Pin2k CPU Fan Replacement

When I first got my Revenge From Mars from a local Pinhead; the fan was clogged with dust and grime. At the time; I simply cleaned the fan, removed the sticker, and added some oil to the bearings. This lasted about 3months before the fan began to make some horrible noises because the bearings were shot. I “lived with it”; but it remained on my todo list.

For years; I had watched threads about Pin2k in Pinside… always feeling a little guilty I had not eliminated the risk that my CPU fan would die… overheat the cpu… and put my RFM in jeopardy of force converting to NuCore or Pinbox. Today was the day I vowed to resolve that noisy fan.

First; I did not want to buy NOS (new old stock) of some 50mm fan made back in 2000 or some china knockoff that wouldn’t last another 18 years. I wanted a high quality fan with very little noise; but a good performer. I’ve grown to like the Noctura brand of fans because they aren’t cookie cut china knock offs. Noctura does not sell a drop-in-replacement for 50mm fans. Going smaller usually means less air flow with a higher “whine” because the fan blades have to go much faster to move more air. So I decided that I was going to try and use the NF-A6x25 FLX 60mm fan:

and build an adapter to fit the larger fan over the existing heatsink. This blog entry documents my solution, provides a TAPR/NCLed DXF for my adapter, and links to a Shapeways implementation of my adapter my fellow pinball enthusiasts to use.

First, I removed the CPU box from my RFM and pulled out the existing CPU heatsink:

Stock Pin2k CPU Fan/Heatsink

Once I had the CPU heatsink free; I unscrewed the old FAN from the heatsink. This was done for two reasons;

  1. I need the heatsink to take caliper measurements in order design a 60mm to 50mm bracket.
  2. Eventually; I’d toss the worthless 50mm fan – but wanted to keep it incase I couldn’t find a working solution.

Obviously; the 60mm fan wouldn’t fit within the 50mm cavity of the heatsink; so I knew I wanted to use some 1/4inch clear Acrylic as an “adapter”. I went into qCAD resulting in a DXF file which I could then send to my laser cutter. I wanted to reuse the 50mm fan/heatsink screws and the 4 qty Vibration-Compensators provided in the Noctura kit. My second proto resulted in success and looked like this:

60 to 50mm Fan Adapter

Reusing the 4 qty 50mm countersunk heatsink screws; I attached the clear acrylic bracket to the top of the heatsink. Then I put the 4 qty Vibration-Compensators provided in the Noctura kit thru the acrylic bracket and into the NF-A6x25 fan. The whole assembly fit together quiet nicely.

60mm Fan Adapter – Test Fit

I carefully; reinstalled the fan-sink combo back onto the cpu and socket. This was a little tricky because the 60mm fan is bigger; but as you can see the whole contraption fits well:

60mm Fan Adapter – Motherboard Install

Conveniently; my Pinball 2000 motherboard had a FAN header right next to the cpu socket; so I simply attached the CPU fan’s 3pin PWM connector to that unused mobo connection:

60mm Fan Adapter – Fan Header

I powered up the Pin2k system on my bench with both the original and the new fan connected. !That old fan really needed to be replaced! This new fan is ultra quiet; I don’t think you can hear the fan over the PSU fan even when the box is open. You won’t be able to hear the fan at all when its in the backbox behind the backglass. Success!

I’ve decided release this design to the public under the TAPR Non-Commercial Open Hardware License which indicates:

You may make products based upon this design, provided you do not make more than ten units in any twelve month period for your personal use.

If you agree with the license terms; a DXF Drawing is posted here under TAPR/NCL license:
60mm to 50mm Fan Adapter Package

If you don’t have access to a laser cutter; you can 3D print this adapter from Shapeways:

M.2 60mm to 80mm bracket for Udoo X86 maker board

I recently received my Kickstarted Udoo X86 maker board but did not actually end up ordering any of their Accessories. They offer a Transcend MTS600 SSD (M.2 60mm) with somewhat small capacity. I decided I wanted a Transcend MTS800 256GB SSD from Amazon.com for the SSD and a Intel Dual Band AC 8260 WIFI NGFF card. Additonally; I ordered a set of Wifi Antenna’s to connect to the AC 8260 card.

