照咁睇打蛋器都可以做船

tomtso

https://www.youtube.com/watch?v=p51cbFpVxBg

david

呢隻船嘅兩個渦輪撥出嚟嘅水只係渦流, 各方向全對稱, 並無特定推向船尾, 船不能向前行, 根本就唔work.  要有嘢罩住佢, 在一邊開口導流, 咁先至work. 不過效率都重係低過螺旋槳.
揾隻舊鞋裝一個車葉和一個舵都行得好過佢啦. 媽子個D尖尖地頭嘅舊鞋就啱嘞, 去水D.

cmpang

this type of propeller works on  variable pitch.each individual blade's pitch angle varies according to its dynamic position  in relation to the boats axis. due to its symetrical geometry, it can push the boat in any 360 degree direction as desired. operation similiar to the rotor head of a helicopter and is most useful in the modern tug boats in an over crowded harbour. Some fire boats also uses this type of propulsion for its superb manouverability. On spot rotation and moving sideways are some of its major advantage over conventional driving mechanism.
方舟 has made a Los Angeles class fire boat using a Voilt system from Robbe.

no 船王 should miss this one from his fleet collection.. 吾知我地既老，中，青船王們點睇?

oldv1rr

外國人做 HMS Penzance

http://www.youtube.com/watch?v=Ahg1t-oZliM

david

The Voith Schneider Propeller (VSP) propulsion system is an Austrian design of which two propulsion units are included. Each unit has a variable pitch propeller that is vertically mounted at the bottom of the hull so that its thrust can be varied both in magnitude and direction and hence provides propulsion and directional control of the boat. The amount and direction of thrust is controlled solely by varying the cycle pitch of the blades and the motor only needs to run at a constant speed and in one direction, regardless of the maneuver being contemplated.
The VSP system requires a minimum five channels to control the boat fully. Four control servos for the drive units (two for each) and one for the electronic speed controller.
Such sophisticated mechanism with complicated maneuverability are too difficult for those lazy people like me to manipulate. Is there any Rosenfans boatmate would like to try ?

cmpang

The basic principal is complicated but the real world control is easy. You control each of the two servo pairs by the two control sticks on your transmitter. Each gimble determines the X/Y corlordinate direction of the trust flow as desired while a fifth control knob control the total power output from the propulsion system. As  easy as playing a computer game...

e.g. pushing both sticks up will move the boat forward, right stick up to turn left, right up and left down is rotating anticlockwise... sounds familiar enough ？ What makes it different to our tank control is it can shift the boat sideways by pointing the left/right gimble to the left/right direction ...

oldv1rr

急拿有出 VSP kit tug
http://www.modelboats.co.uk/news ... ed-harbour-tug/465/

吾鈡意隻大陸拖  可以買 powerpack 自己黎
http://www.graupner.de/en/produc ... 358.BL/product.aspx

Nevertheless, they are 船王級 toys from the cost's standpoint.

david

It is rather expensive, just only one Voith Schneider drive (including the brushless motor) will cost you 235.95 Euros, that is about HK$2420. The twin motor system costs HK$4840, not to count in the 35 inches long 1:33 Graupner tug boat Parat, five servos, a multi-channel emitter and receiver, and the postage fee. The total sum will be more than $10000, that is too expensive. Does it worth to spend more than ten thousand dollars on such a toy ? Or if you want to give a hand to the economies of the Europeans just like our 強國女人 buying Louis Vuitton, Prada, Ferragamo,.... so enthusiastically and wholeheartedly in Paris and Rome. Haha, more than 80% must be paid by men, and the rest by the women themselves.