Star Trek 4B Computer

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New Member
For a while, I've wanted to get into the whole "building" community, so when I found depictions of the Star Trek TOS 4b Computer (possibly from this site) with dimensions, i wanted to build it. I mean, it's an angled box, how hard can that be? (that's an honest question, btw, I want to know what I don't know).

Still, while the wood pieces look relatively simple to design and cut out and I can substitute contemporary switches and knobs for the controls, there are other parts I don't know how to replicate. Specifically, the light domes and the light bar in the front.

I'll settle for contemporary knobs though think I can make my own out of wood, given time. I found a link on of someone selling TOS style domes, think I might purchase those and, if they work out, look into making my own molds off of them so I can do my own colors and don't have to purchase additional parts, but I have no idea how to make that light bar. Any suggestions on how to make either the domes or that bar?

Current plan is to make all the wood pieces with beveled edges so as to hide the join seam, make it look like plastic.

Lights would be run off an arduino or such in the back. I plan on making all of the controls functional. The toggle switches would correspond to screen functionality - the red turn on the bar and the grid, the blacks each turn on one of the 1x5 grid lights. For the knobs, i have a few ideas:

  • Overall LED brightness
  • Light bar blink mode (solid, alternating, morse code letter styles, etc)
  • Light bar blink speed
  • TBD - possibly separate bar brightness from grid brightness? Set a pattern for the 1x5 lights? Set a time delay for the bar to light up to simulate performance in Mirror Mirror?

Anyways, I fully admit I'm new to all this and would appreciate any direction or advice I can get.

For example: for the knobs, i would seem to need two different types but I don't know how to describe them. One knob would turn to any position and determine intensity (a rheostat, I believe) while the other would ratchet to predefined positions (say North, North-East, East, etc). What are the proper names for such?

Thanks for any help!

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Legendary Member
feek61 could give you some pointers as he has built this and other TOS Computers, that is his graphic you are using


New Member
So, I've spent the past few weeks working on this. Have been working on some wooden blueprints to both plan things out and to give to someone (I don't have tools myself, so it's either borrow and learn how to use them or see if I can get someone to do it for me)

Got an arduino Mega 2560 R3 knock off and it's working pretty well thus far. Only real reason I got it was because it had enough ports that I could dedicate a wire to everything without having to get clever with matrices or such. I may be running into an issue though.

My initial plan was to have the arduino and a half-sized breadboard velcro'd to the interior of the flat panel, idea being that if I can install everything on that one panel, it'd be easier to remove and do maintenance. I plan on powering the thing using a panel mounted USB B port and a cell-phone wall charger. Anyways, I just plotted out my breadboard in Excel, trying to see how much space it will take up, and I came up with this:


Breadboard layout 1.jpg

Orange maps to pins on the arduino, blue lines represent LEDs, black lines represent resistors, and the red lines map outgoing power for either the 4 potentiometers (green) or the 7 buttons (red and black squares). There's about 1 free row on the breadboard and I'm concerned I'm packing things too tightly - concerned that the lines will cross. I hear there's tubing you can get to insulate things, but maybe I'll just tape things directly to the wood.... or maybe use that conductive paint, as long as it wouldn't be a fire hazard for the wood in case of a spark or something.

So - all you experts - am I putting too much circuit into too little breadboard there?

Found some interesting things too.

These knobs here are perfect for the TOS 4B Alpha design:

And this LED backlight would be perfect for the light bar for nice even coverage:

Still have no idea on what to make the amber light bar out of - saw a piece of wood and cast it myself? Disassemble a bike reflector? Find a translucent tray table and cut it to size?

Another possible issue I've found is that the potentiometers I plan on using come with screw threads but aren't long enough to hande quarter inch plywood. I'm hoping that the knobs I've displayed higher up will fix this - they come with a set screw placed under the elastic band and I'm hoping that would be sufficient friction to keep the potentiometer in place (with a small notch drilled for the alignment tab, naturally.