Armed with this new equipment I set about figuring out how to install them on the Udoo X86 board. The board is only setup to support 60mm M.2 drives; so I opened up SCAD and created a quick 3D printed bracket to bridge the gap between the 60mm mounting hole and 80mm M.2 drive’s mounting hole. I 3D printed this using my M3D printer, drilled out the 3D printed #4-40 holes and taped it so I could run some #4-40 polycarbonate screws I had in my modding bins. Any 4-40 screw should work. The bracket I created also has pockets for a #4-40 nut incase you want to drill out the bracket and use a nut. Printing took about 45minutes on my M3D using clear PLA.

I’ve decided release this bracket design to the public under the TAPR Non-Commercial Open Hardware License which indicates:

You may make products based upon this design, provided you do not make more than ten units in any twelve month period for your personal use.

If you agree with the license terms; OpenSCAD and .STL files are posted here under TAPR/NCL license:
M.2 60mm to 80mm Bracket

For those that do not have a 3D printer; I’ve made the bracket available at my Shapeways shop:

Here are some OpenSCAD renderings of the bracket:

M.2 60mm to 80mm Bracket Render Top
M.2 60mm to 80mm Render Top
M.2 60mm to 80mm Render Bot
M.2 60mm to 80mm Render Bot

Actual 3D printed bracket (In use):

M.2 60mm to 80mm Bracket
M.2 60mm to 80mm in use

The Fluorescent Green Zip Tie is used to stabilize the WIFI antennas so they do not come loose from the AC 8260 connectors.

M.2 60mm to 80mm SSD Bracket
M.2 60mm to 80mm Bracket (SSD side)

Finally here’s a side view of the stack of both cards:

M.2 60mm to 80mm SSD Bracket
M.2 60mm to 80mm Bracket (side)

Chicago Dynamic Industries Sound Card (EM Gun Games)

A fellow Arcade collector sent me this Private Message a few months ago on the KLOV forums:

I’ve got an old EM Chicago Coin “Shoot Out” gun game. Works great, but came without the sound PCB that generates the gunshot sound. They also made a “Coney Island” game that used the same sound PCB, but I’ve been searching for ~5 to 6 years for a used board with no success.

The problem with the soundcard is it used older End-Of-Lifed (EOL) transistors that can’t be easily found. I offered to help him design a PCB and BOM which would duplicate the sound and provide a “modernized” BOM which could be ordered off Digikey.com. He reported back that after some rework to the pinout; the card worked as expected. As a result; I’ve incorporated the rework (ie corrected the design)… and have provided the materials here for the public to duplicate and use for any older machines which are missing (or has a non-functional board) the EM Gun Soundcard used in these games.

The major changes to this board vs the original are as follows:

  1. The PCB is double sided with large ground plans to aid in noise reduction.
  2. Additional caps are placed on IC1 (LM380) and the Zener diode regulators to help improve the immunity of the circuit to noise. CIC1, C22, C23 – all .01uf.
  3. PCB’s has both a top and bottom silk screen:
    1. Top has values and reference designators to aid in assembly and debug.
    2. Bottom has used edge fingers labeled as well as the legs of the transistors; again for debug.
  4. All transistors were replaced with 2N3904 NPN transistors which are very much still in use today. The single PNP was replaced with the 2N3906.
  5. Test points for the 18V, 12V, 9.1V, and ground rails are provided for easily troubleshooting the voltages on the sound board.
  6. LEDs provided for the 12VAC and 30VAC lines coming into the sound card. Again quick glance that there is at least some voltage going into the sound board.
  7. Although not needed in a real game; two mounting screw holes are needed if you have a non-standard installation.

I’ve decided release this design to the public under the TAPR Non-Commercial Open Hardware License which indicates:

You may make products based upon this design, provided you do not make more than ten units in any twelve month period for your personal use.

If you agree with the license terms; Schematics and BOM lists are posted here under TAPR/NCL license:
Rifle 444-310 Soundboard Package

Ordering should be easy: https://oshpark.com/shared_projects/6GKvZu4s
The boards are $67-ish for a set of 3 PCBs… and they are high quality. Gold plated fingers, two layer, silkscreen on both sides. It’s the cost of doing prototypes. OSHPark usually get the PCBs back to you in about 2 weeks.

BOM Cost from Digikey came to a WHOPPING $17 for one board. My advice is to take the BOM and multiply it by 3 in Excel or some other spreadsheet app. It’s usually cheaper to by 50 or so of the resistors. IE in one qty; they are 8cents… in 50s they are > 3cents. I usually buy 50-100 of each; just so I have them around when I prototype on breadboards and such.

