Santos Dumont No. 18 Hydroplane 1907 by Greg Davis - Scale 1:16

[KeithAug]

All looking rather nice. It would appear that the foils were quite small.

[Keith Black]

Beautiful work, Greg, 

[Greg Davis]

4 hours ago, KeithAug said:

All looking rather nice. It would appear that the foils were quite small.

Yes, they don't seem to have a large chord. I've done my best to interpret a number of photographs and then made them with a 2cm chord - that would make them roughly a foot in reality.

[wefalck]

I remember reading the research thread, but somehow missed until now the building log.

 

I am interested in everything that happened on the Seine, after all it flows past in sight from where I live. However, judging from the background on the photographs, I think Santos Dumont must have run his trials on the Bassin d'Argenteuil, a quiet lake-like stretch of the river between two barrages a few kilometres downstream from me. 

 

Coming back to the construction material: I also would think that steel-tubes as in bicycles were used. Aluminium tubes would have been extremely expensive at that time, if at all available. There was no welding technique at that time that would have not drawn the temper from the steel-tubes. So, I think they were silver-soldered, as is the practice for steel bicycle frames.

 

Edited March 13 by wefalck

[KeithAug]

4 hours ago, wefalck said:

So, I think they were silver-soldered,

Yes - I had thought they might have been brazed.

[Greg Davis]

Here's my start on the cockpit. I've made the platform, the steering column structure and the footrest. I'll trim down the parts that go thru the cockpit after they have been attached.

 

Still to come the saddle / seat and the steering wheel (doesn't look easy at all, ugh!).

[Greg Davis]

A couple days of work on the steering wheel has gotten me to here:

First I cut and milled a piece of brass to serve as the spokes of the wheel together with a rim. Two pieces of C Boxwood with a circle cut out were used to sandwich the brass piece - all attached with epoxy. Then the exterior was sanded to about the correct diameter. Sanding the wheel to a round cross-section then followed. A few more details to add, but this is what I'm trying to mimic:

I feel that I am getting close - probably as close as my skills will allow!

[Greg Davis]

Today's little project - a saddle to sit on:

It was shaped out of C Boxwood and is approximately 1 x 1.5 cm. Right now the saddle is shiny because it was just coated with linseed oil.

[KeithAug]

17 hours ago, Greg Davis said:

A few more details to add, but this is what I'm trying to mimic:

Nice steering wheel but I love the bicycle seat.

[Greg Davis]

16 minutes ago, KeithAug said:

Nice steering wheel but I love the bicycle seat.

Decades of amateur bicycle racing and countless hours of watching pro-cycling finally became useful on this build!

[Jim Lad]

Just catching up, Greg. She's looking great!

 

John

[Greg Davis]

Again thank you so much to everyone that is watching this build come together!

 

The nacelles and hydrofoils are now permanently connected:

 

[Greg Davis]

Today's accomplishment was coating all of the wood with linseed oil - there is more surface area than you would expect!

This will need to dry / cure for quite awhile. While that is happening, I plan to turn my attention to engine work.

[Greg Davis]

Today I began to work on / solve the exhaust pipe installation process. The pipes have quite a few bends and need to connect to a short stub on the cylinder castings. Several very failed attempts before getting to this version of which I've placed on two different cylinders to see how it looks:

The shape is getting close (should be flat a bit longer across the top and there's a small blip in the tubing that I didn't shrink out well enough), but this is what the pipes are suppose to look like:

This one has a 1/16" brass wire rod as a core. A short bit of brass tubing soldered to the start to form a coupler with the cylinder casting stub. Finally, black rubber shrink tubing was slipped over the wire and shrunk. I made enough attempts trying to bend brass and aluminum tubing to the exhaust pipe shape to believe that will not be an effective method of fabrication. Given that the exhaust pipes will be buried amongst other engine accessories I'm currently thinking that this may be a reasonable way to make the 16 needed pipes.

 

Thoughts / comments?

[wefalck]

Doesn't look too bad at all, but seems to be a quite complex process. What about cored solder of an appropriate diameter? It bends easily without tools (so as not to leave marks) and can be drilled out at the ends as needed. It would also be easily painted black/rust.

[Keith Black]

Greg, the way you've done the exhaust pipes looks convincing. Did Alberto run this beast long enough to burn the paint of the exhaust pipes? 

[Greg Davis]

2 hours ago, wefalck said:

Doesn't look too bad at all, but seems to be a quite complex process. What about cored solder of an appropriate diameter? It bends easily without tools (so as not to leave marks) and can be drilled out at the ends as needed. It would also be easily painted black/rust.

I can give that a try - it does sound like it would be easier to do!

 

Thanks

 

Greg

[Greg Davis]

2 hours ago, Keith Black said:

Greg, the way you've done the exhaust pipes looks convincing. Did Alberto run this beast long enough to burn the paint of the exhaust pipes? 

thanks!

