09-02-2006 03:35

Darkswordsmith

Re: pic: Top Gun With Wheels

wow! Very nice chassis, everything strong, sturdy, and...SHINY!!!

that's going to be a beast on the field, but how much does it weigh?

09-02-2006 10:25

Rick TYler

Re: pic: Top Gun With Wheels

Weight: the raw frame is reported to weigh 15 pounds. The wheels and axles add another 16 or so (I am starting to respect the "small wheel" faction) and the electronics board about a pound. That's 32 pounds as it sits. The official weight spreadsheet shows it weighing about 60 pounds with motors, gears, and chain, but without electronics and the shooter mechanism. Fortunately, the sweeper/shooter is very simple and pretty lightweight. It should come in fine, but it will probably weigh a little too much. Last year, we had to shave 20 ounces at weigh-in.

At least one of mentors doesn't want to add bumpers because he doesn't think we need them. I want to add bumpers because, well, they're free and might preserve our wheel-shaft ends from damage.

09-02-2006 14:18

Greg Ross

Re: pic: Top Gun With Wheels

I am not a mechanical engineer, but it looks to me like your slots (for adjusting your chain tension and wheel height) are awfully close to those great big speed holes. I think I would be concerned.

09-02-2006 21:43

Éowyn

Re: pic: Top Gun With Wheels

Hmm... judging from the wheels, you are going for the ramp. Also, the indentaton in the chassis to the rear suggests you are attatching a vertical belt system? to get the balls to your shooter.
Nice strong chassis, but bumpers are probably a good idea.

09-02-2006 22:37

Rick TYler

Re: pic: Top Gun With Wheels

Heck, I have nothing to hide:

1. Ramp climbing for sure.
2. Single-wheel over-the-top launcher mounted high on the front rail, with custom bent-back design to launch over 60-inch robots. We are using dual Skyway 8-inch KOP wheels with lexan wheel covers to launch.
3. Vertical belt lifter on rear (drive backwards to load, frontwards to shoot).
4. Quad-CIMs into KOP gearboxes.
5. Big CIM drives wheel. We are running at 2:1 ratio to take advantage of motor torque curve. Lightweight wheels allow us to use step-up gearing.
6. Geared motor on lifter/loader.
7. Medium-speed motor (500rpm with gears) on sweeper.
8. Camera-driven aiming system, using either angled aimer on wheel or wheel speed (final testing TBD).
9. Lovely Blue Angel fabric on the bumpers.
10. Lots of sensors, and a really cool Navy-inspired control panel (our only sekrit wepin.)

Here's the big question: should we equip the whole team with aviator-style sunglasses?

09-02-2006 23:00

Andy Baker

Re: pic: Top Gun With Wheels

Definitely. All members should have nicknames, buzz cuts, and good tans, of course. Maverick, Ice Man, Jester... etc.

I feel the need... the need for a 6 wheel drive base. Good plan.

Andy B.

09-02-2006 23:07

Wetzel

Re: pic: Top Gun With Wheels

Definitely.

Wetzel

09-02-2006 23:15

RogerR

Re: pic: Top Gun With Wheels

while i'm a recent convert to small wheels, i'll always have a special place in my heart for those big 'ol beadlok wheels...

i noticed that in addition to being able to slide the front/back wheels horizontally, you can also slide the middle wheels up and down. did you do this so that you could tension the chain? and if so, why not slide the gear boxes?

10-02-2006 02:03

sanddrag

Re: pic: Top Gun With Wheels

Same here. We're going with 3.5" wheels this year. Scares me, but they should work.

Our best driving robot we've ever built so far had 4 Skyway 9x2 wheels turned down flat. That foam rubber tread drives nice on carpet. I would recommend turning the tread profile flat though. From the factory, they have a pretty small contact patch.

10-02-2006 02:30

Rick TYler

Re: pic: Top Gun With Wheels

It's more so we can tinker with the center wheel height than for chain tensioning. It's our first 6WD bot so the chassis guys aren't sure how low the centers are going to want to go. (I said, "just set them at a 1/4-inch and let's call it good." They said, "what if we can get away with an 1/8th?" I said, "We can't go wrong if we just copy Titan Robotics." They said, "well, this way we can fine tune it." I said, "JUST MAKE IT DRIVE!!3!" They said, "here, Rick, take your meds.")

10-02-2006 02:33

Rick TYler

Re: pic: Top Gun With Wheels

I've only suggested that to the chassis team about 20 times. The response is, "Oh, no, that ridge will make it grip better." My response was, "Race cars have slicks for a reason." Their response was, "We're going to go with it this way."

I swear I'm going to print some business cards with "MS Mech Eng" on them just to get some cred around the shop...