The most significant challenge in this project is easily the Dreamcast serial connector. As a comparison, Dreamcast "AV connectors" can be purchased at a unit price of roughly $1.70 USD on Ebay or $1.00 USD on Aliexpress. These are quality connectors that appear to use a copper alloy for the conductive pins. The dimensions and fit appear to be reasonably perfect, and the mounting style is suitable for direct soldering to a 2.0mm thick PCB. In contrast, Dreamcast "Serial connectors" only exist either as Sega-original parts (and therefore not available in consistent bulk quantities), or in the "Dreamcast SD adapter". I asked many sellers whether they were able to provide the raw connector (not yet soldered to a printed circuit board), and in all cases the vendors informed me this was not available. The best-advertised price for a complete "Dreamcast SD adapter" appears to be about $7.00 USD. The Dreamcast serial connector from the "Dreamcast SD" product is also vastly inferior to the Dreamcast "AV connectors", despite being a very similar connector differing only in width and pin count. At least the following issues exist: - the outer dimensions of the Dreamcast SD serial connector are too small - the retaining holes that are intended to "latch" with the female connector's detents are slightly misaligned - the injection molding is significantly lower quality compared to the Dreamcast AV connector - the conductive pins appear to be a plated aluminum alloy, a downgrade from the AV connector's copper alloy Despite this, $7.00 USD is still a decent price. I then investigated the viability of salvaging the Dreamcast serial connectors. However, I was discouraged when I found desoldering to be too difficult. The issue is a combination of: - the pads on the Dreamcast SD PCB are too narrow (both as a general statement, and as it applies to desoldering specifically), which increases the difficultly of applying copper braid - a high-temperature solder was used--this means excessive heat is required, which risks deforming the injection-molded plastic I found the best approach to salvaging "Dreamcast SD connectors" is to instead cut the PCB, first separating the Dreamcast serial connector from the bulk of the PCB, then cut the PCB between each conductive pin. The pins can then be removed individually, which makes cleaning the pin much easier. However, all of this considered, I felt that surely it would be easier to just make a completely new connector, rather than undertake this scavenging process. This would have an additional advantage that already-cleaned connectors could be installed at a PCB-assembly factory, no doubt more cleanly, quickly, and cheaply than I can do myself. My original idea was to attempt to directly copy the design of the Dreamcast SD adapter's Dreamcast serial connector verbatim. In my discussions with rapid prototyping factories, the most immediate issue is the outer metal shield. This metal shield must fit between a small gap (roughly ≤0.5mm) inside the female connector. At that size, it effectively means the only practical material that could be both the appropriate thickness and simultaneously durable would be sheet metal. The Dreamcast SD's serial connector uses 0.3mm aluminum sheet metal. After re-creating a technical diagram for the reverse-engineered dimensions of the serial connector's shield, I was correctly informed by rapid prototyping factories that this type of sheet metal bending/tolerance requires a mold, and the minimum order quantity would be somewhere around 10,000 units. I don't think I can sell 10,000 units, so the idea seems too risky. I then redesigned my 3D model to be appropriate for SLM 3D-printing. Compared to sheet metal, printed metal is significantly more brittle. To counter this, the shield needs to be thickened and reinforced significantly to prevent cracking and excessive fragility. I decided given the overall maximum outer dimensions of the connector, the placement and size of the conductive pins, and the consequences this would have on the durability of the interior plastic, that the maximum shield thickness would would be around 0.7mm. This thickening has a further compromise, in that 0.7mm will not fit in the ≤0.5mm gap inside the Dreamcast serial connector. Taking inspiration from the RetroOnyx SLS 3d-printed connector, I decided it would be acceptable to remove that area of the shield entirely. After ordering SLM 3d-printed aluminum shields for a fit test, I found the results simultaneously impressive and disappointing. - the outer dimensions, particularly after light sanding, are far superior to the Dreamcast SD connector tolerances - my slightly-corrected detent-receptacle positioning appears to be perfect; the connector mates with a Dreamcast with a satisfying "snap" feeling. - I don't know exactly what happened, but during assembly testing at the rapid prototyping factory, the shields were about 0.5mm too long. The factory then corrected this by grinding the parts by hand. This grinding was not done carefully, and many parts are visibly no longer square as a result. Most importantly, SLM-printed aluminum (and aluminum in general) very strongly resists naive attempts to plate it with tin. In my discussions with factories, I was surprised to learn that they apparently have never tried to make custom connectors like this, and don't formally support any surfacing options that would be explicitly usable for soldering. This causes two problems: - the solder joint between the PCB and the connector shield is the primary means that the connector is mechanically joined with the PCB - not being able to provide a solid electrically-conductive path from the ground plane of the PCB and the shield causes the shield to lose some of its "shield" properties. After thinking about this for many days, I decided that it would be "ok" to join the connector to the PCB with a precise application of (non-conductive) glue, if I were not able to find a factory able to provide tin-plated 3d-printed aluminum (or an equivalent surfacing option that makes the part usable for soldering). The next issue is in price: - the factories are able to provide fairly nice laser cut conductive pins, but these are still very expensive: about $1-2 per pin, depending on material/surfacing. I could "save" up to $4 per connector by simply not installing the unused 5V and 3.3V pins, but this feels "too cheap" for me to be comfortable with. - overall, the material cost for a rapid-prototyped Dreamcast serial connector appears to be around $21 to $31 USD. I personally think these are quite nice, but I doubt most people think the "satisfyingly tactile snap" is worth +$31 USD to the cost of a Dreamcast USB-UART adapter. The next option is to look at higher-volume production. This would mean commissioning: - molds for sheet metal bending for the shield - molds for injection molding for the pin guides - cutting stamps for the conductive pins All of these have minimum order quantities around 1,000-10,000 units. The goal would be to get the price of the connector down to somewhere on the order of $2-$4/each at 10,000 units. Is it just me, or is anyone else interested in crowdfunding "a better Dreamcast serial connector" into existence?