dude ..that was so yesterday.....

 

and for what it is worth...ver few ball screws are stainless....

 

This thread has been Jacked so bad. Goddamn kids need to go to the time out section.

Im sure your teacher is looking for something to improve (whatever it be) not complicate. IF you have to finish this design I would reduce the 8 ball screws to just two working off a crank sensor and cpu. I dont see the improvement to your project except adding cost and bulk to the motor. You have a good idea it would eliminate the timing chain/belt and all complications that come from a worn one like stretching and breaking but 8 is to many.

There are other items where more is better like eliminating the distributor and longwires to have a coil pack for each cylinder. This improved engine performance, hotter spark, increased fuel burn and less emissions. Also if one failed the vehical still runs.

 

For what thats worth. They can make em out of titanium if they want to or even bubble gum.

 

I'm an M.E. grad student at Michigan State. A new field of research at the automotive engineering complex is fast-acting solenoids for use in vehicle valvetrains. A solenoid is like an electronically actuated plunger that can rapidly move between extended and retracted positions, like what justasquid is talking about. What's nice is that they provide a lot of force and speed without being very heavy, and they can be timed to change valve lift duration at different engine operating points. I don't know all the drawbacks associated with them, but I'm assuming they haven't been more widely adopted because they're both expensive and their response changes when they get hot.

I think the ball-screw idea is an interesting one, but I would look into sizing up the motors you would need to make it work. In a worst-case high-rpm scenario, how rapidly would you have to accelerate the mass of the valve and motor components in order to close the valve properly? From that you can get a rough guess of how many watts your motor should be, and then you can look at how large motors in that size range from different manufacturers are. You should be able to get a pretty good idea of the size of the whole system that way.

Yes, I'm an engineering dork.

-Fisher

P.S. Aweasel, where do you go to school?