Category Archives: Misc.

Articles that don’t quite fit into other categories.

Making Atlatls & Meeting Great People

One of the nicest things about working at Thunderbird Atlatl is the people we meet as we travel around or on the phone when you call our shop! We’ve been making atlatls for over 20 years so we’ve met a lot of great people over the years. Thank you all for your support and stories. We love hearing about how much people enjoy using the atlatl and that they appreciate our products. Our atlatls are being used all over the world even in Mongolia thanks to our son, Peter! Peter recently traveled to the Gobi Desert and introduced a family he stayed with to atlatls.

Here are some of your comments:

Thank-you! I received it! Its awesome! Definitely worth the wait!!

Thanks, I am very pleased with the atlatls and am sure I will be with the darts as well. I will use your company for any future needs and recommend you to others.

Love your products! We have had HUNDREDS of youth and adults using your atlatls as part of our programs.

I took my new toy, a Kanakadea, for a maiden test flight today. I’m totally hooked! I even had the neighbors, who had never heard of such an instrument, commenting favorably.

I got my atlatl today and it was in great condition, thank you for packing it so well. I used it today at lunch and was shocked at how easy it is to pick up on. Thanks for the atlatl, I can’t wait to get a deer this year.

A young woman in Mongolia tries a Catatonk atlatl!

A young woman in Mongolia tries a Catatonk atlatl!

Peter Berg visiting with a young friend in the Gobi Desert of Mongolia. Thunderbird Atlatl darts are in the background near the yurt or ger.

Peter Berg visiting with a young friend in the Gobi Desert of Mongolia. Thunderbird Atlatl darts are in the background near the yurt or ger.

Hot/Cold Hybrid Drive Train

A Cool Way of Squeezing More Energy Out of Fuel

A hot/cold hybrid automobile drive train uses fossil fuel to run a small engine that compresses its own products of combustion, mixes it with liquid nitrogen that runs pneumatic engines that power the drive wheels of the car.

Typical internal combustion engine vehicles are less than 20% efficient because they loose large amounts of energy out of the radiator, tailpipe, radiation from engine parts and drive train friction. The Hot/cold hybrid drive train system uses both sides of the thermodynamic equation to produce kinetic energy to power the car. The heat generated by the burning of fuel and the compression of the products of combustion mixes with and boils the liquid nitrogen creating high pressure utilizing heat that would normally be lost. The liquid nitrogen absorbs enough heat to go from ?196 C or ?321 F to over the boiling point of water. If the liquid nitrogen were not confined to its pressure tank it would fill a volume nearly 700 times its liquid volume.

Click on the picture to see a larger version.

Diagramatic Car Concept

ln2-flow-chart

Car Concept

This concept drawing shows the small internal combustion engine to the left, attached in line to a compressor. The exhaust from the engine goes directly into the intake ports of the compressor. As the exhaust gasses are compressed they become hotter. At this point the hot compressed gasses are mixed with liquid nitrogen through a special valve. The mixture passes into a tank which has provisions for removing water before being used in the pneumatic engines located as close to the drive wheels as possible.


So Where Do We Get That Much Liquid Nitrogen?

Answer: Windmills
The largest problem with wind electric power generation is that for every megawatt of power a windmill may produce you need to provide an equal amount of alternate electric power somewhere else that can operate when the wind isn’t blowing. The alternative power station must be able to go on and off as the wind changes and respond immediately to demand. Windmills also have problems operating in very cold weather.

This proposal solves several problems.

Windmills could be designed to directly power large capacity compressors connected directly to the wind turbine in the nisscell at the top of the mast. The Von Linde system of converting gasses to liquids would be used which essentially uses a multi-step process where air is repeatedly compressed and cooled. The initial cooling fins containing hot water which is a byproduct of the Von Linde process could be located in the routers of the windmill which would make it usable in even the coldest weather when normal windmills are dangerous to operate because of icing. Windmills used to generate liquid nitrogen would work best in near blizzard conditions when the wind is blowing hardest and the cooling system is most efficient.

If windmills were used to make liquid nitrogen, when the wind did not blow it would not cause the immediate need to turn on an alternate power generator. Tanker trucks would pick up the liquid nitrogen when the wind mill’s tanks were full. Wind mills can be located close to where you need to fuel your vehicle instead of Saudi Arabia.

