Star Trek: TNG MkVII Science Tricorder Build


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Hi all! It's been a looooong time since I’ve posted a build. I'm not a speedy prop builder as I have a lot of other hobbies. I think the last one I shared was my cricket phaser some time ago. But I’m proud to say I’ve managed to complete this long-term prop build before the end of 2023 - a MkVII Tricorder from Star Trek: The Next Generation.

The MkVII is my favorite prop of all time. I’m quite literally obsessed with these things and study them like a scholar. I’ve had a couple prior to this - a Playmates Tric with updated electronics and a static pre-built Stapleton that I added lights to. This is my first actual build and attempt at a screen-accurate replica. I am slow but meticulous, so this took the better part of the year, on and off. I've had the kit for over 10 years and have been intimidated to start until I decided to go for it this year.

Below are some finished photos of the prop, but I will cover the build overall in posts that follow. I’m in the process of completing another two of these, a Roddenberry MkVII science and a season 3 MkVI, so suggestions for improvement are welcome.

This particular example was a half-built kit I bought maybe a decade ago, I believe from Dennis Stines. If anyone knows the source of the body based on photos, I’d love to know its provenance. It’s not a Roddenberry or Stapleton body.

Finished pics of the prop and a custom case I made for it:






Thanks for looking! More to come...
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Looks great! I love the Next Generation props, but the absolute best is the science tricorder. I've built a mark VII and I have a mark VI (first season version) I haven't got to yet. Maybe this year!!

Great work!!
Looks great! I love the Next Generation props, but the absolute best is the science tricorder. I've built a mark VII and I have a mark VI (first season version) I haven't got to yet. Maybe this year!!

Great work!!
Thank you! Completely agree - TNG props have this very futuristic but accessible, functional and utilitarian look to them. Love em. I've also got a MkVI science (no head) and a MkVI science/medical (medical peripheral) waiting in the wings. I just acquired a MkVII Medical kit (HMS original parts) so that's out there too. My shelf is full for a while!
Thank you all for the nice comments on my Tricorder! It was truly a labor of love. I thought I'd start the build log with the project brief and some of the reference I used.

The objective was to create the most screen/set accurate MkVII I could within the confines of the vac-formed body I had. The origin of the body is lost to time, but it was obtained from Dennis Stines years ago as a partially completed build he had worked on. I suspect it might be a nicksdad body, but can't confirm that. What I fell in love with was the filming prop and its overall look. I know lots of folks enhance their Tricorders with LCD screens, functioning buttons, and so on but I like prop replicas that duplicate the pieces used in the production. I'm a huge fan of the art of film/tv and I wanted to experience the challenges the original prop makers had, duplicating as much of their methods as possible with some concessions for play value and longevity/performance. These small enhancements also ensure it can't be confused as a real prop down the line. That said, duplicating "mistakes" common to the real props was on the table.

I gathered a lot of reference images, some of which I will post below. Not pictured is Ryan Nagata's stellar build of a MkVII, which for me was a benchmark build.


One of my favorite shots. A "mistake" I chose not to duplicate is the visible hinge screw protruding into the EMRG recess. This tricorder also has my favorite screen graphic, also used on some medical variants.


I believe this shot is from "Timescape". The amber Library lights (Alpha, Beta, Gamma, Delta) appeared on some props, but green is what I most remember. Perhaps an option to switch the color could be done in a future build. Fun fact: this is the exact same Tricorder prop used for the Interactive VCR Board Game piece! I used that as a reference a lot too.


I believe this shot of a different MkVII is also from "Timescape." Note the different screen and non-lit ID light. There are two versions of what I call the "meatball" screen. One has an LCARS frame that wraps completely around the graphic, one doesn't.


Geordi again using a MkVII in "Ethics". Here you can plainly see the raised button pads. Also note green Library LEDs and the red LED spill in the power meter - something I duplicated. It also nicely shows off the gray inner border around the graphic inside the screen area.


A couple of nice shots of the front array area from Note missing antenna grill from the blue sensor and the textured surround on the green LED bar. Most kits come with a smooth piece for this which may be correct, but my best reference from TNG-era MkVIIs shows a textured piece. Some props built later for DS9 and VOY appear to insert a horizontal bargraph piece instead. I like this one. Note also the upper right red LED and that the square piece surrounding it is body color with the same silver mist coat. The black area is not paint but vinyl or electrical tape.


The upside down tricorder shots from The Art of Star Trek turned right side up. Great view of the front of hero and static MkVIIs. Note missing foil piece in orange sensor, but the present antenna grill on the blue sensor. Interestingly it seems both green and clear green LEDs were used for the white sensors. Also see the size of the white sensors: shorter than some others which can appear rather long. I like the shorter ones.