The PCB is very compact; it was done this way to save on the prototype PCB sq inches cost. If you find some of your components are tight; you might try laying them similar to this:
http://pcb.bastl.sk/?page_id=50

Here’s a picture of the assembled board:

Rifle Ricochet sounds w/ AMP Fab B assembled
Rifle Ricochet sounds w/ AMP Fab B assembled

Hope this helps the EM Gun collectors out there. If it does… please drop me a comment letting me know it’s done some good!

Stern Star Trek: Vengeance Nacelle Mod

I really enjoy my Stern Star Trek LE Pinball machine… But one of the things which has bothered me on the machine was the way the USS Vengeance shines it’s bright blue Nacelle LEDs right in the eye of the player.

This simple mod aims to correct that. I knew I wanted laser cut some blue acrylic pieces to help defuse the LEDs; so I consulted google images to give me some ideas what the Nacelles were suppose to look like:

USS Vengeance c/o TrekCollective.com

Without redesigning the whole Stern Nacelle; I decided a piece set about 1/4″in into the nacelle would be closer to film accurate. Also; in a couple of the google images; the Bussard collector looked more cylinder shaped; so I figured a deep etch in the back side of the plastic would be ideal. Here’s what my first prototype looked like in CorelDraw:

USS Vengeance Nacelle Prototype
USS Vengeance Nacelle Prototype Peices

I then proceeded to Techshop.ws and laser etched/cut these pieces out on some 1/8″ Blue acrylic.

To remove the Nacelle; simply remove the top two philps screws holding the Nacelle to the ship assembly. Then remove it… On my ship; Stern was rather liberal with the hot glue; so I had to work the nacelle off by pulling the sides of the nacelle from the hot glue. The Blue LED is attached to the ship assembly; so you shouldn’t have to worry about it coming loose.

When I got home; I used some plastic epoxy to glue the piece into the left nacelle. This piece is to be position just past the flat ridge in the nacelle:

USS Vengeance Nacelle

Here’s the Bussard collector installed with a little epoxy:

USS Vengeance Broussard collector
USS Vengeance Bussard collector

NOTE: the curved etch faces the rear of the Nacelle (etch toward LED)

In my case I found it a little easier to bevel the sides of the pieces with a file so the sides of the plastic pieces would make better contact with the sides of the warp nacelles. I put some epoxy on the sides of the piece and on the little round nub at the top of the nacelle so the piece can’t be shaken loose during the Vengeance battles.

So; How’d it turn out? I only modded the left side (right in the picture) and took this picture:

USS Vengeance Mod
USS Vengeance Mod

A close-up Before and After:

sStDSC_B4After
USS Vengeance Mod Before & After

Want to do this yourself? Have access to Acrylic and a Laser Cutter? Great; I’ve decided release this design to the public under the TAPR Non-Commercial Open Hardware License which indicates:

You may make products based upon this design, provided you do not make more than ten units in any twelve month period for your personal use.

If you agree with the license terms a PDF  is posted here under TAPR/NCL license: Vengeance Nacelle Mod Package

Don’t have access to a laser cutter? Visit our store to get an inexpensive set:
http://pinball-mods.com/oscom/product_info.php/products_id/33

Star Trek: The Next Generation Klingon Bird of Prey Mod

I recently purchased a
1994 Hallmark Star Trek Klingon Bird of Prey
from a fellow Pinsider. This Ornament came ready to install into my 1996 Williams Star Trek: The Next Generation Pinball machine. However before I installed it in the machine; I wanted to make further modifications to the item. My previous installation had installed a die-cast

2005 Corgi Klingon Bird of Prey

for which I’d followed the recommended installation of putting the incandescent light bulbs under the ship:

Before – incandescent light bulb sockets- ICK!

Immediately upon this installation; I knew it wouldn’t do… but I waited several years until I got one of the hallmark ship mods. I decided back then that I was going to put some Electroluminescent panels under the wings… but then came to my senses that the EL panels loose their brightness rather quickly. So; after getting the Star Trek: Mirror Universe pinball machine to a Phase1 complete state; I returned my attention to this mod. I decided this time that I was going to use superbright surface mount LEDs to replace the light bulbs and their bulky sockets.

I started by researching the type of LEDs. A Digikey search came up with some super brights; relatively cheap but with a lot of light output. I figured I could fit about three of these LEDs under each wing; so I began the design phase of the project. I started by doing a pencil rub of the wing’s paint job. This gave me an approximate size of the PCB I needed under the wing. I scanned this pencil rub into the computer and vectorized it into a PCB using the technique posted here. With the PCB outline created; I proceeded to create the schematic of the LED board. I made a design choice to rectify the 6.3VAC GI power rail so that polarity wouldn’t matter during install. I also decided that I’d use a BJT current mirror to light the first LED and drive 20mA thru it. Then use the second leg of the current mirror to drive the remaining two LEDs. To ensure stable voltages/currents; I put a 3.3V LDO regulator and some caps on the first leg to try and keep the brightness from flickering with the 120Hz FWB power rail.

