pic: Team Rush 27 - Shooter Concept

[Elgin Clock]

Thanks Paul.

Yeah, basically to make it from scratch in solidworks, I would draw one tooth, and rotate however many times.

Nowadays, gear manufacturers have all CAD drawings in easily converted formats for your applications that you could just drag and drop in.

We customized a gear just the other day from the firstcadlibrary by extruding cuts and what not, and it was pretty straight forward.

[bbehnke]

ya im not realy a fan of the side by side wheels either. wat i think would be alot better is putting them vertical so u dont have a problem with turning while the ball is in flight due to one whele spining faster/slower than the other. the vertical one would somewhat elimate this factor and it would be a better idea if the bottom one is spinning faster than the top to creat back-spin on the ball. although i looks realy good

[Parker]

Keep in mind that if the wheels aren't spinning at exactly the same speed, the balls won't fly straight. Every motor, even if they're the same design, will spin at different speeds.

[Chriszuma]

Originally Posted by Parker

Keep in mind that if the wheels aren't spinning at exactly the same speed, the balls won't fly straight. Every motor, even if they're the same design, will spin at different speeds.

A simple chain and sprockets can be used to ensure that both wheels are spinning at exactly the same speed, and additionally eliminate the need for two motors, saving weight. In our mockup testing, this actually outperformed alot of other methods.

[Alekat]

Originally Posted by bbehnke

ya im not realy a fan of the side by side wheels either. wat i think would be alot better is putting them vertical so u dont have a problem with turning while the ball is in flight due to one whele spining faster/slower than the other. the vertical one would somewhat elimate this factor and it would be a better idea if the bottom one is spinning faster than the top to creat back-spin on the ball. although i looks realy good

But couldn't you have the same problem with verticle rollers moving different speeds? And instead of having poor accuracy left and right it is poor accuracy up and down? it's a circular goal so either way you'd be likely to miss if you don't match your speeds.

[ajlapp]

Thanks for all of the great responses......

As for the gear drawing and SolidWorks. I did draw the gear in AutoCad, and I do have it in my solid models, both UG and Inventor. Though it is my general practice to leave that sort of CPU draining detail out of my drawings.

Fear not, for I have built many a turret, and have designed many a spur gear......I have even milled one that was nearly twice that diameter.

The side-to-side design.......

Also not my favorite. We chose it after several prototypes mainly because of it's low profile. A vertical style two-wheeled shooter was becoming to tall, and a one-wheeled design didn't allow for the lowered RPM and increased torque we were looking for in a shooter.

We have tons of adjustability in the design which allows us to tune the wheels for both compression and alignment. To keep both wheels spinning together we've opted to skip any sort of mechanical coupling and just tune the wheels using a tachometer. Worked well for the prototype.