Louis Brennan mechanical gyro stabilization

Just my design for building my Brennan mechanical gyro stabilization,
see also blog of January 2015

America's cup gyro control revealed

 COPY of cupexperience.com

Super clear explanation of the control system, thanks!

remains of the question what this all really means and what are the limits, just generating power by humans, which is then used by machinery/eklectronics to controll the beast (and next, to drive it?) Interesting question is when sailing stops and becomes motorsports ....

AC72 foil control secrets

Some people have questioned whether Oracle Team USA had a secret (and illegal) foil control system in their AC72 that helped them defend the America's Cup.
OTUSA has released drawings and photos of their system, which used a simple "mechanical feedback" loop to allow precise control of the daggerboard rake. Helmsman Jimmy Spithill had buttons on the wheel to rake the daggerboard fore and aft in precise increments of 0.5° giving him better control over lift for hydrofoiling.

OTUSA designers Dimitri Despierres (mechanical systems) and Eduardo Aldaz Carroll (electronic systems) began work in late June 2013 to help the team gybe better. The goal was to reduce distance lost in a gybe from 150 meters to 30 meters. To do this the engineers needed to deal with the problem that board movement varied depending on hydraulic pressure, making it impossible to control lift. What they needed was a way to move the board a fixed amount independent of the pressure and drag load on the board. Within a month, mechanical engineer Alex Davis developed a test bench with a servo control, hydraulic valve and hydraulic ram to simulate movement of the daggerboard box (see photo below).

Once the test bed system worked, the system was tested on board. Accuracy was fine, but it reacted too slowly. Mechanical engineer Neil Wilkinson and hydraulics specialist Rolf Engelberts improved the system to improve response speed and make everything more reliable and robust.

AC72 daggerboard controls on OTUSA Boat 1

The hydraulic ram for rake is not visible in the photo below, but you can see the rams for board cant, as well as the daggerboard cage and daggerboard box. The box moves within the cage, which is fixed in the hull.  Rendering of AC72 daggerboard cage below. The cage is fixed in the hull. The daggerboard box moves fore / aft (rake) within the daggerboard cage. The daggerboard cage moves inboard / outboard (cant) within the hull. Controversy and protest by Team New ZealandOTUSA wanted to make sure their system complied with the AC72 Class Rule. They filed a "Public Inquiry" to the Measurement Committee and got approval on 8 August 2013 - only a month before the America's Cup Match was to begin. Team New Zealand then tried to have OTUSA's system ruled illegal but the Measurement Committee stood by their initial decision and the International Jury ruled that New Zealand's protest was made too late, but would not have succeeded even if it had been filed on time. The marked up schematic below was part of Team New Zealand's submission. OTUSA eliminated the spring labeled "Component X" making the TNZ protest moot.  

How fair was the America's cup win by USA

There is debate about the changes team Oracle made to their boat, during the "break".
Was it a fair change, using gyro's
Have a look at the Sail world article on this link.

A gyro should have been fitted to control the frontfoils and thus stabilize the platform and allow for smaller and consequnetly faster hydrofoils. The gyro is as far as I am concerned only allowable when both teams could use them, which still is unclear.
On a higher level and that is quite clear in the sailworld article, America's cup sailboats should be manually controlled and a computer (plc) controlled hydrofoil should then lead to disqualification.

From the races it can be clearly seen that team USA had severe stability problems in the earlier races before the "break". After the addition of the gyro's the boat looks very much more stable than the New Zealand boat as is apparent in many of the close quarter high speed racing where team New Zealand is all over the place and Dean Barker at the helm is constantly correcting course.

I am very curious what we will hear about this and what will happen next America's cup challenge, lets hope the sailing feast continues.



Below the complete sailworld text from their webpage.

The following notes are circulating in Auckland media circles, as an explanation for Oracle Team USA's improved foiling performance, as time progressed in the 34th America's Cup.

The notes were dated September 23, 2013, but were received by Sail-World mid-morning September 26, after the regatta had finished. But the device was first highlighted by the Television NZ commentary team during their coverage of the vital Race 19, of the 34th America's Cup. Click here for the full race coverage and NZ commentary including comment on the Oracle Team USA foiling performance.

