Two screws, one on either side of the battery bay - battery removal required:

One screw on each side, just forward of the wheel mount

Bumper screws - 1 of 4

Bumper screws - 2 of 4

Bumper screws - 3 of 4

Bumper screws - 4 of 4

After all four bumper screws are removed, flex the gray bumper skin until the catch on the bumper skin comes off of the black under structure and lift the bumper. Keep it close to the body of the Roomba as there is one wire bundle connection to the base that can be disconnected after the bumper is lifted.

Two screws, one either side, in the depth of the brush carriage on the forward edge.

Lift the white body skin, again not too far as there is a wire assembly connected to the base

Two screws for each wheel mount

Four screws on each wheel cover. As you remove the cover take careful notice of where the wiring is routed between the structure of the wheel and the edge of the wheel cover.

With the wheel cover removed, remove the drive belt and pull out the tachometer pinwheel

And now the goal - the exposed tachometer IR emitter

Debris will get caught here and disrupt the tachometer IR sensor’s read of the IR emitter signal through the tachometer pinwheel

Clear the debris, put the pinwheel back, put the drive belt back, put the cover back on the wheel being careful to route the wires around the outside of the guard that keeps the wires from being destroyed by the drive belt, rotate it back into position with the wheel mounts, then put the skins back on and reseat all the screws.

Should be fairly obvious the entire show is scripted. Challengee is at a remote location, dressed up, wearing makeup, already has all the appropriate cooking equipment and supplies on location.

If they were there for an planned event like the show claims, the food would be pre-cooked or partially pre-prepared, and most of the work would be done by employees not the cook.

After I had the chassis assembled out to the suspension arms, I finally hit the point where it was time to buy upgrades. Since the DF-02 only comes with bearings for a portion of the chassis, with plastic bushings provided for the drive train components past the front and rear differentials, I went to my local hobby shop and picked up a total of 8 bearings. While I was there I also splurged on a radio - a Spektrum DX6 Park Flyer.

Since I have no interest in ever trying to fly a model rc vehicle, I don’t need the full range of the more expensive aircraft controllers, but my robotics interests necessitate more than 3 control channels and a stick controller is a good idea.

The bundled AR6000 receiver is wired into the chassis at the moment but there’s a danger. The AR6000 has a failsafe position only on throttle and all other control interfaces go to a maintain last command signal during signal loss. Since the DX6’s throttle is a position-hold stick, it’s better to use the right hand stick (Elevator) for throttle. Since during signal loss the receiver would maintain last command, that means that on signal loss my car would keep throttle at whatever I was doing at the time that signal dropped.

So, since then I’ve also gotten two BR6000 bot receivers which have firmware that provides a failsafe position on all channels. That’ll let me put a failsafe signal on what is actually plugged into my ESC on my bots.

I’ve received a Tamiya DF-02 chassis based Gravel Hound buggy kit. This kit has everything from the ESC and motor on out, so to get operating I need a battery, battery charger, servo, radio, and receiver.

Now to find out what my local hobby shop carries.

Had to google for some how-to on dismantling a Roomba (and couldn’t find one for the plain Roomba Discovery that I have). After the obvious task of removing all the visible screws on the bottom of the main body, the ones holding the front bumper skirt on, and two deeper in the wheel wells, it’s pretty straight forward.

Pop the front skirt off (it’s friction fit held in place by the screw posts from the screws and two clips on the edges), unseat the IR sensor cable, and set it aside. After that, pop off the top, unseat the buttons cable, and set that aside. You’re left with a topless roomba and the task of getting the wheel covers off so that you can get at the tachometer IR diode and IR sensor in the wheels. Here’s the problem. One of the screws isn’t reachable on some models because of the exterior “fender” portion of the body. Some newer roombas have a removable fender, some don’t. Some howtos suggest drilling a hole but I found it just as easy to remove the wheel. From the bottom of the roomba the bottoms of two screws are visible next to each wheel. The heads are at the top, under the lid. You have to remove these two screws at which point a plastic block holding the wheel assembly into the base will fall out. Once both of these blocks are removed you can push the wheel up out of the wheel well and get at the fourth wheel cover screw. Remove the wheel cover (carefully note how the wires route along the wheel cover edge - this is important as they’ll rub against the drive belt if they’re out of position), remove the drive belt, and remove the spoked wheel. It is on a plastic axle that rests inside a planetary ring gear assembly inside the wheel. Near as I can tell these are all trapped gears so you don’t have to worry about anything inside the wheel slipping out of position when you remove the tachometer gear. Clean the two translucent probes (one’s an emitter, the other’s a sensor - same as in a mechanical ball mouse) and reassemble.

