GravityBowl Updates

Photos from Burning Man 2004

2005-04-03T21:01:00.000-07:00

Here are some photos of the Gravity Bowl at Burning Man 2004. More are posted on
bm2004-gravitybowl.htm.

At Night -- Demonstrating the Anti-Gravity System

At The Man


Working in the Dust


Working at Night


Early Test Runs

gravity bowl up on blocks

2004-10-06T23:02:00.000-07:00

IMG_2182.JPG
Originally uploaded by bradyf.

when we first got to bm we had to put together the dogdish and it was on blocks for many days. when we first moved everyone was amazed; they had thought we were just some cool sort of couch.

Action videos!

2004-09-09T17:47:00.000-07:00

Here are a few video's of the car in action!

In the first two notice that the direction of motion is independent of the orientation of the car:

Here we are spinning:

Loading

2004-08-27T12:28:00.000-07:00

Some generous friends helped us move and pack the car:

We rented a 24' truck for transport:

To fit the pieces we stacked them up, basically flipping the car on top of itself. Three pieces in place:

One piece left, the shop is looking empty:

All packed!

We'll be back from our test drive in the Black Rock Desert in two weeks. Check in early in September for photos and movies of the car in action!

Disassembly

2004-08-27T11:30:00.000-07:00

Made a lot of last minute progress. The network code is now working and the wheels can be turned and rotated via the central console.

Time to pack it up! The GravityBowl is significantly wider than a highway lane so we need to break it apart to move it. The car breaks in to 7 pieces - a floor and six pie shaped wedges.

First we put the car on blocks and remove the tires:

Then we disconnect the wiring. Two main wiring harnesses (for lighting), network cables and battery cables pull out of the individual sections and wrap up for shipping storage in one main section:

Then we remove the floor:

Unscrew each of the sections:

Here's the disassembled car in six sections:

The whole process took about 3 hours.

Blue Lights and Motor Testing

2004-08-20T13:48:00.000-07:00

All five of us enjoyed testing the newly made cushions, basking in the blue glow of the Gravity Bowl, and listening to its sound system.

Simon gave the motor controllers a workout. (See video!)

Flash! Bang! ~smoke~

2004-08-19T12:05:00.000-07:00

A mixed and late night last night.

On one hand we got the drive shaft rotating accurately under computer controlled power. Here is a video of one of the drive shafts doing quick 60 degree turns.

Rotating Wheel

There is a bit of oscillation, but that should be seriously reduced once the wheel is under load (the car is still up on blocks).

On the other hand, we managed to blow up one of the motor controller boards. Hopefully the components weren't too badly damaged and we can repair the board, or Simon has a spare board and we may be able to piece together enough to build a new one.

Storage and cushions...

2004-08-19T11:55:00.000-07:00

Storage compartments are now complete and painted red. They contrast well with the cushions:

Cushions look great on the car:

And are damn comfy too!

progress update

2004-08-19T02:58:00.000-07:00

Simon, Lars and myself left the shop tonight at 2:30am. In the course of testing all three wheel assemblies we found two bad cables and damaged a board, which was very exciting! Simon has it all under control.

NOTE: In light of the additional work that's required to repair the board, and in light of how useful it's been to test the electronics in situ we're not going to disturb a good thing by taking the car apart for testing. We gonna work through till the end. We can test the backup system on site if need be.

Cushions!

2004-08-13T21:16:00.000-07:00

The women of Groovig have been hard at work on the cushions:

They are looking great:

...thoroughly testing them for your safety:

Lots of wiring...

2004-08-12T13:25:00.000-07:00

The amount of wiring in the car is getting pretty insane.

Getting into the tight spaces can be a challenge:

Once inside it's not too bad:

Kevin sqeezed in too:

Here's the main junction for the lighting:

A Big Night of Testing Electronics

2004-08-04T22:41:00.000-07:00

Tonight was a significant event! We got a chance to do a some testing of the wiring, control box, and the motor controller circuits. Simon brought in his laptop with a debugger, and took current readings as he powered the drive motors for a fraction of a second. (Well, it only sounded like a small "click".)

Geoff finished wiring up the backup system, with a two-pedal arrangement which can drive one wheel or all three together. Simple, but it works! We got to hear the drive motors roar!

Some words of wisdom from Kevin about lessons learned tonight...

1. Fuses are good! We discovered this burning through several 10amp fuses until we realized that the diodes on the contacters were causing a short. The diodes are in the right direction for the main control, and the wrong direction for backup mode.

2. Disconnecting the power completely before messing with wires is highly recommended. We burnt through a thin wire that accidentally shorted with a loud ZZZZAAAPPPPPP which scared the hell out of us.

3. 24V will probably be too fast. But we can re-wire it for 12V very easily.

4. Chains are loud. Sorry. I shoulda used belts or gears.

New design docs posted...