I ordered a series of TOS gumdrops from a third party site, came in different sizes and I'm considering making molds of the larger ones to make my own. Not exactly happy with the color selection - too many purple, not enough red/orange. Green's good, but a number of pieces are just washed out.

I also plan on deviating a bit from the actual prop. Sure, authenticity helps and makes it look good, but I'm not one of those who will say "it's the wrong shade of gray, it's junk!" or something like that. So, instead of those plunger buttons, i plan on using these:
16mm push buttons, kinda large but I think it better suits the design aesthetic somehow, another rounded bulge.

Planning on using 3mm white LEDs for all the gumdrop lights, mainly as they came in a handy 25 pack, but I figure if I want to upgrade, I can redrill the holes after the fact and change the resistors. One benefit of not planning to solder anything (yet) is that I'll be able to easily modify things.

Anyways, that's all for now, heading back to coding and doing schematics. For the most part, I'm working finalizing the design while waiting for parts on order, probably overthing things but ounce of prevention/pound of cure, right?

Anyways, that's all for now.


New Member
Hey all.

Thought I'd do a follow up on this. Hadn't realized it'd been size months.Made quite a bit of progress. Here's how it currently looks:

The wires on the side are meant to help connect the buttons and the top part - they can separate in the middle so I can remove the panel. The tube is going to be cut and painted for the side tubes. At the bottom, you can see the planned dome arrangement and the key fob. I've installed that to allow for the appearance of voice activation, to make it look like you can say "Hello Computer" and it powers up.

All of the lights work, as seen here:
Currently, the grid is set to blink randomly, though I may include the functionality later on for planned sequences. The top knob on the left controls the grid blink speed and the second knob would control the grid blink pattern, but currently does nothing. The bottom two knobs control bar blink mode and speed, respectively. I currently have the bar set up to blink a selection of Morse code letters as I thought it would be simple to code and engaging, but it's not quite as I expected. The bottom pot snaps on and off, which allows me to lock it into the solid state mode.

The light bar is pretty bright and I'm happy with it thus far.


As you can see, I've made a blue bar for this unit rather than red or orange. I made it from a sheet of lexan and a sheet of blue plastic meant to simulate a calm ocean. It's not completely flat though, but looks good. I think the color arrangement isn't quite TOS level random, but we'll see. The domes came from a site called "".

Here's the internal wiring. All of the lights are secured using Gorilla tape and the arduino microcontroller is attached to command Velcro strips on wood double stick taped to the panel. It's elevated so as to allow clearance for the potentiometers. The bundles of multicolored wires came as a large pack, but the individual cables are color coded. Black for ground, red for 5V, yellow for input, green for output. The green board on the right just under the red jumper wire is the radio receiver. The key fob comes with four buttons, currently using one for the grid, one for the bar, and one for all five strip lights. It's not perfect - the signal is a pulse so you have to push the buttons just right, but works fine and dandy.

20171206_221229.jpg 20171206_221333.jpg

Pictures showing the construction. My dad did this, much to my surprise. I asked him just for some advice on how to cut the wood and he offers to make the whole thing. Not perfect - somehow he added about an inch on ever dimension, most notably resulting in an extra grid column and the empty space next to the black buttons, but it worked out. The extra space gave me sufficient clearance to use a long breadboard and made wiring a breeze.

I plan on wiring the buttons by using 3 and 6 wires respectively - wires for each button and one wire for power jumpered between each button. This was to help cut down on the total wires needed.

One final shot showing the profile and the microtapes my Dad was considerate enough to make for me. The red and the yellow are closest to the correct sizes, but the white and blue aren't half bad (perhaps I can play them off as special extra-capacity discs).

Anyways, that's where I'm currently at. Still need to paint and mount the tubes, wire the buttons, glue the domes on, and a couple other tasks, but this is turning out better than I could have hoped!

Any feedback would be appreciated.


New Member
It's me again.

Before I get into it I wanted to thank Apollo up there, I did end up talking to Feek61 and he did help me out. So - thanks!

