Let's talk about the difficulties of the assembling process.
Noone should be discouraged, but we don't want anyone to waste 200 euros.
There's a step-by-step manual for the assembly. The manual is available here .
What has to be assembled?
3Digi is a complex hardware including:
- Power supply
- Processing unit
- Sensor unit
The entire hardware consists of 5 PCB's using SMD (surface mounted devices) technology. This results in 2 small electronic devices.
Many parts are just 3-5 mm in size.
Here are some pictures to get an idea:
Power supply:
Processing unit top:
Processing unit bottom:
Assembled device:
Sensor unit (25x25mm):
Here is a sensor PCB with soldering iron and the smallest component (other components are somewhat bigger).
The soldering tip is 0.8mm .
Important points
The assembly is an ambitious process, since many small devices have to be soldered exactly.
Poor craftsmanship leads to:
- damaged components
- 200€ worth of junk (-> totaled beyond repair due to assembling faults)
- a crashed heli due to faulted soldering joints
- hopefully nothing more…
I don't want to spread panic, but the assembly has to be taken serious.
But: it's feasable.
Folks, who have tinkered with electronics, should get along with the process.
Although there are some special soldering techniques required for the assembling process.
This link leads to a website on SMD soldering (hints, manuals, videos).
Can I make it?
There's an excellent construction howto from Dirk Schmidt (-> Thanks!). It describes all the required steps to assemble the boards.
If you're familiar with small electronic components and have some experience with soldering, it should work.
It's useful to find an experienced person to help you with the first steps.
Once the first few components are soldered, the rest will follow easily.
Some parts are difficult to solder due to small spaces between components, but the right technique will help to complete it.
Heads up!
How long does the assembly take
It takes some time to figure the correct components and solder them then.
- An SMD expert completes the kit in about 3-4 hrs (single kit)
- An SMD expert needs roughly 2-3 hrs, if the produces a small series
- An amateur needs 5-6 hrs
- A rookie needs 7-10 hrs
Required tools
The following tools and accessories should be available:
- Temperature controlled soldering iron or soldering station with small tip.
- Sponge for tip cleaning
- Fine soldering tin, 0,5mm diameter (leaded tin is recommended, since it's easier to use)
- Soldering flux (e.g. Reichelt id nr „FL 88“)
- Desoldering wick (e.g. Reichelt id nr „ENTLÖTLITZE 00“)
- Small tweezer (-> to grab 2-3 mm components. There are special SMD tweezers available ~20€)
- Multimeter (to check soldering joints)
- AVR programming device (in case the microcontroller doesn't come preprogrammed)
- Hot glue gun
The following is recommended:
- Magnifying glass (to check soldering joints)
- Desoldering pump
- PCB cleaner (e.g. Kontakt LR, Reichelt id nr „Kontakt 360“) to clean the PCB after soldering
- Adjustable power supply
Where to get all those parts and PCB's
There's a 'kit', that includes all the required components.
There are collective orders on a regular base. Details here.
These collective orders result in a significant discount.
How much do the parts cost
If you buy the components on your own, the costs will be about 250€.
If you join a collective order, the costs will be about 170€, although you'll have to wait until enough buyers joined the order.