Sprint Cat 40 to brushless

[Racerscott69]

Been around RC for years..... new to electric. I've owned this boat for 20 years. Looking to convert to brushless. The boat is currently powered by a 7.5cc OPS. I've looked through the forums and to tell you the truth, I'm a little overwhelmed. I have brushless electric trucks. So, I'm not completely unfamiliar with the concept. Just looking for some direction on mounting, motor collet, etc. Thanks in advance.

[Fluid]

I've been running a SprintCat 40/60 (which is the hull I believe you mean) for a number of years, mostly set up with a Neu 1527/1Y motor, 6S2P packs and the usual hardware. Below are some photos of what I've done with it. This is a serious race setup, you can spend less money for a good sport setup using less costly motor, ESC and packs. What are you rgoals for the boat in terms of speed, run time, type of running, budget?

fw87d2.jpg20sfvo.jpgLayout111.jpg

[Flying Scotsman]

Welcome...a few questions...existing hardware....what speed and run time do you desire...what budget do you have in mind for..batteries, ESC, motor, charger etc....a picture of existing hull, hardware would help...what rc radio do you currently have?

EDIT

Jay, you are fast on the keyboard!!!

Douggie

[Racerscott69]

Sorry, I didn't give much information in my first post. The boat is an aeromarine sprint cat 40. Dubro strut and rudder, prather 245 prop. Looking for similar speed and runtime to the current nitro motor.... 40 mph, 8-10 minutes runtime. I have a good selection of LiPo batteries from my trucks, 2s and 3s, most are more than 5000ah. I'm looking for a starting point on electronics. I have a "water resistant" 130 amp esc and 1850kv motor for an 1/8 scale truck. Will this motor work if I add a cooling jacket? What kind of mount? Is there a collet to go from the motor to the existing flex? Or do I need to change the flexshaft? Thanks in advance. Scott

[Fluid]

Okay, the SprintCat 40 is 29" long, is that the hull you have? If so, then to get the longer run time get a 4-pole brushless motor 40mm in diameter and at least 75mm long with a Kv around 1100 running two 3S packs wired 6S. Get a marine water-cooled controller or it will over heat in over 5 minutes. With a P230 prop that will give you speeds around 40 mph and run times in excess of 6 minutes with a well setup hull.

If it is the larger 34.5" hull, then use a larger motor (40mm x 90+mm) with a Kv closer to 900. With the P245 and four 3S packs wired 6S2P you should get similar performance.

You can use the existing cable and stuffing tube, OSEW sells collets to go from motor to cable. You will need to toss the radio box and make the entire hull waterproof....either a new hatch or filling the holes on the current one. Water and FE parts do not mix.



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[Rumdog]

Actually, Jay, the Sprintcat .40/.60 IS the 34.5" hull..

[Fluid]

Actually, the 29" hull was called the 20/40 and the 34.5" hull the 40/60. The 42" hull was called the 60/80, there was always engine size overlap. Plenty of nitro racers put the .40s and .45s in the small hull for fun...


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[madmikepags]

1850kv is a little high for a 6s setup and I would use a higher amp speedo., jay (Fluid) outlined the perfect setup for this hull, Neu 1527/1Y 6s2p 10,000 mah a 450/2 prop will put you in the mid to high 50's for 4+ minutes, the rest is up to you with hull setup and propwork, my SC.40 which has won 5 national titles in Q offshore runs this setup, I use either a 450 or 452 (modded) depending on conditions and competition. I can get over 5 minutes of full race runtime with this setup on 6s 10'000 mah. with a 445-447 you will get good speeds and longer runtimes.

[Racerscott69]

Nice. It was running around 50 on nitro. Any recommendations on a mount? Is the motor mentioned comparable in size to an 1/8 scale motor on a truck? Had any experience with the vxl-6s that comes with a traxxas spartan?

[Racerscott69]

I measured my hull. It's 35", so it's the 40/60. Thanks for the help.

[madmikepags]

the neu 1527 is rated at 2500 watts but probably is closer to 4000 it is way underrated, it is much more powerful than the traxxas motor. My experience is with NEU motors, the setup outlined by fluid is perfect for this boat. if you have rails then a williams rail mount is recommended, by southriverrc.com

[madmikepags]

and no the 1527 is probably over an inch longer than the truck motor.

[Racerscott69]

Thanks madmike. I like the rail mounts. It's nice to have help from guys who have already been around the block. I poked around online for the neu1527. Most places listed it as unavailable. Any info on locating one or something similar?

[jcald2000]

Call them

http://www.neumotors.com/Site/Motor_Price_List.html

[T.S.Davis]

The 1530/1y works well too with a bit more prop.

Steve at OSE can get either for you as fast as anyone else. His prices are usually pretty fair. Plus he's one of us so to speak. RC addict.