I have decided to release the schematics to the public under the TAPR Non-Commercial Open Hardware License which indicates:

You may make products based upon this design, provided you do not make more than ten units in any twelve month period for your personal use.

If you agree with the license terms the resultant schematic is posted here under TAPR/NCL license:

STNG KBOP LED schematic
STNG KBOP LED schematic

You can buy the bare PCBs from OSHPark from here. Total cost to build this board in single unit quantities as of 6/15/2014 was $14.55 / a pair of boards.

The entire project package is here: STNG_KBOP TAPR Package
It contains the schematic, NCL license, Bill of Materials.

This project requires SMT soldering skills so be prepared. I used a syringe with solder paste to populate the PCBs then used a skillet to reflow the solder. Here’s the assembled PCBs:

Then I assembled tested the circuit first with my 5V bench supply; then with a 6.3VAC transformer from RadioShack:

With the boards tested; I began refitting the Hallmark KBOP mod which looked like this:

I removed the green heatshrink hiding the LED wing guns and cut the red & black wires as I had recreated the wires in the PCB and had embedded the resistors hidden under the black heatshrink near the guns:

Originally and in the PCB file; I had decided that I wanted to use 2 qty #0 self taping screws to hold the PCBs in place. These were speced at McMaster Carr as #94209a005; but I didn’t want to pay for S&H for that single box of 50. Instead I drilled out the holes a little larger and used #2-56 @ 3/16 of a length. I carefully marked drilled the wings of the KBOP and taped them with my #2-56 tap set. You MUST be careful here not to drill through the wings. Here’s the PCBs mounted:

I then proceeded to solder the cut GI wires for the wing guns to the Jin connections on the PCB. I also connected the Guns to the JWing connection at the edge of the PCBs with a short piece of red rework wire after removing the inline resistors at the LEDs. I secured the electrical connections at the gun LEDs with some liquid black electrical tape:

I then proceeded to attach the GI connection from my machine along with the bracket. Reusing the older wireing harness as desoldered from the bulb socket assembly made sure the under wing LEDs lit in the same was as the bulbs:

With that the modification of this mod is complete. Here are some mandatory money shots to encourage you to do the same to your machine:

Overall I’m very happy with the results; the Red LEDs really light up the Playfield and I do not have to look at those light bulbs any more. The only thing I noticed with this mod is that my machine doesn’t seem to give me enough voltage at the GI connector to fully lite the two LEDs on the second leg of the current mirror. I think this is because the STNG controls GI; which means there is an extra silcon device between the 6.3VAC transformer and the GI lamps. This is evident when running the shuttle craft missions when all the PF lights are of in this video mode. In a future revision of this mod; I might try directly hooking the second leg of the current mirror straight to the GI input (not FWB rectified) to see if I could coach more voltage across these two LEDs in series.

This PCB obviously fits the 1994 Hallmark ornament seen here and it also seems to fit the Corgi 2005 Klingon Bird of Prey also used in modding these machines.

Enjoy Modding!

Stern ColorDMD adapter plate

If you’ve been following ColorDMD‘s updates on Pinside; you proably already know that ColorDMD is currently working on color DMD dots for the Stern Star Trek Pinball Machines. Several months ago I helped formalize plans for an adapter plate for the Stern Star Trek Premium/LE machines.

This DIY mod will allow you to install a Color DMD in a machine without modifying the stainless steel speaker panel. This Adapter completely covers the studs on your metal speaker panel; thereby preventing the studs from scratching or cracking your $400 ColorDMD (LCD) display.

Plans for this MDF ColorDMD adapter plate are posted here:
ColorDMD adapter plate plans
or you can purchase a pre-made kit from us here:
/oscom/product_info.php/products_id/32

Installation Instructions:
ColorDMD Adapter Installation Instructions

Sega Star Trek Captain’s Chair Coinbox

Madaracs on the KLOV forums was kind enough to loan me his Sega Captain’s Chair CoinBox for measurement of the dimensions. With his coinbox I was able to modify the preliminary plans I had posted to my Captain’s Chair Restoration.

