3D Printing Connectors

The connector dilemma.. How often when working on games do you find yourself in the position of “dangit, I need connector x in order to be able to proceed.”

On the hack side of the decision matrix you can go with twisted connections, solder and shrink tubed, electrical tape or wire nuts.

On the OCD side of the decision matrix you place an order for the connectors, pay $8 in shipping for $5 in parts and have to wait a week for them to arrive so you can finish your task.

Eventually, you end up with something like this. Varied pins and housings. Some for DC applications, some for AC applications.

Once you get bitten by the “I need this one part” bug enough times and you end up over-buying spares or mixed-lots that include dozens of varieties of pins and connectors.

Cost Considerations

$.14c in material cost for a connector is a pretty decent deal.

Working on Ice Cold Beer, I recall paying ~$8/each for the 18 position dual-leaf PCB edge connector housings and around $70 for 30Au Gold 22-26AWG pins. (Sourced from arcadepartsandrepair.com )

Working on my first pinballs (Data East Star Wars, Sega Star Wars) I recall waiting a week for appropriate .156 IDC connectors or .156 molex-equivalents to improve interconnect reliability.

2 or 3 position Molex connectors are often used in arcade / pinball power or modding situations. I’ve paid $.50c up to $2 for individual Molex connector pairs. $.14c for a 3D printed pair in under an hour is pretty nice!

Originality Vs Pragmatic Convenience

Detail-oriented collectors might focus in on sourcing exactly the right connectors, something like the Red AMP connector that was manufactured in the middle-80’s. Profit-oriented operators would often direct-solder wires to board pins or use electrical tape and shrink tubed solutions in order to keep their amusement machines in service.

I’m not wholly opposed to a wire nut or compression slice with the justification that most of the wiring in our homes use these methods inside of electrical boxes for switches and plugs.

But mostly for arcades and pinballs I try to use connectors when it makes sense.

Finding Models

Connector-housings are actually pretty easy to “eyeball and approximate”. Taking measurements or looking at the spec, there are alot of connector-housing models on thingiverse to support peoples’ electronics projects. The two sets I found below were some of the most impressive in terms of quality and closeness to originals.

3-pin Molex
https://www.thingiverse.com/thing:4139433
https://www.thingiverse.com/thing:4131380

2-pin Molex
https://www.thingiverse.com/thing:4139450
https://www.thingiverse.com/thing:4139409

Searching around, it turns out the CAD models for Molex (and other) connectors are available from the official sources

For example, the commonly used .093” pin connectors often found on the AC lines of arcades:

Plug Side
Receptacle Side

Broader categories
- you will recognize alot of these from wiring harnesses in cars, common appliances in addition to arcade and pinball uses.

AMP Dual Leaf 28 Position (like a JAMMA card edge connector)

The file formats are common CAD formats that can be converted to printable .STL files pretty easily.

I’m not sure around the legality of using them but for the sake of this post we are going to assume hobby use one-offs won’t be a problem.

Finally, GrabCAD has a really handy library of all sorts of engineering CAD models, connectors included.

FINDING THE CONDUCTORS

There are so many different connector and mating-conductor standards used in Arcades & Pinballs, I’m not going to even attempt a comprehensive list but here are a few that you will probably run into frequently.

MOLEX .156

Molex .156 are often used in Arcade monitors (RGB, G, Sync) connections. The .156 size is also what most Bally, Williams, Data East, White Star, Sega and SAM Pinballs use for power interconnects. Though the pinball applications are typically as IDC (vampire tap-style) connectors. Molex is a solid upgrade and will mate perfectly with the .156 header pins on those boards.

https://www.aaarpinball.com/TwilightZone/TwilightZone.htm

https://www.flippers.be/basics/101_general_illumination.html

Some sources I like for these pins and connectors:

https://www.arcadeshop.com/search?q=.156%22

https://www.arcadepartsandrepair.com/product-category/connectors-sockets-pins/156-kk-molex/

MOLEX .100

Yellow one is .156 spacing, red one is .100 spacing.

http://www.ukvac.com/forum/connector-idsolvednow-id48-drive-board-versions_topic359385.html

Molex .100 are often used for lower voltage interconnects or in cases where component spacing was tight on the original board designs. Stuff like, Controlled Lamp to Cabinet Harnesses for Pinball and IO interconnects on some arcade cabinets.

https://www.arcadeshop.com/search?q=.100

https://www.arcadepartsandrepair.com/product-category/connectors-sockets-pins/100-kk-molex/

