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RC models by Robert Holsting

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  Custom Scania R620, 8x4. Scale 1:14.

Main features: Twin axle steering, saddel and trailer coupling all have individual servos. 132 LED's make up the low beam, high beam, turning signals incl non-standard on the sides, reverse, license plate light, side markings incl 2x4 lights at the rear edge of the main lamp, position lights, work lights, amber rotary lights, flash in the front, fog lights, light in the cabin, various indicators on the dash board and the lights in the sun shade over the windshield (3 settings). All are either automatic via the regulator (Servonaut M20+), or controllable via remote. Digitally sampled sound is delivered by the Servonaut SMX, which include starter, engine sound w. rev's matching the regulator, and the all important horn. A 7,2V Integy 65T motor delivers the power needed, and yet another servo controls the three gears.
Only original, un-altered parts: Fenders over the rear axles, rear axles and the front wind shield.

Length: 63cm, width: 18,7cm, height: 29,3cm. Weight: Just below 7kg.             Note: Videos available here!

  My tractor was born like this. An everyday healthy, standard, 3 axle Tamiya R620 Highline.

Take a good look. This will be the last "standard" you'll see for a while!

  First the original frame was used to copy the holes to a new set of frame rails, only 77mm longer.
This allowed me to add another steered axle. I wanted a four axle truck.

It was to be driven on two axles, and steered on the other two. A so-called 8x4.

  Here they are: New frame rails, and the originals.

  The gearbox was altered too. The two springs marked in red were removed, so the gearbox does not center itself (2. gear).
That makes it easier for the gear-servo to keep it in 1st gear, with only a minimum of work.

It is extremely rare that any other gear than 1st is used..

  The front axles were altered too. The area marked in red was filed down, so the axle could turn sharper.
It really does good for the turning radius!

  Now we're at the very front of the frame, and at yet another modification. Normally only the gear servo sits here, as the steering servo sits on the left side, but that makes the steering quite loose. The fix is to place the servos as shown here: Steering servo to the left, gear servo to the right.

I used a low profile servo for the gear servo, so the height of the servo would match the rod from the gearbox.
Both servo's were raised slightly so the motor did not have to be moved.

  Here's the servo for the second steered axle. The two servos will be controlled by the same channel, but with a "Twin steer module" between them.
That module allows me to adjust the mix to match the different turning radius the two axles.

  Back at the front, steering and gear servo removed so I can better show you what goes on. (You can still see the two spacers for the steering servo though..)

This is the bracket that will extend below the bumper, and form a very rigid base for the push-pull coupling made later.

  I'll have a cabinet on either side. This one will go on the right side, and it will hold tools.
The little square holes above each other are for steps.

  This will go on the left side.

  When opened it reveals the charge plug, on / off and the volume button.

  Seen from behind.
The charge plug will automatically disconnect the battery from the electronics, and connect it to the charger instead.

Both cabinets will go on a metal base for strength.

  Moving around the frame, and to the very back: The custom bumper!
This was hand made over a few days, and the coupling was bought from someone who makes them by hand.
The white strip with all the holes in it is a 1mm plastic strip. I need that so I can glue the rear lights and stuff on later.

  Here's the assembly seen from the wheel side. The five holes to the left will host LED's for the rear lights.

  This bumper will, just like the push-pull base in the front, transfer any and all mechanical stresses and forces applied, directly to the rigid frame, and not some plastic part that will only break off.

The trailer coupling will be connected to a servo hidden inside the frame later on, thus remotely operated like everything else.

  Seen in profile. The backbone in the structure is the 3mm aluminum L profile, bolted to the frame.

  Then it was time to wrap the entire a... eh, rear end in deck plating.
This aluminum plating takes a bit of practice!

  After a while, it got easier. Shaping was done using a chunk of brass, and an aluminum bar.
Tapping gently and slowly shaping the metal was the best way forward.
Holes were cut using regular scissors, and the edges were filed slightly.

