speed-king

hey guys, im building a rc mono, as a school project, i am currently looking at a Graupner Hydrospeed Flexdrive with a 700 motor as my power. what size boat is this meant for im looking to build something in the 18-24'' range, is this the right choice of drive system or is there a beter one that i should be looking into? any help is apreciated.
thanks

CadillacDTS2001

for the 700 a 27-30 inch boat should be good and quite fast as well.

sportygreg

My Feedback: (2)

It should work fine for a 24" boat-outdrives tend to be a little sloppier than separate hardware and not as fast but for sport boating they are good enough.For racing,separate hardware is best but gets expensive-at least $100.00 for a decent setup like Octura or Fuller's.

speed-king

the boat im building is 24inches long, 7inches wide has a 18degree v, and will be made out of fiber glass, does anyone have an idea of how fast it will go with a Graupner Hydrospeed flexdrive and a 700 motor? also would there be any point in puting two drives and motors in for extra speed or would that be too much for this little boat?
thanks

ryan_t888

No, it would be slower.

Ryan

kahnen

What kind of batteries you plan on running? 700 motors run best on 14.4v +. Can you fit 12 cells in the boat or you useing lipos?

I would just stick with one drive/motor for your boat. Twin drives don't equal more speed. Also your boat, I don't think could handle the weight of two 700s plus mount/hardware/batteries that needs to go with them.

peterpella

Hi there

I built few boats with 700 Graupner class motor. First of all, this is rather huge e - motor to be used with boats with 700 - 800 mm hull lenght. I put this motor to the Kyosho boat called Bladerunner instead it's complicated and stupid geared drive. Also 700 motor was used by me in transformed Sea Dagger produced by Academy. If I can say something additional, I used to use 700 motor with 12 v. 14.4 is a little bit to much.

Try to take a look on Robbe site on the boat called Magin One. It uses 700 motor. Or find a similiar boat on Graupner site. Few years ago I built Graupner 'Systems' boat. You can still buy this motor sell together with flex shaft. 10 years ago there were huuuuge amount of different versions of 700 motor with flexi shats. Now, there is still two solutions with this motor and flexi shaft.

Peter

peterpella

Hi there

take a look on my new project. A fiber glass hull with lenght of 650 mm. A piercing prop. Motor 700 Speed Garupner ( the old version produced in Japan, not in China ! ).

I can't wait for the first run!

Peter

speed-king

thanks for all the information, what type of prop is best with this motor and drive system, surface peircing or a regular submerged prop? what should be used for speed control? "this is rather huge e - motor to be used with boats with 700 - 800 mm hull lenght." is that because of its power?
thanks

peterpella

Hi

gimme some time I will find for you all info you want.

I tried to put on forum two pics of my last project - something went wrong and I these two pics are not seen.

Yea, this is a huge motor. It's weight is over 320 g that's why it's bigger than standard 600 motor.

Peter

peterpella

Hi there

ok.

A 700 e motor usually has 67 -68 mm case lenght. Weight: 320-330 g.

No laoad current: 2 - 2.5 A
Stalled current: 70 A
Max efficiency current: 12.5 A
5 piece armature

So, 12,5 A x 12 V gives 150 Watts. Is this much? I think so.

Because it's five piece armature it works smoother and takes less power than motors with three pieces rotor.

Surface prop: 39 - 40 mm diameter. 2 blades.

If there is Robbe near you, buy Z - drive with coupling ( No 4137 ) with prop of 42 diameter. it also will work fine.

Peter

ryan_t888

150 watts is nothing. A 700 motor should be running 30-35A on 12 cells with brush and can water cooling, making 450 watts.

Ryan

peterpella

Hi

I was talking about 12.5 amps.

If we talk about 35 amps and 14.4 voltage it giges yoy 504 watts.

But lets help our young racing boater in understanding 700 e class motor idea.

Regards
Peter

speed-king

hi
thanks for all the great info guys.
with a surface prop should the center(drive shaft) be set below at or above the bottom of the v?
what should i buy for a speed control?
what do i need as far as servos?
can two 6 cell batteries be used or can i buy a 12 cell battery?
i know im asking a lot of questions but this is my first rc build and i appreciate the help
thanks

peterpella

Hi there

first of all, if you are new in this bussiness, try to use cheap and not sophisticated equipment.