MOLEX .093

https://primetimeamusements.com/tech-tips-monitor-issues/

https://www.pinballlife.com/power-tap-and-8-way-power-splitter-board-for-williamsbally-wpc-pinball-machines.html

Molex .093 are very commonly used in 2 position and 3 position AC applications in arcades. Usually from a power tap before the isolation transformer running to the marquee light.

https://www.arcadeshop.com/search?q=.093%22

https://www.arcadepartsandrepair.com/product-category/connectors-sockets-pins/093-molex-connectors/

AMP and MOLEX Leaf Connectors

https://www.youtube.com/watch?app=desktop&v=WYi6_xv1mSY

https://www.instructables.com/install-a-JAMMA-harness-in-an-arcade-cabinet/

These edge connectors are the basis behind the JAMMA 56 pin card-edge connector found in many arcades.
Taito’s Ice Cold Beer uses three partially populated 36 pin card-edge connectors. I’ve also seen them used as beefy interconnects between some multi-board stack arcade PCBs.

https://www.arcadeshop.com/search?q=edge

https://www.arcadepartsandrepair.com/product-category/connectors-sockets-pins/edge-connectors/amp-twin-leaf-edge-connectors/

That’s enough to get you started though there are obviously others. As like most things in the electrical component space, you can also find these things at mouser.com, greatplainselectronics.com, digikey.com and other electronics suppliers. Personally, I try to support arcade and pinball specific suppliers when shipping is convenient and pricing isn’t out of hand.

A Note ABout Materials

Did you know PLA thermoplastics come from corn? PLA is formed from the sugars in corn starch by immersing corn kernels in sulfur dioxide which breaks down the corn into starch, protein and fiber components. Sort of like a fermentation process.. The oils are extracted into long-chain polymers that behave similarly to fossil fuel byproducts that can be made into plastics, polystyrene and textiles.

The most common thermoplastics used in 3D printing tend to be great insulators. The exception being, any filaments that might be reinforced with metal fibers and some carbon-fiber composites. Heat is the largest concern. You wouldn’t want to use 3D printed connectors in a service environment where it might be exposed to heat greater than the material tolerance.

src: https://www.simplify3d.com/support/materials-guide/properties-table/

PLA is a solid electrical insulator but only within a nominal temperature range. You can use PLA but understand that applications above 125F degrees carry risk as PLA starts to break down and loose structure at higher temperatures.. A moving truck or storage unit can reach temperatures of 120F degrees. You can use PLA to print connectors but it isn’t the first choice for electrical applications.

ABS can keep its properties above 200F Degrees. going to have similar temperature properties to PLA but a flatter melt-curve at the melting temperatures. (It will deform less)

PETG falls between PLA and ABS with support of temperatures up to around 160F degrees.

Nylon, which also support 200F+ Degrees (often much more) is commonly used in electrical applications. Wall plates, even some electrical wall boxes are constructed from Nylon or Nylon composites.

I make most of my connectors from Nylon, ABS, PC, or sometimes enhanced PLA. (ToughPLA or PLA+)

3D Printed Scared Stiff Slings (cont’d)

About a month ago, I started down the path to try to create:

(in my best sarcastic George Carlin voice) Scared Stiff Inspired, Slingshot Alternatives

You can follow along the first part of this adventure by clicking here.

front: single color extruded, masked then painted back: dual extrusion Red and Grey Kodak PETG.

First, I tried a transparent red PLA from 3D Universe and dissolvable PVA for supports.
This yielded a really decent single-material result, though the inclusion of PVA pushes up the build cost by a couple bucks.

-Not a huge deal, these are just for me… or friends that ask for them but it also takes a bunch of time to clean up the PVA boogers or let them dissolve all the way. It ties up a build plate for 12-24 hours while it dissolves.

But what I really wanted to do is to get a decent dual-extrusion print template, separating out the transparent red from the original from the opaque parts. The idea being, if I could match the red translucent and print the rest in grey, each one is just a little detail paint work away from being closer to the originals.

In order to do multi material / multi extruder prints, you need a model that dissected into pieces.

Though not perfect, I eventually ended up with decent enough cutouts for a multi material print.

Getting the model broke into components pushed the limits of the capabilities of Shapr3D and my skills in this arena. Shapr3D doesn’t give you a great way to perform contoured or free-hand cuts so I ended up duplicating the model into three copies and erasing away portions of the model with varied overlapping edit-cylinders used to mask out subtraction zones.

I tried an EDU copy of Solidworks as well but I have more learning in that area before I can be effective. A couple days ago, I ran across Mesh Mixer, which may end up being a better solution for my use case in the future.

