Monthly Archives: October 2015

Personal Transporter V2.5

This project is a continuation/improvement of the Personal Transporter V2.

The personal transporter V2.0 has improved significantly from the V1, but it still has some problems. One of the problem was I had used too thin of a plywood (10mm) and when I stood on it, it flexed and would cause problems for the motor/coupler mechanism. It also had a PVC pipe mount as I had originally thought of using a PVC pipe for a handle for the personal transporter but ended up not using it. The V2 was also quite large, it was about the same size as the V1, only lighter. There was a lot of wasted space. Another problem of the V2, although minor, but still quite important is that the motor is mounted on a bracket meant for shelving units. The last problem was that the V2 is a three wheeler, which means I had to balance on the one caster wheel and with 2 driving motors (The V2 was front wheel drive).

With all that, I decided to improve the V2. I am going to be using almost all of existing parts from the V2 to make V2.5.

Plans:

  1. Use a proper bracket for the motors
  2. Use a thicker plywood (I used 12mm)
  3. Make it smaller
  4. Use 2 caster wheels

Extra Parts:

GW370 Motor Bracket Ebay Link

Plywood

For the plywood, I used a leftover that I had found in my school’s Fab Lab. It was 12mm thick, with 3 layers. I had it cut to 30cm x 35cm as I found this is the perfect spot because I did not have to squeeze my legs together so close. Always plan by placing down the parts on the uncut plywood. ¬†Using a power jigsaw that I had loaned from the Fab Lab, I had it cut with the help of my friend holding down the plywood down. Make sure to use a dust mask and goggles as the plywood particles a very fine.

Once cut, I used a dremel with a grinding attachment that I had borrowed from a friend to file of the surface irregularities and straighten it.

After that, I placed all the parts again on the cut plywood to make sure everything fits, just to make sure. I then marked and drilled the mounting holes for the motor, caster wheels and the bearing using the appropriate drill bit size. As I wanted the the plywood to be flat and all screws flush, I had to also drill counterbore holes. However the bolts for the caster wheel had a 13mm diameter on the screw head, I had to use a dremel with the grinding bit to make the holes fit the screw head.

Once all of the holes have had their counterbore treatment, its time to spray paint it. I had some leftover from the V2 project, so I just used the same grey spray paint. I sprayed 2 coats on the top base and 1 coat on the underside part as I thought nobody would really see the bottom part.

Finishing Everything

I reused all the screws from the V2, except for the motor mount as it it different. I used M4 x 15 screws for that. As for the battery, I changed the mounting method by attaching one side of the velcro on the battery and the other side to the plywood. The adhesive is really strong, so it is guaranteed not to come off while travelling. As for the electronics, the arduino and the motor driver was mounted using the same velcro as the battery. As for the HC06 bluetooth module, I used a cable tie adhesive base and cable tied the module to it.

Every wire was cut to be just enough to reach its intended place, including the motor wires. I also used the cable tie adhesive base to keep wires secured.

New Android App

The old app that I used was a ‘digital’ control. Its had only 8 direction of movement. I had originally planned to make my own app but I haven’t really got the time to do it. So in the meantime, I found this app called “Joystick bluetooth Commander”. It is much much better than the previous one I had used. It has analog control and speed control on a joystick, meaning you can control it only using one hand. (That is if you can hold your smartphone in landscape mode using one hand). It is also very customisable, you can add buttons to the app and receive data values such as battery level from the arduino.

More close up shots below