The Bugatti Type 35 was made from 1924 to 1931 and one of the most successful racing cars of the era, if not of all time.

This downsized version is my interpretation of this classic that I built for my grandsons. March 2018

 

What follows are the details of building this machine which took 4 months from Dec 2017 to March 2018.

Below is a 1930 Bugatti 35B.

 

 

These photos are of the Scale version of a 29 Bugatti. It is powered by a 500 watt 24 volt motor and can also run as a gravity racer (billy-cart) by disconnecting the drive.

I started by downloading a few photos of original cars and then sketching the basics on an opened out cardboard box until I got some decent perspectives. I measured some kids up to the age of 12 to get an idea of

how much room they needed to reach the controls. Then I spent a few days in AutoCAD drawing the basics and then some parts to laser cut to get started. At the same time I searched the web for motors, controllers,

differentials etc and started the ordering process.

This is a small part of the CAD drawing. The plan view shows my working out the toe-out-on-turns and also shows the 4 bearings that hold the rear axle. The battery reside under the knees.

 

The first round of laser parts:

The motor and diff carrier was made from 2.5 mm steel plate and I used tabs to hold it together before it was welded. 20 x 20 x 1.6 SHS steel was welded in 4 places crossways to give it strength.

 

The chassis was also made from 20 x 20 and welded to the rear carrier.

The next part was to shape the body, and alloy was new to me. I started with a flat panel, curved it around the frame then shaped the top with hammer and dolly, heating to anneal as I went.

I next cut out a rough shape for the top section and shaped it roughly. The anneal process is to burn soot onto the alloy, then heat until it dissappears which indicates that the metal is about to melt.

It was like working pasty.

I left some tags when I cut it to shape, then welded between, then ground them off.

I then started on the axles and wheels.

I laser-cut a jig so that the stub axles were welded at the correct angle of 3 degrees camber. The axle above is set at 3 degrees castor.

The knurled part below is where the 15 mm ID roller bearing sits. On the outside edge sits the 10 mm ball bearing that came with the wheels.

 

Rough assembly to see where it is headed.

I rolled up a bonnet, the first was too small but got it second time. I figured making the bonnet first would allow me to fit the sides to it, not the other way around making it simpler.

I mucked with the bonnet angle, then cut it to fit the radiator shell, and made a dashboard to rest it against.

I intended to run a bonnet strap so welded on some loops, but later found it ruined the lines. I rolled the sides diagonally and folded the top edge, then cut ann welded to rear section.

Then to shape and cut the sides.

The edges were shaped, wired with 6 mm alloy wire, and the rear seat shaped and rewelded to smooth it out. The holes are for the battery switch and charge port.

From this point I put some more time into shaping the body. I originally intended to paint the body but it looked so good in metal that I left it that way. I figured that the boys would eventually scratch it

and now all they need to do is to polish it out.

The wheels came from China via the internet, as did the diff. I added thering to hold the brake disc and also the drive flange. It was threaded but I welded it to the wheel hub.

The axle bearings were originally 10mm balls both sides but I machined out the inner and put in a roller bearing 15 mm ID so as to make the axle stronger. I added seals to the fronts. Wheel OD is 12 inches, rims are 203mm...

With all the small stuff complete I sent out the chassis and front axle to be powdercoated RED, and started assembly by adding a 3mm alloy floor.

The diff and axles mount on 4 self-centering bearings. The axles are keyed for thte drive hubs.

Floor under seat, dash and steering installed. Motor and chain fitted.

Batteries installed with fuse, and motor controller, throttle and brake pedals.

Panel on the left keeps little feet out of the brake cables and micro-switch that cuts the motor when you hit the brake.

To keep the steering shaft up and out of the way I used a bell crank at the front.

Brakes are equalised with a rocker connection. Micro-switch at top. Brakes are discs from a mountain bike.

Off to the sign-writer for a few decals. I took these from photos of original Bugatti emblems. Note the over-centre bonnet catches.

Thanks Peter Mac for the lovely seat. Not sure white was an ideal choice but I like the look. I added a tee handle to push it from the rear, and a bumper, and a rope hook for the return trip at the Billy Cart championships.

2 very happy boys with their new toy !!

On the start ramp at Corowa Easter 2018.