It has been a while!
This log is continuation of this video, where I demonstrated the electric components of the screwdriver. Everything was set up on a bread board, now we need to figure out how to crank all this electronics into the body of the vape pen.
To do so, I have done some modeling in Autodesk Fusion 360.
I took a caliper and measured the case, battery, motor and the cap. From snapeda.com I download the 3D models for the buttons and the UBS Type C connector.
When I put everything in place it becomes obvious the we have very little space to work with.
First lets deterring the rules of the game:
- Use as many parts of the original vape pen as possible.
- Use as many as off the shelf components as possible.
- All the parts should be cheap and really available.
- 3D printed parts are fair game.
The motor I have chosen is 6V DC motor geared at 60RPM. You can find one around 10$, which makes this the single most expensive component of the project.
Next is which battery should we use. We have two choices the first one is from the flat vapes.
The up side of using this cell is that the space constrains are greatly relieved. We can place the PCB board in the middle and attach the battery to one of the sides. We have nearly 7 squared cm of PCB space.
The problem is that capacity of this cell is only 280mAh.
The other cell 13400
It has nearly twice the capacity of the 501447, but it is quite bigger. The space left for 3.5 squared cm which is twice as less and the board is split in two.
We can put the connector and the charging circuit in the back, while the front PCB holds the buttons, the motor driver and the boost converter.
There are a few things that we can do to remedy this space constrains. First is to choose how are we going to orientate the PCB on the left (back). Here are the two options depending on our choice of USB connector, vertical or horizontal.
When the port is vertical arguably it is easier to mount in the body of the vape and I have a hinch we will have a bit more room to work with.
Another thing we can do is stack two board on top on each other in the space in the middle like so.
Where we can see on the top is the location of the buttons + some RC network. Then the red marked surface will be free for placing boost converters and motor drivers.
Now to question is do we need the extra battery life, so we justify the more complex approach?