Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[seahunt56]

Hi Everyone,
 I am new here, and have gotten a lot of info off the forum.  I am in the process of starting a new tug build from scratch.  My tug is going to be about 15 inch long by 9 inch wide.  I am planing on using a steerable kort nozzle with a 60 mm prop.  My question is, is there specific props for kort nozzles?  Also, what about pitch?  Would I be better with a shallow pitch for more motor rpm, or high pitch and less rpm?  I not picked out a motor yet?  Thanks for the help.  Steve 

[craftysod]

Hi Steve,
Welcome to the forum,to answer one of your questions,
There are specific props for kort knozzles,they have flat tips on them instead of rounded ends.
With regards to pitch,it depends on the motor your using and what do you want to do with the boat,potter about or tug towing.
Hope some of that helps
Mark

[seahunt56]

Thanks for the info Mark,   I guess reguarding the pitch of the prop, I want the tug to move at a scale speed through the water.  I do plan on makeing a barge of some kind, but i do not think I will be getting into any kind of pulling compitation.    Does any one know who sells props for kort nozzles?
  My little tug is of my own design kind of.  I like the look of the BRATT tug so it will be something along thoes lines.  Latest pictures are of the plug ready for glass.  It will have a keel, and fender along the lines of the BRATT.  Hope to get some glass on it in the next few days.

[plattypus-oz]

Looking good that model. Good motors to use are found in cars to circulate the air and draw about 1 amp. and are of good quality. If you use a 20 amp/hour battery then you get 20 hours run time.  Smaller props need to run at a higher rpm. to move the same amount of water, as a larger one running at a slower speed. I use a three bladed prop 3" diameter with a 3.5 to 1 reduction and it seems to work OK. The smaller prop doesn't need the reduction gear box.  Hope this helps. Cheers

[DickyD]

    Does any one know who sells props for kort nozzles?
 

http://www.cornwallmodelboats.co.uk/acatalog/R149-05.html

[seahunt56]

  I was able to get some glass on the plug yesterday, and today I sanded it down and pulled the plug out of the inside.  Inside is perfect, and outside needs a little filler yet for some low spots.  It ended up being 16" x 9".  I am going to down size to a 50mm prop in a steerable kort.  The fan motors that I have replaced in my cars over the years seem to be 3 to 4 inch in diameter.  That might be a bit large for my little tug.  Still would need to get a battery and electronics in there too.  Going to add a couple pictures from todays work.  First one has a line on the side which is somewhere about where I will cut down the sides and back.  Second one is an inside view. 
  So far, so good.  Steve

[plattypus-oz]

Check out the Japanese cars motors they are smaller and better quality. Try from a Dihatsu. Cheers

[seahunt56]

  I have planned on ordering a new motor.  Not many auto junk yards around in SW Florida that let you walk around and pull your own parts.  To much of a liability I guess.
So while i am waiting for my Kort Nozzle to arrive, which I need to figure out the length of the prop shaft, and what size keel I will need to house  the prop shaft, I started work on the fendering, got a stand made of Cherry, and cut the upper sides to shape.  Have to figure out what I will need to do to hold the flooring but still leave enough room to get in to work on stuff.  Going to start working on the pilot house also.