Volvo C202

indigo

Supporting Member
Almost two years ago, I introduced myself and my intention to scratch build a Volvo L3314 (also known as Laplander or Valp) (here). While working on chassis, I decided that it would become a Volvo C202 (the somewhat newer brother of the L3314, designed for civilian use). I like both, and the C202 is more or less as old as I am. :cool:

It's not yet finished at all, but as I like reading the build threads here, I thought it was time to post something myself.

The original one looks like this:







And its chassis (rather simple, with two straight beams) looks like this:

 

indigo

Supporting Member
Volvo C202 chassis

I bought a second hand RC4WD Trail Finder 2 as a donor for the drive train and leaf springs. Everything else will be scratch built. Based on the width of the RC4WD axles, the scale will be 1:7.4 (the real Volvo C202 is a very small car, 405cm, including its spare wheel on the back).

As an easy start, I moved the rear leaf springs a bit out. Rather than adjusting the RC4WD axle, I added a small part in between the axle and the leaf spring:



The chassis beams with the leaf springs and the axles:



Moved the motor to the same side as the gearbox (in the original Trail Finder, the motor is on the other side):



And fixed engine and gearbox to the chassis:



Added the transfer case and connected it to the transmission:



And added servo mounts for both the steering servo and the gearbox servo:



Ready for a first test drive with my old Graupner FM314 TX/RX set (the front shocks and the link between the gearbox servo and the gearbox are installed too):



The battery fits between the rear axle and the body:



And finally, I installed the rear shocks:



Chassis finished. ::D:
 

indigo

Supporting Member
Since the body is rather square (and because I like to work with wood too), I'll make most of the body from plywood.

The bottom part:



Adding the front (headlights are made from clear plastic Christmas balls, the turn signals from two layers of plexiglass):



Rear side of the headlights:



Adding the sides:



And building up:



And this is where I am right now:

 

indigo

Supporting Member
Today, I added the roof structure (sturdy oak profiles for the sides and plywood front and back). For me, the body now really starts to have the look of the original. The main part of the roof will be removeable for easy access to the interior afterwards (but I need to do some plywood shopping first).



Since everything is fixed now, I can start making the doors. Especially the front doors will be a challenge because at the front, they fold on the edge just above the front lights while at the back, they fold just below the rear windows. But if I didn't like a challenge, I was driving a RC4WD TF2 LWB Mojave instead of building this one of course. ::D:
 

RubberDuck

New member
Love the project! Looks really nice. I guess it will be as much fun driving as the real thing. Thumbs up [emoji106]

Sent fra min E5823 via Tapatalk
 

cooper

Well-known member
Love the clever solutions on the chassis. Ended up well packaged. I have no words for the wooden body,so nice...
 

indigo

Supporting Member
Remote control

The prototype for the custom remote control is finally ready. Because I would like to make it a self-driving car, I need somewhat more sensors and flexibility than a standard remote control offers. With all electronics modules available nowadays, this isn't that difficult anymore.

For the remote control, I used a Teensy 3.2 microcontroller, a Nextion touch screen, two joysticks and a nRF24L01+ 2.4GHz transceiver module. The car has an encoder on the driveshaft, a 9 DOF IMU (orientation, rotational velocity and acceleration sensor) and a GPS.

The remote control offers a speedometer (with trip and odometer), a 3D compass (roll, pitch, yaw), a GPS (just coordinates for now) and can be configured using the touch screen.

The speedometer with trip and odometer:



The 3D compass:



I'm not a big fan of the Nextion display's coding, but it is a quick and easy way to create a touch interface. It should do for now.

I assembled the prototype on a breadboard. Cabling is a mess. I'm going to design a PCB to fit all electronics below the dashboard, to keep the interior of the car clean. Should fit (although it currently doesn't look that way with cables everywhere).



The position encoder is made with two Hall switches and two magnets on the drive shaft:


Everything works now.





I'll try to make a video if the weather is a bit better.
 

Small Factory

Fancy-Walkin'
Amazing!

I've been thinking of a similar setup with the switches and magnets on the driveshaft to record rotations to create an odometer.
 

indigo

Supporting Member
Since we're all locked in our homes and gardens due to the corona virus, I have some time to work on the Volvo. I ordered some more plywood (and other stuff) (at my favorite brick-and-mortar model shop because I really want to support them now).

I started with the driver and front passenger doors. It was a bit of a puzzle because they don't fold at the same height front and rear, but with three pieces it's possible to solve the geometrical constraints:



I added some thick paper in between to make sure everything still fits when assembled and painted (been there, done that...).

The doors work like a charm with their temporary tape hinges (I found 'real' hinges, but I want to finish the doors first):



The rear one was next. Two rectangles, nothing special:



And the last ones were rather easy too:



I also made the roof (before have only small parts of plywood left):



It really starts to look like the real thing now: :cool:



The next step will be finishing the doors. Not sure yet on how to make the door handles. I'll probably try to saw and file them from a piece of aluminum. If you have other ideas, please let me know...
 

indigo

Supporting Member
I've been thinking of a similar setup with the switches and magnets on the driveshaft to record rotations to create an odometer.

I use two TLE4905L Hall switches (mainly because my local electronics shop had these on stock). If you don't need to know which direction you're driving (or assume it's always the same direction you send to the ESC), one is enough.

Implement some wear leveling if you want to store the odometer in a microcontroller's EEPROM (typically, these last for around 100k write cycles). There are some algorithms on various electronics forums, but I don't mind sharing my code either.
 

dagabba

Supporting Member
Looking so nice, I'd almost be tempted to varnish it and show the wood grain. At least the virus creates some hobby time, eh?
 

imthatguy

Putting it in "H"
Fantastic update. I'm really chuffed to see another Volvo build on the forum. Thank you for sharing!
 
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