This afternoon, Tim Smythe, principal of Core Composite Builders, Oracle Team USA's Warkworth (NZ) based building facility, said that the team used the same set of foils through the regatta and that the 'special foil adjuster system, was there before the regatta started'.

Click here for the TV3 report and interview with Tim Symthe.

The matter was taken by Emirates Team NZ to the International Jury on September 3, and a Decision issued on September 6, just one day before the regatta started. It was rejected on the basis on being filed outside the allowable time, but added a rider, that had it been issued inside the time limit, but on the basis of what had been heard, the application would have been unlikely to have been upheld.

Emirates Team NZ's Ray Davies said 'their boat is rock steady up wind, that takes us a lot of effort, and we have been trying to it for a long, long time, and yet they master it in just a few days.

It is well recognised that Oracle was having serious foiling stability difficulties at the outset of the regatta and that their performance could not match that of ETNZ.

Half way through the series it was acknowledged that Oracle had fitted an automatic control to their hydrofoil trim, and that this modification was approved by the measurement authorities.

Since this modification Oracle's performance has almost unbelievably improved. This has been 'explained' by skipper Jimmy Spithill as being due to the superhuman efforts of the crew to improve their handling skills. However, in view of the intensive training Oracle were able to do, prior to the regatta, with their highly skilled team partner, it seems unlikely that only now have they discovered the 'magic bullet' they they clearly have. It is much more likely to be the result of the modifications, possibly enabled by their surprising decision to use their lay day card and the subsequent lucky postponements.

It must be remembered that this is the first time that this contest has been sailed by yachts 'flying ' on Hydrofoils and it is probable that new and different criteria should have been applied.

In the aeronautical world it has long been known that the stability of swept wing aircraft can rapidly be lost by uncontrolled yaw leading to a dangerous situation known as 'Dutch Roll'.

A device known as 'Little Herbie' was developed during the commissioning of the Boeing 747 Jumbo Jets over 40 years ago, to over come this tendency. Little Herbies, or 'Stability Augmentation Systems' (SAS) as these are now designated, are equipped with sensors such as Accelerometers and Gyros which can detect and instigate corrections to stability with a speed and accuracy which exceeds the ability of even experienced airline pilots. They are therefore now installed in virtually all swept-wing aircraft.

The 'legality' of this device has been justified and accepted on the basis that it does not actually 'drive' the trim of the foils.....this is still performed by the muscle power of the crew, via hydraulic linkages. That may be so, but the device, using its sensing and directives, has been described as 'automatic'. This implies that the trim of the foils is determined by what can only be described as 'superhuman' technology. If this technology has been used to overcome the foiling stability difficulties of Oracle it will have enabled the use of higher speed/lower drag foils which the crew would otherwise be unable to manage. This would give a significant speed advantage during foiling. This has been clearly in evidence since the modification. Improvement in stability and speed has been staggering.

The high speed/low drag foils do have a downside in light conditions where, due to their lesser lifting characteristic, foiling is difficult or impossible. This was also clearly seen in the abandoned Race 13 when ETNZ were only 4 minutes from the finish, with a lead of over 1000metres.

Oracle Team USA have not provided any official comment on the system they used.

While it would seem that the actuator device is legal, if it is attached directly to its own power supply, the wider question remains as to whether a boat should be raced with a computer, rather than a human, driving a primary control function.

The Racing Rules on the matter are very clear RRS42 Propulsion states: A yacht shall compete only by using the wind and water to increase, maintain or decrease her speed. Her crew may adjust the trim of the wing, sails, rudders, daggerboards and hulls, and perform other acts of seamanship.

The vital words are at the opening of the second sentence 'her crew' - meaning that an automated adjustment which works independently of crew intervention is illegal.

Then BMW Oracle Racing did have very sophisticated on-board systems in 2010 in the Deed of Gift Match, which amongst other things they were able to overlay a line image of the optimum wingsail shape against the actual image, enabling the crew to make the adjustment required to get the two shapes into alignment, and achieve the ultimate performance.