You can use any standard servo and two chanel fm radio, for example futaba or similiar.

Thinking about your next projects, buy esc which can be conected to water cooling system in your boat, when you want to build bigger one.

In my opinion, buy two 6v batteries instead one 12v. Then you can always place these two in any position you want according to the conter of gravity. It's much easier to do it with two batteries. Strat with capacity of 3000 mAh. Do not buy expensive batteries like Sanyo or any of that kind. Try to learn how to use them, time for buying sophiscticated equipment will come very quickly.


You are to learn a lot about NiMh batteries. Probably you do not have any NiMh charger. It's your choice what to start with. Start with any computerised delta peak charger or buy the simplest one without these function, but remeber that you will be forced to check the time of charging carefully, also voltage and loaqding current are to be checked.

For the 12v operating you don't have to buy any water cooling system, when using 700 e motor.

Peter

sportygreg

My Feedback: (2)

I am using a Revolver 700 motor on my Electro Vee which is similar in size to the boat you are working on.It has a solid shaft direct drive to a Graupner outdrive unit.The shaft exits the hull right at the bottom of the Vee.I will be running 12 cells with a Jeti Navy 600 ESC and a 42mm Graupner prop.It was converted from the original 7022 Hydrodrive 3:1 reduction with a 550 size motor.The 700 motors take 14.4 Volts no sweat and the Revolver motor has BB and fan cooling.By the way,the Traxxas Villain outdrives are almost identical to the old Graupner units but do not use flexdrive and parts are available cheap on Fleabay![8D]

ryan_t888

For 12 or more cells, water cool the can and brushes.

Ryan

speed-king

hey guys
i have a battery charger that i use for my electric rc truggy, it does both 6 and 7 cell batteries and shuts off by itself when done charging. i also have a number of 6 and 7 cell batteries that i have been using in the rc truck, can i use that equipment in the boat with the 700 motor and jeti navy speed control? where is the best place to get the 42mm Graupner prop, and all the other equipment? are there any hobby lobby or Graupner dealers in ontario in the barrie area or do I need to order everything online? should i try to get it online or should i be able to purchase it at my local hobby shop?
thanks '
Morgan

speed-king

if any body has a boat with a set up similar to what im building could you please post some pics of them. particularily how you mounted the motor, and the propshaft set up
thanks

Quicksilver

I dont have an all in one hardware combo. I made some parts, like the rudder hardware. It uses a Aquacraft sv27 strut, but this is the basic arrangement of them motor in a mono.

Some pics of when I was building her. She has a 700sc from offshore electrics, uses a graupner k-series 42mm. It's a Traxxas Villain EX hull and runs on 16 cells, 19.2v. Uses brush and can cooling.

speed-king

how does the flex shaft attach to the motor and the prop? are both ends threaded?
would anyone happen to have or know of a flex shaft and a 42mm surface prop and attachment for a 700 graupner motor for sale?
does any one know where i can buy just the flex shaft?

kahnen

http://www.offshoreelectrics.com/pro...oct-oc130L-24c flex cable set with 3/16 shaft
http://www.offshoreelectrics.com/products.php?cat=68 motor coupler=use a 5mm to 0.130
http://www.offshoreelectrics.com/products.php?cat=58 42mm carbon prop for 3/16 shaft
http://www.offshoreelectrics.com/pro...dh-ks-brass-tb brass tubing stuffing tube, 7/32 size

Everything you need.

peterpella

Hi there

tried to put some pics of my new boat with 700 motor but something went wrong.....

Don't buy at ebay. Go to the nearest model shop and buy all you need.

peterpella

Hi there

this is my last project. Fiber glass hull with 700 motor. 12 v. I built model of that kind using the same equipment few years ago. Now it's time for remake....but some changes will be added. No water cooling. With carefully chosen prop this hull goes like a bullet.

speed-king

thanks Kahnen ill check that stuff out.
what shoudl i be using for a rudder assembly?
also what would the best strut be to use on this hull?
is the speedmaster drive strut for 3/16 shaft on funrcboats.com good?
thanks