François

Not sure about the fire truck frame, the info I found states that the body was installed on a commercial truck frame. I guess a fire truck is a commercial vehicule. Whichever frame was used, I based my frame on the Mercedes G4. the prop car under construction

Bugatti Fan, from what I've read and seen, the prop car was drivable. There is a youtube of it being driven on a flatbed platform. It had a v8 engine of some sort, nothing like the v16 powerplant the designer envisionned.

Almost there!

More work done on the body today. I had my doughts on how easy it would be to do the body with Inventor but I must say it's turning out pretty good. I still need to tweak the form here and there and to add many details such as the hood scoop, the spare tire bump, the exhaust ports... Once I'm satisfied with the shape, I'll create the seams for the hood panels, doors and trunk lid. These will all be separate parts since they will all be openable. I will definatly need to separate the body in multiple pieces to be able to print it.

Thanks big John ! I started the bodywork, it will definatly be a hard one to do as the cad system I'm using is not exactly the right tool for this type of form. But, being very patient and stubborn, I should be able to eventually get it right.

I've been busy with the mouse and key board the last 2 days. I'm a long ways from being done, especially since I need to design a complete 16 cylinder engine. But before I start on that, I decided to work on the enveloppe first, to better know what volume I have to fill with mecanical stuff. So I started with the front end working my way towards the back. I first 3d modeled the radiator with the 4 head lights being careful to draw printable parts and adding as many features as possible such as lightbulb housing for the head lights and wire routing. I base the design of certain parts on similar bentley blower parts such as the radiator core. I'm very satisfied with the result so far. I also started the firewall. Once it's done, I'll be able to do the hood. I'll then have a very good idea of the engine bay volume. Here are some progress pictures.

The fun thing about this build is that I know what the enveloppe will look like and it's limitations in space (height, width, lenght and curves). Everything else is speculations and up to my spur of the moment whim. So today I decided to create the fuel tank based on the only known parameter for the tank, I know where the fuel filler caps are (yes, they are 2). Then it was just a question of giving the tank a somewhat plausible shape that would fit in the general area dictated by the caps. The location in just dehind the rear seat and above the 2 differentiels, just under the trunk lid, a pretty standard spot. But the area is quite small since the spare tire seems to be located just under the trunk lid. I'm using the tank as a spare tire holder, this gave the tank a rather nice shape. But it will be a small tank so this v16 will definatly not be winning any mileage contest.

I found a partiel transmission housing already modeled. I added the shifter mecanism, really not sure how it will print. I guess I'll find out eventually.

Big John, thanks for the engine suggestions. I've read somewhere that the car's designer envisionned it with a v16 airplane engine. I might investigate that a bit. I do like the Auto Union engine. Which ever engine I choose, a big decision factor will be how much info I can find on it (existing dowloadable cad files, dimensions...) Absmiami, Thought one: glad you can get something out of my crazy obtention Thought two: I'll certainly look it up, I don't know that one Thought three: it's already in the plan, each frame rail will be printed in 3 sections and I plan to incorporate a brass or steel rod from front to back. And probably some aluminium tubing for cross members. Thought four: ha ha! Definitely not in the city! All the parking spaces are taken by construction cones! Good thing I rarely go there... in one of the text I read on the car, it say that the movie car had a 38 foot turning radius and wasn't very fun to drive.

I started the ground work on the cockpit. I inserted 3 bentley seats ( I'll eventually model new ones with the correct shape and upholstery pattern) and the Bentley's steering column. The idea is to position these items correctly so I can continue with the transmission, firewall and eventually the engine. After a few minutes of web search, I found a 16 cylinder motor but it's too modern and the proportions are wrong. I need a very long v16, I'll probably end up modeling it myself. I might use some parts from the v16 I found such as pistons, con rods, crank... it's extremely detailed.

Here is a second version of the drive shaft. It now has an 8 spline shaft so orientation is no longer an issue.

Nobling, you are absolutely correct on both counts, the drive shaft is a prototype and the phasing is off by 90deg. I made this same mistake on one of the very first machine I designed back in 87, shame on me for doing it again.Thanks for noticing this!

The printer is an Anicubic photon M5. And the ujoint parts were printed separatly. I would't know how to print as 1 working unit.

