Scout at the Spring 2010 ITP Show

Here are a list of articles on Scout:

BBC News

True/Slant

PSFK

Gizmo Watch

Semageek (French)

Scout from Nisma Z on Vimeo.

Scout (2) from Nisma Z on Vimeo.

Here are photos of Scout, showing the progression of the project and all of iteration of Scout along the way.

Scout’s First Test from Russell de la Torre on Vimeo.

Scout

For my final mechanisms project I would like to build a twin tilt-rotor remote controlled helicopter.  I am calling it “Scout”.  I found that most types of remote control helicopters are very hard to fly for beginners.  Current R/C helicopter design come in two style coaxial rotors and single rotor with a tail rotor.  The coaxial rotors offer very stable flight but are not agile.  The single main rotor design offers great maneuverability but are hard to fly for novice users.  I want to create a hovering aircraft that is easy to fly and very nimble.  I also want the helicopter able to carry loads such as cameras and small payloads.

I will be building Scout out of LEGO Technic building blocks.  I choose to build Scout out of LEGO bricks for several reasons.  First, LEGO bricks are a great prototyping platform.  I can build and rebuild my ideas very easily.  The cost of materials is cut because I can reuse LEGO bricks.  If I were to use a material such as aluminum once I cut a piece thats it I cannot go back.    Second, LEGO bricks are accessible to everyone.  I want people able to build Scout on there own with minimal amount of tools.  Third, going back to my first point, LEGO bricks offer modularity.  If I decide later that I want to add another battery bay or a camera arm to the helicopter, I can easily snap those parts into the main design.

I will be using two electric ducted fans (EDF) for the propulsion.  The frame will be made out of LEGO Technic.  I am using several kits to build the helicopter.  I need to use several kits because one kit doesn’t include all the parts I need to build this helicopter.

Here are the LEGO Technic  kits that I will be using:

• LEGO 8297 Off Roader
• Qty. 2 – LEGO 8265 Front Loader
• LEGO 8258 Crane Truck

I also acquired various parts such as gears and shocks off of eBay.  The helicopter is essentially two helicopters in one, hence I will need two of everything.  Each EDF will need an electronic speed controller (ESC), and battery.  I will also need a decent radio system.  I choose the Futaba 7C 7-Channel 2.4GHz Heli with 4 S3152 servos.  I choose the 7C because I need to do servo mixing.  Servo mixing is when two or more servo move together with only one joystick movement.  Cheaper radio cannot do this function.   The motors I will be using are 3600kv Outrunner Brushless Motors.  I will be using two 45A Brushless ESC.  The batteries to power Scout are lithium-ion polymer (LiPo) batteries.  I chose two 11.1 volt 2800mAh 30C batteries.

Scout isn’t cheap but compared to current helicopter in it’s class it is a bargain.  I sourcing the EDF and batteries directly from Hong Kong, China.  I saving over $300 ordering directly from China.  All the electronics parts are made in China.  The US stores order their parts from China.  I am cutting out the middle man by ordering directly from China.  The downsides of ordering from China instead of order from the US is the shipping duration is weeks instead of days.  The other issue is the build quality of parts can be can be hit or miss.  You may order two batteries, one battery may operate perfectly while the other is DOA.  Chinese seller will replace your defective battery but you will have to send them the defective battery and they will not reimburse you for the return shipping cost.  Even with the risk of a DOA parts, it is still cheaper to order directly from China.  Price list of Scout are below.

Price list:

• LEGO 8297 Off Roader….$130
• LEGO 8265 Front Loader….$80  x2
• LEGO 8258 Crane Truck….$250
• EDF with Motor and ESC….$48 x2
• Futaba 7C heli with servos Radio System….$350
• 11.1v 2800mAh 30C LiPo Battery….$25 x2

Grand Total $1036

Schedule:

March 15 – April 10….Order supplies

March 20 - April 16….Begin Construction

April 17 – 20………….Begin testing and setting up the radio

April 21 – 27………….Test flight and revise

April 29……………….Present

Here is my concept design for Scout.  I used Omnigraffle to create the concept design.  I measured the parts and input them into Omnigraffle to get an accurate scale of my design.

