Scania airport fire truck

[egronvold]

Looking good!

[Wombii]

Finished the top of the light mast. Plastruct diamond tread plate on top. Front part of the lamps: Sanded lexan as glass surrounded by 0.5mm styrene strips with 24AWG wire as bars. Painted with primer -> gloss black -> TS-17.

[Wombii]

The light mast and ladder both ended up a bit too wide, so I've very carefully cut out some support pieces to shrink the light mounts. I'm very happy with how the paint finish ended up on these.





Made a joystick and control panel for the cab interior.






The control panel / display is a box with a 3528 LED with a transparent plastic piece and reflective tape to spread out the light, and a sticker on the front.



The joystick paint doesn't look super clean in this shot, but it's tiny and looks fine in real life. For reference, the control panel is 14mm wide and the widest part of the joystick is about 5mm.

[frizzen]

The light mast looked good, but that remote station for the cannon is absolutely killer!!!

[liddy102]

Very nice
Great job.

[Wombii]

It's a bit rough, but I don't think I'll dive deeper into the details than this. Obviously missing a steering wheel and gear lever.

I'm no expert, but I believe the main joystick has all the relevant controls for the big monitor on the roof. The small stick would be the small monitor on the winch platform? The display / control panel shows info about and controls all the added functions on the truck, like emergency lights, flood lights, siren, pump, tank levels, and so on. In addition to that there would be a portable remote control for the winch and optional jet fighter rescue platform (which this truck does not have), which I have yet to model.

[Wombii]

The dash panel sticker is mounted on a 0.5mm styrene plate which diffuses the light nicely, but that unfortunately means the turn signal indicators look lit even when off. Will have to fix that. The switches are painted with liquid chrome and white paint, but the next build I'll definitely add light boxes to the whole panel after seeing how good the hazard light switch accidentally looks as it's right on the border of the backlight for the gauge panel.

[Wombii]

I've been looking for wheel hubs for the rear wheels, but never found a good match. Turns out the truck has reduction hubs, with planetary gearing inside, and that's why they're so big.
https://www.scania.com/group/en/wp-c...res-033241.jpg

I've also been looking for a better match with the wheels. I believe Tamiya's rear wheels are made to match the front wheels of the American trucks like the King Hauler, and after some research I believe those are modeled after 24.5 inch wheels with a 285.75 mm bolt circle. That means the scaled down bolt circle is very tiny compared to the European style 22.5 inch wheels with a 335 mm bolt circle that I'm using for front wheels.

The real fire truck uses 20 inch wheels, so the perfect scale version would probably use 1.55 rims, but I'm not going to get custom wheels 3d printed and cut down the tires. What I will try is to do some basic modifications to the Tamiya rims. I've mocked up a couple of different sizes of the hub to find a good looking compromise between what's actual scale and what looks scale.




(And for reference from the first page: )


edit:
I think this will work

[egronvold]

An eye for details

[Wombii]

I've spent a lot of time playing around with building a sound unit, so there hasn't been a lot of updates to the build. I never planned to use a proper sound kit, because I was never convinced they sounded good enough to be worth the price, so I didn't design a space for it in the truck. This winter I found an open source engine sound project, using an ESP32 microcontroller to play multiple sounds together with the engine sound. It's also in control of the ESC signal, so the truck has a simulated inertia, with slow acceleration and coasting.

I liked it better than the TBS/Dasmikro/Benedini micro sound unit out of the box, so I started to play around with modifying it to my use. I've now coded in an approximation of an Allison automatic gearbox, so it sounds like it's changing gears, and I've added recordings of two Norwegian sirens (a fast one and a slow one).

Because it's now in control of the ESC, I was also able to code in a function that lets me switch between reverse and forward mode with a separate transmitter switch, while keeping the brake function of the ESC. It works by sending a "double tap" of backwards input to enable reverse mode, and staying in backwards range when the switch is flipped, and makes sure to blip the throttle in normal mode when coming off the brake, to ensure it doesn't accidentally enter reverse mode when it shouldn't.