Nice shot of a closed Tricorder from the PropBlock auction. Note wear on front graphic, missing power meter graphic, and overall wear.


A seldom seen side of the MkVII on TV: The rear access panel. Note size and hardware used. My door is smaller, but the Roddenberry kits get this right (obviously).


Rear of the MkVII. Only the MkVIs from S3 and the MkVIIs had the vinyl applications here. Black areas do not extend to between the hinges and appear to have hand-cut edges. Great shot of wear here too.

There are a ton more in my reference folder, but these represent the shots I used the most as a guide for accuracy.
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The first task was to assemble the body. This tricorder was actually already assembled and painted, but the lower door was not attached and for some reason had one of the panels completely cut out (the entire panel that includes the EMRG button). I ended up fabricating an entirely new patch panel with correctly shaped EMRG recess myself and gluing it in. Unfortunately I don't have any photos of that process as I actually did it a decade ago, then put this project on the shelf.

In the intervening period, I had acquired a vac-form MkVII kit, so I decided to tackle them both at the same time for economy. You'll see two tricorders, but the assembly process is the same. I'm still working on the Roddenberry kit, prioritizing this one.

Assembling the bodies has been covered I think, but you basically glue two vac-form halves together along the seam line, backing them with "cleats" of clear plastic. I reinforced the inside of the seams with epoxy. I've seen a number of screen-used props with cracks, so I thought this might help.

The next step was to eliminate the seams. For this I used bondo. First filler and then spot putty. Lots of sanding ensued! I may have applied too much bondo, but it goes quickly.


I decided to mock up the front array and drill the holes now before priming and paint. I'm sure this could be done after and perhaps that would be more ideal. I also used graphics mockups to determine where and how much to mask the clear areas.


The left hand Tricorder is the subject of this build. The right is the Roddenberry. The left one had no ID light in the sealed lower door when I got it, so I cut it open on the back and installed one along with the reed switch magnets, then cut and installed a replacement clear styrene patch.

After primer, you will find flaws. Spot putty will fill small pinholes and scratches. Don't forget to mask the areas that need to remain clear for lighting! The beauty of the clear vac-form body is that you do not need to cut holes for many of the lights, they simply fit behind the clear plastic and the graphics.


In the pic above the doors are not attached yet. I sprayed the first coat of primer only using the hinges as a convenient way to hang the lower door. The screws for the hinges will need to be covered with filler and smoothed as well.


Above I am attaching the hinges. A spacer is used to ensure the door closes properly at the hinge point. Captive nuts are used on the inside for the screws. Note that the hinges are also used to transfer power to the ID light in the door. The hinges are coated in a non-tarnish coating that MUST be removed to solder the wires to them properly. The lower door is completely sealed, so you MUST add the ID light before you assemble the lower door and paint it.


Primed with smooth hinge areas!


Next up is applying the distinctive Tricorder 2-stage finish...
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Great work! One of my all time favorite props.
Thanks, Dean!

After priming I did another sanding with 600 grit to smooth the primer coat and provide some bite for the base coat. The door has to be attached for the painting of the base color so that you can smooth out the screws for where the hinges mount on the main body.

The base color is Krylon #51605 Stone Gray Gloss. This color supercedes the original color of Krylon Dove Gray used on the props for the show.


I hung the prop any way I could so I could paint it a little more evenly versus painting the top first and then the bottom. I believe I did 2 light coats and a medium coat until I had good even coverage.


Paint the door at the same time to save you trouble and ensure a match, but I painted it separately from the body. The paint will add thickness to both the door and the body, so make sure your door fit isn't too tight before painting. The interior of the tricorder was carefully masked to avoid spraying the clear areas on the inside. Don't forget that step!

One issue I had is that after painting the body color opening the tricorder wore away the paint on the hinges. Basically the body rubbed on the moving portion of the hinge. I masked around the hinge areas, sanded them down to primer, and then painted them with the Krylon decanted into an airbrush, laying down only enough paint to have coverage.


The most challenging part of painting a TNG tricorder well is the "mist" coat. All the MkVIIs (and Season 3 MkVIs) had a very evident sparkle layer to the paint. Not a covering coat of silver, but an even and prominent misting of paint over the base coat. I believe this gives the prop its futuristic "what is it made of" kind of look, perhaps suggesting a lightweight metal or even a textured surface. I think the Technical Manual describes the material as "micromilled duranium foam".


The color I used was Krylon Brilliant Silver for the mist coat. I find it best to stick to the same paint manufacturer where possible for compatibility reasons.