  Well.. it's getting there..
Note the little air hose connectors, and the electrical plug. It all in the details..

  There are many ways to do the rear end. Some like a more open look, some box the whole thing completely off.
I did this.

  I could only get the deck plating in about 200 x 300mm, so I had to take another sheet for the front half.
The two pieces interlock right around the saddel, and only very few people spot the joint.

  After fitting it all, adjusting and such, everything is removed again.. Time for paint!

This is my completed frame, and some other parts being painted.
Note that I do not use black.. not ever. I use a dark, dark grey instead. Black would hide all details and structures, giving a flat visual appearance.

  These are the rear lights, and the PCB with the five LED's.
One just like it, only mirrored is on the other side.

Left to right: Reverse, normal driving light, bright brake light, turn signal, position light.

  Here's another detail that does deserve a little extra spotlight: The rectangular hole cut in the side of the housing for the tail light.
That's for the side marking that the real Scania R620 has. Inside will be a white LED. A transparent yellow piece of plastic will color the side marking, while transparent red color on the rear cover will ensure a red light towards the rear.

  Here's another Scania specialty! Four little lights in the rear edge of the front light housing.
This is 0,5mm holes all the way through, and with a 1mm hole only a tiny way down, giving the LED somewhere to sit.

  Here are the four SMD-LED's.. !
Note the wires! Thin as hair.

  Here they are on.
Though you might think so, it does not influence the turning signal at all.

  -and here it's off. That's unique, haven't seen that around on models before.

Also notice the aluminum deck plate on the steps. A piece of painted plastic should have went here, but it did not look good, so I made yet another alteration.

  Look between the steps! A small turn indicator peeks out right next to the reflective field.
That is also not standard, but the real 620 has an indicator there, so....

  When the right size of LED's were not available, I used fiber optics on top of a regular LED.

  I can then glue them in anywhere!
I often use silicone glue for this kind of things because it does allow later removal, in case something breaks.

  Here's the bracket for the license plate, and the built-in light.
It'll be glued on to the vertical deck plating at the rear, left side.

  Oh.. got the cabinets mounted!
And the steps! (Folded deck plating..)

  Some tech info, and it's done!

  The right side,

  ..... tools as promised.

  The deck plate at the very rear.. Notice the removable panel...

  ... giving access to the trailer coupling mechanism and servo for easy adjustment.

  Here we are at the rear-most of the two front axles, and again we see a removable panel in the deck plating...

  Ah! Here's the servo for the steering, and the servo and mechanism for the saddel.. again accessible for easy adjustment.
A rod connects the smallest servo and the saddel, hidden so well that most never see it!

  I don't like all shiny rims, dipped in chrome.. so I paint mine with aluminum color paint.
Also mounted is some hub caps in matching color.

Looking carefully, right in front of the saddel you can catch a glimpse of the rod mentioned earlier...

  Time to start the custom cabinet behind the drivers cab.
This feature took a while to plan because it holds ALL the electronics; regulator, receiver, sound module, RC switches, twin steer mixer, flash controller, battery, speaker and what not. On top of that, all resistors for every little LED will be here too.. and a fuse!

  .. and of cause the smoke stacks!
The rest was pretty straight forward, so let's surf by a few other details...

  This is the front grill. Note the small tubes, forming a base for a sign later: "Særtransport", meaning something in the lines of "Special transport"

(No kidding, Sherlock.... :-D )

  A quick glimpse into the cabinet building reveals one of the doors. Round plastic tubing (Ø2 mm) allows an open design, letting in air to cool the components. It getting done, so let's go for another walk...

  Here's the drivers cab, and the holes for the flash lights.
In fact, many changes was done to the cab.. A few holes in the door normally holding a support rod was filled and sanded, and a hole in the back for an electrical plug was made invisible. More alterations later...

  The roof! The two black tubes was put in to give the amber light bar a flat spot to rest on, and to ensure that the light bar will sit horizontally.. something many other builders forget..