It's more the printer's high resolution. At 12k, the print quality is pretty good right off the bat. Small or big, the quality is there. I did no sanding on this. I printed the ujoint and they came out looking great. End they work !

I assembled the differentiel I printed and so far so good. I had to tweak a few things like adding a compression spring to maintain a proper contact between the crown gear and pinion and modifying a few parts for better printing but aside from that, everything went together as planned and the diff works well. I also decided to design proper universal joints for the drive shafts. You can see the compression spring on the left side of the crown gear 20240808_220653.mp4 And the u-joints

Thank you everyone for the nice words. Bugatti fan, Inventor is a professionnel 3000$ plus/year 3d cad software. A far cry from free. And even at that price, it's still a mid level tool. It used to be a lot more affordable but as it evolved, so did the price. I guess the same will eventualy happen with Fusion. I still have a license for it thru the company I used to work for. I'm very lucky to be able to use it althougt not sure how long that will last. The day I'm cut off, I'll have to fall back on the free version of fusion or some other free software. Inventor is not perfect for this type of designing, but I've been using it for so long that I can work around it and make it do pretty much what I want.

I printed a first batch of parts for one of the differentiel. I'm pretty happy with the result. Still need to tweak a few parts in order to have proper mating surfaces but all in all, it's a good print.

A bit more done on the rear end. I added what I think are torq arms, all the ubolts for the leafsprings are there as are the 4 hanger posts with the hanger brackets. I believe that the 4 hanger brackets should be made out of a flexible material or maybe even a strap so that the complete bogie assembly can pivot by it's center. I'll figure something out. Torq arms Hangers With tires and wheels

Thanks Dave, it is a cool project! At least it is on the screen...

Big John, I decided to go with a full scratch built on this one and keep the rolls for my intended restoration project. I'm doing the Hydra at 1/12 and it will still be a huge model, over 24 inches long. The 1/8 scale of the rolls was just too big.

Hi Bugatti fan, glad to see you're on board for this one also. Effectively, the Hydra car designer, a guy named Daniel Simon, found inspiration for his design in Hitler's car (the Mercedes G4) among others. He also found inspiration in the Bentley for the blower. Unfortunately, everything stopper at the inspiration stage. The car does have 6 wheels and a blower but under the body work, it's an ordinary truck frame with a v8 and the blower is just for show. Let's not forget this was a movie prop. In one of the pictures I found, you can even see some piping held in place with C-clamps. But that's what makes this project so interesting to me, I want to make what's under the bodywork as close to what it could have been if this had been a real car. And since it does not exist, that's where my designed skills come into action. Fun times ahead!! As for the cad software I use, it has always been Inventor. I did download fusion but never used it. I'm just too used to Inventor. I do want to try out Rhino, I was told it's a great tool for designing free forms like car's bodywork.

Thank you all! BK9300, I use Inventor.

Made a little more progress on the rear suspension today. Started the central pivot assy on which the rear bogie is attached. I have to say that I'm really enjoying this. I have very little info to base my design on so I'm basically winging it as a go along. I was a machine designer for over 35 years so designing stuff from the ground up was pretty much my way of life. But what's so refreshing with model making and this projet in particular is that contrary to the machines a used to design, this doesn't have to make sense or work. It just needs to look good. And the best thing of all, it just needs to please me (and you). So nice...

I started work on the frame. At close to 24 inches long, it will need to be printed in at least 3 sections. Printing will definatly be a challenge unless I get a bigger printer. I also modeled the blower and front bumper. And started the rear suspension. The rear end is based on the 1930's Mercedes G4. It's a complicated suspension system to reproduce when all you have are 2 pictures. Frame Blower and bumper Real blower and bumper rear suspension embryo G4 rear suspension

I did a bit more work on the drive train and aside from a few bolts, fittings and brackets, it's pretty much done. I should be able to drive all 4 wheels from the drive shaft. I inserted a top and side view of the complete car so I can better see if the parts I'll draw up have the right shape and proportions. Like I said yesterday, this car is a movie prop, it doesn't really exist so no dimensions to be found. All I have are 2 printed artist drawings that I can mesure off. Last thing I did today was to insert the Bentley in the Hydra assembly just to better see how big this model will be. Both car are the same scale !!