Kodak makes filament? Yep and it is really quite decent too. Good price, the spools have smooth cylinder walls and roll well and the material properties are very consistent. They are even food safe.

I’m mostly okay with the luminosity of the translucent PETG. The color is a little off from the original but a stickler could print on clear and used translucent hobby paints to tint in the red.

I still need to paint the feet lime green but so far my play testing set is holding up.

Have a Scared Stiff and need slings? You can pull down my models from here:

https://www.dropbox.com/sh/0t7wzhce1593ljl/AABL449nCkC3ols3Zp2hge2ba?dl=0

(please note the current prototypes still have a few small flaws but they are definitely playable)

Williams Indy Roto Lock

On Williams, Indiana Jones: The Pinball Adventure, the Roto-Lock is a plastic ball diverter atop a metal shaft connected to a coil. It is used in the rotating idol mech to dispense and lock balls.

When it breaks and you try to find a replacement, you might see the same thing I did. Some guy trying to sell a used one for $75 on eBay.

I thought: $75? No way! I want to spend $3500 for that part and get threatened with a lawsuit, so maybe I can pay my attorney a couple thousand too and bring the TCO to around $6500.

Yea, Let’s do that, instead. Companies apparently don’t like you 3d printing their parts even though they aren’t making them available for purchase.

(sarcastic guy, is sarcastic)

So, I reproduced the part for my personal pinball machine and created a model so I can print a spare whenever I want.

Because my caliper-based measurements are always off by a few fractions of a mm, I glued, taped and painted a broken original and scanned it in.

Using the scan to get measurements and angles exactly right, I recreated the part out of primitive shapes

It took several test prints, I had some sort of vertical dotted line that would appear in the prints but not the model. I eventually solved for this by fusing the primitive shapes in the model into a single body.

After a bunch of test prints, I finally got a usable result and fit-tested it.

The original part is translucent yellow. I’ll probably grab a roll next time I’m ordering filament and make a closer version from that translucent PETG.

Want this 3D model for your own personal use to get your Indy Operational again?

Enjoy! - https://www.dropbox.com/sh/lhoboi7ekkyvibf/AABO0BAPum7rI5t55TDHgQsxa

No Good Gofers Reconstruction

Typical “don’t sue me” stuff applies, here.

A friend of mine sent me his broken gofers and some non-painted reproductions. I used the facial details from the broken original with the structural benefits of the reproduction to create a couple models for 3d printing replacements. You can grab the models for your personal use and printing, here:

https://www.dropbox.com/sh/06tmsbnqvcm2ncz/AAD-tWBVPFfBnVCCPDQoOioJa?dl=0

I’m not interested in doing this for cash but if you are desperate, need a set - I’m happy to help you out as a favor, just email me.
I also found this thread on Pinside, recommend you reach out - their results look many times better than my scans :)

PLA Print w/ PLA Supports - these turned out pretty good

PETG Print w/ PETG supports. The PETG support boogers are too difficult to remove to be practical.

PETG Prints w/ PVA SUpports

The results are good pre-painted, extremely tough. The print layer lines are obvious, in this batch.

Scared Stiff Sling Reconstruction

Scared Stiff Sling Plastics… They are getting to be rare finds. The last set I found (and won) on eBay, they told they couldn’t mail to the US because of COVID-19. (?) Something I’ve been wanting to do for awhile is to devise a way to make more. Not like.. to sell or anything but just to have and help others along the way…

Granted, probably the solution involves making a mold.. But I’m the kind of guy that uses racing drones to cut down trees, so you know.. I went down a nerdier path..

3D Printing as a Vector for Replacement Parts

3D Printing has come along way in terms of available materials. The challenge comes from getting a usable 3D model. I’m a reasonably capable novice for modeling and CAD but trying to model something with lots of detail and contours is a real challenge in the CAD apps that I’ve used.

Attempting to get a 3D Scan..

My first thought was to try to use the new LiDAR camera stack in the 2020 iPad Pro.

via LiDAR scan

via TRNIO

SOL 3D Scanner by ScanDimension

3D Print / STL Files can be found at this Dropbox Link.

The Importance of Setup: Indy Adjustments

I’ve noticed lately that my Indy gameplay has been a bit of a struggle. This is weird because for over a year I played Indy every morning, almost as if it were a ritual. Get up - > do hygiene thing -> take the kids to school -> get coffee-> Play Indy -> get more coffee -> Log in / go to work.

Now, I can’t hit anything and worse, I can start a mode if my life depended on it. Whiskey Tango Foxtrot?