The sun roof is in for a treat as well.. so we will not mount the black standard plate!

  Good news!! The cabinet is done!

  The little lip ensures that no rain will collect on top, and run in. Netting will be placed after paint.

  This side will face the cab. The square hole is for the speaker, and the funny shape at the base is to accommodate the gearbox, and to allow a LOT of wires to enter.

  Back at the rear side, we now see the 15 pole plug for the trailers.
The plan is to have a flatbed with many functions and all the light-functions as well, so I need a lot of poles!


  Seen from above, with the removable top removed: The PCB for the rear lights are on place, held by two screws.

  The track indicated with a red arrow, and one just like it in the opposite side, are the brackets for the resistor-board.
It'll get here later...

  Back working a bit on the cab, and making the service doors behind the entry doors.

  The hinge is glued on using epoxy, and the door has a strip of steel on it. A magnet on the inside of the hole serves as both a stop, and a magnetic lock.

  The door thereby closes completely flush, and stays closed until opened on purpose.
Anything else would be sloppy.


  What is going on at the workshop??
An M4 nut glued to a piece of 1mm plastic, grinded to a perfect circle... whaaaaat?

  Oh.. a center hub for the front wheels!
Because the axle will not revolve, the hub won't either, and I do not want to look at a stationary, regular M4 nut, however nice.

  While we're at it, let's make some more stuff to put on!
Made in a 3mm aluminum L profile, this is the base for the push-pull coupling that will be made later on.
This bracket extrudes under the bumper and inwards, and is bolted to the other bracket, shown earlier.

  Here you go: The push-pull base bolted on to the bracket, in effect now a part of the frame.
This ensures that the plastic parts will not be a part of the supporting structure.

  We've waited long enough... gotta do it now.. The inside of the cabin!

  The challenge is that the motor and gearbox extrudes into the inside of the cab, so we have to build around it.
The two semi-compartments in the rear-most half of this structure will form the compartments behind the service doors we made earlier.

  A few strips of steel allows for more magnetic magic, so the inside cab will stay put.

  The U shaped metal brace will support a curtain behind the seats later on.
The rest starts to look as the inside of a cab!

  The very basic seats are standard, but I made the stands, arm rests, control buttons and so on, along with the furniture.
I'll leave the inside of the cab for now, but we will return to it in a short while.

  Here's the non-standard motor, the Integy 65T. The standard motor is WAY to fast, so don't even bother.
The Integy, or any other slooooow, high torque will do great, especially if you use another regulator.. for example the Servonaut M20+ or so.

Being able to maintain realistic movements is half the game!

  As promised: The resistor board.
All LED's live in groups. One example, the two brake lights at the very rear end up in one wire --> one resistor.
All groups have their own, dedicated resistor.
This method allows me to adjust individual brightness, optimizing the lights on the model!

  This took a while, but finally all's in the cabinet!
-and all lights work too!

  Note that I have four rear lamps; two at the back and two at the rear top of the cabinet!
The visual effect in the dark is great.

  The final piece, the cab.
Here the four yellow LED's for the flash light is mounted, and about to be hidden behind the front grill mesh.

Note the non-standard mirrors.. These are a replica of the real Scania mirrors, the originals are no longer with us.
In fact, the bracket from the original mirrors has been used for a TV antenna bracket.. I'll show you later.

  First the sun shade was mounted.. NOT easy! I had to extend the four little plastic tabs on the shade by gluing some 2mm rods into holes in them, and them epoxy those rods to the cab roof. The tabs them self are simply too short! (Redo... someone!)
There are 12 LED's in the shade, including the four high beams!

Also visable in the picture are two of the four interior cab lights, a REAL cool feature in dark conditions!

  That just about concludes the cab... or does it?

  Nope.. the interior is not done.
Close though..

 

We do need indicators on the dash, right? There are six:
Turning signals, high beam, and three red ones. (Amber light on, work light on, fog light on.)

