After having achieved a pretty stable basis of the Tilting Trike V6, it is now time to move on and to begin the design of the next major evolutions:
- add power unit to the front wheel
- add battery
- build structure for the solar panels
- install solar panels
- connect solar panels to the battery
Once these evolutions have been put in place, the Tilting Trike V6 will become the Solar Tilting Trike V1 (STT V1).
Add power unit to the front wheel
After having evaluated my experiences during the Sun Trip 2017, it was clear: the choice for the new motor was for a DIRECT DRIVE unit.
The final choice for the brand was for a FALCO direct drive motor, essentially for the following reasons:
- technological superiority compared to other similar units (to be verified of course!)
- very low “cogging” : very important for me, since I like to use the pedal power as much as I can (even here to be verified in real life)
- ease of use of regenerative braking:
- either by simply retro- pedalling
- or pushing on the “minus” button
- 5 levels of assistance and 5 of regeneration power levels
- 5 years of warranty
- 11 speed cassette
Once the motor was delivered, I put it on the scale: 7.2 kg.
But then…bad surprise!
In the package all the options I ordered were there, but the CABLE to connect to the battery was not there!
This cable has a proprietary plug on the motor side, so there is no way I could find locally a replacement…
So I lost almost a month before the cable was received (from the US), and this was just for the supplier’s fault.
This is the end result: the installation of the hub motor was quite strightforward.
I just had to take 1mm off the support for the brake caliper because the disc was almost rubbing on it.
The battery is a Lithium one, 48V and 16Ah: total capacity around 800Wh.
The position to be installed on the bike is below the frame in a place which is very low and it is not taking out space to other accessories.
Given the weight and the size it is very important to add an extra security in order to fix it very strongly to the bike frame.
Build structure for the solar panels
In parallel with above activity, I have started the design of the support structure for the 2 solar panels (100w each)
In the previous 2017 project I had 1 solar panel of 150w with following layout:
- width 4 cells (550 mm)
- lenght 11 cells
Since my bike had the smallest solar panels amongst all the 40 teams…I decided to install 200w in the new project, with a particular layout:
- width 5 cells (650 mm), normally is either 4 or 6 cells. I have chosen a shape for my new panels of 5 cells instead of 6 in order to reduce the width.
- lenght 6 cells (for 2) , 810mm
For the front support of the panels I have decided to use the beam which normally is used for the front derailleur.
In fact in my Raptobike model there is no derailleur …so this is available to attach the supports for the solar panels.
The idea is to build two supports in aluminium to be used as “clamps” to be tighten on the support for the front derailleur.
Here it is a simulation in order to get the exact dimensions.
On my first Solar Bike project I had serious issues on the clamps to attach the panel support on the front. Here you can see the broken clamp: it happened to me twice, so for this new project I needed a much more robust solution.
Here it is the way the clamps have been made (from a 25mm aluminium plate) and installed on the support for the front derailleur.
I was able to design and make the clamps with the help of Pierre, who is always really helpful and happy to give me support for this project!
They look definitely really solid and hopefully they will last much longer than the ones I used on my first solar bike!
In the meantime I have been able to build the frame to mount the solar panels. It is in aluminium, very light and rigid: I have used 4mm bolts to link all various pieces.
It is a very time (and patience…) consuming job, but from the quality of this activity it derives the life cycle and reliability of solar panels.
In this picture I can easily hold the frame with one finger!
At this point I have started to install one of the flat aluminium supports: the challenge here was to find the EXACT angle to bend the support in order to obtain the desired height.
This is how I did it: I cut a carton triangle and I used it to bend the support with the exact angle required.
This is the end result with both aluminium “flat wings” that will support the frame for the solar panels on the front of the trike.
In parallel I designed the support on the back of the bike.
It took some ‘trial and error’ and also the support of my wife to check that the position was correct and there was no interference with my helmet.
After above checking it was clear that there was contact between the helmet and the support structure behind my head.
Here we can see that both supports are touching the helmet: for this test I have chosen the POC helmet whose aerodinamic shape is more evident than my other ‘non aero’ ones.
There was no possibility to move further back the supports, since they are attached exactly where normally the rear brake calipers are positioned.
So the only practical way was to slightly bend the supports giving them a ‘V’ shape to avoid direct contact.
This is the end result: the process to bend the rear supports has been slightly harder than for the front supports.
In fact here I have a square shape, so the bend has to be maximum 30° in order not to damage the aluminium support.
This is the end result of the complete aluminium structure to support the solar panels.
The flat top structure is connected to the front supports with 4 M4 bolts and with 2 M4 bolts in the back.
Install solar panels
These are the solar panels that have been attached to the aluminium frame, with these overall sizes:
- width = 670mm
- lenght 1600mm
The weight of the frame including both solar panels is roughly 5kg.
Here I have prepared the connections for the Batt-man cycle computer with:
- the plug to be inserted in the battery.
- the cables to be attached to the GENASUN solar controller
The reasons why I have decided to use the Batt-man cycle computer for keeping solar charge data under control instead of the Cycle Analyst are:
- it is much simpler
- it is also more compact
- and it is cheaper…
Connect solar panels to the battery
After all this preparation work it has finally been possible to test the various connections amongst:
- 2 solar panels
- GENASUN controller
- the battery
- and the Batt-man computer
This is the final result, the Solar Tilting Trike V1!