Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: Krishna on April 17, 2012, 02:24:01 pm
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Friends.. Colleagues.. when ever we think to make a rowing boat, we instantly Googles net, and astonises while looking in to the mechanisms, one used in RC rowing botas, like an RC bike.. it all are based on complex gear boxes, with pricsise lathe work, and some are equpped with four, six, and some eight servos to activate the rowing mechanism.. so, we soon tired while looking in to it all.. leaving the idea behind.. and some of us, istantly rethinks about some robotic gear boxes and complex mechanisms.. if we carefully study the action of the rowing action we will find some thing common in nature.. a cam mechanism.. its all..
and Mother Nature, gave us all ideas around us, if we thinks.. when i was required to make a landing gear demonstrator of a famous fighter aircraft, in big scale, at beginning i feel it as some tough job.. because when retracted, the wheel must be in a flat position under the belly of the fuselage.. but instantly i realizes, that this mechanism is entirely based on Human Hand.. and i demostrated in front of the Officials.. and worked within hours to complete it.. just like that, a rowing boat mechanism is simple, that if we looks carefully.. the entire action can be achieved by two parrallelly linked cams, with drive beams, or can be with individual cam and drive beams.. :thumbsup:
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this one is not my first row boat.. i compleated many before, but most of them are done for some Engineering istitutions and Academy.. when i took charge in Academy, as a model instructor, one of the senior Official requested me to make a rowing mechanism.. while, another Senior, came and commented as, "the rowing mechanism is a tougher Engineering project.. and i think some western Engineers done it very complexly..".. but my job was to proove him as wrong.. so, its so easy to make a rowing mechanism and rowing boat..
the idea came in my mind instantly, while looking and cleaning the MILKOOSSA.. after RCying.. anyhow, my teacher was used to come in a rowing boat.. then why i cant make one for her.. ? sure its the time.. finding some time within serious modelling project is not a problem.. just leave the sleep.. will get about 4 hours at least.. so, done..
the colour of the boat is choosen as Honda Red.. and it looks nice in water..
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once again Friends..making a row boat is far easy..we must need some good Coffee along with some omlets..for greater energy.. :-)) the craft features..
full hand build electronics..
very low current consumption..
with MP3 player..
i started with a piece of foam board.. the scale of the craft is based on the same doll that i used in MILKOOSSA..
you can see the simple plastic gear box that i used.. the 3 volt motor was reworked for 6 volts.. but because of the light load, the brushes were retained as original..
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you can see the simple cam mechanism that made from 5 mm foam board.. this configured as parallel, because of the single gear box..
single gear box, because my idea is to use a conventional rudder on craft..if we wont using any rudder, we can assemble with two identical gear box, to drive oars, then can turn, with the speed variation of each oars..
then can see the completed rowing mechainsm, without oars.. see how simple it all..
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in detail..all simple..
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now time to make the boat.. the boat is entirely scaled to the doll size that used.. and the entire boat was made from 3 mm foam board..
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the keel and transom.. look how simple all..
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basic structures..
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it is very easy to make a boat from foam board..
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completed and start painting..
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all internal mechanisms were painted in dull matte black..
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now.. the rower.. i bought same dool that i used in MILKOOSSA.. i am thanking to my Friend for these dolls..
adding atriculations on doll..
he also gave me a spare big cap for the rower..
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body is reworked and attched needed atriculations.. all by PU putty..
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doll in place..
and the row oars.. all made of foam board and bicycle spokes..
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now test time..
the craft is equipped with a rudder system.. and i added a high valanced rudder panel, as the craft is slow..
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and painting time.. i finished this craft in Honda Red from Duco..
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see the rowing mechanism..
http://www.youtube.com/watch?v=AYk_uURdMkA
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now the doll is completed.. i am thanking to my Elder Sister, Dr Rajina Keeriyaatt, for the cool dress ups..she made it from her old saree..
and ready for the action..
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time for the show.. the craft is powered by a simple battery pack..and in full load it dropped mere 600 mAmps, so ample of running time..
and now.. she is in water.. see how stunning she is..
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see more actions..
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she is big enough to go anywhere...
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see action video..
http://www.youtube.com/watch?v=qTafXJdedqg
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Excellent!
What is "PU putty"?
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see all respected Friends.. how easy to make a rowing boat..!! make one within 4 hours.. paint is.. fix it.. and RCYitttt.......many..many.. we need nothing extra ordinary.. no expensive materials or items.. all handy...have a lots of craft to you all...
