This post is about doing the conversion - taking the mini and making it thumb controlled.
The .stl files are available here.
I introduced the idea last time. Since then it was launched on the forum.
You'll need additional things as well:
- mini remote (obviously), or here
- 8x16x5mm bearing
- 1s LiPo charger, or here
- 300mAh LiPo - 20x30mm
- Things for the regulator (see below)
- (five) M2.2x10mm self tapping bolts
Let's start!
Open the mini
The mini has 5 bolts which hold it together, with 1, slightly larger, bolt which secures the battery lid.
Unscrew all of them
The thumb wheel is held by additional bolt, unscrew this one as well.
Inside there is a PCB which connects to trigger pot (potentiometer) assembly, thumb wheel pot assembly and two leads which go to the battery box.
Snip the battery box leads, at the battery end.
Unscrew the trigger pot assembly (two bolts)
Unscrew the thumb wheel pot assembly (two bolts)
You should have the following:
- 10 small black bolts
- One board, with two pot assemblies attached by wire and battery leads
- Control panel cover (a fancy description for this tiny U shaped piece)
- Two sides of the case, thumb wheel and battery cover, and one bigger bolt.
We'll need only the first three things for the conversion.
Some soldering
This is how it comes out of the mini:
We are using the thumb wheel pot assembly.
Let's reverse the leads direction, and make it longer.
Unsolder the trigger.
Use its lead to make longer wire of the thumb wheel pot.
Look at the wire routing directions (both PCB and the pot)
This is the final routing of this stage:
Make the regulator
The reg is a simple thingy made with one AMS1117 3.3v regulator, one 0.1μF and one 22μF capacitors.
These three get soldered neatly on a tiny 3x4 holes piece of proto board.
I like to put the reg and the two capacitors on opposite sides, see pictures.
Install the electronics
Solder the battery to B+/- of the charging board.
Solder OUT+/- from the charging board to IN+/- of the Regulator
Solder OUT+/- from the regulator to the mini board
When everything is wired up, hot glue the charger, regulator and the battery to the new case (see picture)
Finishing with the internals
Take two of the 10 bolts you have and clip them ~2mm short. Luckily they are very soft, and any cutter will do the job.
These two will be used for thumb pot attachment.
Finally, put in the mini board and secure it with 3 bolts.
Put in the thumb pot and secure it with the two clipped bolts.
See picture for wire routing
Final touches
Insert thumb piece on the wheel pot assembly.
Slide in the bearing and the U-shaped cover piece (see picture). You can secure these two to the case with several drops of CA.
