Lightening Pattern Help?
 

What is the most idea form for lightening two-speed transmission gear boxes
and a West Coast Drive Belly Pan? I see that teams (254/973) have the diamond shape design, but I am not sure how to do it myself using Solidworks. I have been informed that the minimum strut length for the aluminum is 1/8 inch. Can somebody please offer me technical help?

Thank you.

Re: Lightening Pattern Help?
 

For the belly pan youn should be able to just make one diamond and then use linear sketch patern to copy it

Re: Lightening Pattern Help?
 

You can check out 973's CAD right here on CD for the bellypan. There's links in Adam's signature. I don't have the dimensions on me at the moment. As for the gearbox, I think the webbing looks approximately 1/4" thick but this is just a guess, better to check out their CAD and ask questions from the source! :)

Re: Lightening Pattern Help?
 

It's been a while since I've used SolidWorks (you use Inventor when you intern at Autodesk I guess), so this may not be the most efficient way.

Bellypan:
I make four holes in the corner of the bellypan - two triangles and two squares - and then use patterns and mirrors to complete the entire cheese hole pattern. If I want to and holes/extra webbing for gearbox cutouts/electronics, I go back and make them separately by cutting away the material I don't want and then extruding the shapes I do want back in.

Gearbox:
With a gearbox it's just a slow process of outlining the areas that will remain (around bearings, spacers, bolt holes, etc.), followed by adding in the lines that will connect them. Attached is a picture of the drawing I created for the lightening pattern I used for a gearbox project I've been working on. Notice how I used fairly few dimensions for the amount of sketch geometry. I did this by using a lot of sketch constraints, ultimately making the sketch easy to use if I ever want to go back and make changes.

Hope this helped, I'd gladly try to answer other questions.

Re: Lightening Pattern Help?
 

Yes, that definitely helped. Here is the final gearbox that I've designed.

Re: Lightening Pattern Help?
 

You should fillet all of the inside corners. If these are plates that will be milled, try to design them use the largest end mill that is reasonable. If it's water/laser cut, you'll still want to add fillets to make the cuts faster and cleaner and to reduce stress concentrations at the corners.

Re: Lightening Pattern Help?
 

Agreed,

Also put a little support between your shifter/bearing block square to the bottom of the plate.

-RC

Re: Lightening Pattern Help?
 

Thanks to the both of you. I have updated the gearbox. Is there anything else that you can see that should be improved upon/changed/added?

Re: Lightening Pattern Help?
 

What purpose does the inner snap ring groove serve on the output shaft?

Re: Lightening Pattern Help?
 

Sorry about the late response. The inner Snap ring is designed to hold the other side of the wheel in place. I added this feature to the output shaft to ensure that the wheel would be held in place. If I were to take it out, what would prevent the wheel from sliding inwards?

Re: Lightening Pattern Help?
 

just wondering: did u stress test these plates, including for collisions that may be less then ideal?

edit: o, and did u example the irl ability to travel to ensure the gears stay where u want and don't generate undesired interactions?

Re: Lightening Pattern Help?
 

is this for a standard cantilevered wheel drivetrain?

If so, your wheel is captured by your bearing block in the outside of the frame rail.

If not, add a spacer. Your shaft is all but 100% guaranteed to fail at that snap ring as it stands.

There's no need to perform FEA on those plates. By visual inspection they look similar to multiple other successful gearboxes. 1/4" Aluminum plate is ridiculously strong, even pocketed out like that.