holes - not threaded holes.

[JDMather · Accepted solution]

see attached

Verify that you can drag the crank and everything works.

Find the Drive This angle constraint and right click on it and Unsuppress.

Right click on the Drive This angle constraint and select Drive Constraint.

Click Play.

[Anonymous]

So basically, I was so frustrated with that, because I had the wrong planes selected for the angle constraint.

wow.. I'm A dumb*****

thank you very much for your assistance! that is exactly what I was looking for!