Help with Building Rover for Engineering Class

[Tommy B]

Just wanted to preface this by saying I am a complete noob when it comes to engineering and HATE asking others for help with homework. However, I desperately need help in my engineering class to maintain my high honor roll grades. I need to come up with a comprehensive design by Monday and have been procrastinating for the past week.

So the final of the class is to design a rover with four wheels that can drive through the obstacle course (It's basically a turn and a hill).

The requirements of the rover are:

Must "stand" on a cardboard platform

Use 2 motors

Have at least one worm gear

have a mechanical advantage between 72-120 using LEGO gears

must have "vertical" axles meaning the axles go from the front right wheel to the back right wheel and the same for the left.

Must be less than 9in by 9in including wheels

Can only utilize worm gear, 8 tooth gear, 16 tooth gear, and 24 tooth gear although using a differential or whatever it is called is also ok.

have wooden structural pieces that strengthen the chassis

The motor cannot be glued down

Must be able to turn while "stationary" by having wheels on one side go in reverse and the wheels on the other going forward.

Thanks for the help everyone! I'm sure you guys think this is really basic but engineering really is not my forte. 

[Saberwing40k]

Okay, what kind of parts do you have? And what kind of motors? Does the rover need to have a battery box onboard?  Also, this is the smartaft in me talking, but why such low gear ratios? Lego motors are quite powerful, and do not need that much reduction. Also, having worm gears just bleeds power, and I think this would be something you could point out. Finally, I really think you're doing yourself a disservice by asking this. You won't learn as much, and is that not the purpose of your class? To learn the principles of engineering?

[allanp]

So something like this?

Each motor drives a front and a rear wheel with a reduction of 72:1. 

Edited March 31, 2017 by allanp

[Aventador2004]

why are you asking this on a Lego forum when you could ask on a engineering forum. also like what saberwing said shouldn't you try to really learn instead of just asking to have the answer 

sorry for the bluntness

signed,

confused

Edited April 17, 2017 by Aventador2004

[aminnich]

I remember when I was in highschool (not too long ago) and doing these kinds of projects. I loved doing the hands on activities that you were able to see how he concepts you were learning about could be used in the real world. 

I will say you came to the right place to ask for help, but I do not agree with you asking us for help. 

I wish you luck wit your project.

btw, what Allanp posted would work perfectly. 

[allanp]

It should be noted that out in the real world if you do not know something you are encouraged to ask for help from others, at least that's been my experience  . 

[Aventador2004]

allanp i know you should ask for help but no like this

though if you do use Lego motors XL will have the best efficiency 

Edited March 31, 2017 by Aventador2004

[Jurss]

6 hours ago, Tommy B said:

I'm sure you guys think this is really basic but engineering really is not my forte. 

So whay are then takin engineering clases?!

[Didumos69]

I agree you have to do the assignment yourself, we can only give some pointers. I suggest you make the left and right bogies communicate with gears such that the body inbetween the bogies averages the position of the bogies. In other words: The body behaves as a differential with the bogies secured to the output axles. Just as is common to rocker-bogie suspension:

See also this post for inspiration:

 

Edited March 31, 2017 by Didumos69

[Nazgarot]

Hi Tommy B

I also think you should solve the problem by yourself, but of course we can help you along the way.

To get going you could follow these steps:

1: You need to make a sketch for what you want the design to be.

2: You should make a inventory of the available parts

3: It is important to know what motors you will be using, and how you are intending to power and control them

4: Start building as soon as possible. No plan survives first contact with battle i.e. you will have design ideas that won't work in real life...

5: If you want our help you should start by making a basic design and show us the results of 1 and 2

 

Best of luck with your project!

-ED-

Edited March 31, 2017 by Nazgarot

[Hay Ewe]

interesting

Mate, I dont mind you asking for help, but a pointer from an older fella, you should have asked sooner - dont leave it till the end next time. something better / more important may have come up on the weekend and now your stuffed becuase you didnt do this sooner.

As for asking for help - not one person can learn all the mistakes, learn the mistakes made by others and endevor to avoid them. Or, in this context, I dont mind asking colleagues for help, I could spend a day trying to solve something in Excel and a work mate may know a better or more appropriate way.

 

[Tommy B]

Thanks guys figured it out by myself. Not as good as the one suggested but it'll do. Thanks for the tips everyone and especially for teaching me a life lesson. Really should try to do things on my own wits next time and you guys made me realize that.  Really felt empowered by the advice that y'all gave me.

Thanks again