Hello zmajcek

If the propellor shaft is 4mm, does the propellor need to be threaded (M4) so it screws on directly?

If so, Graupner makes a wide range of plastic propellors for 4mm shafts which would be suitable - see below for examples:

http://www.cornwallmodelboats.co.uk/...submerged.html

At the other end, 4mm is not a standard size for motors - standard motors have 3.2mm or 5mm shafts, so you will need a suitable coupler or universal joint if the prop shaft has not already been reduced to 3.2mm.

Will you buy your parts from a local hobby shop or by the internet? If by internet, do you know which company (website)? - maybe I can make some more suggestions for motor and speed controller for you.


By the way, it is not typical to have two link rods from the servo to the rudder. Unless the rod spacing on the servo arms and the rudder arms are exactly the same length the two rods will fight each other as the rudder turns and could damage the servo - you only need one of them sop take one off it the steering will work better.

-yellow-bird