Use Locally Available Fossil Fuel

It is easy to operate small engines on liquid natural gas by changing the carburetor and adding a pressurized tank to hold the fuel. Liquid natural gas is energy dense. Not only does it contain the energy of combustion but also, like the liquid nitrogen, it has a reserve of energy contained in its heat of vaporization that can also be used to help propel your future car.

Symbiotic Uses of Local Power

The flow chart above shows several ways to produce liquid nitrogen and the byproducts that can be gleaned from the process.

Symbiotic relationships with other industries could be formed. An example of that would be a hospital located near windmills that could use the hot water, oxygen, and xenon produced in the process of generating liquid nitrogen.

Steel mills that use a lot of oxygen could form symbiotic relationships with auto fuel suppliers by supplying them with nitrogen rich gas left over from separating out the oxygen.

Welding supply companies use argon and oxygen and could liquefy the nitrogen for use as auto fuel.

Aztec Atlatl Battle Instructions

Aztec Atlatl Battle is a field game that pits two teams consisting of eight atlatlists against each other. Each team will have one person designated “Chief” and one person designated “Shaman”, all other players are designated “warriors”.

The 12 yard by 80 yard playing field represents a section of causeway that once linked the Aztec city of Tenochchitlan with the mainland. Each atlatlist must have an atlatl and three darts. In addition each contestant must be represented by a target made from ethelfoam or similar material that is 24″ square and two inches thick. Radiating concentrically from the center, the targets must have a 6″ inner circle of blue, around that is a twelve inch circle of red , and outside that is the final ring of 20 ” in yellow. The targets are held off the ground by hardwood tripods three feet high. The tripods should be of a design to be able to be easily moved with “feet” that allow them to be planted sturdily into the ground yet hold the target center 3 feet from the ground.

The field of play is cordoned off with rope or tape in a rectangle 12 yards by 80 yards inside a safety zone 50 yards by 120 yards. The playing field is divided into eight 10 yard sections called zones.

The play occurs in rounds. In each round each person shoots the amount of darts allotted to him or her from directly behind his or her respective target.

Each person starts with 3 darts. Regardless of the order of shooting everyone gets to shoot all of his allotted darts for that round. For safety’s sake only one shooter is allowed on the field at a time. The order of shooting is of no importance and may be determined by the Judge. Everyone must be ready to take his or her turn as it comes to keep the game moving.

After everyone has shot, the round is over and the “dead” are removed from the field. The wounded give up one or two of their darts.

  • Those hit in the yellow ring give up one dart and those hit in the red must give up two darts. Anyone hit in the blue is considered dead.
  • The Shaman reside in their respective end zones. Shaman are not allowed to move to any other zone but they may move to any location in the end zone that they desire.
  • Chiefs are allowed to move to any zone except their opponents end zone, at the end of a round. No one may move beyond or into a zone occupied by a “live” opponent. In other words a person may not move past the “war front”. However after a round where all opposing soldiers are killed in a particular zone the zone may be occupied by any one who is in position, when the round is over.
  • Warriors may be in any zone except the end zones, however they must move only one zone at a time between rounds.

At the beginning of the game the Chief and Shaman start in the end zone and two warriors start in each of the other zones at their respective ends of the field, so two contestants will occupy each of the zones at first. The Shaman may allow the Chief to shoot his three darts if he so desires, as long as the chief is alive. The Chief may shoot the Shaman’s darts from behind his own target regardless of his location on the field.

It is the duty of the Chief to direct his team, be he dead or alive.

At the beginning of the game the chief determines the placement of his team members targets. A very important part of the game is the strategy and game plan. Each team should be constantly trying to devise a plan to foil their opponent.

It is recommended that each team provide their own tent on opposite sides of the field for shade from the sun. It will also make it safer than to have people roaming around if people stay in the general area of their tent.

A field judge shall be chosen who is familiar with the rules of the game and general safety rules of the sport. All decisions of the Judge are final as to scoring. In addition to this the Judge has the right to dismiss anyone violating safety rules from the field. The Judge may appoint a Safety Assistant to watch the field for safety problems. Both the Judge and his Assistant shall have a whistle, which when blown shall stop all shooting. After the safety issue has been resolved, the Judge may resume play with a verbal signal.

This is a preliminary draft of the rules of this game. The rules may need to be changed as necessary to assure the safety first of all and the fairness of play.

This game is authored by Robert S. Berg of Thunderbird Atlatl, Copyright 2000.