I have decided to release the plans to the public under the TAPR Non-Commercial Open Hardware License which indicates:

You may make products based upon this design, provided you do not make more than ten units in any twelve month period for your personal use.

If you agree with the license terms and are interested in the coinbox plans; they are here:

Sega Coin Box Plans (PDF)
Sega Star Trek Captain's Chair CoinBox Plans (PDF)

Thanks to Muel and Madaracs for the help enabling these plans. Now all I need to do is gain access to Austin’s TechShop to waterjet me some material from these plans.

Color Vector Pattern Generator

Almost a year ago I posted in my Star Trek Captains’ Chair worklog that I intended to modernize a old XY Pattern Generator design on the interwebs. Many of the guys on VectorList provided valuable insight into the interworkings of the circuit… and provided many layers of helpful advice.

The result was a working prototype board from BatchPCB.com as a dual sided board. Surface Mount ( yes; I can hear the screams of horror ) as I wanted to minimize PCB size and thereby cost.

There were several key learnings that I’ve noted while building, debugging, and using the Vector Pattern Generator. These learning were as follows and have been incorprated into the FabB design:

  1. The clock generator circuit (3.578MHz xtal) and U1ABC was not “locking”. This was due to the buffered logic of the newer 74HC* logic. Some research on the internet indicated I needed a 150pf cap from pin1 U1A to ground to allow the clock generator to exite enough to lock.
  2. The -12V buck converting power supply wasn’t outputing the correct voltage. It’d start out at ~11V…. the drop to ~5V over several minutes. On my debugged board; shorting R26 (10meg ohm) allows the -12V to become rock steady at -11.8V. Unsure here; the Maxim EE sim was very specific on the 10meg ohm value… but the maxim datasheet indicated two modes for VL to operate in. So for now will error on the practical side.
  3. The 5V regulator did not have enough copper to heatsink to. FAB B has a large 5V copper heatsink built into the board for the linear regulator. For my prototype; I thermal epoxied a small heatsink from a old motherboard onto the top of the regulator to give it some thermal sink.
  4. The Linear POT datasheet was missing details regarding the LED side of the POT. One hole was off and was moved to match the device.

I also included the following “Nice to Haves” into the FabB design:

  • Retrofitted EPROM sockets to enable A11 for a 27C32 eprom(s)… allowing for more user designed test patterns.
    NOTE: A11 is hardwired to high to match 2716 eproms configurations. No clock/decode is provided for A11. Future FabC work if a solution can be found.
    At this time you can use either 2716 or 2732 eproms in this design.
  • Renamed topside adj pots to indicate X and Y.
  • Converted to 3pin jumpers so the jumpers can be mechanically sound when output swing is not shorted.

I have decided to release my portions of this design under to the public under the TAPR Non-Commercial Open Hardware License which indicates:

You may make products based upon this design, provided you do not make more than ten units in any twelve month period for your personal use.

If you agree with the license terms and are interested in the FabB schematics; they are here:

Vector Pattern Generator: Fab B Schematics(Click here to open as PDF)

For those without PCB layout tools; a bare PCB is available from the batchpcb service for under $65. You can purchase the boards from this link:
http://batchpcb.com/index.php/Products/91905

The Bill Of Materials (BOM) of the board is available from Digikey for $75.51 (as of this post).
A bom is included with the schematics PDF above, but An XLS file with the digikey part numbers with the complete package of the materials above as a single download: XYpatternFabB_pkg.ZIP
You will need to source your own 2716 or 2732 EPROMs as Digikey does not carry them. You’ll also need to source your own 14-16VDC wallwort … you may already have a donor in your parts bin leftover from a defunct piece of equipment.

ROM images for the EPROMs can be downloaded from several sources. Hint: Do a search for XY ROM images .zip in Google.

Use the ROM images as-is for 2716 EPROMs. For 2732 EPROMs; just dup the roms using the following dos commands (as an example):

copy /B X.BIN+X.BIN x32.bin

/B is important as it tells copy that the files are binary, not ASCII files.

The Author is still using the FabA prototype; he has not yet built FabB so YMMV.  The changes from FabA were relatively simple; so building these should be a low risk.

The active components (switches, linear pot, adjustment pots, jumpers, and video connector) are all populated on the reverse side. This will allow me to put the board on standoffs and a acrylic top on the device to protect it from dust/flying multimeter/scope probes.

The board is still quite big even with the surface mount components measuring 5.1×3.9in tall. By far the largest parts on the board are the EPROMs… maybe one day I’ll figure out how to move the EPROMS into a single EEPROM device and surface mount it.