In regard to the mist coat, it just takes finesse. It's about finding the perfect distance and speed to avoid laying down an opaque layer. PRACTICE FIRST with something else. I tested my mist strokes on plastic containers that mushrooms come in. The rectangular shape is similar and there are some complex areas, plus they were already on hand.

I painted the top and bottom of the Tricorder separately for the mist coat. Be careful you use the same technique for both sides and you don't add too much on the sides where the mist overlaps. When you paint the bottom, make sure you fit the door with its screws (you should have already painted the screws gray separately) so that you have a matching mist pattern on the back.

Note that you will need to mist the opened area of the Tricorder as well without adding too much paint to the power meter area. When closed, the mist on the top of the Tricorder should appear even.

The final step is to apply a clear coat. I used a Krylon semi-gloss clear applied the same way as the base color. Be judicious here. The clear is a protective layer, gives the Tricorder its non-gloss look and evens out the metal flake a bit.


The two Tricorders before mask removal. Now you have clean bodies ready for electronics and graphics.
Thanks for going over the paint process in detail, that'll be really helpful if/when I eventually build one. Wonderful results!
IMHO, the hinges are one of the most critical steps of the build as paint chipping off of them will cheapen the overall look of the piece, no matter how nicely the rest is built. Yours came out great!

Love seeing the detailed steps of the build! Good stuff!

How long did you wait between the paint coats, and how long before you added the clear coat? Amazing build, really looks perfect.
How long did you wait between the paint coats, and how long before you added the clear coat? Amazing build, really looks perfect.
For the waiting times, I followed the instructions on the cans. Between base coats I waited 10 minutes. Then I let the final medium coat of base cure for 24-48 hours. I used the same 10 minutes for clear coats, which after the last wet coat I let cure for a week before handling. (y)
Great build Thank You. Do you know where a person could source the hinges? I have tried but they are smaller than the original hinges even though they look the same just a bit under sized.
Great build Thank You. Do you know where a person could source the hinges? I have tried but they are smaller than the original hinges even though they look the same just a bit under sized.
That's a great question, but unfortunately I don't know. The hinges were included with the kit, same for my Roddenberry kits. I do have an original production made set of vac-form pulls for a MkVII medical Tricorder and to build it I will need to find hinges as you're right -- they kind of make or break the look.
I took fewer and fewer progress photos as the project continued, so I apologize for that. But after painting I turned my attention to the graphics. The graphics that came with the Tricorder kit as I had it were completely unusable. They were the wrong material and WAY off in regard to typeface and overall look.

Something I was determined to do was make the graphics as close as I could get to the real deal. Now, the screen-used props weren't designed to have the most durable graphics, but I still chose to duplicate their general construction—primarily to get the right "look."

Here's a good shot of a MkVII with the lights off showing significant wear and peeling of the original multi-layer graphics:

The graphics are made up of 3 layers on the hero originals:
  1. The base layer with the gray background and white text with holes for lighting to shine through
  2. Separately applied buttons with black text, some of which with holes for lighting (EDIT: some of the originals built later didn't have a button layer. If you want to omit this step, you could just print the buttons on the base layer and be accurate to later MKVIIs)
  3. A clear sheet overlay on top

I used my references and past discussion threads to determine things like the typeface, etc. and put together my own set of graphics, first in black and white to get the measurements, sizes, and etc. correct.


I'm a graphic designer by background and a creative director by trade so this was relatively easy work. I'll talk about the screen graphics separately in a moment.

I have gotten some questions as to why I did not illuminate the EMRG button. Well, that's because the genuine prop NEVER had an illuminated EMRG button and don't let anyone tell you different. GMProps and I suppose other electronics makers will include it and the Stapleton MkVII even includes a transparent red piece for this, but it is not at all accurate to have this button illuminated on ANY MkVI or MkVII TNG Tricorder. That was a later development for the MkIX and MkX models, which are radically different in other ways.

The EMRG button (as you can see in the reference earlier in the thread) is actually a red reflective adhesive sticker. In fact I have one photo of a hero MkVII where the reflectivity was visible:


It's a bit of a pet peeve of mine. I understand some like it, thinking the lower door is too boring with only one light. To that I say: hogwash! This is the best Tricorder design ever. :)

All that was a lead up to say that you need to paint the recess for the button black. It will need to be semi-gloss. You can do it before the full clear coat, but I added it after.


