Doctor Who - Key to Time Tracer build

Metaluna mutant

Sr Member
I decided to build a replica of the Key to Time Tracer seen in Doctor Who.
It’s basically 12 (non-lit) buttons on a small hilt with two nested clear acrylic tubes sticking from the front and a ridged/ringed tip.

I’ve based it on this plan someone made on the Tardis Makers board that I stumbled on some time ago. It’s seems to be spot on. However since the prop is not extant and there's no publicity/close-ups of it, the only reference shots are from the DVDs. At least one original (there were at least two - one broke during filming) had a light which was occasionally used in close-ups, but I decided to forego that.

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(Most) pieces/parts cut to length
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Rough assembly
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PARTS
The clear tubes & hilt are from Plastruct and the buttons from Newark electronics. The buttons are pretty specific so I had to search some time to get a set that match. If anyone is interested I can give you the exact page and item number - it took a while to find copies of the 1970s Honeywell originals.
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BUTTONS
Here’s the buttons. I removed the button bases and filed off the “plug” to make the bottom flat. They will be glued on to the hilt.
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HILT
I cut the hilt box to size and cut sheet plastic for the top part. I drilled a hole in it for the “cuff” to slip through the bottom of the outer tube. The hilt should be light grey.
Hilt with Buttons resting atop - putty sanding of top edges started.

The bottom part I cut from sheet plastic, then doubled the thickness with more sheet. It will be gloss white. The bottom white square looks to be separate as it if could be removed - and I’m sure it was. I left the seam visible like the original - it was probably removable to plug in a power cord to light up the prop in the actor’s hand. Ah! The best of 1978 BBC effects tech.
Bottom plate - need trim, fill & sand.

Rough mockup
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TUBES
This is the complicated part. I bought acrylic tubes in this order: 5/8“, ½”, 3/8”, 1/4” and one 1/8” red florescent tube. All these will fit inside each other like a telescope.
Tubes sleeved inside one another
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Cuff
The 5/8” tube will be the “cuff” protruding from the hilt about ½“. It rests inside the hilt and will hold the main tube in place.

Outer Tube
The outer tube is ½” with a ¼” tube sleeved inside, with a void/space between them. I cut enough to stick inside the cuff fully in the hilt and seat it firmly. The ½“ tube is the main tube and runs to the tip. I masked off 20 sections and the tip with 1/4“ tape and shot it with rattle can flat clear to give an etched rings look. I also sprayed the end to make it frosted as well.
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With line/segments painted with flat clear
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Inner Tube
The inner ¼” tube inside the outer ½” tube has a void between them, so I cut two small 3/8” rings to place at either end of the inner tube to make the space for it. The 3/8 rings will hold the inner ¼” tube in place at either end.

Inside the ¼ tube I’ve placed a 1/8” florescent red tube. The original was more pink, but it’s close enough for me.
 
TIP
The original prop tip was probably a plastic syringe plunger of soft, frosted plastic, cut off and sticking out of the end. I decided to just make one from clear tube scraps left over.

I cut a solid clear 3/8” section about 1-1/2” long to serve as the “plug” sticking out from the tip. I then cut 3 thin rings from the ½” tube, sanded them flat, sanded their edges to make them “frosted” them glued them onto the solid clear“plug” end.
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I then glued that into the tube end. This section should be entirely frosted, but I only left the rings frosted. I like the clear look with cloudy rings better.
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I think it came out pretty well. I have enough scrap tube/parts left over for another tracer, I may build a second. If so, I'll pick up a another set of buttons. Otherwise a fairly straightforward build.

And to celebrate, I invited an old friend well acquainted with Doctor Who.

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I had enough tubes/parts left over from what I bought to whip out another tracer.

So...what the hell, I'm building another.

Much faster build this time. Just had to order another set of button lenses and they came in today. Will post pics later.
 
This looks great. Since I hope soon to have a key to time, I was planning to build a tracer. Any chance you could post the details of the buttons from Newark Electronics? They're the one part I'm having real trouble finding. I could always use coloured acrylic sheet or similar, but if the buttons are available I'd much rather have them.

Also, what sort of glue did you use on the acrylic tubing? I've not done much with it before and want to make sure I don't use a glue that melts or clouds it.

Cheers.
 
This looks great. Since I hope soon to have a key to time, I was planning to build a tracer. Any chance you could post the details of the buttons from Newark Electronics? They're the one part I'm having real trouble finding. I could always use coloured acrylic sheet or similar, but if the buttons are available I'd much rather have them.

Also, what sort of glue did you use on the acrylic tubing? I've not done much with it before and want to make sure I don't use a glue that melts or clouds it.

Cheers.
Since I've had a few others ask about this, here's a more detailed part listing

Here's the links to newark electronics where I got the buttons

64T3 - TE CONNECTIVITY / ALCOSWITCH - LENS, RECTANGULAR, ORANGE | Newark
64T9 - TE CONNECTIVITY / ALCOSWITCH - LENS, RECTANGULAR, WHITE | Newark
64S4 - TE CONNECTIVITY / ALCOSWITCH - LENS, SQUARE, YELLOW | Newark
64S2 - TE CONNECTIVITY / ALCOSWITCH - LENS, SQUARE, RED | Newark

The buttons runs about $35 with shipping. You need 4 red square, 4 yellow square, 2 white rectangle, 2 orange rectangle.

