Medicycle - Urban Responder

Here is a sneak peak of the design we have chosen for the medicycle, it is a 2d 1:1 scale foam model complete with a dimensionally accurate representation of human, commonly used by car designers etc to help come up with an ergonomic design.

More Balance control electronics parts 14/6/14:

Sparkfun 6 degree of freedom (DOF) Inertial measurement unit (IMU):

US Sparkfun site:

https://www.sparkfun.com/products/10121

UK supplier:

http://proto-pic.co.uk/imu-digital-combo-board-6-degrees-of-freedom-itg3200-adxl345/

SERIAL 7 segment 4 digit displays from Sparkfun

(Instead of millions of wires from Arduino to each display, these just have 5V power, GND and a single serial transmit wire from the Arduino to the display. This means the Arduino Uno running “Software Serial” code can control 3 of these with no problems:

US website:

https://www.sparkfun.com/products/11442

UK supplier:

http://www.hobbytronics.co.uk/7segment-serial-display-green?utm_source=google&utm_medium=googleshopping&utm_campaign=googlebase&gclid=CjkKEQjw5e-cBRDysazatpTm5b8BEiQAWxTHh3CkG_1EvzuOCBxjqrGpfYGs9gtD8FARtM1O6XOFn2vw_wcB

DC/DC step down voltage regulator 9V to power the 2 Arduinos in control electronics:

Tracopower TSR-1-2490

US site:

http://www.newark.com/tracopower/tsr-1-2490/dc-dc-conv-step-down-switching/dp/86P6890

UK site:

http://www.amazon.co.uk/Converter-DC-24V-Sip-QTY/dp/9820666252

NOTE: We also need a Tracopower TSR-1-2450 which looks exactly the same but puts out 5V not 9V. This one will be used to provide power for the serial LED displays as we do not want to overload the on board 5V regulator on the Arduino Uno.

Small on/off switch to turn the two Arduino boards on and off. Example:

Ribbon cable.

Example website:

http://www.ebay.co.uk/itm/Grey-Ribbon-Cable-Wire-34-Way-Per-Metre-/301137855697?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item461d3704d1

Note: Does not have to be exactly the same as this. “20-way” would also be fine, or a pair of “10-way” cables from under seat where Arduino live, to front of the machine, where the displays / controls will live.

Potentiometers, 4 of them, 10K Ohms each:

Example:

http://www.ebay.co.uk/itm/1-5-10-20-50-100-500-K-M-ohm-Linear-Logarithmic-Mono-Stereo-Pot-Potentiometer-/170703080727?pt=UK_BOI_Electrical_Components_Supplies_ET&var=&hash=item27beb24d17

Also need 4 knobs to fit to them.

CIRCUIT BREAKER to protect your OSMC catching fire when the motor jams or shorts out. OSMC rated at around 150 Amps when it has a cooling fan on it. Therefore having “lost” an OSMC in the past, we choose a circuit breaker that trips out at about 75 Amps, this should preserve the OSMC hopefully! It also functions as the main power on/off switch. Mine is very similar to this one.

Example:

http://www.ebay.co.uk/itm/Durite-70-Amp-12-24v-DC-Panel-Mounting-Circuit-Breaker-0-388-70-/321200698065?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item4ac90db2d1

Here is a possibly cheaper one but the 80A one is out of stock, they still have the 60A one though, see below:

http://www.ebay.co.uk/itm/20-30-50-60-80-100A-Car-Stereo-Audio-Inline-Circuit-Breaker-Reset-Fuse-12V-24V-/310793751700?pt=UK_BOI_CircuitBreakers_RL&var=&hash=item485cc04c94

This is a preliminary list of components for the balancing and power electronics and where to find them.

Arduino Uno

http://store.arduino.cc/index.php?main_page=index&cPath=11

Arduino Mega

http://store.arduino.cc/index.php?main_page=index&cPath=11

OSMC Motor controller

http://www.robotmarketplace.com/products/0-OSMC.html

XBEE wireless receiver

http://www.adafruit.com/products/128

BATTERY PACK:

Cheap (relatively) e-bike LiFePO4 20AmpHour 24 volt pack from Hong Kong:

Here is a similar one on ebay:

http://www.ebay.com/itm/24V-20AH-LiFePo4-Battery-Electric-Bicycle-Scooter-E-Bike-Rechargeable-Free-ship/181426354090?rt=nc&_trksid=p2047675.m1851&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D22425%26meid%3D7497033859865692253%26pid%3D100005%26prg%3D9723%26rk%3D1%26rkt%3D5%26sd%3D371075633814%26

When working on a new project its always a good idea to plan ahead, its easier to build around parts you have then to find parts that will fit what you have built.

This is a preliminary list of components for the helmet display and where to find them.

Head up display (Receiver part in helmet):

Arduino Pro-Mini 3.3V

Example of an Arduino Pro-Mini with USB programming attachment 3.3V Atmega 328

Adafruit OLED display board

http://www.adafruit.com/products/661

XBEE wireless receiver

http://www.adafruit.com/products/128

Will need 2 of these as one transmits from bike and the other receives data in the helmet mounted OLED display

USB Lithium battery charger (for helmet mounted OLED display module):

https://www.sparkfun.com/products/12711

LiPo battery for helmet mounted data display:

https://www.sparkfun.com/products/10718

NOTE: Circuit diagrams and details of transmitter section within the main bike will come later as we build it into the bike.

When working on a new project its always a good idea to plan ahead, its easier to build around parts you have then to find parts that will fit what you have built.

This is a preliminary list of components for the mechanical aspect of the Medicycle and where to find them.

Chain tensioners 15mm for Pit Bike

Sunstar 32T Steel Rear Sprocket Kawasaki KLX110 03-09 (Jawzy’s PowerSports Inc., 1515 West 130th St STE A, Hinckley, CH 44233-9169 330-273-6161 USA)

Sprocket needs to be for 420 chain size basically.

You can get alloy sprockets but as sprocket smallish in relation to wheel (so lots of pull on it from gear motor via the chain) we preferred to get a steel one.

420 pitch chain:

15mm diameter Pit Bike axle and spacers, 210mm length. (www.petrolscooter.co.uk)

MY1020Z Electric Motor 24V Bike, Scooter 24 volt Gear Unite. UK supplier: Nova Products, Unit 51 Burtonwood Trading Estate, Phipps Lane, Burtonwood, Warrington, Cheshire, WA5 4HX, UK.

£74.98

Example of current motor on US ebay:

http://www.ebay.com/itm/24V-36V450W-Electric-Motor-Electric-Scooter-Bicycle-Tricycle-MY1020Z-Unite-Motor-/141106089253?pt=Cycling_Parts_Accessories&hash=item20da940d25

Welding gear:

Nothing sophisticated here:

Basic hobby MIG welder with disposable CO2 cylinders will be fine.

Box and round section steel in lots of sizes. At each stage consider the weight of the machine, need to keep total weight under control but keep very strong where required. Our wheel/motor frame is probably over-strong right now and area around hinges also very strong to avoid twisting. Our steel came from hardware store – an expensive way to buy it but then we do not need large amounts. You can also get steel box section etc on ebay delivered to your house if you prefer.

Alloy would be better for a commercial machine but advantage of steel is it is easy to saw off and change something, also project has to be capable of being built to a basic working standard by a hobbyist.

Construction has begun, progress report coming soon