Diyouware TwinTeeth is a open-source PCB mini-factory targeted to the electronic hobbyists. It is an innovative fabricator of Arduino™ shield-size PCBs which will help you to make PCB prototypes at home.
It includes the following functionality:
- UV Laser photoengraving on sensitive film or presensitized boards using an ultraviolet laser.
- Drilling vias and holes using any mini-rotary tool like Dremel® or Proxxon®.
- Dispensing solder paste with precision on SMD PCB pads.
- Plotting circuits with a permanent pen-maker (if you prefer this method).
- 3D printing knobs, casings, front-panels, even print circuits with conductive filament, or make circuits supports.
- Milling/Carving soft materials or etching PCB copper with a v-bit (if you prefer this etching method).
And much more… because it is extendable and you can use any other tool you can fix on it.
We developed an alternative method for making PCB vias through-hole.
There are several commercial products for making DIY PCB vias. Some based on special pins made for this purpose but they are ugly, cost money and difficult to install. Others methods are based on conductive epoxy which also is expensive and resistivity is not good.
Electroplating is the method used by the PCB industry. There are on the internet some interesting experiences, but all of them require special equipment and unpleasant chemical products difficult to find.
The traditional DIY method consists in threading a wire through the holes and then soldering it and then cutting it off. For example, if we have 100 vias in our PCB, we have to insert the thin wire on each hole, cut it and solder it 200 times. This is time-consuming, but also tedious, absurd, prone to failures and produces a melancholic state of mind.:-)
So we decide to innovate in this area developing a new method which consists in drilling blind vias instead of holes and filling them with conductive ink.
Really we don’t need holes to make vias. Well, we need holes, but not through-holes. I mean, we can avoid drilling to bottom copper layer and make tiny wells instead of vias!
Then fill the wells injecting the conductive ink. We do it from inside, inserting a needle into the well, mainly because it will be difficult to fill it from outside due to the air inside the well and also surface tension forces.
We published a lead-screw improvement to the original design. We decided to reduce the size of
the acme screws to reduce possible wobble and we also designed a new
lead-screw top support which will hold the bearing and a bolt to adjust
the motor coupler flexibility.
Mainly because in that configuration the laser beam is not attached directly to the motion system. We already tested a traditional cartensian robot and we could not avoid vibrations and resonances produced by the mechanics and the belts. Also the inverted delta configuration allows us to change the tool in a question of seconds. This is very important in a multi-functional robot. We don't care too much about the Z axis lenght because the robot was mainly designed to process PCBs and 3D print small things.