Test Boat

[harry smith 1Participant @harrysmith1]

Hi All

I had an old 33" fibreglass hull(beam 11 and 1/4&quot sleeping under the house for 35 years.

So grandson wanted a boat, so , I said I would build him one.

A bit of a basher boat and also a test boat for motors and props.

The boat weighs in at 7lbs with a 5800mah 3s battery.

I started with a 3639-1100kv motor with a car ESC 60A.

Prop 38mm x 1.4 pitch (HK-2B01x38).

Current speed sits up on the plane, very stable.

The rudder was a bit small and I set it to low on the stern, so I added a home made fixed trim tab extension today(see my ABLUM (blue boat).

Bit of an experiment , hope to test it at the weekend!!!!!!

I am waiting for my new Turnigy IA6B V2 receiver to go with the temperature, voltage and optical sensors.

These feed the information straight back to the transmitter so to get this info in run time will help me work out temperature, revs and voltage loading.

So interesting to match props to motor will be less of a guess and safer than frying motors and ESC's.

I have not fried one, so I had help from club members and forums.

[harry smith 1Participant @harrysmith1]

20 degree deep vee

[harry smith 1Participant @harrysmith1]

Hi All

I testing the trim tab setup today, it made the boat bury the bow on the turns.

I am raising rear of the tabs up and trimming a bit of the sizes.

Ye it's not the weekend, but, I had to pickup the wife and a beach was only 1/2 a km out of the way!!

The car auto pilot was ON!!!

[ashley needhamParticipant @ashleyneedham69188]

Harry. Picture ??? Ashley

[harry smith 1Participant @harrysmith1]

Blue Boat pictures added today

[Bob Abell 2Participant @bobabell2]

Harry……I hope you don't mind

I've posted one of your photos, to help you out

Bob

[ashley needhamParticipant @ashleyneedham69188]

Harry. A functional project. you are no doubt aware that the snazzy rudder is more suited for a hydro/surface piercing prop arrangement, but absolutely no reason not to use it as you are.

Going with an underwater prop is also the recipe for success, as getting the shaft in the right place for surface operation is very difficult, but rewarding when it works.

You have by the looks of it a hydro prop, again will work ok underwater, but a change might be advatageous, possibly before trying a different motor. If it is a dog drive then this might be tricky, however a bit of file and junior hacksaw work can make X or S pitch two blade plastic props fit a treat!

Ashley

[harry smith 1Participant @harrysmith1]

Hi Ashley

The prop is a Hobbyking HK_2B01x38(dog drive) from my other boat as the 3639-1100kv motor.

As for the under water prop setup it was from the original hole drive line setup for the boat years ago.

The young chaps(grumpy old men now days) got it right to start with!!!!

The setup under water gives a more constant drive in rough conditions,but, in flat conditions the surface drive is faster.

The boat runs very well on this setup for it's first run and other than the rudder setup I was very happy with the boat balance and ride.

The large spray rails work beautifully so if I get around to building the Swordsman Mark H she will have large spray rails.

The mount motor is a Hobbyking 100 mm wide aluminium which with the slotted motor mount holes will hold smaller and larger motors than the 36mm.

Also a very good heat sink, I run the boat hard for about 1/2 a hour and the motor was only warm.

As for the rudder well it was in the spare parts.

Next to test when it arrives is a D3548/4-1100kv 910watts which will handle 3-5S Lipo batteries.

I will go 4S as the ESC handles 4S(4000rpm added) but not 5S.

I do not wish to over power the boat for the grandson, but, I have a B36.50-07S 5000kv 1100watt 2-3S motor to test.

I worked out how to insert a photo!!!

[harry smith 1Participant @harrysmith1]

I changed the prop to a 3 blade 37mm x 1.4 pitch(plastic) and increased the top end speed.

I changed the battery from 3S to 4S to run on the 3639-1100kv motor.

These motors are not rated to run on 4S, but, I did!!!!

Run for about 1/2 a hour and the motor was only warm with NO water cooling.

I ordered a 3 bladed metal prop from Hobbyking(code 215000032-0)$11.98 AU.

The plastic one was $33.50 AU at the local hobby shop!!!!!!!

The only problem with Hobbyking is boating stuff is International and no spare parts for half there boats.

Like the Sprint outboard units(no flex. drive shafts.

Working out their website is an ART!!!

[ashley needhamParticipant @ashleyneedham69188]

harry, not sure about the "not wishing to overpower this boat for my grandson" bit.!

With this sort of gear in you could almost go racing. To my mind a grandson boat this size would go plenty fast enough with an MFA 850 in it …

Ashley

[Paul TParticipant @pault84577]

Ashley

"not wishing to overpower this boat for my grandson"

Some time I will have to introduce you to my 8 year old grandson lol

Paul

[Dave MilbournParticipant @davemilbourn48782]

Lol? I thought his name was Ryan…………………

[Paul TParticipant @pault84577]

Ho Ho

He will think that's funny.

None of my boats ever go fast enough for Ryan even the little plastic one that I 'supercharged' a few years ago isn't fast enough.

[harry smith 1Participant @harrysmith1]

Hi Ashley and Paul

My grandson is 16, I learnt him to drive a ride on lawn mower at 10.

He is learning to drive at present(that's his father's job).

Show him a video today of the boat running.

He cannot wait for the weekend(rain hail storm).

The only thing is the tide(low tide or water).

[harry smith 1Participant @harrysmith1]

Hi Ashley

My grandson is going on 17.

Showed him a video clip of the boat going, we are going boating this weekend.

He is a good sheerer, I learnt him to drive a Rover Ride on Mower at 10.

[harry smith 1Participant @harrysmith1]

My grandson is going onto 17 what's the problem!!!

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