Again little SMD LED's were used, and connected to the same outputs on the regulator as the regular turning signals etc.
Also finished now is the CB radio w. a mike, small table, and the driver's blue Nokia.. and the navigator!


  Then the cover plates for the inside of the doors were made.. and real rubber mats layed out.

Agreed: I did skip the fence at the lowest place with the door covers. I could have made them 3D with pockets and all, but since I only need the visual effect in this very unlikely to be seen spot, this 2D version will do.

  Seatbelts mounted... cup holders checked.. navigator checked.. (It's a replica of my TomTom...)

The round edges on everything is made using 2mm plastic rod. Hopefully it'll save the driver from scraping he's legs. :-)

  Yep.. we're ready!
Later I got some filt to put as a mattress in the back, and some fabric for curtains behind the seats. The cab walls were covered with fabric to match, just like a real truck!
Also: Here yo can get a clear picture of the compartments behind the service doors in the cab. (The lower space right behind the seat, under the mattress base.)

  Let's step out of the detailing for a bit, and mill some brass!
There is nothing like the sound of brass milling in the morning!

Somewhat later: This is 2mm brass, ready to be soldered.

  Done!! All that's left to do is to bolt it on to the base plate, temporarily taken off the truck again.

For that I got some 2mm brass bolts and nuts with excellent hexagon heads!

  And the fat lady sings!
The pin was made by grinding an M4 bolt down to 3mm, thus removing the thread. Then I soldered a handle on top, and painted it.

Oh.. Also got the license plates! As always, I check with authorities online which numbers the real number series are at, at the time, and order mine to match. That's where the "BF 96" comes from. "371" is my birth month and year.. 3, 71. :-)

  To widen the usability of my truck, I made this little removable flatbed for it.
Here seen from below, you can see that there are two white feet that will rest on the deck plating, and a king pin that will go into the saddel.

(Feet left white so they won't smear the deck...)

  Here it is, flipped over.
The bed is about 20x30cm.. more than enough for most applications around the house... include bringing food for the cat!

  Here is is mounted and locked in the saddel.

This configuration is far easier to drive around the house, besides the six axle flatbed is a total overkill for most jobs.

  That just about concludes the Scania..
I have without a doubt forgotten a 1.000 small things, changes, alterations and what not.. but I think that's ok.
If I were to give it all right here, you would not have the same joy in finding your own solutions, as I have had. :-)

  It's time to test-drive it, so let's turn on the power. (7,2V NiMh, 5000mAh)

  Tadaa...

  All doors open.. including the small service doors in the side of the cab.

  Right behind the top spoiler are two antennas: TV and radio. The bracket for the antennas are the modified brackets from the original mirrors.

The truck got a very clean look...

  .. and yet it holds a lot under the skin!

  Service doors for servos below the deck.. and the upgraded aluminum saddel.

  Here's the often used removable flatbed, locked into the kin pin etc.

The red bar is the push-pull bar that fits both in the front and in the trailer coupling in the back, allowing me to push or pull stuff.

  I have put 1,5kg of lead balls in the four inner rear wheels to ensure a good grip.
Because of this, the weight is close to 7kg.

  Small glimpse inside the cab. It's possible to see all the way into the sleeper between the curtains, that hang right behind each seat.

  I mentioned the sun roof earlier, remember? The basic kit includes a black piece of plastic, but I used a clear piece and some genuine sun roof foil.
In daylight it brings light and life into an otherwise dark cabin, and in dark conditions the cabin light shows through the sun roof. Killer detail!

Another detail: The little square reflectors between the lights inside the light bar was replaced with genuine, polished steel reflectors, as the original tape (....) curled off after a while.. :-(

  A few things to haul around. The pressure bottles were painted, and when the paint was almost dry, I smeared some almost-dry-black on them, giving them the usual dirty look.
The oil drum also got a little, but not as much.

  This box was made to hold the spare battery for the transmitter. It looked bad with a spare battery on the flatbed neck, so I wanted to hide it, and yet bring it around with me.

Note the address label.. :-)