What Motor To Use On A 36" SprintCat?

[mm123521]

RumDog: This is aimed at you.

I was looking at your posts on "Ultra Fast Options" thread.
I imediatly ordered a 36" SprintCat with carbon reenforcement and no rails and the "Classic" hatch.

Now what do I need to do to get 70+ MPH like your twin?
Can I get it with a single NEU / Castle 1717 @ 1600KV and 6S ?
OR
Should I twin this thing?

Please advise on motors.

Please help!!

I wanna run 6S so the speed controlers are cheep.
I have a machine shop in the basement so I can build rudders, struts, cooling jackets, etc. So the extra $$ for twin hardware does not count, for me.

THANKS!!!
Mark

[FighterCat57]

1520 or 1717 :rockon2:

OR... twin 1717's (http://forums.offshoreelectrics.com/showthread.php?t=17954&page=2).


Note the air version 1717's would run cooler, but have a 6mm shaft. The 1717 cooling cans do not fit in the sponsons.

[Rumdog]

Fot 70 plus, and a single motor you'll need more than 6s.
Twin Neu/Castle 1515's on 5s each will do it, or 1520's on 6s.
A neu 1527 on 8-10s may also get you to 70 mph.

[mm123521]

Ok Rum & Fighter:

I have a 12S1p and Leopard 5692 setup (in another boat) that I could install.

Of course it will be a single motor.
It is an extra pound of motor weight.
I wonder if the extra weight & power will mess up the good handling??

Mark

[Rumdog]

Nope. I've ran mine with twin 1520's each on 6s. That's more weight total than the 5692. Go for it!

[mm123521]

RumDog:
TNX for the advice!
Thats what I'am gonna do!
Power wont be an issue with the 5694 and I allready own it.

I ammended the SprintCat order to include 4" rails.


Thanks!
Mark (near Chicago)

[Rich]

RumDog:
TNX for the advice!
Thats what I'am gonna do!
Power wont be an issue with the 5694 and I allready own it.

I ammended the SprintCat order to include 4" rails.


Thanks!
Mark (near Chicago)

How is the 5694? I was looking to build a boat with one?

[mm123521]

Rich:

That was my first electric boat build,

http://forums.offshoreelectrics.com/showthread.php?t=18888

Its a 41 inch homebuilt hull (thin plywood over foam).
I had it out for its first run last week. It was only 2 minutes of running.
It looked FAST!
It had killer acceleration.
Boat is 12 pounds All up, RTR weight.
Running 12S1P 5000 MAH.
Motor is Leopard 5692, 730 KV. I home built a full water jacket for the motor.
It turns 32000 RPM.
Using a X452 prop & at 20% slip, it should go 69 MPH - but I dont have anything to verify that speed.
ESC is a castle ICE 160 that I water cooled.

Will run it again this weekend and let you know.

Mark

[Rich]

Excellent Mark! That would be great! You live near Chicago? Me too! I live in northern Illinois, by the Chain of lakes. Thats where I run my mean machine. Anyway let me know, I was thinking of getting a mono for that motor when I get the cash.

[mm123521]

Rich:

South burbs around 185th and halsted.
I think we are about 70 miles apart.

Mark

[Rich]

Thats a bit of difference :)

[mm123521]

Rich:
Not that far! Maybe we get together in the summer.

Fighter and Rumdog:

OK, I been thinking about this all day.
I have ordered a pair of Neu/Castle 1518 motors (1800 kv).
From what you did Rumdog and your pictures Fighter, they should fit in the sponsoon.
They are just a little longer than your 1515 motors, Rumdog and smaller than Fighter's 1717 motors.
At 6S and 1800 KV they should give similar RPM as you are using (about 40,000).
Then, it looks like a x442 should yield about 70 MPH, and a X447 should yield 79 MPH.

I also ordered 3 cheep as#ed ESC,s :

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14500

I'll water cool them and see how they work.
At $29 each, you cant lose too much on the experiment.

Now I need advice on the flex cables and struts.
Will 3/16 inch cables be big enough??
and how do you get enough strut movement to allow adjustment and still keep the hull watertight?


Thanks!
Mark

[Rich]

Maybe we could! As for the cables I would say the 3/16 would be big enough just my 2 cents

[keithbradley]

Rich:
Not that far! Maybe we get together in the summer.

Fighter and Rumdog:

OK, I been thinking about this all day.
I have ordered a pair of Neu/Castle 1518 motors (1800 kv).
From what you did Rumdog and your pictures Fighter, they should fit in the sponsoon.
They are just a little longer than your 1515 motors, Rumdog and smaller than Fighter's 1717 motors.
At 6S and 1800 KV they should give similar RPM as you are using (about 40,000).
Then, it looks like a x442 should yield about 70 MPH, and a X447 should yield 79 MPH.

I also ordered 3 cheep as#ed ESC,s :

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14500

I'll water cool them and see how they work.
At $29 each, you cant lose too much on the experiment.

Now I need advice on the flex cables and struts.
Will 3/16 inch cables be big enough??
and how do you get enough strut movement to allow adjustment and still keep the hull watertight?


Thanks!
Mark

You may need a pistix with those escs...not sure.

[mm123521]

keithbradley:

What is a pistix?
A programming card?

Mark

[keithbradley]

http://www.offshoreelectrics.com/proddetail.php?prod=msw-pistix&cat=136

Its sometimes needed to use an airplane or helicopter esc with a pistol remote.

[mm123521]

OK , I see .

Thanks!