2004-08-04T14:54:00.000-07:00

We added a few new design documents to the web page. Specifically some detail on the cladding, flooring, railings, the electronic control box and the upholstery and some detail on the circuit boards.

Lessons learned

2004-08-04T08:35:00.000-07:00

Geoff and I got the back up system working. As Simon predicted it is simple and it worked. Geoff's pedal arrangement can drive one wheel or all three together.

However! We learned a few things:
1) Fuses are good! We discovered this burning through several 10amp fuses until we realized that the diodes on the contacters were causing a short. The diodes are in the right direction for the main control, and the wrong direction for backup mode.
2) Disconnecting the power completely before messing with wires is highly recommended. We burnt through a thin wire that accidentally shorted with a loud ZZZZAAAPPPPPP which scared the hell out of us.
3) 24V will probably be too fast. But we can re-wire it for 12V very easily.
4) Chains are loud. Sorry. I shoulda used belts or gears.
5) A kill switch that cuts all power at the main fuse panel is pretty essential for safety, i.e. the backup control system has no "Off" switch without it.

progress this weekend

2004-08-01T21:03:00.000-07:00

This weekend everyone pulled the stops out and accomplished huge amounts of work!
- Final wiring on the vehicle is virtually done.
- The back-up control system has been designed and about 75% completed.
- Headlights and interior lighting are complete. More lighting is in the works.
- We had another guest helper, Nancy aka "Rosie the Rivetter", help with doubling up rivets on the interior.
- A number of the seat cushion foam pieces have been cut.
- And! the fabric is all cut including a big round cushion to fill the center.

Control Box & Foam

2004-07-31T18:35:00.000-07:00

Simon's coming along with building the control box. We temporarily lined up 6 batteries to get the 36v needed to power it up.

And, the foam arrived! Here are two pieces cut for the seats.

More Photos of the Processor Boards

2004-07-19T09:03:00.000-07:00

Electronics

2004-07-18T16:00:00.000-07:00

Simon has made great progress on the electronics.

Almost all of the components have been soldered onto the boards:

This was a long and meticulous process as many of the components were very tiny. Here is a picture of some of the resistors:

Each board has a port for an LCD screen that can be used for debugging and eventurally getting feedback from the main CPU:

Simon hooked up the cpu board to one of the motor control mosfet boards and began testing. He connected a motor to the mosfet board and lo and behold was able to control the speed of the motor quite nicely.

Lights...

2004-07-14T14:01:00.000-07:00

Just ordered lights for the GravityBowl from Cool Light. We will be using super bright LED arrays for both the headlights and accent lighting. Not sure we'll be able to do much more with our budget. Note that they are offering a significant discount for Burners!

We've made a lot of progress on wiring over the last couple of weeks and Simon and broken through a couple of roadblocks on the control boards.

Seeking help....

2004-07-05T16:58:00.000-07:00

As you can see from the blog we’ve been working hard since last October, and progress on the GravityBowl has been great.

Unfortunately we underestimated the cost of this project. Despite getting financial assistance from Burning Man and putting in 10k of our own money, we are now at a difficult decision point. We’d prefer not to pass on including comfortable seating, lights and shade, but we’ve already tapped our personal resources.

We discussed the idea of trying to put on a fundraiser but realized that that would take too much time away from finishing the actual car, and fundraisers often only break even. As an alternative, we were hoping that maybe members of our community might be willing to make small donations to help us complete the car. (You would of course be guaranteed a ride on playa!)

If you are interested in helping out, please visit:

Help the GravityBowl!

Thank you.

- The GravityBowl Team

A busy 4th...

2004-07-05T16:51:00.000-07:00

Much of the main wiring has been completed. Here is the main power junction:

Kevin is busy working on the boxes to hold the motor controllers and CPUs:

The drive and battery sections have been detailed:

Suzanne helped double up on the riveting:

Fabric has been chosen and ordered for inside cushions:

Circuit Boards

2004-06-27T17:43:00.000-07:00

Simon's CPU and motor controller circuit boards were built this week. Now all that's left is to solder on all the components and their hundreds of tiny pins!

More Progress

2004-06-27T17:07:00.000-07:00

A lot has been acomplished in the last two weeks. Kevin built 6 removable access door panels to cover the drive motor and battery areas. Behind each panel, a couple of long bolts stretch from side to side in order to provide the tension necessary to obtain the desired curvature.

All of the high current wiring has been finished, along with trays to hold the batteries.

Geoff built 3 under-seat storage compartments.

Wiring the Motors, Installing Battery Trays

2004-06-12T18:04:00.000-07:00

Today we accomplished much: Wiring the motors, and working on the battery trays and storage compartments.

Click these links to see movies showing a steering motor and a drive motor in action!

Here's some photos of the wiring:

Kevin Drilling

CPU Design...

2004-06-11T14:11:00.000-07:00

Simon worked an 18 day...