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

[Greg Davis]

Sort of jumping around on this project! I milled slots into the top portion of the engine casting to accept 1/8" square tubing:

The brass tubing has been epoxied in place. Once it has cured, the ends will be cut off matching the slope of the engine casting leaving behind the three-sided engine mounting brackets. Hopefully better looking, and closer to the correct placement, than the ones that had been part of the castings.

[Greg Davis]

Here is what the brackets look like after a bit of filing:

[Greg Davis]

Reduced the length of the crankcase castings to match the length of the upper portion of the engine. After cleaning up the result, it was attached to the top of the engine casing. I filled the brass tubes so that you can no longer see thru the engine!

 

Made my first attempt on the fuel tank. This one is made from 5mm brass rods - the two cones are pinned with a 1/16" brass rod. 

I had taken measurements from pictures of the hydroplane and the 5mm (scale) diameter seemed reasonable, but I think I'm going to remake the tank with 6mm rods as this looks a little slim to me.

 

I also did a bit of looking around on the web and found that an Antoinette  V8 consumed fuel at 30L/hr. Assuming the V16 consumes twice that, i.e., 60L/hr or 1L/min, the tank I made would hold 10L of fuel or about 10min of run time. While it might be possible to do the two 1K passages at 100Km/hr in 10 minutes, it probably would be cutting things close. Moving to a 6mm tank (same length) the volume increases to a full size tank holding 15L (15min run time). I can see how the boat could be started, run a kilometer, turned and run back in that time frame. So, the current tank is probably just practice!

[Greg Davis]

New, larger fuel tank - this one 'looks' correct compared to the historical pictures. Once it is polished up, it should be a keeper!

[Jim Lad]

More beautiful work, Greg.

 

John

[KeithAug]

On 1/13/2025 at 11:53 PM, Greg Davis said:

Spent literally hours cleaning up castings today and there is still more to be done.

Well worth the effort Greg - they look amazing. Great progress and attention to detail.

 

[Greg Davis]

A couple of days ago I primed the engine block and cylinders a dark grey. Today they got a coat of aluminum. In another couple of days I will add the copper color to the cylinder castings. 

Not sure if the paint will need to be toned down a bit with a wash. I'll better know after the engine is assembled. Since the model is open framed, I would like the engine to be relatively clean.

[Greg Davis]

The water jackets have been painted brass (not copper as I mistaken mentioned in the previous post).

 

AON - thanks again for having me reconsider painting the castings!

 

The bases will be repainted aluminum and then I'll install the castings on the engine block.

[Keith Black]

 Greg, the photo didn't post, please post again, I'm anxious to see your progress. 

[Greg Davis]

57 minutes ago, Keith Black said:

 Greg, the photo didn't post, please post again, I'm anxious to see your progress. 

here it is - I hope you can see it now!

[Keith Black]

 I can, thank you, Greg. I'm throughly enjoying your build and look forward to each new post. 

[KeithAug]

Thank you Keith - I couldn't see it either.

[Greg Davis]

The remaining painting of the cylinders was completed and now they are attached to the engine block. It is really starting to grow (and get heavy). I think the fueling system needs to be worked out next.

[Greg Davis]

14 hours ago, Keith Black said:

 I can, thank you, Greg. I'm throughly enjoying your build and look forward to each new post. 

Keith -

 

I really appreciate the support from you and everyone else following this adventure!

 

Greg

[Keith Black]

24 minutes ago, Greg Davis said:

really appreciate the support from you

 My pleasure, Greg. 

[Greg Davis]

This is my first try at making the fuel distribution system - two copies are needed. I drilled 4 holes through the center copper piece, soldered and then bent the distribution pipes. I think I can improve on this trial a bit, but most importantly, I hope that it looks a bit more like what was on the hydroplane than the castings that came with the engine kits (see pic of the V8 from my 14bis build below). The copper seems to be about the right diameters, but the bends need to be done without so much damage to the wire.

 

[Keith Black]

1 hour ago, Greg Davis said:

but the bends need to be done without so much damage to the wire.

 Greg, you need some jewelers pliers. The jaws are smooth, makes what you're doing much easier as one isn't so worried about creating tool marks. 

 

  Your project fascinates me to no end, I'm throughly enjoying your build, great stuff. 

[KeithAug]

16 hours ago, Greg Davis said:

but the bends need to be done without so much damage to the wire.

Greg

 

If the copper is hard soften it by heating (to red) and then quenching - this should make it very easy to bend, then it should be possible just to bend it by hand around a piece of metal rod of appropriate diameter.

