Thermal Detonator - WIP Thread

spoudastis

Sr Member
RPF PREMIUM MEMBER
I have been sitting on this project for awhile now and decided it was time to start it up. The thermal detonator has always been one of my favorite props from Star Wars and i hope that i can do it justice.

The first challenge is coming to terms with the scale, this thing is small, and realizing how small all of the components are is difficult, especially the LED bezels. The second challenge is reference material. Although the TD has been on public display quite often it seems difficult to come up with decent images of it. The easily found reference images are almost always taken from above and from far behind glass.

As a starting point i found a thread here on the rpf which mentions that the Master Replicas version is 60mm in diameter with 3mm of thickness.

Since I do not want to 3d print this, we have all seen some pretty poor results, the first step was to find clear hemispheres. I searched through the Plastruct catalog and found some clear acrylic hemispheres that would work. Im sure these were what was used on the original prop as well. There were two possibilities that would get me in the same range as the MR version, VHH-225 (57.2mm diameter) and VHH-250(63.5mm diameter), i went with the smaller 57.2mm diameter hemisphere which has a wall thickness of 3.2mm, very close to that of the MR. I also bought VHH-200 which nests perfectly inside the outer hemispheres to serve as the inner surface. As a side note, the VHH-600 at the bottom of the page is what the prop makers used for the training remote.

PLASTRUCT.jpg

Because I am planning on building the training remote at some point I picked up the Fuman 1/48 Panther G model kit which has parts for the training remote as well as the correct tank tracks for the TD activation switch. I found out the hard way, the Tamyia 1/48 panther does not have the correct rubber tank treads. here is an image of the model kit, the hemispheres, and track i will be using for this build. Ill elaborate more later but the larger clear hemisphere with the 90 degree cutout will serve a jig for scoring in the lines to the main TD body. One last item i picked up is some tiny aluminum tubing that i will use for the LED bezels, in this case i am using k&s 8103 (3.97mm in diameter).

Panther G - 01.jpg photo 1.JPG photo 3.JPG KS_8103__03496.1411546405.1280.1280.jpg

I am working on the 3d model now in order to come up with the correct pattern for the lines as well as sizing for the activation switch and red button. The only part that i anticipate 3d printing is the activation switch. Eventually ill also add lights and sound which will be brand new elements for me to work with. At first i thought this build would be a breeze but im very quickly realizing that this could be a rather complicated build. More to come later.
 
Great ... I got a TD from a previous run as a second hand ... but the wiring inside is so crude and shady ... I already broke the light and sound fx ... I hope my dad can fix them ... but I'd rather find another TD ... since it's not really round enough for my taste and the Master Replicas a bit to expensive . . . for now. So I'm looking forward to your progress :)

Chaim
 
MR Thermal detonator owners:

If someone could take a quick photo of the side and top of the activation switch (in the "on" position) that would be hugely appreciated.

I am modeling the activation switch now and based on the views i could find and measurements of the tank tread, it seems close to correct but the proportions seem off when i spin around the model. In the image on the left it looks fine but in the image on the right it appears to me to be too wide and short. What do others think? It may also look too wide now because the edges have not been filleted. i think that will make a huge difference but i dont plan on modeling the fillet in, just sanding it when it comes back from printing.

activation switch01.jpg activation switch02.jpg
 
I don't have any input on your research questions, but wanted to wish you best of luck with this.
Sounds like your really gonna do this right.
 
Is this project still progressing? I've had a TD project "on the back shelf" for a while and had some questions for anyone with real knowledge of the actual prop.

1. I've seen reported on some websites that the three lights in the front of the original prop were yellow LEDs. At the time the prop was made that would be possible but IMO mini incandescent bulbs might have been more likely. Anyone know for sure what's in there?

2. The red light lens under the front of the slide switch (revealed and illuminated by sliding the switch back) -- anyone know whether that was a scratch build, or an off-the-shelf part? If it was a found part, I assume it would be a general purpose panel indicator LED, but which exact model?
 
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Good quesions. This project has been put on the back burner. We had another child and bought a new house so I think this may be paused for quite some time..

1. After making the 3d Model I have realized the lights are Sooo tiny, everything on this prop are smaller than you would think. I have not seen any incandescents that small but I'll look around more now.

2. I think it's a stock indicator light for sure. I found one on eBay that has the same exact circular pattern on the top and matched my model dimensions perfectly. I'll post up some pics at some point.

Is this project still progressing? I've had a TD project "on the back shelf" for a while and had some questions for anyone with real knowledge of the actual prop.

1. I've seen on some websites that the three lights in the front of the original prop were yellow LEDs. At the time the prop was made that would be possible but IMO mini incandescent bulbs might have been more likely. Anyone know for sure what's in there?

2. The red light lens under the front of the slide switch (revealed and illuminated by sliding the switch back) -- anyone know whether that was a scratch build, or an off-the-shelf part? If it was a found part, I assume it would be a general purpose panel indicator LED, but which exact model?
 
The lights are close to 3 mm which could be a "T-1" size LED, but "grain of rice" incandescent bulbs about that size were fairly common then too.

BTW, that's nowhere near the smallest incandescent bulb available. I have several of a style that were used to edge-light wristwatch LCDs, before Timex popularized electroluminescent backlighting with their "Indiglo" line. These bulbs are about 1 mm diameter by 3 mm long!
 
Did you ever make any more progress on this thermal detonator?
Sadly i never did, everything is in a box up on the shelf.

As an alternative to building one myself I have considered buying either the KR sabers or Romans versions.

To me there are a couple of problems with these that has given me pause.

1. On both, the score lines are way too thick and in my opinion they dont look good.
2. The thumb switch slide on the Romans is way too flat based on reference images, the KR switch looks perfect
3. The lights on Roman's are far too bright and the bezels around the LED's are too thick

I have been thinking of revisiting this project but it probably wont happen anytime soon.
 
Sadly i never did, everything is in a box up on the shelf.

As an alternative to building one myself I have considered buying either the KR sabers or Romans versions.

To me there are a couple of problems with these that has given me pause.

1. On both, the score lines are way too thick and in my opinion they dont look good.
2. The thumb switch slide on the Romans is way too flat based on reference images, the KR switch looks perfect
3. The lights on Roman's are far too bright and the bezels around the LED's are too thick

I have been thinking of revisiting this project but it probably wont happen anytime soon.
Sad to hear that the project is on the shelf, but it happens to all of us.

The KR Sabers and Roman ones are great (and metal!), but I definitely see your concerns as well.

I'm in the process of 3D printing one myself and had the same issue with all the currently available 3D models, either the scribe lines are incorrect (taper off towards the top and bottom), the thumb slide switch has the wrong shape, is not tall enough, has the wrong detail for the tank track, the bezels for the three yellow LED's are incorrect, and even the opening for the RED LED lens on the top is incorrect. Pretty frustrating.
That's why I decided to start making my own 3D model where I can control all these parameters myself. I still haven't done the switch from scratch, but may do that later, in the mean time I'm using a pre-existing model that has a shape that's close but not perfect (and has the incorrect tank thread detail.)

1662971254661.png
 
looking forward to seeing your progress. After looking at the KR sabers site, it has much more info than i had in 2015, eg 2mm front led's, 5mm top led with lens cap and the install video even has how they did the led bulb holders.

Dont model that track. I may have some extra from the Fuman kit that i can send you.
 

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