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thank you Martin sir.. its all simple..PU putty is actually based on polyester.. and can buy in two forms.. one is as PU Putty, is based on Poly urathane.. is used to apply on car body surfaces.. cant fill dents..
another one is PU seal, as Plasto seal.. is same, but can fill any holes and dents in any depths.. will not shrink.. and so easy to sand off.. its a white butter like texture can buy in tins.. one of the very positive side of the PU putty is the drying time.. we can adjust the drying time by adjusting the quantity of the hardner, comes in seperate tube.. dries within a minute..
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here is the sample..
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Ah! Car body filler.
Thanks Krishna :-))
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yes sure.. thank you
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very good krishna, but i feel there is something you have missed about the western complicated methods. What we are trying to achieve is to make the boat not only row (the easy bit) but also make it steer using the oars without a rudder (the hard bit). It is the challenge itself that draws us as engineers to attempt the more complex systems and more often than not the easy way is avoided.
this model for example, steers by stopping one oar. Now thats fairly easy, the hard bit is once you've finished turning to start rowing again with both oars hands togeather in synchronisation.
http://www.youtube.com/watch?v=gMforBwFkPw
the 4 servo method is favoured because you can use a 2 channel RC and a micro chip to mix the servos so that when you stop steering the micro chips matches the oars togeather again. I read some where that a bloke in germany made the micro chips for a £100 or something silly like that.
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Mike.. thanks for the great inspiration..so, my next build ( will be some later , because , i have to work so seriously on a jet engine cut away of a famous jet engine, to teach pilot Cadets in Academy), will be on your idea, is simple, and can turn by changing the speed of individual oars.. yes, after turning and stopping, the synchronisation of two oars can be achieved by a simple rotating switch, one rotates along with the cam, and when switched on, any of the one oar, or two, by one gear box, or by two gear box, individually, the supply from ESC to motor will pass through the wires, directly connected to the ESC.. when switched off, the supply from the battery pack, settled in a peculier voltage, passes through the cam switch, through a simple electric relay, makes the cam rotate, untill it reaches the open point of contact, that a contact open point can be adjusted according to our needs with a screw.. so, while rotating, the cam reaches the open point, then stops instantly.. this point must be set up in a position, that the oars must be in up position.. so, after any movement, or stoppage, the cam will neutralizes the positions of the oars simply.. this kind of cam switches can be found in wind shield washer wiper assemblies of automobile.. so, whatever maybe the position of the oar while in drive, will be neutralized automatically by the cam switch..
so, we can arrange the throttle set up, as with one channel, as individual, and can control the speed variation by the next two channels, means, more clearly, we can choose any of the the potentiometers, on TX usually, controls the landing gear or Flap, for throttle, so can retain in a specific value, while we can use two main control sticks, from Left and Right, for individual throttle, as one for left oar and one for right oar..
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so, if you shuts off any one of the oar control, the cam switch automatically positions the oar to up position, untill the next input.. just like, a wiper arm of a car.. means, if we switches on the wiper switch for a second, the wiper arm, will go to the extreme end, and rests back, in its neutral position, as normal , near to the vent grilles on bonnet..
this also can be achieved by a simple micro switch, attached to the driving beam of each oars, a switch, that positiond to off, or depressed, when the drive beam, or cam reaches to a particular position, the position can be adjusted us us, according to our needs..
this also can be achieved by simple DPDT PCB relay, controlled by TX automatically..
this also can be achieved by a simple L E D and a photo transistor, with a perforated disc attached to the cam, as a phoelectric sensor.. when the opening or drilled hole reaches the L E D, and photo transistor, the circuit instantly triggers, shuts off the motor supply , and makes an instant regenerative braking..untill next TX input..
this alos can be achieved by a simple electronic differentiator, that we used for the traction controls of an RC car..
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eh %%
dont talk about it build it!
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here my effort was to make a rowing boat without any complication.. and with handy things.. and i will display you all, a simple mechanism, that we do not need anything as extra ordinary, but all with the TX and Rx already we have.. two simple reed switch, attached to the cam will do the job nicely.. and do not need any electronics chip to make this movement.. so, after any movement of any oar, will be at up position in any istances.. give me a little time.. will make a simple mechanism, that works, and synchronises with movements.. its all easy.. :-))
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hi..hi.. dont angry on me.. i cant explain much with words.. its a kind request.. will make one to show you how simple it all.. need a little time.. please..
your challenge is approved Sir..
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well i reckon that a rowing boat is my next project so ill be watching this next one because i want the oars to do the steering. if you can make it mechanical then thats even better :-))
not angry just confused
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Mike.. may try to build by tomorrow.. its a great pleassure to know my humble works helps you.. and too excited to see a rowing boat from you.. so happy..on the mark..
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this foam board you use. what is it and where can i get some?