That is one step away from having the wingsail shape adjusted by a computer independent of the crew which under RRS42 is illegal. Even under the current America's Cup rules such a system is quite legal, and it is hard not to believe that such systems were not used again in the 2013 America's Cup. The key point being that there must be a crew intervention between the computer and the sail or other control named in RRS42.

Of course computers are not infallible, and any intelligent computer system requires a lot of tweaking and refinement to be operate consistently and at a refined level. It all takes time - and time is the most vital commodity in the America's Cup.

The time for application to the International Jury over such a matter, is long gone. The rules require that a competitor protests or lodges an application to the Jury as soon as they are aware of a measurement issue, not later or at the end of a regatta.

by Richard Gladwell

Gyro stabilized monorail

Louis Brennan

gyro monorail

Interesting history of the gyro monorail to be found on Wikipedia
The small Louis Brennan Wiki page here.

His invention was a mechanically controlled set of gyro's that could keep up a 20 ton railwaycar running on a single track.
The mechanically interconnected counter rotating gyro's were forced to rotate so that the combined precessing force would righten the monorail. The Patent can be found on the gyros.biz website
A first glimpse of how it works is the below drawing.

Peter Healy made a Brennan style stabilization which is very stable Youtube
Note that therotational axes of the gyro's are horizontal (as with Brennan) contrary to almost all other examples on the internet including Lit.

That the Brennan inventions works quite well can be seen from the pictures of children in the model car. The one with the boy showing the transition from the rail to the steel cable and the girl seems suspended in mid air.

The last reference (for now) is Dave Woolard who had some very interesting gyrobike simulations on the internet. I cannot find him anymore .... But I copied one of his prictures, lets hope his simulations come online again some time.

Lit motors

Lit motors

Rekindle the exitement

Jealous, that's what I am when I see the progress of LIT motors.
How does Daniel Kim do it, how does he fund his team ....

Ok enough of this.
Their mock-up is phantastic.
There are several video's online and their website has some also.
This youtube movie can be a good starting point for you.


What is their basic idea? 
They want a monotracer design (ie. motorcycle, vehicle riding along a single track) but without training wheels / landing gear to keep the vehicle upright when driving at low speed. (they have a parking stand)
Their solution is using twin gyro's for stabilization. The precession of the gyro's is controlled in such a way that the vehicle will always stay upright.
Looking at the video's it becomes obvious that there are some issues with the gyro control, too many people around the vehicle, a wobbly motion when standing still, video's cut short suddenly.  Hope they wil soon solve this.

Streamlined shape.
The shape of the vehicle obviously will have to be re-designed as the side windows are not high enough for comfortable view even when small persons are sitting inside.

Battery capacity.
The gyro's  take up a lot of room below the seat(s) and that leaves little room for batteries for the electric motor. From my own designs (for sem) I know that the drive batteries are the major problem, if you want performance in power and endurance you need a large number of relatively high capacity batteries, which take up a large volume ....
In the Lit design I do not see where they intend to store the batteries.

Just some more Lit eye-candy.
Keep up the good work Daniel Kim!

Stephan Nitsch gyro copter glider

Stephan Nitsch

During his lifetime Stephan Nitsch has made some amazing gliders. His most comprehensive work was making replica's of Otto Lillienthal's and Cahnute gliders.
What got me on his trail was something completely different.
Years and years ago I saw a small picture of a gyro glider in "Drachenflieger" now called "Thermik". This small picture I could not find again, so also the name Stephan Nitsch was unknown.

Surfing the internet extensively resulted in me finding the Stephan Nitsch website . Soon I contacted him and we exchanged some flying information.
It is a pity that Stephan died, but luckily his website still exists and I would like to share him with you.

The gyro glider.

Images below speak for themselves, but lets speculate a bit about the gyro.
From the video on the website you can see he had some rotational stability problems, also gyro's are not known for their great glide ratio.
How about keeping the gyro into the apparent wind / direction of flight. The vanes, of vertical planes on the gyro seem small.
The wind speed required for sufficient rotational speed for lift off seems to be quite high.
He had to do it with materials from behind the iron curtain as he was living and experimenting in east germany.

But, he made one and started experimenting!

What would be possible with modern light weight materials and engineering?
Who picks up the gauntlett .