Pinside has the usual ratio of buttholes suggesting you Google before posting a question, mixed with a potential fix that involves yet-another-$5 thing that isn’t in stock anywhere.

(Also, I found that via Google, so… good job internet forum snake for eating your own figurative tail.)

I event went so far as to design a rail and ball-stop brake pad to be printed on TPU95.

3D print file here, if you want it.

I have a playfield protector and a Cliffy but the mode-scoop start issues didn’t start until recently and both have been installed for awhile. Once I got the POA off, you can see in the pic above what was happening. Over time, the Cliffy had actually moved. Which.. kinda / shouldn’t happen with the adhesive on it - but it did. So, the ball would hit the ball stop and deflect back down but the front edge of the scoop was partially obstructed by the Cliffy.

The solution was to pull the Cliffy, re-flatten it on a vice. I slotted the screw holes in the Cliffy to allow more forward placement, put new adhesive on it (3m spray adhesive on a paper plate, then brush on), re-center and re-install it.

I also re-leveled the game while the glass was off, it was leaning a smidge to the right.

Huge difference right?

Glass Corners (3D Print Stuff)

My basement floor is a nightmare hell-scape for pinball glass. The hardest of hard concretes with a rough brushed finish. I haven't broken a sheet yet but I'm always skiddish of the coming shard-po-calypse when I do.

You don’t eat yellow snow, you don’t eat tug on superman’s cape and * you never buy pinball glass in single sheets.
* Unless maybe Invisiglass or PDI Glass where you can reasonably only afford one at a time.

I usually try to bring home spare sheets of playfield glass from Marco when attending SFGE. When ordering by mail, Pinball Life has shipping pinball glass down to a science. Shipped two-at-a-time, they are well padded with ginormous foam corners. Those foam corners are great for shipping but at roughly 4in wide by 6in length, they are overkill for storing spare sheets.

I found this clever 3D print design for a compact but effective solution for pinball glass corners. He designed the print to be used with TPU95A filament, which is a rubbery-plastic about the consistency of a dog bone chew-toy. The design worked well in that it grips the glass and provides a little cushion in a compact size.

TPU95A is the way to go for these. For invisiglass I might scale up by an inch or two in length and height but keep the same thickness for grip. If you print them on PLA, you will want to scale them up as well, uniform scale of 115% will do the truck. I understand the drive to use PLA, I’ve received glass with plastic corners before but if you have TPU available - go that route.

Thanks to 80sPinTech for a good design!

Hobby Tools Finding a New Use

As an avid listener of The Broken Token Arcade and Pinball Podcast I’ve enjoyed following Brent’s adventures into getting into 3D Printing and Vacuum forming. It doesn’t take a lot of imagination to see how the ability to make your own parts at home can be handy.

I’ve had an eye on 3D printing for hobby usage back since a really insightful article from Microsoft Developer Blogger, Scott Hanselman back in 2015.

My takeaway from both, broadly, was that 3D printing would be a massive time suck. Who has time for that?

Well, it turns out we are quarantined at home now and my social calendar just freed up for 30-90 days. Time to jump in.

Three different printers had my eye.

Budget Conscious: Creality CR-10S

I see lots of forum posts where people struggled to get started with the Creality CR-10 and CR-10s printers.

“Please refer to the 50 page sticky post about common setup issues and how to solve them”

Once running and once the material specifics are worked out, most owners seemed thrilled with their choice, though. Almost to the point of shilling for the machine and overlooking minor flaws.

Pros:
Nice Entry Price (~$500)
Impressive build surface ~(12.75 x 12.75 x 15.5) inches

Cons:
Kit-built
Easy but fidgety assembly and setup
Machine footprint, Spool placement
Looks like the offspring of an erector set and Johnny 5

Middle of the Road: Prusa i3 MK3S

Time and time again the only bad thing I could find about the Prusa MK3S was that it wasn’t a major change from its predecessor. Usually with a footnote of “but we can’t really think of anything we’d like changed” though. The Prusa came up time and time-again as the winner amongst Maker enthusiasts in posts and articles, based on my research.

Pros:
Reasonably priced (~$750)
Good (but slightly compromised) build surface ~(9.8 x 8.2 x7.8) inches
Flexible options, available as pre-built or as a kit
Good Software
Exceptional reputation amongst enthusiasts, known to be a workhorse

Cons:
Occasional failures on long prints
Still has the erector-set aesthetic.

