Hellboy's Room Key buidup...

Hey all,

You all might've seen this already in the junkyard as an interest thread and I've been so full up with stuff lately I haven't had time to do a proper build thread until now. With my current situation being "sans-proper-workshop" I'm having to find props that are suitable to make without destroying the apartment (keeping the missus & cats happy and paint-fume-free). I'm also on a quest to bust some myths about 3d printing (more on that in an upcoming thread...) and push the envelope of what can be done in terms of "finished props" using the technique.

The original prop (as photographed when it was sold a few years ago I believe):


This is a project I've been kicking around in my head for a long time and now finally got around to it. Finding new props to do from Hellboy isn't that easy these days! I worked on the 3d model for a couple weeks and just barely managed to finish before a trip to San Francisco a couple weeks back (where I briefly met up with A Savage to discuss and pick up some parts for the Hellboy Mechaglove project I've been helping out with).

Anyway, when I got back from my trip the prototype models were waiting for me and I've been toiling away at them since. Initially i was going to make a "static/open" version of the key and be done with it, but decided at the last minute to have a go at making a spring-loaded, trigger activated "functional" one.

Challenges:
They key is SMALL so cramming mechanisms or the trigger, travel-guides for the moving parts (trigger and key) was really hard- I was down to measuring every available 0.5mm in there! It's also difficult to be absolutely certain that everything is gong to move and work as intended. It's easy to overestimate material tolerances of clearances. Luckily, the print process is pretty exact... down to 0.1 or 0.2mm tolerance.

The project is also an experiment in the tolerances and characteristics of the different 3d print materials when making "functional" items. I had prototype parts made in different types of plastic. In the end it turned out that one of the cheapest materials (which are still admittedly expensive compared to resin) was actually the best for doing the prop since it has both flex and strength depending on how you configure the parts.

Finding suitable springs for the pop-out was also a worry. I bought some for RC car shocks but they were too stiff and also ended up 2mm too wide- no way to fit them in there. Luckily I found different set that was a lot softer and would just BARELY fit inside.

The idea was to do this as a "kit" of about 8-10 pieces in plastic. I just recently decided to upgrade and try to make the trigger out of metal, also printed. The grip will be covered in textured vinyl. The trigger will work and activate the front end to "shoot out" like in the movie. Some of the "interior" details like the greenish circuit boards on the sides will be drawn up and printed on decal sheet, then layered in with paint to give some depth. The circuit detail on the top/back have been modeled and will be inserted into the depressed area, but a couple small details have out of necessity been modified.

More info as I go, but for now, on to some photos!

3D renders of the prototype pattern. The trigger areas was a nightmare to model due to the "bulges". i redid that piece from scratch 3-4 times! :




1st prototype parts loosely assembled:


After some fine sanding:


Internal parts. Visible are the trigger hook, spring compartment and two shafts that serve as "guides" to keep the movement stable:


Progress to date. Still only loosely assembled but the first coats of paint and primer have been applied. Surface has been sanded perfectly smooth but still needs a little finish before final paint.




Closeup of the internal trigger mechanism. The trigger will be spring-loaded. I have a special spring-holder made that "slots" into the inside of the trigger housing, keeping it stable. A bit of shimming with styrene will need to be done to get the trigger movement really smooth:


That's it for now... more as the build progresses!

Looks great so far

Nice work
Russ

Great, Are you gonna chrome it?

Contec said:

Great, Are you gonna chrome it?

Click to expand...

Haha no the cost would be astronomical here for just a few pieces like this so it will have to be spraypaint. Might try a coat of Alclad2. (Unless you know of a real cheap vacuum metalizing place near Stockholm?)

Update time!

Working steadily on the first two keys, one static and one "fully functional" while I wait for the metal triggers. I had a couple of setbacks (one major) due to the weather. I was trying out Alclad chrome for the first time since I want as shiny a surface as I can get for the metal parts but i was working against the clock (it was getting dark). Before i was done, the sun went down, which meant a drastic change in temperature and humidity. This stopped the solvent in the paint from dissipating, causing it to eat away at the undercoats which created the dreaded (in all cases but when painting a W13 Farnsworth shell) crinkling! So, there went one $15 can of chrome paint needlessly (Alclad is expensive here) and a couple days waiting before I could strip down the pain again. I shot a new coat of gloss black (needed to prep for the chrome) yesterday and it came out pretty nice. Also finished up the circuit board decals.

Some new photos showing:
- Chrome test against a stainless countertop
- Handle covered in textured, self-adhesive vinyl
- Final circuit decal (with variations in color), printed on clear decal sheet
- Testing the size of the decals before printing on decal sheet

joatrash said:

Haha no the cost would be astronomical here for just a few pieces like this so it will have to be spraypaint. Might try a coat of Alclad2. (Unless you know of a real cheap vacuum metalizing place near Stockholm?)

Click to expand...

Nope, Can't say i do :lol
What about doing a cold cast and then buff it to chrome shinyness.