So; what does the Fab A prototype look like?

Click to see higher rez pictures

Vector Pattern Generator: Primary side

This is the primary side; which faces the workbench in normal operation.

Vector Pattern Generator: Secondary side

This is the secondary side. It becomes the “top” of the unit so the user can adjust settings and the like.

Please Note: This implementation is not perfect… there are some issues with the vector generation that I haven’t been able to debug. The imperfection does not really limit the functionality; as you can easily converge and debug a vector monitor with the vectors. I am hopeful someone can help me debug the issues so we can release a better project long term.

Overall the generator worked quite well as I was able to get my ElectroHome G08 monitor converged.

Vector Pattern Generator: Box pattern

I can’t explain the center vectors… nor why the lines become squiggly. They don’t move; it’s always that way.

Vector Pattern Generator: Cross pattern

Strange that the site pattern doesn’t seem to suffer from odd vectors.

Vector Pattern Generator: Box & Cross pattern
Vector Pattern Generator: Horizontal Lines pattern
Vector Pattern Generator: Vertical Lines pattern
Vector Pattern Generator: H&V Lines (crosshatch) pattern

As you can see; the generator works well enough to converge a vector monitor…
At this point I’m not sure if the odd vectors / none straight vectors are the result of a software problem (EPROM images) or a hardware problem.
It’s possible the software isn’t reacting well with the faster hardware (HC logic, better opamps); but unsure.

Things I still need to do [if I ever find the time]:

  • check the +12V portion of the buck converter. Right now I’m using the backup +12V linear regulator (U9).
  • Create an enclosure to house the unit.
  • Figure out how to clock A11 to enable full 2732 support; thereby more test patterns.
  • Figure out why the vectors aren’t “clean”.

DIY Arcade Leg Lever Plates

I knew this was going to happen; When I first got the wood shell for my Sega Star Trek Captain’s Chair – Someone had already ripped several of the Leg Leveler T-Nuts from the wooden bottom. I figured – hey; can’t be a real problem so I epoxied in some new T-Nuts and went off to Texas Pinball Fest ’12 . Needless to say; three of the T-nuts didn’t make it back to Austin.  Call it carelessness; or whatever, but I had to fix this.

T-Nut damage (photo by SaminVA on KLOV)

When I first saw the original t-nut design; I thought it was stupid. The tnuts won’t hold… and neither will those two massive staples the put over the Tnut. If the nut can be pulled; so will the staples. Besides; it’s not like the sell those big staple guns at Harbor Freight or any home improvement store.

I whipped out Corel Draw and laid out some simple plates to “improve” the design. My goal is to make the t-nuts resistant to torque forces while keep the plates simple. Here’s my solution to help keep the T-nuts in place.

I have decided to release this design under to the public under the TAPR Non-Commercial Open Hardware License which indicates:

You may make products based upon this design, provided you do not make more than ten [sets] in any twelve month period for your personal use.

Suggested materials:

  • 3x3x0.25 inch poplar sheet
  • 5minute epoxy
  • white Gorilla Glue
  • 1/4″ Crown Staples (18 gauge, 1″ long)
  • 3/8″-16 T-Nut (McMaster Carr  #90975A031 )

The first three items were sourced from Lowes – but nearly any home improvement store should carry these items. The Staples were sourced from Harbor Freight for a previous restoration project.  The T-nuts from Mcmaster Carr for the original Sega Star Trek restoration.

The design I came up with is as follows:

TAPR/NCL Leg Leveler Plates

I cut the poplar sheet to fit to 24″ length so it would fit on my Laser table. Ran the Laser cutter at 50% power, 1.6 speed, 250 pulses per inch (ppi) to cut on the red lines. The Etches were vector engraved at 40%, 10 speed, 500ppi. Was it necessary to laser cut – heck no, but if you have the equipment; why not use it? Took two passes to cut through the 1/4″ poplar at these power levels.

You can download a full package ZIP file from:
Leg Leveler Plate Package
which contains the Corel Draw file and measurements in PDF form.

After Laser cutting; I had these nice plates. Since the wood on the bottom of my Chair was fairly beaten up in a couple of cases; I needed to secure the TNuts with more than just a hammer. I mixed the 5 minute Epoxy per directions at 50/50 ratio and coated the inside of prongs with the epoxy; then hammered in place. I coated the nut with more epoxy in an attempt to secure it better to the wood. Here’s an example of what I did to a friends dedicated Upright Star Trek machine which had simular issues:

Epoxy & wood filler curing on T-Nut

In this picture; some wood filler was used to help secure some missing wood from where the tnuts were ripped out. Be sure not get any epoxy in the threads of the tnut… one way to do this is to run a old leg lever into the hole while the epoxy is setting.