The ”All In” Option: Ultimaker 2+ or 3

The Ultimaker was the only one that seemed to offer a hassle free setup process from the beginner’s perspective. Most of my research landed on “we love it but it costs too much” as the shared consensus amongst Maker enthusiasts. The Ultimaker machines support NFC chips installed in the Ultimaker material spools. This means that the machine has built in profiles for Ultimaker materials and automatically adjusts by reading the NFC from the installed spool. It seemed to me that the vast majority of bad prints come from improperly calibrated settings in respect to material type, so extension of that logic is:

Foolproof material settings means less fouled prints.

Pros:
Easy setup
Comes pre-assembled
Well-supported by manufacturer
Parts availability
Automated print settings when used with Ultimaker Materials
Gold-Standard in Slicing Software (Cura)
Helpful companion apps for iOS and Android (monitor prints, reprint, pause - resume

Cons:
Highly priced (UM2+ is $2500, UM3 is $3500)
Slightly smaller build surface ~(8 x 8.5 x 8) inches
More expensive parts and consumables

Ultimaker 3

After much deliberation I went with a refurbished Ultimaker 3.

I chose the Ultimaker line (among other reasons) because it seemed like a more self-contained machine, something I’d be apt to just leave set up on my desk. I chose the UM3 specifically because it was Wifi capable, supported dual-extrusion: the ability to print with two materials at once. I chose refurbished because of parts availability, factory warranty and because my Amex reward points only go so far. :)

Software Stuff

Slicing

Slicing is the process of ingesting a model and material properties and building a print plan for the printer to follow. (GCode File)
If you’ve ever done professional publishing where you send off print-ready file formats to the publisher - this is basically the same thing, at the high level anyway. Ultimaker Cura is a gold standard solution for Slicing, it is made by Ultimaker and is free even if you aren’t using Ultimaker printers. Having a 1st class slicing experience contributed to my decision to fork out the extra dough for an Ultimaker printer.

Design

SolidWorks is the Gold Standard Engineering and design solution. At $3400/year for the Standard edition, I can’t even consider this right now. <Closes Tab>

Tinkercad is an awesome solution for building printable 3D models. Schools often use it in STEM or Gifted labs as an introduction to engineering and design concepts.. It is cross platform and has AutoDesk support behind the product. It’s also free. The limitations will come in on high-polygon count or heavily complex models as well as certain import interpolations. But for simple 3D printing, TInkercad is the goto.

If you have an iPad and Apple Pencil, Shapr3D is very powerful middle-of-the-road option.

Shapr3D shares the same solid modeling Engine as SolidWorks (Siemens Parasolid™). It is iPad-only and requires the Apple Pencil but since I’m an iOS and Android Developer I didn’t have to look far for an iPad to commit to this use. The software is free to try and is about $240/year for the pro version. $1 apps might make that seem like a lot but taking in the app’s powerful foundation, level of polish, performance and extensive training library - $240/year sounds like a bargain to me.

Future versions will support object import via the iPad Pro’s new LiDAR camera. (There are videos of this in beta available on Youtube). So, I’m using a combination of TinkerCard and Shapr3D for modeling work.

The Tools are Here, Now What?

This is the point in this story where I’d normally be showing you 3D printed realized objects created from scratch in service of the pinball and arcade hobby. Things like that hard-to-find coil bracket for Ice Cold Beer or 3D printed unobtainium replacements like the Data East Star Wars Death Star plastic that I once paid $175 for.

But first, the ongoing global pandemic and the shortage of PPE have me focused on trying to be helpful in some small way in aiding those efforts.

Make the Masks

The Montana Mask is a 3D-printed mask initiative started by three medical professionals and tested at a clinic in Billings, Montana. The design includes a two-part reusable mask with a place for a filter insert.

Complex prints with overhangs and suspensions will be printed with scaffolding or support material (dissolvable or break-away). This mask design was clever in that it attempts to keep the angles shallow enough to prevent the need for support material, decreasing print times. Currently I’m at about 4 hrs to print each mask at a reasonable quality. I add window seal from MD Building Products, which is a super-awesome company - they donated two cases to me for this cause. Finally, I add in filter material: Flowmark Filters if you can get them. Blue shop towels or tripled up coffee filters can also work.

Stack o’ Completed Masks from Easter Afternoon

Other Opportunities to Help

In addition to masks there are clever initiatives for creating face-shields, respirator parts, ventilator valves and more.
It’ll be neat to get to work on the printer in the future for more entertaining purposes but for now, it whirls away 18 hours a day making stuff related to the pandemic, trying to show appreciation and aid protection for those who aren’t as fortunate as I am to be able to shelter in place and play on the computer all day.

If you know of any front-line medical workers or first-responders with a need for parts that I can print, reach out to me by email and I’ll get something sent your way.