So the Esc and motor get their own cooling system? Not daisy chaining?
P1 Puma RIB racing-scratch building
- Topicstarter Dim L
- Startdatum
Exactly Michael! The motor from the outboard and the esc from the bottom of the hull so that both have fresh cool water...
Alex (@Tamiya1970) had made this "bottom-type" water inlet in one of his monos and I found it cool idea, although, I think that it is standard practice in racing monos.
Alex (@Tamiya1970) had made this "bottom-type" water inlet in one of his monos and I found it cool idea, although, I think that it is standard practice in racing monos.
That is what surface piercing propellers do!
They have super-cavitating blades, which means the trailing edges are a sharp flat side, to induce cavitation in a controlled manner.
I do not think cavitation occurs in scale, but if the speeds are high enough...
Also Jan's cat runs like this as far as I know.
But hey, I am the water-jet guy.
My knowledge about propellers is limited
So anybody, correct me if I am wrong!
They have super-cavitating blades, which means the trailing edges are a sharp flat side, to induce cavitation in a controlled manner.
I do not think cavitation occurs in scale, but if the speeds are high enough...
Also Jan's cat runs like this as far as I know.
But hey, I am the water-jet guy.
My knowledge about propellers is limited
So anybody, correct me if I am wrong!
I am learning
Back in the days when I was kitesurfing, I learned about super-cavitation.
Surfers both with windsurfing as with kites try to break the 100km/h barrier.
Both types of surfing have succeeded crossing this barrier in the last couple of years.
Up to 115km/h has been reached, but never over a long enough (for a record) period.
Problem is normal fins (comparable with fully submerged propellers) with sharp edges start to cavitate at a certain speed.
The water-pressure around the fin drops so far that the ambient water-temperature becomes the boiling temperature.
Fluid turns into gas! And fins designed for water will loose traction instantly, which happens to those brave men on their tiny surfboards in very shallow water!
The fastest sailing vessel is the Vestas sail-rocket 2, made for just one direction of sailing. Purpose build.
After each attempt it has to be dragged to the starting position again, it cannot sail back since it is not bi-directional like most sailing boats and surfboards.
They went over this speed barrier.
How?
They have one fin. the rest of the craft is flying over the water in ground-effect by a horizontal wing.
They steer by a kind of waterski.
The trick is with the large fin.
Up till 80km/h (reaching cavitation speeds) their is a sharp fin.
Inside this fin there is a super-cavitating fin, which is pulled out of the normal fin at this speed.
Problem is a sailing vessel does not have the power to reach this speed using this high drag super cavitating fins.
(the flat part is the super-cavitating part. it is blunt, not like a knife what you would normally think it would look like)
This cavitating fin as the cross section of a surface piercing racing propeller.
Engines have the horsepower to overcome the initial drag, sailing vessels do not!
Back in the days when I was kitesurfing, I learned about super-cavitation.
Surfers both with windsurfing as with kites try to break the 100km/h barrier.
Both types of surfing have succeeded crossing this barrier in the last couple of years.
Up to 115km/h has been reached, but never over a long enough (for a record) period.
Problem is normal fins (comparable with fully submerged propellers) with sharp edges start to cavitate at a certain speed.
The water-pressure around the fin drops so far that the ambient water-temperature becomes the boiling temperature.
Fluid turns into gas! And fins designed for water will loose traction instantly, which happens to those brave men on their tiny surfboards in very shallow water!
The fastest sailing vessel is the Vestas sail-rocket 2, made for just one direction of sailing. Purpose build.
After each attempt it has to be dragged to the starting position again, it cannot sail back since it is not bi-directional like most sailing boats and surfboards.
They went over this speed barrier.
How?
They have one fin. the rest of the craft is flying over the water in ground-effect by a horizontal wing.
They steer by a kind of waterski.
The trick is with the large fin.
Up till 80km/h (reaching cavitation speeds) their is a sharp fin.
Inside this fin there is a super-cavitating fin, which is pulled out of the normal fin at this speed.
Problem is a sailing vessel does not have the power to reach this speed using this high drag super cavitating fins.
(the flat part is the super-cavitating part. it is blunt, not like a knife what you would normally think it would look like)
This cavitating fin as the cross section of a surface piercing racing propeller.
Engines have the horsepower to overcome the initial drag, sailing vessels do not!
Great!
Where did you buy all these goodies?
Need to have some silicon cooling hose and some of those rubber bilges too!
Where did you buy all these goodies?
Need to have some silicon cooling hose and some of those rubber bilges too!
That is the shop I got recommended by a friend too!
I think the same shipping cost to the Netherlands. Indeed buy in burden!
Might add another 4092 motor too (lower kV)...
I think the same shipping cost to the Netherlands. Indeed buy in burden!
Might add another 4092 motor too (lower kV)...
Do you kniow the ac75 ? Mayby you get more ideas i100kmh+I am learning
Back in the days when I was kitesurfing, I learned about super-cavitation.
Surfers both with windsurfing as with kites try to break the 100km/h barrier.
Both types of surfing have succeeded crossing this barrier in the last couple of years.
Up to 115km/h has been reached, but never over a long enough (for a record) period.
Problem is normal fins (comparable with fully submerged propellers) with sharp edges start to cavitate at a certain speed.
The water-pressure around the fin drops so far that the ambient water-temperature becomes the boiling temperature.
Fluid turns into gas! And fins designed for water will loose traction instantly, which happens to those brave men on their tiny surfboards in very shallow water!
The fastest sailing vessel is the Vestas sail-rocket 2, made for just one direction of sailing. Purpose build.
After each attempt it has to be dragged to the starting position again, it cannot sail back since it is not bi-directional like most sailing boats and surfboards.
They went over this speed barrier.
How?
They have one fin. the rest of the craft is flying over the water in ground-effect by a horizontal wing.
They steer by a kind of waterski.
The trick is with the large fin.
Up till 80km/h (reaching cavitation speeds) their is a sharp fin.
Inside this fin there is a super-cavitating fin, which is pulled out of the normal fin at this speed.
Problem is a sailing vessel does not have the power to reach this speed using this high drag super cavitating fins.
(the flat part is the super-cavitating part. it is blunt, not like a knife what you would normally think it would look like)
This cavitating fin as the cross section of a surface piercing racing propeller.
Engines have the horsepower to overcome the initial drag, sailing vessels do not!
Yes, the amazing Americas cup foiling monohulls! F1 in sailing!
Have not heard about cavitation problems with these yachts, but with this yearly increase in top speed they will soon...and solve it probably.
Kite- and windsurfers still go faster, but not in the lower windspeeds these boats hit the 100kmh!
I know some RC enthusiasts are trying to make these in scale...
Have not heard about cavitation problems with these yachts, but with this yearly increase in top speed they will soon...and solve it probably.
Kite- and windsurfers still go faster, but not in the lower windspeeds these boats hit the 100kmh!
I know some RC enthusiasts are trying to make these in scale...
Bedankt Jan!
The white basis helps a lot when you paint other colors plus I lightly sand the surface before I apply another color which helps a lot in the final result.
Indeed very nice and rewarding work .
Love it Dimm[emoji1305][emoji1303]
Love it Dimm[emoji1305][emoji1303]