As for glue, I just used plastruct weldon. Just be careful, it's very strong, runs like water (it's not thick or gooey) and will cloud the (clear) acrylic. Test a few scraps first for practice and use it sparingly. All glued sections are hidden inside the hilt or under the spray/frosted tip but be careful.

Here's the parts I bought from plastruct.com (check their online catalog to verify)

Item Description Item # Cost Sold in min length NEED/USED FOR
3/4" ABS SQUARE TUBING ST-24 $4.20 15” HILT = 3 ¼” long
5/8" ACRYLIC CLEAR TUBING AT-20 $2.25 18” CUFF = 2” plus three thin 1/8” rings
1/2" ACRYLIC CLEAR TUBING AT-16 $1.95 18” OUTER TUBE = 8” total (6 ¾ exposed, rest stuck in cuff)
3/8" ACRYLIC CLEAR TUBING AT-12 $1.45 18” Use as spacers: b/t inner & outer tube. 1st ring=1” & 2nd ring=1/8” or thinner
1/4" ACRYLIC CLEAR TUBING AT-8 $ 0.80 8” INNER TUBE = 7” put 1/8" ring on one end, 1” ring at other
3/8" ACRYLIC ROUND ROD AR-12 $2.55 18” Use 1” solid plug sticking out from end of ¼" outer tube
1/8" FLUORESCENT RED ROD FARR-4 $2.40 17 ½” Use as “red” core – whatever length you want

The parts run about $25 but you have enough for 2 tracers (minus buttons) because they only sell in minimum length.

Other things you'll need:
A mitre box and a thin fresh blade to cut the tubes as cleanly & smoothly as possible.
Styrene sheet for the bottom and top panels of the hilt
1/4 " masking tape and dullcote to mask and paint the frosted "rings" on the outer tube. The tip should also be “frosted” with the dullcote.
Grey paint for the hilt and gloss white for the bottom panel.
Be careful with glue. Most glue that will hold acrylic will “cloud” it, so use it sparingly and carefully. I cut the tubes long enough to hide the glued sections inside the hilt or under the dullcote/frosted sprayed tip

- - - Updated - - -

ASSEMBLY:

HILT

TOP PANEL use styrene to make a top panel with a center hole for 5/8” cuff.

Cut the hilt box 3 ¼” long. From sheet, cut a panel for the 5/8” cuff to pass through at the top. The hole for the cuff will be large so be careful to make it fit exactly. Glue and sand/putty flush. Paint hilt light grey.

BOTTOM PANEL: 2-3 sheets of thick plastic sheet glued together, about ¼ or 3/8 inch thick. Sand smooth and paint gloss white. You can also glue a rubber cork to it or make it removable, so you can place a battery & light inside the empty hilt.

CLEAR TUBES

5/8" CUFF = 2" long with about ½” cuff sticking from hilt. It will be mostly hidden inside the hilt with only ½” exposed. The rest will hold the rest of the tubes in place. Also cut three 1/8" (or thinner) rings. It may take a few tries and some sanding to get all three rings to exactly match.

OUTER TUBE: Cut the ½” tube about 8 inches long. Glue the ½” outer tube in the cuff leaving 6 ¾” exposed. You will have to sand about ½” from the bottom of the outer tube to get it to fit inside the 5/8” cuff. It’s just too tight otherwise. When sanding it thinner BE CAREFUL and mask it off thoroughly. The 6 ¾” exposed section is clear, so no scratches. It will sleeve inside the cuff and extend from the hilt 6 ¾” inches with the first inch covered by the cuff. The cuff will obscure the sanded part of the outer tube sticking from the cuff.

3/8" SOLID PLUG = 1 ½" long. Slip the solid plug into the OUTER TUBE and glue 3/4 inch in. It will extend from the outer tube about ¾”. Glue the three 5/8” sized rings on the ¾” sticking out end. Last ring should be flush with the tip. I dullcoted the entire end to make it frosted. That also hid the cloudy glued rings and plug.

TWO SPACERS: Cut two 3/8” tube spacers. The first will be 1/8 inch long. It will be visible inside the tube so be careful and make a clean cut, no scratches. It will be hard since it’s so thin and you may have to do it 2- 3 times to get it just right. Cut a second spacer 1" long. Both spacers keep the inner tube snug with a gap inside the outer tube.

INNER TUBE: Cut the 1/4" inner tube 7” long. Glue the first 3/8” spacer that’s 1/8” thin on the end of the 1/4" inner tube. It should flush with the end. Slip the inner tube into the 1/2" outer tube until that 1/8" ring and inner tube bumps against that solid plug. Put the above two 3/8" spacers at both ends create a gap between the inner and outer tube.

Now glue enough of the 1" second spacer on the other end of the inner tube. It should be enough to hold it in place inside the 1/2" outer tube, but put it far enough down to hide the glue mark inside the hilt. That will look cleaner.

1/8" RED TUBE = 5” to 7” pink would be best but I couldn’t find a pink version. The original prop had one that freely slid inside it to make it longer like a thermometer when tilted. I glued mine in, but if I built another I'd try that. Sanding it thinner will make it slide easily in the inner tube

Lastly, the frosted rings on the outer tube:

I masked off 20 sections with ¼” masking tape leaving tiny gaps between each piece of tape. I shot the outer tube with dullcote then I removed the tape. That left 20 thin frosted rings on the outer tube. I also shot the whole tip to frost it as well.
 
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