hi mate.
that joint angle on the bottom end of prop shaft seems a little sharp?
not vibrations?
a good place for 'flexi shaft'.
regards
don

Is it a  universal joint that you are using at the strut shaft and prop shaft joint.
You seem to have made complete use of your new Lathe.

@ Sunk?
You are right sir, Flexible shaft is the correct option, but couldn't get right kind of flexi shaft, so made this one with U joint. The stuffing tube is extended upto the U-joint & the inner end fixed in a clamp. There is lot of vibration in off water mode, on water it will be somewhat silent.

@Srikant,
Now it has became a desktop lathe, with a lot of other related tools & accessories like Taps, Dies, cuttings tools, drill bit etc.

hi mate.
another problem solved then  

perhaps if you could alter the angle of the prop you may find a smaller angel with less vibs but still good drive responce.
the trouble with vibrations is that they do damage.

oh the beauty of self build etc
regards
don

Don Sir,
I can't reduce the angle of propeller or fix the propeller at the end of stuffing tube because the overall thrust will be wasted lifting the boat instead of pushing (which inturn may cause the bow dipping problems).  Today I tested the boat, there was no vibration, but still have to make some modification with drive system.

(a) As I am using a motor of 1200 KV, I though a propeller about 6 cm. dia will be fine, later looking at the vibration (off water) I reduced the size to 4 cm. Presently it is drawing less than 20 Amps where the motor is capable of 40 Amps & esc 60 Amps. So I have to increase size of prop. to 6 cm dia.

(b) the 2nd mistake was – I fixed all the drive system with out checking the water line mark, I miscalculated the water line depth, so upper end of the stuffing tube is falling just at the W/L mark, on high speed small amount of water is leaking.

Previously I was thinking this motor & esc may not be sufficient for this boat, but it is quite fine.

hi Sb_Maharana
just because the motor does not draw max amps it does not mean you have to put a bigger prop on............ the esc will take more amps but if the boat is performing well then I would leave the smaller prop and enjoy more water time per battery
I understand the lift/push principle of angle of prop,I was just asking if you were able to alter the prop to shaft angle to minimize vibes......but it seems all is well in the water and under load.  
enjoy

regards
don

Ok Sir, I am trying to upload the video tonight, so that you can judge everything more clearly, and suggest for a better performance.

some more photographs

video:

hi Sb_Maharana
Well.............. that is one superb boat.
  that must be 'at least' equal to or perhaps better than an expensive store bought boat.
well done .very worth the effort put into this build.

as for the power system, it looks as though  you are right and a bigger prop would give the speed to match the looks of this superb craft.
you may need to bring the battery forward to stop 'skipping' at speed

regards
don

Brilliant Build again

Don Sir,
There was skipping at higher speed, I thought to place the battery at the bow end but servo & esc wires are not long enough to do so. Today I emptied the hull completely to rearrange & fix everything correctly:
(1)   I am replacing previous stuffing tube with a new one of 1 ½" longer and positioning it at a lesser angle.
(2)   Pointed / tapered both ends of stuffing tube so that driving shafts fits correctly, will grease it well to prevent water leakage.
(3)   The major problem was the handmade propeller which was creating lot of turbulence. I mean the pitch efficiency. I am planning a get good readymade propeller.  

Quote from: Rooster on June 27, 2011, 09:44:32 AM
Brilliant Build again

Thanks Srikant,
still some modification & Improvisation left.

hi mate.
it does not take much to make a 'light' boat skip at speed try battery around the back half of the outboard stabilizers [ middleish]
regards
don