Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: rathikrishna on December 26, 2010, 10:59:29 AM

Title: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 10:59:29 AM
Friends...when a high speed craft is operated in water, taking turns is not a heavy problem, as such crafts are normaly operated at high speeds.we know,the pressure on a control surface increases when the speed increases.so, with a high pressure at control surfaces we need only a small area to control the craft.and the response also will be higher.but when we consider a semi, or fully displacement craft, its a different story.all such crafts are operated at low speeds, but high torque,the direction control properties will be far lesser.means , with a conventional rudder,such crafts responds a less.so, when we try to turn such crafts from a stand still, its almost impossible to alter the dirction from its neutral position.so we invented the ever classic device...the THRUST PUMPS..and more advanced THRUST VECTORING MECHANISMS.all these mechanisms are complicated, especially the second one.one of the main head ache is while fixing a normal thrust pump to our hull, is the specific space of the hull.it must be predesigned.as i inspired by my  friends in MBMH,i started playing with my crafts  seriously.soon i came up with two problems.first one was the leaves and debries...i overcame this by purchasing a plot for myself, as part of our prawn farm.after cleaning it, its OK..
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:00:20 AM
second thing was the directional controll...with usual rudders at belly all my crafts took more space for a turn.and leaning to one side was a great threat while high speed turns, due to centrifugal force,always shows a chance of capsizing...so i accidently got some guidances and advices from my respected friends, from MBMH,and started to think to fix a pump on my crafts.but soon i came to know, that such pumps are much costlier and it works on heavy motor drops a high amps.and it was far beyond my reach, as i cant use a credit card.

so i burnt my brain a lots...soon i found a solution...make one myself...so i started...now mastered...its nothing but a centrifugal pump, drives in to either directions...a simple ,flat, can be fixed on any craft, and for a disply you can simply remove from hull, and can be fixed back when you need in water... and the mode of working is far beyond explanations...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:01:21 AM
one of the main criteria is the simplicity...to make such pump we need, a good hot or cold coffee...two cutlets or an omlet...to get some energy to work,and for being happier..hi...hi...      then   some silicon gears, from toy or from any source ....

fig 1 shows a crown wheel with pinion...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:02:01 AM
fig 2 shows a spur gear with pinion...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:02:30 AM
fig 3 shows two pulleys and a driving belt from a walkman....you can choose any mode to drive the pump...but remember there must be a chance of slipage
while using a belt drive....
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:03:16 AM
fig 4 shows the toy motors we need to.we can use any motor, but its not nessesary to use a high power high quality motor here..a mere 4.5 or 6 volts motor is far enough, as we using gears here,not only but also we do not need a high spped here because a simple thrust from the pump is enough to control our crafts..
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:03:49 AM
fig 5 shows an alternate for the gear box...we can use a tiny toy gear box to drive the pump....
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:04:38 AM
so now we got the motor and gears, or a full gear box.now we need two switches for drive the motor.a simple single pole double throw switch is needed.
fig 6 and 7 shows such switch.make sure your servo can operate it.
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:05:29 AM
fig 8 shows the ever simple diagram of motor reversing circuit....now in to making...

collect some ball poit refill, a brass rod, or a bicycle spoke.make sure that the rod is free inside the refill and not too loose...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:06:06 AM
then take a piece of foam board in to 1 mm thickness...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:07:18 AM
is there any formula, or criteria to make a thrust pump..?   yes sure here is the formula...    RS+NNF
                                                                                                                           --------------- X100     got it...? no...?
                                                                                                                              PPCSM

OK...RS...means Rathi Says..  NNF   No Need of FORMULA....PPCSM..means Pumping Pressure is determined by Controling the Speed of the Motor...and 100 is for, its need not to think100 times...(OH PLEASE DO NOT ANGER WITH ME...ITS ONLY FOR A JOLLY...Hi....Hi...)...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:08:06 AM
draw two identical circles on foam board, the perimeter is according to the size of the craft.....draw a thirdth one but it must be lesser in diameter than before..its meant to make impeller.
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:09:51 AM
to cut the circles we need only a pair of  sharp scissors...but here i am giving some hints to get some neat circles... fix a bolt in to the chuck of your hand drill...place foam board on it as shown...make a sharp tool ,here i fixed a needle from the package of super glue, and squeezed on a forceps, from  Maa's surgeory kit...you can choose any tools apropriate...