After running through this, my busted roomba drives straight. Now all I need is to replace the brushes that were destroyed in the fight with the cat dropping and get a new battery (the original has since worn out in the new roomba and the new roomba has its original battery). Or perhaps just rebuild the old battery.

The Tamiya DF-02 chassis has a larger bathtub chassis and a longitudinal engine mount.

Also an option, the Team Academy / Model Rectifier Corp. SB Pro Buggy Kit, a very economical 4wd buggy that has some high end racing features.

The Tamiya DF-03 chassis that is the basis of the Dark Impact has a couple limitations. There have been complaints about the tight fit of the bathtub chassis space for servo, ESC, and receiver, none of which come with the kit, such that you have to be careful what you buy for fear that it might not all fit. Separately, the motor is mounted transverse in a socket in the chassis, without space for a heat sink and possibly in an arrangement that may not be able to accomodate motors that are the same size but have different wiring configurations or that are longer.

And thus: The Kyosho Lazer ZX-5. The Kyosho Lazer ZX-5 is a newer higher end kit designed for racing. The kit includes three different differential gear designs and threaded aluminum shocks. It also has a larger bathtub chassis design with a logitudinally mounted motor. These features make it a much more flexible design.

- Start with an HPI E-Savage 1/10th scale 4wd electric monster truck RTR package and a Spektrum DX3.0 2.4ghz radio package. This gets me a 3channel controller immediately as well as an extra servo.

- When Castle Creations releases the Mamba Monster Max, if it fits the E-Savage without wild modifications from a dremel, get one of those sets plus a ubec, a pair of lipo batteries and a decent lipo balancer/charger. This will establish a long endurance run time for the E-Savage as well as surplus out the E-Savage stock battery packs, charger, and ESC. At this point the stock battery packs can be doubled up on the E-Savage as a power supply for the camera, if I have something to transform the voltage.

Then once I’m settled with the long endurance (and fast!) brushless E-Savage:
- Get a Tamiya Dark Impact 1/10th scale 4wd buggy kit, possibly along with a Spektrum receiver. The kit has everything from the motors on out to the wheels so it’ll need a radio, receiver, esc, and servo. I’ll have the stock ESC, servo and batteries from the E-Savage to complete it. I can use the E-Savage radio and receiver or the Spektrum DX3.0 if I get the Tamiya a Spektrum receiver.

Lets see.

I eventually want a 2.4ghz radio system for both. The Tamiya is cheaper, but doesn’t come with a radio so I would have to buy a radio for it. The E-Savage comes with a radio, but it’s a 27mhz AM radio. E-Savage first then the Tamiya would mean I’d at least already have a 27mhz AM radio in the collection to drive the Tamiya, but I’d have to get a 27mhz receiver for it. Best would be to get either one and a Spektrum DX3.0 at the onset, then another Spektrum receiver for the second car whenever its obtained.

The E-Savage comes with batteries and a less than ideal charger out of the box. The Tamiya comes with no batteries. It also has a brushed motor. I think I’d like a brushless system for the Tamiya (assuming they can take one without the application of a dremel) so in the interim the stock batteries from the E-Savage could be used, particularily if I upgrade to lipo batteries.

Should also pick out the batteries and charger I’ll want.

I think I want the Tamiya Dark Impact 1/10th scale 4wd electric buggy kit. As a kit and not an rtr package, it lacks several items, namely a transmitter, receiver, electronic speed control, and batteries. It has everything else from the motor out to the tires.