Scout Diagram

First Prototype of Scout

Scout Proposal PDF

The PDF proposal also includes a part list with the weights of each part.  I also calculated the total power to weight ratio of Scout.

This is a free body diagram of a car jack. This free body diagram indicate some of the force that are acting on this car jack when in use.  Fn is the normal force pushing up from the floor.  Fg is gravity pushing down on the car jack. Ft is the torque force being applied by the user.  Fl is the lifting force being generated by Force torque.

February. 25, 2010

For my midterm project I would like to make a electric generator using steam. The components that I will need are a heat source, boiler, piping, turbine, electric generator,  and a electrical output.

The heat source will a propane torch.  This can be purchased at Home Depot for about $45 with propane tank.  I will also use the torch to solder the piping together.  The boiler will either be a found item that can suit the requirements of a boiler or I will make a boiler out of copper piping and caps.   I will need a 2 inch copper pipe with 2 inch copper caps.  The total cost for these parts is $24.  For the turbine I plan to convert an air grinder into a turbine motor.  I am hoping the boiler can build enough pressure to power the air grinder.  The air grinder will cost nothing because I have an air grinder that I can convert.  I plan on using an electric motor for the generator.  I have plenty of motors to choose from and will have to see which one will work best.  I will need a linkage from the air grinder to the electric motor.  I plan on using spare parts that I have to create the linkage.  I then use a light to show the energy being create by the generator.  The total cost for this project will be around $90 half of this is for the propane torch.  I also allowing $21 for fittings and scrap metal.

Schedule:

February 25 – March 1…. Order supplies

March 2 – 4……………….Construct Boiler

March 5 – 6……………….Pressure test boiler and adjust if needed and construct turbine and motor linkage

March 7.….……………….Attach Turbine (Air Grinder) to boiler, assemble and attach linkage to turbine and motor

March 8…………………..Troubleshoot any problems

March 9…………………..Troubleshooting

March 10………………….Mount and fix components to base, connect output light

March 11………………….Present

• Make a car powered only by 1 Victor brand mousetrap (NOT rat trap)
• No electricity allowed
• The goal is to travel 10 feet.

• There are no specific size, material, or weight requirements. However, it should be able to fit next to 2 other cars inside the class room.
• The only human interaction should be to trigger/start the car.
• Fastest car wins

Using these rules we knew that the racer had to be as light as possible to efficiently transfer the potential energy into speed.

We used the actually mousetrap as the cars chassis.  For the back wheels, we made wooden wheels out of scraps wood and attach rubber strips to the wheels for traction.  The front wheel was made out of a ping pong ball and again we attach a rubber strip for traction.  The front wheel has a aluminum shaft with a wooden dowel through it.  This aluminum shaft and dowel assembly acts as a bearing for the front wheel.

The car’s acceleration is really fast. We took 1st place in our class competition!

Mousetrap Racer Test #1 from Russell de la Torre on Vimeo.

Blender is a free application and is available on the PC, Mac, and Linux.  This is definitely a plus because the other applications cost thousand of dollars more. Every 3D application have areas where certain task are easier to accomplish than others.  For me Maya is very intuitive and easy to work in.

Evaluation:

I downloaded and installed version 2.49 of Blender for the Mac.   I then went to their tutorial section and found that they have a couple of video tutorials of the interface, different modeling technics, animation, and rendering.  I began with the interface video.  I had to re-watch the video because of found the instructor confusing.  Nevertheless, I persevered  and tried to create an object.   Blender has some feature that are similar to Maya such as the spacebar menu.  I found this intuitive to create models.  The manipulation tools of Blender are hard to work with.  Blender relies a lot on keyboard shortcuts.  For a beginner it is very hard to work in Blender without remembering the keyboard shortcuts.  I did get use to the mouse buttons and how they function.  This I liked a lot.  Selecting objects were easy to do and I can move among many objects with ease.  There is a steep learning curve with Blender and compared to the interfaces of Maya and 3D Studio Max it is very different.  I have had only a week to play with Blender and couldn’t judge accurately if this is a good program or not.  I did see some of the examples that were created in Blender and I can see that is program has great potential.