Anyways, in the meantime I've gotten the console to a functional, though not final state.

Here's the final configuration with all accessories:
Front glamour.jpg
Ain't she a beaut?

I glued on the light domes and the light bar. The bar isn't completely rectangular and the domes aren't centered as the drilled holes were too wide for the LEDs, so I simply aligned the dome to whatever looked brightest and called it a day. No one will be taking a level to the thing, after all, and I would have preferred a more regular pattern, but perhaps on the next build.

Currently, all of the buttons and most of the knobs work. The two red knobs, left to right, control the light bar and the grid. The five black control the lower 1x5 row of lights in respective order.

The top knob controls the blink speed of the grid, the 2nd top knob currently does nothing at all. I had some ideas about configuring blink patterns but never got around to implementing, the potentiometer isn't even wired up. The bottom two knobs, in descending order, control the light bar blink speed and the light bar blink pattern. The bottom pot snaps off, which is the "always on" state, so you can lock it if need be. The knobs came with a pink rubber friction ring that would settle into a groove, but I didn't use it. One - I hated how it looked and Two - I had the darndest time removing it from the knob if I wanted to access the set screw, so I left them as is and think they look great.

You can also see the painted CPVC pipe inserts on the side, two coats of Flat Aluminum enamel and a borrowed pipe cutter, looks terrific.


Here's a shot of the other side. You might notice that two screws are missing. Those screws gave me no end of trouble. My dad (much more experienced with wood) cut the wood and brought the console down later. He drilled the holes and installed what I believe are called T nuts on the inside face of the outer four screws and glued in a nut for the center two screws. I have just about pushed out the T-nut on all of the outer screws, even after attempting to superglue the nut to the underside of the panel. Had to cut the head off one screw as it had completely pushed the T-nut inside the enclosure and was rotating freely so I couldn't unscrew it.

I'm hoping when I next see him we can talk about alternatives or see what can be done, say possibly screw inserts or something. Right now I'm not even taking the thing apart for fear that I'll have more screw issues and just make things worse. Last thing I want to do is cause more damage than I need to. Still, was hoping I could easily take the panel off for maintenance and possibly using as a hiding spot for certain valuables, or something.

Join seam.jpg

Here you can see the join seam of the top and bottom. I coated the underside with superglue and then screwed the top to the bottom, idea being to make sure the two were solidly secured, but I think I used too much glue or not enough weight on top of the top section, as there's a distinct seam between the two, and you can see light between the two. It's the kind of thing you'd only notice if I pointed it out (I hope) but it does bug me a bit.


Finally, here's the underside. The USB power/upload cable would ideally be screwed onto the mousehole at the back, but it doesn't quite line up and I'm not sure how to do it - again, waiting to talk to my dad. I ended up not soldering wires to the buttons but instead using quick-disconnect wires that slip over the pins on the buttons, so that I can easily detach them when I want to remove the microcontroller from the top.

Final Thoughts
This isn't perfect, I'm the first to admit, but it is functional. Code-wise, I want to adjust the range on the speed-potentiometers, currently they span two different ranges so I want to even them up. Would also like to add more blink patterns to the light bar. I wish the buttons and card slot were more centered rather than off to the left. One issue I've found is that the underside of the card reader slot is in an ideal lifting spot, so I keep having to remind myself - don't lift it there or you could break it off. One thing I didn't realize until recently is that the light bar bothers me in that you can see the white rectangle at all times. The original prop had a nice black shadow there, so you could easily tell it wasn't on, here it just looks to me like it's on but dim at all times, until you actually see it turned on and go "oh, THAT's what it looks like".

Still, for my first project like this, everything turned out rather well, I think. It's in the final location and plugged into a USB adaptor, ready and waiting for anyone seeking 23rd century computing power. Now if I could just find a Starship to go with it....

Next planned project: Back To The Future Time Circuits wall clock.
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Well-Known Member
I really like this. There's a lot of complexity in something that has a relatively simple appearance at first glance. Good job!

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