Another Boat

[harry smith 1Participant @harrysmith1]

I purchase a Sea Commander from a club member, only used a few times.

He decided it was not his type of vessel .

I have replaced the 2836-750 motor with a 3548-1100, changed the prop shaft to a dog drive and replaced the 3 blade 50mm prop for a 40mm 2 blade prop.

Also installing an oil tube to the drive tube.

[harry smith 1Participant @harrysmith1]

[ashley needhamParticipant @ashleyneedham69188]

Question…why change to dog drive?

I read a good techy article from some years ago in a boat mag (By the proprioter of the prop shop) saying an X pitch prop would just about drive anything,, as a general "all purpose fast prop"

The change from a 28mm motor to a 35mm one is quite a percentage increase, what size is the boat??? Looks a bit big for the fitment of a 28mm motor to start with and a 50mm prop on this sized motor would be a bit large, even at the 750Kv (assuming this is what the figures mean).

I have a P50 being driven by a 35mm motor at 1300Kv on one boat and it drives it effortlessly (Graupner hydro prop).

Ashley

[harry smith 1Participant @harrysmith1]

Hi Ashley

It's a 34 inch Sea Commander, the 2836 750kv was only 210 watts and the 50mm 3 blade prop was over heating the motor.

The motor alignment was a bit out, so I realigned the motor with my mate's alignment tool(my design) and replaced the red universal joint with a solid 5mm to 4mm coupling.

As I have two D3548/4 in the workshop, I used one of these as the 3648 1450 kv 1600 watts(yes I have two of these also) are too powerful!!!!

I changed to dog drive as more props available and Hobbyking had packs of five for $1.79 AU (add about 50% exchange rate and postage)in 40-45mm size, both left and right hand.

I bought one prop from the local hobby shop $32 and it was plastic!!!!!

[ashley needhamParticipant @ashleyneedham69188]

Harry, great answers. Explains it all !! Ashley

[harry smith 1Participant @harrysmith1]

Hi All

I fibreglass resin the insides of the boat and fully installed the drive line with lube.

Reinstalled the servo and cut down rudder throw to about 20%(45% was a bit too much).

Only up the power by 700 watts and the revs by about 6700rpm.

Installed the IA6 receiver and 60 Amp car ESC.

Test run motor to get prop turning the right way and check the rudder for left equals left etc.

But the middle of winter and it's Tasmania and 9 degrees(about 30 knot winds),

May have just work on other projects like the Tipsea, Sea Raven Hydroplane and Coline.

Can-a-bus

[harry smith 1Participant @harrysmith1]

Hi All

Two test days.

The first run the rudder offset was too great and the balance point was a little to aft.

Replaced the 3700mah 3S with a 5800mah 3S and moved it to the side to offset the prop torque.

Decrease the rudder offset a bit.

Second run dead straight run and the bow stop popping up and down.

The D3548/4 1100kv a lot quieter than the 3639 1100kv.

I used the same setup on the ESC as I used on the Sea Hornet.

The low speed worked great and the reverse was very usable with out to much reverse speed.

At full speed she sat back with the water spray exiting about the start of the aft cabin.

I have the cockpit seats out of the boat and remodelling these fit two 100mm figures onto the seats.

I fitted a big AUSSIE flag to the stern cut from a silly umbrella hat.

I have a few props to test on the boat, but, I am very happy with the start setup.

[harry smith 1Participant @harrysmith1]

Hi All

Finished remodelling the seats added the crew(hang on for dear life) and rename the boat SPARKY.

This was our second last Pom dog's name.

I tested a 42mm 2 blade prop with on increase in speed, so plan B a 3 blade 37mm or a 45mm 2 blade.

I missed a duck by 6 inches today, the bugger pulled out the flaps and boot scooted up into the air.

[harry smith 1Participant @harrysmith1]

Hi All

Added two sets of 10mm square magnets under the floor, so as to get rid of that screw hole in the floor.

I used two magnets together at each end, the dam things are so strong I can lift the boat minus the battery.

I think I should have used two not four and they are only chap one's from Hobbyking.

[harry smith 1Participant @harrysmith1]

Hi All

Four props and back to the original prop!!!

My mate's Spearfish is a little slower, but I have 110 watts more grunt!!

Planning a prebuilt later, mainly the keel is total square at the prop end and the spray rails do not go all the way to the bow.

Basically a good boat but requires a bit more finishing without going show room but weekend user!!!

Harry

[ashley needhamParticipant @ashleyneedham69188]

It is a minefield buying magnets, some of the small ones are so strong they simply pull out their glued surfaces.

I am using jewellery necklace clasp magnets on proj N05, these as well strong enough without being super. I have used 4 but think I may cut two out. However depends on how much hold you want on the hatch (or whatever).

I need to fit some magnets to the removable deck hatch on the carrier as this warps a bit in the sun/cold etc etc. Another job to do later on.

Ashley

[harry smith 1Participant @harrysmith1]

Hi Ashley

I used 8 10mm round magnets on the Tipsea because the hatch is 200 x 210mm.

Harry

[harry smith 1Participant @harrysmith1]

Hi All

I was look at the Sea Commander today and the windscreen with the triangle sides did not look right.

The front is OK but does not go to the outer edges of the sides.

The triangle sides does not match the side profile of the cabin.

So I have started making a new windscreen.

Adding a few pics to see what you guys think!!!

[harry smith 1Participant @harrysmith1]

Finally vanished the surround for the front of the windscreen.

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