Nomad Jr. 3D Printed Genesis Clone Portable

[wallydawg]

I have a GN-Twin in my possession, which is essentially an FC-twin but with a Genesis and NES combination clone console. Bought it at a thrift store ($4) pretty much just for a replacement NES 72-pin connector off of the NES side. Even though Genesis clones aren't that great at all in a general sense (this one is no exception), it still works so I might as well do something with it. The board is actually pretty small so hey, how about a 3D printed Mini Sega Nomad portable?

3D Printed Specs:
106.3 grams of filament, roughly 1/10 of a 1kg spool at an average of about 7.1 hours (426 minutes) with 9 Pieces total. The big front and back pieces take up the most time. I'll probably space it out over a few days so it's not so soul crushing. Around 24 hours as well designing it, but not sure how much of that is just opening it and not doing anything to it which happens a lot. Some time was spent widening and lengthening the case parts for a little bit more room just in case.

Front piece: 25.0g 114 minutes
Back piece: 28.6g 122 minutes
Dpad front piece: 11.1g 69 minutes

Dpad back piece: 10.1g 57 minutes
Top piece: 14.8g 65 minutes
Bottom piece: 14.4g 65 minutes
Side piece: 6.6g 30 minutes
Spacers for front & back: 3.1g 15 minutes each
A,B,C Grey buttons 2.0g 13 minutes
X,Y,Z Black buttons 1.6 11 minutes

Designed in AutoCAD in several sections to make it easier to 3D print and assemble.

Even though the controller ports look like Genesis (even famicom I guess), they are neither of those and some strange proprietary controller. Stone Age Gamer made a guide to use SNES controllers on the FC3, which thankfully the GN-Twin uses the same type of controllers.

It's kinda cool how the controller is mapped to Genesis, with the left "Side" of buttons being A, B, C from bottom to top, and the right "side" is X, Y, and Z. Select might be "mode" but who knows, I have nearly 300 genesis games and don't think I've ever had to use that button so that's just a guess. Obviously button placement won't matter as I'll chop up the controller for "normal" 6-button Genesis button placement.

Wired up a SNES controller board for tests and everything works well. I can remove the top board with the power and A/V connections, and the bottom board with the controller ports. I was hoping to remove the NES board as well, but all the controller signals to convert between Genesis to NES is on that board. Luckily it's pretty flat with the 72 pin connector removed so I just rewired the ribbon cable between them and will fold it over.

Here's where the controller signals are converted, into these three chips, which are labeled HCF4066. There's some schematics online and all that so I could probably decode it and use Genesis controllers but I have a spare SNES clone controller and no space 6 button Genesis controllers so it's no big deal.

Printed out the case design at 1:1 to test out it's overall size (compared to the Nomad) and to the console motherboard itself. Overall size is about ~140mm x 76mm x 26mm, much smaller than the original Nomad. Hopefully this will remain the actual size but it may vary by a millimeter or two in the width or height direction, but it is close.

Chopped up the controller really good for the button placements, as I had to rearrange everything with B, X, L being ABC and A, Y, R at XYZ. Superglued it to a piece of polystyrene for support

Tested with my papercraft model, everything good so far.

Did some controller work over the weekend. Cut it into three pieces and etched off some solder mask to reconnect the traces. Got a little too close on the upper left as it lifted almost all but a little section almost right next to the glop top but somehow I was able to salvage it. Hotglued everything down to hopefully stop any accidental tugs for the wires to break.

Here's an overall shot if the completed controller. Some of the wires are a bit too long/messy but I just wanted to make sure everything was still in working order. Luckily there are pads on all the connections so I didn't have to etch mask away for everything.

 

[wallydawg]

3D Prints:
Printed the front piece so I could start assembling things together to make small changes to other parts and print out the rest.

The First attempt did not turn out so well with the edge of the print being snagged and lifted from the extruder nozzle. I was trying to save time and filament by not printing with a support raft, but with all the cutouts for the screen and buttons, and the grooves for the assembly of all that parts it's probably a good idea to print with a raft anyway. Maybe I'll try a raftless print again for the back piece, which should be nearly solid.

I made the case taller so the camcorder battery shouldn't be an issue anymore, as long as I figure out the correct size of connectors to keep the battery firmly in place.

Next I made buttons. I'll probably print the XYZ black buttons again for a bigger overhang (that keep them from falling out the front) as it didn't print very well as compared to the bigger ABC buttons.

Fit test inside the front of the case.

More case parts:

WIP Assembly so far

Normal printed wink the case at 1:1 scale so I can plan out the screw holes that will hold the motherboard for the back of the case as well, and did the same for the top piece to make sure I have the cart slot positioned correctly for ample space in either direction.

Almost done printing all the parts! Just three more pieces to go, with the front and back spacers and the top piece.

I printed these vertically so there's a little bit of cleanup to do on the front piece. My printer does automatic supports (using less filament to make it easy to peel off the model) which apparently doesn't do circles all that well. I used a reamer to clean out the circle and it's not as bad now.

For the dpad itself I decided to try and replicate the Neogeo Pocket Color's hybrid joystick/dpad, which is the best dpad on any handheld controller hands down. It replicates an arcade stick's movement and feel with clicky tact switches from mouse buttons.

 

[wallydawg]

Now back to wiring. Finished rewiring the cart slot. 64 pin slot so not as bad as NES (72) or Jaguar (108!) but still not fun. Spread it out over 4 days so I wouldn't go crazy.

Success! It worked first try, thankfully.

Things are looking good! Just have to flatten the empty NES board there by rewiring the capacitors so it'll sit flatter behind the Genesis board inside the case. I've been looking at datasheets for HCF4066 Quad Bilateral switches that are on the NES side of the board that converts the controller signals (which is why I'm not omitting that board altogether) to consider the possibility of removing it, but we'll see. For the case, need to buy some Acetone to fuse some of the prints together for better structure.

 

[legofan623]

WOW this is cool! But please... For the love of god... Why not use squishy tacts instead of chopping up a controller pad???

 

[wallydawg]

I have way more controller pcbs than squishy tacts, and I didn't figure I had to cut up 6 different sections for the face buttons at the time, but oh well. I will look into squishy tacts if wire bloat is an issue.

Working on the dpad, as I said previous I'm going to try and emulate the neogeo pocket color's dpad. Opening it up and removing some of the plastic parts, you find these:

They are essentially just old mouse button tacts. A lot of the newer mice use rectangle Omron tacts, so instead of blindly buying goodwill mice or buying a lot of switches from china and waiting, one of my IT friends dissected a few decommissioned mice for me
(bag of tacts picture).

The neogeo dpad kind of works like an arcade stick, with the buttons on the underside of the PCB so you have to wire them up backwards. Of course I messed up in 2 directions but it's an easy fix.

(wired tacts picture)

I'll also probably edit in more neogeo pocket color dpad pictures later to help explain better on what I'm doing.

 

[RedmagnusX]

Words cannot describe how awesome I think this is! I may even make my own genesis portable using the same concept. I just have to try and design a case as awesome as your design is. Keep up the good work man!