Soldering machine progress

I managed to put together the chassis of the soldering machine. The bulk of it is made from parts for a Prusa MK3 3D printer. It provides a good start point so I can experiment further.

This is what is looked like in the beginning

I also put this mounting plate to hold the connectors that I need to solder for my test board. With this plate I can insert the connectors, place the board over and get it soldered quickly, then move to the next one.

Here is a video how the head would move along the Y axis

And another one along the X axis. This one needs to hop over the pins.

I used my PrntrBoard controller to drive the motors. This is a picture of the machine in it’s current variation. I added the Prusa LCD display, but have not connected it yet.

“mass” production

The demand for my CD-changer emulator is picking up, so I’m making several boards at the same time. Placing of the components on the board by hand and re-flow with hot air.

These 6 board take about 4 hours in this stage plus another 4 hours or so to solder the optical connector and other connectors. My hands feel tired after a while. I’ve heard that good scotch helps with this condition.

SMD stencil printer is so cool

If you can’t recognize what this is, here is an explanation.

When creating PCBs, one can order a stencil – usually from a thin sheet of stainless steel. On this stencil, there are cut small holes (with a laser cutter) where one is supposed to apply solder paste on the PCB.

So the operation is: you align the stencil on top of the PCB; then squirt some solder paste on top of the stencil; then use a flat “applicator” to smudge the solder paste over the stencil holes. In the end, you lift the stencil up, and you end up with the solder paste applied in a thin layer over the solder pads on the PCB.

To aid in this whole process is this contraption – a stencil printer. You align the stencil on the device and put come L shaped holders on the bottom to hold the PCB in place. The bolts on the bottom are to help to align the stencil and the PCB. When the alignment is achieved you put the PCB in the holder on the bottom; lower the stencil; apply solder paste; lift the stencil; remove the PCB. The whole solder paste application takes about 1 minute.

I should have gotten it sooner. My only regret is not getting a larger size printer, as you can see the stencil frame is a bit larger than the printer base – it still works though.