Back to graphics! I decided to print mine on adhesive vinyl instead of using paper adhered with spray mount or Avery sticker paper like the Roddenberry kits include. This was a personal decision. The appearance is identical, with the only difference being (hopefully) better adhesion over time. Below you can see graphics assembly. The base layer was cut on a Cricut machine to precisely cut out the LED holes in the graphic. Buttons were cut similarly. The Cricut made radius corners on the buttons much easier to do.


I made a bunch of these at once so I could choose only the best ones for application.

A note on button color: the originals were most likely printed black on a sheet of paper. I've seen it called "Canary Yellow" but I failed to find, after searching high and low, a canary yellow paper that looked like the Tricorder's button color in various lighting conditions. My reference photos showed a lot of variation from a pale beige to a more intense mustard color. I decided to print the color rather than use a colored paper, choosing a middle ground color that I personally like. Of course, you do you. But be sure to stay in the more beige-colored areas. There's a good bit of red/orange/brown in the color. It's not just a pale yellow.

If anyone wants to let me borrow a screen-used original MkVII to better color match to a Pantone swatch, I could be even more accurate! :lol:

Next was to lay down the clear overlay. Don't forget: you have to have holes anywhere an LED needs to shine through before your lay down the clear. The holes must have only the clear overlay over them. On hero props you can clearly see the LEDs underneath.

My studio was littered with cast off and failed attempts at these graphics. Of all the effort I put into this prop, this is where I spent the most time. Minor variations in position, color, font, etc. can make a HUGE difference in whether the prop feels "true."

One more thing that helps the prop look right, and it's VEEEERY subtle: there are actually multiple versions of the Library A/B button area, and I integrated a number of "mistakes" into the graphics in my crazy obsession with these things. (y)
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The graphics came out great! Love that you went the extra mile and made yours from scratch!

Thank you! It was the only way to get them right for this particular body. I can't use the graphics that come with the Roddenberry kits because they're wrong in a few ways. Which is odd given the source!

I spent an ungodly long amount of time getting the fonts, colors, etc. correct. I went through a lot of test prints trying to get the color right when printing. I hadn't really used a Cricut machine before (it's my wife's) but after I learned how to use it and set it up for my purposes i now know how to use it better than my wife does!
Sorry for the big gap here - a very busy couple of weeks I've had. Before installing the electronics boards, I worked on the viewscreen for the Tricorder. I know a lot of folks have found really creative and inventive ways to install LCD screens with animated LCARS graphics and those are awesome. But I'm a purist - I want a prop that looks just like the ones our characters held. Aside from one that I know of that was just a white screen, most seem to have been backlit 35mm slides.

The screen in this particular Tricorder build was already installed by Dennis (just without lights), but I did have to build the screen for the Roddenberry kit.

Let's take a closer look at a screen-used viewscreen:

Some things to notice: It's off-center with a flaw! Not all of these builds were perfect. The screen has a gray border inside the body color, framing the slide. Last:, while the screen is not perfectly evenly lit, it is NOT a pinpoint of light right in the middle with a ton of falloff toward the edges like some replicas. It's clearly illuminated with multiple bulbs. I say bulbs, because this screen is lit with warm light. Given white LEDs weren't available in 1989 and the earliest ones had a strong blue hue, I feel confident in saying incandescent bulbs were used here.

I chose to replicate the look but with warm white LEDs, which thankfully DO exist in 2023! The screen on my build has a slightly larger area for the image with less black margin around the outside. But it is an exact match for the original prop's graphic, down to the colors and the text. It must to be production obtained or copied.

The rear of the screen is covered with a vacuum-formed white housing to contain the light behind the screen. Unfortunately I don't have a photo of this. I used 2 warm white LEDs firing sideways into the housing, so that the light spreads around inside. I also stuffed a little poly fill into the LED holes to spread and bounce the light around a little bit. I think the look is pretty authentic.


On both the screen-used unit and my build you'll see a gray border around the slide inside the viewscreen area. This is painted on the INSIDE of the vacuum-formed plastic and provides a frame for the slide. Next comes the slide graphic, and then the vac-form white plastic housing.

The slides are interesting. Here's a sample of what i have in my collection. From left to right: What I believe is a production-made "meatball" screen with the open LCARS frame, a production-made all-button screen with purple LCARS and green buttons, and two slide graphics I received from Ryan Nagata of the open LCARS meatball.


The screens I got from Ryan are excellent, however something to notice about ALL the screen-used Tricorder LCARS is that they have a pronounced distortion. They are not square, but rounded. I don't know for sure, but my guess is these were photographs of CRT monitors with graphics images on the screen, shot on 35mm color slide film.

There were quite a few screen variations throughout the run of MKVII tricorders, some with in-jokes. But that's enough about screens. Up next: a brief look at electronics installation.
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