 

[Greg Davis]

3 hours ago, KeithAug said:

Greg

 

If the copper is hard soften it by heating (to red) and then quenching - this should make it very easy to bend, then it should be possible just to bend it by hand around a piece of metal rod of appropriate diameter.

 

this is dead soft copper, so it bends very easily - to easily in some cases, I believe that is why it damages with little effort. Next I'm going to redo the work using a rod like you suggest.

 

18 hours ago, Keith Black said:

 Greg, you need some jewelers pliers. The jaws are smooth, makes what you're doing much easier as one isn't so worried about creating tool marks. 

 

  Your project fascinates me to no end, I'm throughly enjoying your build, great stuff. 

I had used looping pliers for the first try. The wire notched where it contacted the lower edges of the tool. Some of the nylon faced jewelry equipment might work better with this material. 

 

[vossiewulf]

18 minutes ago, Greg Davis said:

had used looping pliers for the first try. The wire notched where it contacted the lower edges of the tool.

Greg could you use a small tubing bender on the copper?

[Greg Davis]

29 minutes ago, vossiewulf said:

Greg could you use a small tubing bender on the copper?

Not sure - the copper might not be stiff enough to hold the bend when pulled back out of the tubing bender.

[Greg Davis]

Plenty more to work on while pondering the fueling system!

 

So some different metal work; its the mounting structure for the rear hydrofoil:

I feel that I am getting close to being able to tie the main components, less the engine, all together.

 

[Jim Lad]

Crikey, Greg! That isn't model making, it's complex structural engineering! 😀

 

John

[Greg Davis]

It took 5 tries, but now I have 2 intake manifolds that can be used on the model:

There is a small amount of final adjustments that need to be made, but that should be easy since the copper bends nicely. The basic alignment of the pipes were made using a jig I had made for my Santos-Dumont 14bis model - I'm glad I didn't throw it away after finishing the kit!

The central piece is 12 gauge copper. Four holes were drilled through the cylinder to accept 18 gauge copper that form the distribution pipes. The four sets of pipes were soldered before bending to shape. Two 3/32" rods were slid under the 'spider' to lift it out of the jig and the pipes were snipped off flush with the jig. The ends will be smoothed out when the final fitting / attachment to the cylinder castings is done. Need to keep these safe until then! 

[Jim Lad]

Difficult shapes to fabricate Greg - especially when you need two identical ones!

 

John

[Greg Davis]

Today I did test fitting of the pontoon / nacelle harness and engine pylon structure. It went fairly well, I just needed to make a small adjustment on the location of the front engine supports - they needed to come down about 1/16" from where they were originally attached.

While doing the test fit, I noticed I made a mistake on the rear hydrofoil mounting structure. I fit the structure to the second to last hoop location - it should be placed at the furthest back hoop. So I am going to need to rebuild the lower portion of the structure!

 

I'll go back to working on the engine in a while. Still needing to do some research / determination as to how the coolant and fuel systems were set up. I won't be able to model all the details, but I do want what I do put in being fundamentally correct.

 

[Greg Davis]

1 hour ago, Greg Davis said:

While doing the test fit, I noticed I made a mistake on the rear hydrofoil mounting structure. I fit the structure to the second to last hoop location - it should be placed at the furthest back hoop. So I am going to need to rebuild the lower portion of the structure!

After some additional reflection and looking at pictures of the rear end, now I'm not sure it needs to be moved and I may have actually drawn it too far aft in my building plans.

[iMustBeCrazy]

1 hour ago, Greg Davis said:

After some additional reflection and looking at pictures of the rear end, now I'm not sure it needs to be moved and I may have actually drawn it too far aft in my building plans.

It looks like he made modifications in that area:

It looks like there were two different variants or something.

 

Anyway, in the top pic the hydrofoil mounts under his backside and in the bottom pic it mounts approximately under his knees. (I think).

 

 

 

[druxey]

It looks as if some modifications were carried out between the two photos.

 

- The steering column is shorter and more angled in photo 2.

- The hydrofoil mounts look to be in the same relationship to the wheel in both pics.

- Either the aft end has been shortened (unlikely) or the whole 'cockpit' moved aft about two feet.

 

Comments or criticism?

[iMustBeCrazy]

10 minutes ago, druxey said:

Comments or criticism?

Thinking about it, the top one may have been a prototype and may even have been towed.

Edited 10 hours ago by iMustBeCrazy