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Mike..one more point that i forgot.. for a instant turn, we can also change the direction of the oar , one to another, means, one rows in FWD, while the second one goes as REV.. please .. a short time..
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Mike.. actually, no one here is capable to say the exact name of the material that you see in my build logs.. here this also known as 4S sheets, styroflex, sunboard etc.. anyhow, this one is too usefull to us in model making.. this one is a material, just like the expanded polystrene, but with a very high density, too stiff, but too flexible in wrong direction, can bend, and also have a second grade, is too stiff in either side.. can purchase from 2mm to 18 mm, as sheets or as cut pieces.. i also use the 3, 4 mm sheets to make wing structures of my Rc planes.. its too light, but strong.. will update you, about its exact industrial name by asking to a great dealer in my nearest town..
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this foam board you use. what is it and where can i get some?
I've often wondered what that stuff is that Krishna uses, perhaps this is close to the mark.
http://www.ebay.co.uk/itm/3MM-WHITE-FOAM-BOARD-A4-X-3-SHEETS-/120815538157?pt=LH_DefaultDomain_3&hash=item1c212acfed
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and not to be confused.. means, anyhow, with watever may be the equipment, the final goal is, that to stop both oars in a single starting point.. after any rotational movement.. so, even if we are by servos, still, will be based on DC motors.. so, why we cant stop the oars within a particular position..? we have the simplest answer with us, and from around us.. so, i said that to check the mechanism that used to control the wiper arm mechanism of the car..
it is easy to get the point about the car wiper mechanism.. imagine you are sitting on the driver seat of your car.. then just switch on the ignition key to second point, ( first to unlock, and thirdth is to energize the starter motor, in most automobiles).. to energize the primary electrical circuit of the vehicle.. now, all the warning lights comes in to play.. reminds us the car is ready for the starting, or as the elctrical system is in ON.. now, pour a little water on wind screen.. and just switch on the wiper.. can see the wiper blades sweeps across the wind shield.. in a arch position.. and comes back, in to it';s neutral position, after a full sweep.. then while watching the blades, please switches OFF with ignition key, ( but not with wiper switch), then can see the blades will stop anywhere on the wind screen.. it may be at centre now.. but still the switch for wiper arm is still in ON position.. now, switch OFF the wiper switch.. even then can see the blade still stands the stopped position.. and the wiper switch is in OFF position.. so, at this position, the wiper arm will stay there, as the wiper switch is in OFF position.. so, now, switch on the ignition key switch once again.. while the wiper switch in OFF position.. when the ignition switch contacts, you can see the wronly positioned wiper arm instantly goes to it's neutral position even while the wiper switch is in OFF position.. this happens because of the rotating switch, assembled within the cam of the wiper motor.. anyhow, we have to use a DC motor to drive the rowing mechanism.. if so, why we cant adopt the simple remedy to center our oars..? so, each and every time the oars will be in it's preset position after a movement.. still hard to explain..so will make a simple mechanism and explain you.. we need only some good micro switches..
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Hawk.. this material is invented by BASF, Germany, and its actual technical name is High Density Expanded ploystrene, based on styrene-butadiene copolymer.. in your place this material may be known as in various names, but i call it as foam board, as no any other name will be recognized from here.. but the popular name of this material is as Sun board..
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but i also found this solution.. in this web page, the authors indicate it as the PVC foam sheets..here is the link i found..
http://www.caprihansindia.com/index.php?id=22&lang=en
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Ive just googled the foam it and it turns out to be this stuff:
http://www.ebay.co.uk/itm/50-x-3-Compartment-EPS-Foam-Takeaway-Food-Boxes-HP4-3-/290699486930?pt=UK_BOI_Restaurant_RL&hash=item43af0a26d2
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Good Morning Mike.. i found two identical gear boxes for the expiriment.. will update.. have a nice time..
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in your own time krish :-))
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still working.. busy with modelling works.. excuse for a little time..
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Mike.. sorry for the delay once again.. will update as fast as possible..
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Mad.. so sorry for the delayed reply.. actually forgotten.. here is the simple solution for a self leveling oar.. by using a cam, we can position it at anywhere we need.. and by adding two individual mechanism, we can steer it easily.. and next is the boat without a rudder, but two independently driven oars..
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see the action..
https://www.youtube.com/watch?v=biqEbcCWzTA
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That works well Krishna, good inspiration from the self parking car wipers :-))
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yes Jerry.. i already told that.. and by adding two individual units, we can avoid rudder.. as the disc is capable to rotate both direction, we can hold the control sticks as one, in FWD, and the next one in REV.. so the boat will start to turn without rudder.. thank you..
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Wooow, haven't seen this boat, very different, innovative, love the video :-))
Congratulations
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thank you Escipion..