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PostPosted: Mon Dec 17, 2007 3:54 pm 
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I'm not so sure welding will weaken the structure. Things have moved along in the past eighty years or so in the field of welding and materials. Modern tig welding procedures leave a weld area just as strong as the area around it if heat treated to relieve the stresses and so forth. Sometimes, however, an "improved" material is not a good thing when viewed in the context of the rest of the structure around it. I wouldn't want an axel that would be so strong so as to refuse to break off in the event of an accident, for example. The more immediate concern is not the worrying about a catastrophic failure but rather the effects of a lack of rigidity and resulting twisting.

In the case of my front axel assembly, I really have little or no choice. Forging my own is out of the question for all the reasons we can imagine. Buying one from Dutton or one of the others that have made them is cost prohibitive. I must remember that the axel is only one part of the entire assembly - the springs must fit through it, the king pin must be the right size - basically everything must be exactly the same as the original Bugatti in order to use one of those replacement axels. That is not possible for me to do.


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 Post subject: All Hail William.
PostPosted: Mon Dec 17, 2007 5:51 pm 
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Location: Port Elizabeth; South Africa
I am grateful to you for taking the time to explain the complexity of, not only the engineering challenges, but also the decision making process. Untill you took the time to explain to me the reasons for not using a reproduction axle, I just never thought about it.

You have the ability to clearly explain quite complex concepts to a non-technical audience. You wouldn't believe how long it took before I understood the difference between horsepower and torque. And I still do not understand how you can give a car a higher top speed without changing the final-drive gear-ratio.

Please keep on writing and I promise to remain curious.

With Grattitude
Johan


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PostPosted: Mon Dec 17, 2007 10:15 pm 
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Just some notice I still found in my Email, about the steering wheel and gearbox.

Code:
Thanks. The steering wheel - the wood is not the original French walnut but rather bloodwood - at least I think it is. I had some old scraps and used them to make it. I really like the color. Ther transmission gears are from a Borg Warner T-5 with the 5th gear removed. I am using the entire gear set unchanged except that the two shafts are side by side rather than the layshaft below the main shaft, The shifting will be just as close to the original Bugatti as I can make it - including the shift pattern and the shifter outside the body.

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 Post subject:
PostPosted: Fri Dec 21, 2007 3:34 am 
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My friend in New Zealand has finished the first of my wheels - the remaining to be completed in the next couple of weeks. I am impressed! This guy, Gary, knows what he is doing.

I have not given up on the aluminum wheels but every attempt to have them made has met with failure. I found a retired pattern maker who agreed to make the patterns and he decided that he was not going to do it after all. Apparently they are more difficult to build than I originally thought. When I told Gary what I was doing, he told me that he can make the Bugatti wire wheels any way I want them. I settled on the original lacing, rim size, and so forth but the certer hub to be a Rudge type with a Rudge spline.


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 Post subject:
PostPosted: Fri Dec 21, 2007 10:42 am 
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Location: Port Elizabeth; South Africa
A cream coloured T35A has been doing the concourse rounds for a while now. It originally belonged to Edsel Ford and the new owner has painted the wire wheels black, with a thin polished metal rim on the outside. The cream and black looks stunning, while a British Bugatti enthusiast called Terence Cardy has (had?) both a T35A and a T37 on wires painted a very dark blue, much darker than the traditional Bugatti blue in which the rest of the cars is painted.

Yes, the original alloy wheels are indeed very beautiful, but wire-wheels are in no way the lesser choice. Speaking of choices, what do you have planned for the radiator? The original small radiator or the later wider one? Are there any major complications regarding the construction of a radiator?

Regards
Johan


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 Post subject:
PostPosted: Fri Dec 21, 2007 4:25 pm 
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Here are the photos of the wheels:

Image

Image

Image

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 Post subject:
PostPosted: Sat Dec 29, 2007 4:48 am 
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The radiator is the next difficult thing to make after the front axel assembly. I have thought about it quite a bit and have decided to go with the wider T35B type for two reasons. First, because of the obviously better cooling and second, because the width of the wider radiator also means a slightly wider bonnet as it gets progressively closer to the radiator. This is important to me because my engine is wider that the Bugatti engine. I have done everything possible to keep it as narrow as it can be but it still barely fits where the bonnet will close.

As to how it will be built; I don't know yet. It will be several months before I will have to worry about it. I am keeping my eyes open for suggestions, however.

I got the engine running this week. Actually, I have three engines. One is a supercharged Toyota 1ggze. One is a twin turbo 1ggte, and the last is a 1gfe non forced induction engine. All have the same block so I can use which ever one I choose. For the time being, I am using the 1gfe engine simply because it is easier to work with and has a lot less "plumbing". It produces 160HP which is a lot more than the original Bugatti 2.3 liter supercharged eight cylinder which produced somewhere around 130hp. I may end up leaving it in there.

I know it will not sound like a Bugatti regardless of what engine I use. No six sounds like an eight. Having said that and being resigned to the fact that a six is what I am going to use, making it sound great is something I hope to achieve. I well tuned six cylinder can be made to produce an absolutely superb sound.

I finally found a guy who will make the rear springs with the bend at the end where it attaches to the differential. He is also making the eye round instead of oval as original Bugatti. I decided to use a rubber insert to add compliance to compensate for forward/backward movement. After looking through hundreds of engine mounting rubber inserts, I finally found what I was looking for. The "dog bone" used in a '94 Toyota Camry V6 has a rubber insert that allows for very little movement one way and a lot of free movement at 90 degrees. Most FWD Japanese cars use engine mounts with similar inserts but much bigger. I'll post some picture when I get them mounted.