 

I have not seen any pictures that show the pipes with burns. In fact I have never seen a picture with the engine fired up! I have long wondered how they got the engine started. There is a picture of the SD 14bis being started with a large cranking mechanism, but that was on the ground and not in the water. I don't know about turning the propeller blades by hand either. I can only assume that the engine was started only a few times and wasn't run for long. There may have been so much torque from the propulsion system that once started it was turned off immediately. 

 

Related, there is a picture on the SD No17 airplane with apparently the same engine / propeller and the exhaust pipe are clean there as well. There is little documentation of the No17 and it is entirely possible that it was never tested for flight. It is possible it was abandoned and the engine then went to the hydroplane. Going on to his successful Demoiselle airplanes (No19 and No20), Santos-Dumont used smaller (20hp and 30hp) two cylinder engines. However, various Antoinette V16 engines were used to power airplanes in or about 1910. 

 

Here is a link to a great article on Antoinette aircraft engines: https://oldmachinepress.com/2016/05/28/antoinette-levavasseur-aircraft-engines/ . The author, William Pearce has been very helpful in answering many questions on how the V16 may have been set up in the No18 hydroplane.

 

Greg 

[Keith Black]

 Thank you for the link, Greg. This is one of those rabbit holes I could easily get lost in. 

[iMustBeCrazy]

1 hour ago, Greg Davis said:

Demoiselle airplanes

See what you started!

 

 

[KeithAug]

Nice work on the exhausts Greg - the technical observation on the design in various posts all add to the fascination of the build. What is the partial horizontal line on the end of the crank case representing - should it be all the way across or just not present?

[druxey]

Tubing is a difficult material to bend. What about softened copper rod or wire?

[Greg Davis]

9 hours ago, KeithAug said:

Nice work on the exhausts Greg - the technical observation on the design in various posts all add to the fascination of the build. What is the partial horizontal line on the end of the crank case representing - should it be all the way across or just not present?

It is something that should be filled in - a defect in the casting that I could not file out easily!

[Greg Davis]

7 hours ago, druxey said:

Tubing is a difficult material to bend. What about softened copper rod or wire?

Yes, it looks like wire is going to be the final decision. Tubing was a failure and solder doesn't bend into a sharp enough radius (for me at least). The soft brass wire experiment worked the best so far. I can give copper a go as well and see what bends the best, but also seems to be as structurally stable as possible.

[Greg Davis]

Trial fitting the fuel tank. Also seeing that there will need to be a specific order in which engine accessories are added. Things are going to get congested fast!

[Greg Davis]

I've completed the cockpit. The steering column structure, footrest, and seatpost are painted grey-blue to match the other metal tubing; whereas the middle of the steering wheel has been painted aluminum. The supporting board has been oiled. 

I've decided to keep this as simple as possible for now so that the cockpit will be mounted in the forward position. Based on a couple of poor photographs, I believe that this was the cockpit location when the boat was first completed (with engine, propeller, etc.). I also believe that at this point the engine's throttle was mounted to the right of the steering wheel on an extension of the tube that crosses the base right-to-left. It appears that soon after the cockpit was moved back and a different throttling system was introduced - one that was more complicated and mounted directly on the steering wheel.

 

For both locations of the cockpit, I am still not able to piece together how the steering column / rod would have been connected to the rudder. In particular, it appears that the steering column is mounted centrally - directly over the upper pontoon stringer. For structural strength reasons, it seems doubtful to me that the stringer would have been pierced to allow the steering apparatus to pass through it. Also, I have not been able to decipher if / where steering cables attach to the rudder. For a while a wondered if the rear hydrofoil turned with the rudder as a unit, but it seems that the geometry of the bracing rigging would prevent that. 

 

Without evidence, I don't want to guess engineer a mechanism so for now I plan on adding the bracing but not having a way to move the rudder. Hopefully, down the road I will fine (be made aware of) additional information that solves this mystery and then I can determine if I can add it to the model. Going with the premise that no detail is better than making stuff up!

 

So here is what the model looks like with engine / fuel tank / cockpit all in place.

Mostly engine / propulsion work left now - I think all the woodwork is done.

 

[Jim Lad]

Coming along nicely, but I have to say that the whole setup looks horrendously unsafe. I'm glad I wasn't asked to drive it!

 

John

[iMustBeCrazy]

Greg, do you have any evidence of a rudder? I can see what may be a rudder in the middle of the rear foil in the early version and perhaps aft of the hull in the later.

If I'm right about the early version the entire foil must rotate to turn.

I don't think the wheel was used for steering at least in the early version, I think the lever on the right was. It's too big for a throttle lever and a lever was how he steered his aircraft.

I think the speed was controlled by 'blipping' the engine with a kill switch on top of the lever, this would be consistent with aircraft through WW1.