The epoxy sets in 5minutes; but takes a minimum of 1hr to reach some strength; so I let the epoxied Tnut set for an hour and played some Star Trek Pinball.

The plate will be installed with the arrow facing the outside edge of the machine. For the Captain Chair; the orientation of the arrow doesn’t matter as the tnuts are far enough inside the machine to not matter. For the Dedicated upright machines; the Arrow side is 0.1inch shorter; so it will not overhang the front of your machine.

After the hour; I dampened the base of the machine and the plate with some water per directions on the Gorilla Glue packaging. I used the White version; because it cures in about 30-60minutes. I put a spiral pattern on the wood plate and stapled it in place with the 1/4″ crown staples. The Staples provide the clamping pressure while the glue sets.

Plates on Upright Star Trek machine

For the first 5 or so minutes; watch the foaming action. Clean up any over spill of the foam – particularly in the hole near the tnut. After about 5minutes the foaming should stop and you run that same used/scrape leg lever into the threads to keep the hole accessible for your new leg bolt when completed. I used a large blade of the screw driver to scoop out the foam. I put about about 4 staples in an X pattern outside the 1 inch etch hole; which represents the metal Tnut which you don’t want to try to drive a staple into. 😉

I put about 10-15 staples in the plate after initial orientation check – these staples may seem excessive; but I want to secure the wood plate to the bottom of the machine and provide a good even clamping pressure for the gorilla glue to dry. As the package says “Strength of the bond line improves with better clamping.”

Closeup: Plates on Upright Star Trek machine

Wait about 1hr for the gorilla glue to strength… At this point you can gently set the machine back on it’s legs. If you can wait at least 24hrs before any excessive moves – this will allow both the epoxy and the gorilla glue to reach full strength.

Oh; and don’t forget your new leg levers:

Complete!

This plate should be nearly in-destructible; which could prove a problem if the tnut ever needs to be removed. Not sure why that would need to happen – comments / suggestions?

FreePlay 555 Coin Circuit

My Sega Star Trek Captain’s Chair is destined to be present at the 2012 Texas Pinball Festival. As a result; the game needs to have a FreePlay feature (IE a way for the public to play the game without needing quarters). I know Sega Star Trek has a freeplay rom hack available; however, at this moment, VectorLabs isn’t supplying freeplay roms with their devices. I haven’t spent enough time with the multi-vector boardset to determine how easy/hard it would be to convert to Freeplay. As a result; I wanted a simple inexpensive way to credit up the machine when the user pressed the Start button (1UP).

I toyed with the idea of using a cheap 8pin ATMEL microcontroller; but decided a simple 555 timer could be developed to do most of the heavy lifting. In the end I decided to go with a dual 555 timer (NE556) in a cascaded mono-stable configuration. The circuit features:

  • PowerOn Reset to “credit up” a single credit when power is applied to the machine. Jumpered feature.
  • Ability to drive COIN_NO signals
  • Ability to “interrupt” COIN_NC
  • Can be alternatively stuffed for AC power supplies (6.3VAC GI circuits in Pinball Coindoors).
  • Jumper configuration to “disable” circuit.
  • Barrier Diodes to help prevent “installation error”.

I have decided to release this design under to the public under the TAPR Non-Commercial Open Hardware License which indicates:

You may make products based upon this design, provided you do not make more than ten units in any twelve month period for your personal use.

Schematics :

Click to view FreePlay 555 Schematics in PDF

The first timer conditions the active low switch connected to J2-3 (1P [aka the start button]). On the Sega vector hardware; this signal is tied high to 5V via a 2.2K pullup resistor. The start button connects momentary grounds at this signal. The Trigger on the 555 timer is also triggered when the voltage at pin 6 transitions below 1/3VCC. D4 protects the cpu board by preventing current from flowing back into the cpu board. This timer “de-bounces” the switch which sends a single long pulse via OUT1 (pin 5). This timing is created by TA = C6*R4 or ~242mS. I’ll explain the function of R5, JP3, D1, and C7 later.

OUT1 drives the “armed” LED to notify the user/debugger that a “start” pulse was received. OUT1 is coupled to Timer2 via C4 and R6. The purpose of these components is to provide a “negative” trigger pulse at the falling edge of Output. Timer2 then drives based upon TB = R1*C1 or ~60mS. This is the coinup signal which is sent to the coin circuit of the arcade machine. 60mS was derived from measurements of my acutal Star Trek Captain’s Chair by dropping a quarter into the slot via an Oscope.

