Gon'a need a bigger prop

[wrk134]

Smit Rotterdam 1:72 Scale . I finally was able to get the ship on the pond. But I was surprised with how slow it moved though the water at full speed. 10 mph wind gave it a hard time. So I'm thinking a bit more pitch to the prop, maybe more blades (3 blade comes with it) I can't tell what size they are, knort nozzle make putting a larger prop on unrealizic. Motors are 12v. well please look at my blog for equipment list. Any ideas?

[toesup]

If you cant get a bigger dia prop inside the kort nozzles, go for a 4 or possibly 5 bladed brass 'kort' prop.

http://www.harbormodels.com/site08/main_pages/prop_manufacturer.htm

[patmat2350]

I'll wager you need more shaft speed, not more prop.
What size props are they, and do you know how fast the motors are spinning on 12v?
Not sure what your motors are... but if they'll take it, try an experiment with 18v (12v + 6v battery). If the ESCs won't do that, just wire it up straight with on/off, use an Rx battery to run the radio and rudder.

[Jay Hargest]

I don't know if this would help but it appears from your photo that the props turn toward the center of the vessel when going fowrard. All twin screw vessels that know of have their props turn outward when going forward.

(That is, for American/English, the starboard prop would be called right handed while the europeans would call it left handed.)

I'v never operated a twin screw vessel with the props rotating inward while in forward. However, it would certainly effect the low speed handling and I believe it would adversely effect speed as well.

Perhaps all you need is to switch the props and motor rotation.

Oh well, it is just a suggestion. Would like to see what others think.

Jay

[Greg Hiltz]

Hi;
A few years ago, I was asked to finish off and power a Rotterdam kit for a gentleman in our club, and esp since this guy was sort-of-rough with his handling of previous boats, I was determined to make it rugged. I did not even consider using the stock Kort nozzles, being plastic, or the stock white-metal props, so I turned a set from brass, 2.25" ID, and used a set of 60mm X 4blade Rivabo props with the outer tips spun off on my lathe to look right in the new nozzles. I used a set of Robbe 4107or8? 3:1 gear motors for power, through a pair of ESC's, from a 12v7AH gel-cell. Needless to say, it performed awesome, and under power, would dig a sweet hole midship, and handle great, doing a water ballet with the throttles fwd/rev, you could literally write your name in the water. She ran faster than a PO'd duck, if that's any measure of speed.
If you can't access a set of custom brass nozzles, Robbe sells one, with rudder, that fits over the shaft tube for centering, which would be a close match. I would probably use the Robbe 5:1 gear motor instead of the 3:1, make for more torque, less amp draw, and good realistic speed.
-Hope this helps.
Greg Hiltz

[cos918]

hi there. The plastic props that came with the kit are rubbish and only fit for the bin. The faster they spin/turn the blades lose there pitch. What you need is a pair of decent 4 bladed kort nozzel props . They will make all the diffrence. they did on mine. If i was you i give simion at prop shop a call . What he dont know about pops ant wort knowing as he cast the props him self. here a photo of my smit and happy hunter with his props.
john

http://www.swangroup.co.uk/propshop.php

[wrk134]

You guy's and gal's are the best!

I'm amazed at the skills and keen eyes you all have. I admire a lot of the work I see here. And the help you give is second to none. You should give your self a collective pat on the back, while I give you a big THANK YOU for your help.

You = All the Dock Talk & Scale Boat gang.

I never would have thought, I had the props on the wrong sides and turning the wrong way. Hmm...maybe thats why reverse dosen't work well either.