RIG's First 3lb Bot-Leftie

This is the concept for our first Beelteweight, a wedge-vertical, as yet unnamed.

Many decisions still need to be made, but the chassis is coming along:

Drive: "1000 rpm ebay motors"
Banebots 3-9 ESC
Banebots 1 7/8" Wheels

Frame: 1/2" UHMW Walls
.093" Lexan Top and Bottom plates


Weapon Design will depend on our machining capabilities and sponsorship, but at least will consist of an Aluminum drum with Flat Head screws partially countersunk into it as impactors.

Is there an idea for teeth??

Are the left and right sides held together only by the wedge in front?

looks a lot like my aus friends bot.
http://www.robowars.org/forum/viewtopic.php?t=1348&postdays=0&postorder=asc&start=75

it kinda looks like a mini torrent/atomic shock

radiationleak wrote:

Is there an idea for teeth??

It depends on our machining capabilities, if Magnum Steel can/is willing to cut parts this small we'll get nice end caps with teeth integrated and weld them to the drum, looking similar to K2. If not we'll go with the more traditional route of bolts threaded into an aluminum drum with exposed heads as teeth.

rdubard wrote:

Are the left and right sides held together only by the wedge in front?

.093 Lexan Top and Bottom plates will hold everything together with binding posts going through both plates and the frame rails.

aluminum drum??? Spin up time will be down right wicked, but what about it's capacity to do damage to the other bot/itself?

This is the new idea.

It's more space/weight efficient than the previous design, but I've never seen a half drum, so i'm wondering if there is some design flaw i'm missing.

Top and Bottom are modeled as 0.05 Al, but that may increase depending on the final weight, wedge cover is hardened steel and the orange bits are UHMW.

Weapon Motor:
http://www.hobbycity.com/hobbycity/store/uh_viewitem.asp?idproduct=9257

That looks wicked! Big improvement over the first design. (A bit harder to make , tho)

While it's more space efficient, keep in mind it's going to have a ton of gyro during left turns and almost none during right turns (Dynamics of Rigid bodies: it's already paying off!). Other than that, looks good.

Jeff L wrote:

While it's more space efficient, keep in mind it's going to have a ton of gyro during left turns and almost none during right turns (Dynamics of Rigid bodies: it's already paying off!). Other than that, looks good.

I was about to suggest moving the wedge piece to the weapon frame rail and do a similar wheel cover on both sides the other night till I thought about what jeff said. Theres a slight chance of it working for you when in gyro

Why the total offset?

Seems like the whole structure would be tied together a bit better if centered??

Could work for and/or against you....driving skills required

rjw wrote:

Why the total offset?

Seems like the whole structure would be tied together a bit better if centered??

Could work for and/or against you....driving skills required

Battery pack and esc to one side and weapon motor mounted parrallel to the drum makes sense being more space efficient. And we all know space is weight

thick frame members are also weight....and they need to be thicker when unsupported.

but that's the whole idea and learning process.....how to juggle and come up with a better mousetrap..that makes weight....

I agree that this bot may have some interesting driving characteristics that may work for or against it.

I also must admit that a good portion of the design, and materials selection deals with what we have to work with. We do not have access to a machine shop, but we can get UHMW and laser cut it for free.

I was also wondering what you guys think of the weapon motor? I don't really know much about how to size one so that it won't go up in smoke.

RJW,
My intent is that the weapon shaft will help hold the front of it together. I'm using ball bearings, and borrowing some of your tricks from Sting.

actually the more i look at it i see different things
do you have a render from another angle?
I think i'm seeing the furthest frame rail wrong. On the far side is the wheel cover the same piece as the front wedge?
You may have a problem with the weapon frame rail twisting since it doesnt look like there anything to support it from the ground

do it up, different is awesome, one look at that will get every ones attention

Right Side:

Bottom:

Right:


The wheel guards will be spring loaded in place.

We are still debating whether or not to put the front wedge all the way across, or use a wedgelette as it is modeled now. this is slightly weaker, but it gives the opponent two independent wedges to get under, it is also obviously lighter.

The outboard weapon support rail has a support to keep it off the ground.

I was also wondering if I could get some input on my weapon motor choice. I really don't know much about how to size motors for weapons.

http://www.hobbycity.com/hobbycity/store/uh_viewitem.asp?idproduct=9257

Though it is now looking like the school does not want to make purchases from China...so i may be looking at more expensive options.

what if you sell it to the school? Sorry i dont really know much about beetle motors

my suggestion would to just make that outside wedgelet into the weapon frame rail you would save a fair amount of weight on fasteners.
Im also no a fan of wedges running across the front. The weakest spot will be right in front of the drum and it eventually will get jammed into it. If you do, roll the lip infront of the drum to give it a little more strength

that motor should work fine, I use a slower turnigy motor from hobby king in my beetles witch is about the same size.

and hobby king is a great place to buy your robot stuff from, they are cheap as dirt. just make sure your stuff is in stock or else it will take FOREVER for you to receive your order

Thanks for all the help. We should start ordering/making parts soon.

Cool..good luck with it!!

I look forward to seeing it in action

Progress!
We did the lathe work on the drum earlier this week, and laser cut the UHMW last night.

lol it looks so funny, i love it.

its a little on the small side isn't it?