If you machine a forging , it is never realy round . So you do not know after machining if the hole is exact in the middle . Today you make the ends red hot and wheel it in whit a 3 or 5 wheel fixture , like the aircraft industry is doing it . Very exact and small tolerance .

Udolahr

Bugatti machined the hollow front axles inside AND outside.This made fettling easy.It is not necessary for the axle to be perfectly round.

In the last 20 years of playing with Bugattis I saw different non Molsheim hollow frontaxels, of wich the forged ones looked best. Simon Klopper made some of them and Ivan Dutton made at least 5 new axels. In my opinion Duttons axles looked and palpated verry close to the real ones. Of the weldet ones I saw at least two wich have been weldet in the middle, ( one in the workshop of C & G and one on the ex Ralf Lauren 51) and some others wich have been weldet togeteher with a one piece middlepart. Helmut Leicht of Ulm in Germany made one of those two years ago. It is currently for sale. There is an original but repaired frontaxle on display at the Trust. It belonged to the late Hugh Conway who never used it after it had been weldet.
When I think about wich force such an axle has to stand at higher speed, espescially, if you forgot to dismantle your shock absorber over the winter, if the tyers weren't mounted perfectly or you are driving on let's say the M5, I would never trust a weldet one. It's much more fun to play with the toys for a long while.

Marco

Although I agree that wheeling is a nicer process (a smoother way of forging) your comment illustrates that you have not yet understood completely. After forging the ends closed the axle is machined around the centerline of the drilled 28mm hole. In 1924 Molsheim had no problem with that so why now?
Bugwrench

exactemente dear Watson !

One reason to wheel the ends . To forge I have to send the axles to a forging company, wheeling I can do in my place .Maybe I still do not anderstand this front axle from 1920 , because we only build aircrafts and aircraft engines like this one .

Udolahr

and also Jaguar engines I see! Nice bit of plumbing on the rotary or is it a radial? I saw many of these engines recently [Gnome et Rhone] at the museum Safran near Paris.Just full of Hispano and other aero engines,quite beautiful.

It is a Oberursel Rotary , coppy from the Le Rhone 1916 . This one is brand new , scratch build . The plumbing is very diffycult . We are the only company today , bulding this kind of engines and suply parts .

Are you the gentleman from Strasbourg who took over the de Dietrich Paris-Madrid project from Richard Day as a bit of light relief from building aircraft engines ?

yes

Straßburg

Udo, is there a chance to see a picture of the internals of that radial engine ?

I am sure there are quite a few technically interested people on this forum who would see more of that Oberursel engine. The crankshaft must be a beautiful piece of mechanical engineering.

Perhaps you also have a link to see that engine running or even flown in an aircraft ...

I can show fotos about all parts in this rotary engine , because I am building this engines .But how long will it take that some people will complaine , because it is not Bugatti ?

Udo

Why not give us some information about your de Dietrich "recreation".

When I spoke to you in Strasbourg you said you used crankcase castings from Richard Day. What about the rest of the car ? When will it be running ? How much will it have cost ? Is it going to be raced ?

A bit of advice : if you leave it parked-up in a van overnight don't use a smart new Mercedes. Like the MNA with their Royale, use a skanky old Renault Master which no one can be bothered to thieve. And avoid Hounslow.

You think there is an interest for Type 5 fotos ? I have some Fotos from the machining work .