Well, for one, these can't be cast! They have to be 3d printed. First is the internals- the mechanisms and slides/guides are printed into the outer shell (like you would do if the parts were injection-molded) and there's no way that could be done with silicone molds. I suppose a version could be made where the internals were printed and the outer shells were cast, but man... what a nightmare to do! Just factoring in the shrinkage ratio of the shell against the printed internals would be a chore. The cost-to-work ratio wouldn't be worth it in the end. I'd rather pay the hundreds (or whatever) of bucks it would cost to metalize the thing! :lol

The shells are also very thin- down to 0.7mm in places. The nylon these are printed from is flexible and much more durable than resin would be at that thickness. The downside is the fine grain texture that needs to be polished and filled with spray filler, but luckily it's entirely possible to get it mirror-smooth with the right technique- something I'll get to when I one of these days get around to starting a big thread on mythbusting 3d printing!

I've also yet to see a cold-cast piece that is a lot better than just using a good metallic paint. I tried it once myself but the result was so-so. The thing with cold-casting is that you have tiny metal particles just like you do in metallic paints- the difference in appearance isn't THAT big. The first QMx Mal pistol was pretty shiny (no Firefly pun intended) and is probably the best example I can come up with. Matsuo does some incredible stuff with cold-casting but as I understand it (please correct me if I'm wrong) what it mostly does is add a heavy, cold feel to the item and it's great when you want to naturally weather something that has been coated with paint.

Contec said:

Nope, Can't say i do :lol
What about doing a cold cast and then buff it to chrome shinyness.

Click to expand...

Spent some time with the decals and metallic paints over the weekend. Here are some results.

A couple images after circuitry decals have been applied over gold and chrome paint. The "slide" was done with alclad and the "trigger body" was done with Plastikote silver metallic. (This is actually the static non-working version that I am using to experiment with. The final builds with probably all use Alclad rattle can laquer. It's certainly more delicate than Plastikote but I figure that folks will not handle the "metal" parts of this prop that much since it has a handle.





Here are the parts together with a handle covered in Plastidip instead of vinyl. (Most likely all final versions will have the vinyl.)

Think we all agreed vinyl is the way to go

planet said:

Think we all agreed vinyl is the way to go

Click to expand...

Indeed. It should hold up better. Only downside is that the vinyl needs to be applied in three pieces, so there will be a seam at each corner. (It will not stretch to wrap around snugly enough to do it as one piece.) I wanted to try the Plastidip on one anyway, just to see the results...

Ouch how big will the seams be?

Well, each vinyl piece is precision-cut to meet up with the next vinyl piece and the handle underneath will be colored black, so while there will be a seam, the actual gap will be minimal-to-nonexistant. It's not like there is gonna be a big, glaring gap of several mm between vinyl pieces!

Thats a gap I can live with
looks great so far

So... while waiting for parts to arrive I decided to start on a holster for it...

looks great

***** man, I think you have put more work into this thing than the prop dept did!

It looks pretty awesome. I really dig the circuit board decals.

Can't wait to see the movie of it popping open!
Chris

he is amazing

Haha, thanks guys.

If I'm putting a lot of effort it's because I'm doing some of this for the first time (like the working trigger) and am working against the elements (spray-painting on a windy balcony in the very little time when it's not too dark, raining or too cold for the paint to dry- winter comes FAST in Stockholm). The last trigger-system I did was in my Ghostbusters Proton Pack (to extend the wand emitter like in the "make 'em hot" scene) and that took a couple of tries to get right, designing a pulley system that would work around and fit in the same super-cramped space as the electronics. I'm kinda proud of that one, haha.

I guess the big difference here, both from the PPack and screen-used room key is that I'm trying to make this work exactly the same in several copes of the same prop with the added difficulty that I don't have the tools or $ for "proper" R&D. (A degree in mechanical engineering would have come in handy too, haha.) It's still a big experiment but the "can I pull it off?"-factor is half the fun. I'm fairly confident that the trigger will work out but if it doesn't, at least I know for certain that it will look good as a static piece.

So far, the circuitry was probably the easiest thing to solve in the build and the hardest was the bulge around the trigger. I would guess that in the original, the bulge was not intentional but a natural result of the metal tube being bent. Trying to replicate it in a 3d model took a bit of effort and a few reboots!

I tried to get better photos of the key but could not. parts of this prop are still a mystery. It seems to be a very involved piece for having such limited screen time. Luckily, I had some photos saved from an auction a few years ago when the original was sold, so that helped.

Well, the triggers arrive a few days ago and I've been toiling away at this. The working prototype is done and working fairly well. Here's a short vid of it in action:

vid2 - YouTube

It was a bit nerve-wracking putting it together because during final assembly I basically have ONE shot to get it together and once the glue has set, it's sealed permanently.

I've started on three more (one for myself even- imagine that, haha) but the weather here is now too cold and windy most of the day to paint outdoors. The other day when I tried to put on a black gloss coat of paint (needed as a base for the Alclad2 chrome) I ended up with microscopic humidity spots in it from the evening air. So, I went out and bought a new compressor for my airbrush so that I can finish them up indoors without filling the apartment with paint dust and fumes. Not the most optimal solution, but hey... they gotta get done!