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 Post subject:
PostPosted: Wed Jan 09, 2008 2:57 am 
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I'm working on the front axel assembly. Just to keep it simple and things moving along, I decided to use some of the parts from a MGB front trunion assembly. It might seem to be a heavy dinosaur but, with the top and bottom of the trunnion cut off and only the bearing surfaces used, it is probably lighter than the original Bugatti.

The difficult thing to deal with is those boxes for the springs to pass through. I know how Bugatti made them and the workmanship and innovation of construction is commendable. However, from an engineering point of view, it seems to be just plain silly - the kind of thing that a trained engineer would have disregarded out of hand. The fact that it worked at all is a testament to the outside the box way of thinking that Bugatti was famous for.

I mocked up one side of the axel using 4130 tube with a two inch O.D. and a .120 wall. First I put the bend in it and cut the hole for the box to be welded in place with a milling machine. Next I cut and trimed a piece of 4130 box tubing 2"x2" with a .120 wall. Next I cut a slot along the end of the axel tube so as to allow it to taper to a smaller end. Then I welded a solid piece at the end for the trunnion to pass throug. Next, clamped the piece of box tubing intop place and tig welded everything. Last I machined the end of the axel to let the trunnion pass through with a nice tight fit. Now to test it. I will have to find someone with a monster torque wrench for me to borrow. I am hoping for six hundred ft. pounds of twist with no failure and no more than one degree of deflection. I am guessing at what is required but that's the best I have to go on.


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 Post subject:
PostPosted: Wed Jan 09, 2008 9:53 am 
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Smart way of tackling the front axle. I hope it lives up the the expectations. I looked in my toolbox, but no monster torque wrench there. (just a small one)

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 Post subject:
PostPosted: Thu Jan 10, 2008 6:24 pm 
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I'm thinking of taking the cheap way of dealing with the torque wrench issue. A six foot long bar loaded to one hundred pounds. I know a woman weighs exactly one hundred pounds. If she barely keeps her feet of the ground while pushing down on the end of the bar while I measure the deflection...that will work.


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 Post subject:
PostPosted: Fri Jan 11, 2008 7:20 am 
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A hundred pound woman and a 6 foot long bar? It reminds me of a joke I once heard, but the lady in question may be a lady; and/or related to you.....

Now that would be rude.

Johan


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 Post subject:
PostPosted: Sat Feb 02, 2008 3:53 am 
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Hi everybody. It has been a while since I posted anything here. Been busy with my project (not to mention the rest of my life).

My replica project is nearly a rolling chassis. By that, I mean, being able to roll it around the shop and steer it. I am waiting on all four springs to be finished and delivered. When the company claimed they could bend the back springs the "hard way", I was not sure he knew what I was talking about. When he told me the exact angle it had to be bent, I knew he could do it.

I tested my front axel as best I could with the limted resources I have available. It twists less than one half of one degree with six hundred foot pounds of torque. When it is assembled to the chassis, I will block the springs with some pieces of wood and weight it down with perhaps 2000 pounds just to see if anything is going to break. I doubt anything is going to break but front axel catastrophic failure can be the end of the line. I would also like to test the steering under heavy load too.

I'm told the original Bugatti T-35 steering is one turn lock to lock. I had to make a gear mechanism to "Speed up" the steering as I am using a modern automotive steering gear assembly. The modern type with ball screw technology has virtually zero free play and is essentially so strong as to never be suspect of failure. I didn't quite get the one turn lock to lock but one and a half turns is okay with me. Actually, it may be closer than that because my turning radius is probably smaller than Bugatti's.

We are also working on the tail section. It is being built as a foam core with carbon fiber over it and then the foam core removed. On the surface, it may seem the shape is very easy to copy and by comparison to more modern cars it is but it still is not easy to get the shape right. It is also not easy to get the eight louvers in the layup. I decided to make the individule louvers and epoxy them into place after the tail is finished.

I will post some pictures in a couple weeks when it is a rolling chassis.


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 Post subject: need help
PostPosted: Thu Feb 21, 2008 2:18 am 
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I have been told that the Bugatti T-35 and T-37 gear shifter pattern were backwards from modern convention. I have studied the drawings as best I can and it looks to me like that is so - that first and second are reversed and third and forth are reversed. The movement of the shifter is the same as "normal" - the two low gears on the left and the two high gears on the right. Now one of my pals tells me the shift pattern is the same as any other modern car. I sure hope I didn't make a mistake. I don't know how Bugatti treated the "throw" of the shifter but I am assuming he did as I did. The total movement at the top of the shifter from first - through neutral - into second is 42 mm - very tight.

If anybody can shed some light on the shift pattern, I will be grateful


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 Post subject:
PostPosted: Sun Feb 24, 2008 12:27 am 
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Location: Atlanta, Ga.
William, Do you have Bugattis in your blood? I just realised that my copy of "The Bugatti Book" is inscribed: D.Kelsey, Washington, D.C. 1955. I got it in a bookstore in Atlanta. Pico


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 Post subject:
PostPosted: Sun Feb 24, 2008 4:48 pm 
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I would like to think that whatever is in my blood was not tainted by the corrupting influences found in Washington D.C. . Having said that, it brings up an interesting question. What kind of people find such a deep affection for Bugatti's and things relating to them?

I have come to believe that it is an appreciation for the art and the engineering displayed in his cars. I think it also requires an acknowledgement that we are all flawed individules as Ettore Bugatti certainly was flawed in many ways. Even so, he produced several thousand beautiful cars. It is no wonder to me that there might be at least one other Kelsey among the many thousand of us living in the U.S. that appreciate Bugatti's.


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