OUT2 (pin9) drives Q2 and Q1 respectively. When not processing “start/coin up signals” Q1 is “active” providing conduction between the CPU Board and the Switch (PNP active when base is low). On the sega star trek; I found that I had to interrupt the NC signal of the switch in the coin door to get the cpu to “detect” a coin from our COIN_NO (J2-4) – Q1 provides this interruption. Speaking of NO, Q2 goes active when OUT2 outputs a high… which drives a “low” to the COIN_NO. In the Vector machine; COIN_NO is pulled high thru another 2.2k resistor and drives the !Set signal of a Set/Reset Latch made out of NAND gates. Incidentally; the NC signal drives the !Reset signal. The Q output of the NAND gate drives the clock of a D latch which drives the interrupt pin to the cpu board.

I promised to talk about the R5/C7 combo. These components control the “poweron” coin up timing. TpwrCoin is a function of U2’s timing and R5*C7 which is basically ~1.2seconds. U2 is a ActiveLow microprocessor supervisor IC. It monitors the 5V powersupply and holds !RST low for about 150mS. This allows the top of R5 high thru a 5.5k internal pullup resistor when the device is non-active. Meaning U2 will drive RST high on each timer after 150ms once the 5V rail is at least within 15% of the 5V target (4.25V). This effectively provides a “credit” signal to the game about 1.2seconds after the power button is pressed (for initial credits). In theory; this circuit can be disabled by removing JP3’s shunt.

JP1 provides a mechanism to “disable” the freeplay circuit. IE virtually removing the circuit from your game. Use this in position [2-3] to disconnect the timers from the bases of the transistors which should return the game to normal operation. IE if you want to start charging people money. I plan to use it to enable money when I take it for charity work.

Please be aware; this circuit still allows the coin shutes to work… even if the circuit is enabled. This was intentional.

The PCB is designed as a two layer PCB with through-hole parts on the top layer to enable those less skilled with a soldering iron to build the circuit.


FreePlay 555 Fab A Top Layer w/ Silkscreen


FreePlay 555 Fab A Bottom w/ Silkscreen

For those without PCB layout tools; a bare PCB is available from the batchpcb service for under $14. You can purchase the boards from this link:
http://batchpcb.com/index.php/Products/75967

The Bill Of Materials (BOM) of the board is available from Digikey for $9.02 (as of the time of this post). A bom is included with the schematics PDF above, but An XLS file with the digikey part numbers with the complete package of the materials above as a single download: FreePlay555_pkg

The author’s prototype was built from mostly RadioShack parts he had in his parts bin including the breadboard. He intends to replace this with a PCB from batchpcb in a few months.

Installation note: You need to make sure this circuit used the same voltage rail of your cpu board. The authors’ G08 wiring harnesses did not follow either the Cockpit (which is correct) schematics or the Upright harness (which is incorrect). The J4/P5/p12 harness  shows that the cockpit connects the coindoor lamps to the +5V rail at P5 pin6 and pin8. However, The author’s harness had it connected to the -5V rail which is BAD and will prevent the circuit from working properly (and possibly damaging your machine). The upright schematic shows that +5 and -5V goes to the lamps for 10V… also bad.
Either wire up a new +5V signal to this board; or correct your wiring harness to be like the schematics of the cockpit. Seriously – go double check it.

I wired in this circuit into the coin door harness so the board can be bolted to the inside the door. You’ll need to “cut” the NC wire of one of your coin switchs and put this circuit between it at J2-5 and J2-6. Then wire in the NO signal at J2-4. The Start Button goes to J2-3, the +5V rail to J2-1, and Ground to J2-2.

The circuit works as expected in my machine…. providing an inital “Free” credit upon powerup and then providing additional credits each time the start button is pressed (after the game starts). If you want more than one credit; the circuit can be redesigned; or you can press start multiple times during your “inital” game. 😉

I’m fairly sure this circuit can be adapted to any arcade machine. I provided a bridge rectifier stuffing option at B1 to enable “AC” voltage inputs from 6.3V AC.  Or Jp2 can be “bridged” with solder to enable 5V to via the D3 shottkey diode.  I plan to test this circuit on my Bally Star Trek Pin once I get the PCBs back.

Enjoy… I’ll post more pictures when I get the PCBs back from batchpcb.