This is what it currently sounds like:
https://www.youtube.com/watch?v=9ex9XDmr8_Q&

Short test drive:
https://www.youtube.com/watch?v=qc6XIntvkuc


Youtube channel of the original author of the project:
https://www.youtube.com/user/TheDIYGuy999
And the original code:
https://github.com/TheDIYGuy999/Rc_Engine_Sound_ESP32

My poorly documented and highly specialized fork of the code, for anyone curious:
https://github.com/Wombii/Rc_Engine_Sound_ESP32

I managed to squeeze the controller and amplifier under the rear bench in the cab. The amplifier has a volume pot sticking out under the cab floor. Well hidden, but usable without opening the cab.



I also made a custom telemetry screen for the transmitter. Here's a shot of that, with an overview of my control layout.




After some digging, I was able to find the correct SCBA fixtures / rear seating. Here's a nice reference pdf from Rosenbauer:
https://www.rosenbauer.com/fileadmin...A_fixtures.pdf


1mm + 2mm styrene sheet with the Tamiya seat as size reference:





Mounted using magnets and shims






Most of the interior is now painted. Still needed are some hand rails, door panels and rear bench. Very happy with how much the locker box between the front seats looks like painted metal. I painted the seats with a brush because I wanted a slightly worn look, but I went a bit too rough, so I might have to do another coat.






Warm white cab dome lights when ignition is off







Low intensity red lighting when ignition is on

[Wombii]

One step (or bench) closer

[Wombii]

Some more wheel hubs. Rear:



Front:




I made them so they screw onto the end of the center axle bolt, to cover the wheelnut, but if you're smarter than me you will of course know that the bolt and nut on the non-driven front axle doesn't actually rotate with the wheel, so I might have to find a low tack glue and stick them to the rim instead.

I've been trying to come up with a simple way to add baffles to the water tank without ripping it apart, and I spotted some spare separators from some component / assortment boxes. Perfect fit, can be assembled inside the tank and are easily removed for maintenance.
Video:
https://www.youtube.com/watch?v=m6BDHUII7Jo

Bonus picture. It's odd how small details change the whole truck. The black wheel hubs helps a lot with making it look heavier, and makes the wheels look less like plastic:

[kaptain Jack]

Spectacular !

[Wombii]

Exhaust pipe. Styrene tube with Tamiya primer, then a smooth coat of Motip gloss black as base for the silver. Top third is then sprayed with Tamiya TS-85 Rubber Black and the bottom half a light dusting of TS-30 Silver leaf. I'm starting to see that I would really like an airbrush instead of spray cans for my next build.





I've also started on some shackles for the rear end. Yes, scale shackles are cheap on ebay, but it's hard to find accurate measurements for most, and it's fun to try and make stuff even though I'm finding I don't have the patience for doing metalwork properly.

[egronvold]

Your patience is top tier

[skeeter]

You've got more patience than you give yourself credit for! It is extremely difficult to make a matching set of shackles.

[Wombii]

Tank internals. The black stuff around the edge is a thin rubber or silicone sheet with adhesive backing.




I wanted a way to access the tank without removing the roof plate so I stole a screw top off a juice or milk carton and made some holes.




Hot glued on the inside of the tank lid.




Very low profile, but just enough grip to unscrew it.




It will be hidden below one of the tank inspection hatches.



I had to do a lot of guesstimation as I don't have any good direct reference shots, but the end result is passable from a distance. (Top left is the model, the rest are all the reference material I have.

[Wombii]

Blind spot mirrors and front work light. The work light seems to be mounted on the sun visor on most Norwegian fire trucks, but looks like it's mounted on a plate sticking out from the roof platform on the RNoAF one. This is the only non-functional light on the model because when I planned this out I didn't actually know that it was a light. Carved and sanded from a few layers of styrene. The reflective part is from a roll of a sort of self-adhesive home interior vinyl (d-c-fix) that will last me several life times at this rate.

[Wombii]

Emergency stop button for winch/hydraulic rescue platform if mounted and activation switch for remote controls.






Driver's side external start button. The driver can hit this button while getting dressed and jump into a ready to run truck.

[jerry56]

Such attention to detail, I don't even know how you even handle something that small. I like your reflective material, I tried something like that with some silver mylar ( actually a poptart wrapper) the first attempt didn't work so well I'll probably try it again at some point.
Very impressive truck..!!