start drill..lock the power switch...hold with your one hand..simply place the sharp tool on the line we drawn....so simple..finish the edges with 600 or 700 grit emery paper or with dust free....

now we have the circles....make a inner circle on any of the bigger circle as you can see here..its meant for water inlet...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:10:53 AM
cut a strip from foam board...cut a slot, up to 2 cms..on it as shown...


fix the strip as shown here with super glue....
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:11:44 AM
now take the smaller circle and fix a piece of ball point refil, while making sure it is tight on the rod we use....
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:12:51 AM
now fix a ball point refill as shown on main assembly we made earlier...the height of the shaft is determined by the hull of the craft...but make sure it is above the water level...fix gear on rod and insert it through...

fix the impeller assy on rod, and glue the cover with super glue...make sure free rotation of the impeller....
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:13:42 AM
now time to fix the motor...here i am showing only the key idea...we can go for any type of gear box, or motor...but remember...by fixing a motor
one works in lighter Amps with a gear arrangement works longer and eats less battery...

the additional attachments are not need when we fixing it on to a craft...

its time to check...you can simply fill the whole gaps with model putty, or car body filler, or with two part epoxy putty...and sand it for a great finish...

can try various designs...here we can use this pump on any craft that we need a pricise control...at bow or at stearn...a configuration at bow will gives
us an instant alteration of course, with a steep angle, while at stearn, gives us a more reallistic feminine control...withought any leaning....effect....

now 100% of my crafts are employed this configuration....and i am too thankfull to all of my friends of MBMH, as i got ample of guidance and ideas
from all, to realize this mechanism...so try it once and feel it...and you can save lots of money...and with that saved money,oh..no..no ice creams to
 me...but..you can make a next craft  for a great play...again..again..again....ommmm...koooooyaaaaa.......



Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:15:11 AM
if you feel anything about the excess drag, then you can simply streamline this pump in to the hull as i shows here...and sure see the INSTRUCTIONAL VIDEO HERE...   http://www.youtube.com/watch?v=A2YQVwcWhVQ
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:16:40 AM
see some actual working models of my new makings...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:17:37 AM
and some more waiting o be finished...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 26, 2010, 11:18:34 AM
So Friends...make it , fix it..forget it..and play with it...zig zaggggg.....hi..hi...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: Mankster on December 26, 2010, 01:10:06 PM
Absolutely amazing and ingenious  :-))
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: AlanP on December 26, 2010, 03:05:07 PM
Thats realy good, I will have to make one of them
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: john s 2 on December 26, 2010, 03:50:56 PM
Yet another wonderful idea. How you consruct from such basic items is a lesson for us all . Thank you John.
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 28, 2010, 12:30:36 PM
John..i hope now you may got some ideas..it works nicely...and simple...but effective, as you can see in my videos...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: david j on December 28, 2010, 04:36:31 PM
hi, rathi, yet again another simple solution. i hope there are some young people and senior people out there who will give this hobby of model boat making a try, with your simple ways they cannot fail

davidj
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 29, 2010, 11:12:08 AM
sure Davi..we must try..
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: pier33 on December 30, 2010, 04:55:05 PM
Bonjour chez vous :-))

very interesting
cheer cheer cheer

Du modélisme du vrai, tu es une passionnée
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on December 31, 2010, 09:08:06 AM
Thank you Pier...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: kiwi on January 02, 2011, 07:26:47 PM
Very nice, very simple, very clear instructions.
Very well done rathi
Will have a go at one of these myself
cheers
kiwi
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: rathikrishna on January 04, 2011, 01:10:30 PM
thank you Kiwi...
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: bijou on February 15, 2011, 08:48:20 PM
All I can say is sincerely :THANK YOU,THANK YOU,THANK YOU. :-))  ok2  :-)   8)
Your "bijou"
Title: Re: MAKE THIS SIMPLE BUT EFFECTIVE THRUST PUMP AT HOME...
Post by: Davy1 on March 18, 2011, 05:55:11 PM
That looks like a really good idea for a thruster.
Thank you for sharing it!