SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Sep 07, 2012, 01:35 AM
Registered User
Joined Jun 2012
73 Posts
Question
A better prop for Exceed RC (Dragon Boat) Shark 650 ep?

Hi!

Recently I have got an Exceed RC Shark 650 ep for myself and my little daughter. Here is the link. http://www.nitrorcx.com/99b-10021-650-ep-artr.html It goes in decent speed.

But I am wondering if a better prop pushes it a little faster. If any experienced boaters can give me advices, it will be greatly appreciated!

Thank you for your attention!
savage0102 is offline Find More Posts by savage0102
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 08, 2012, 09:29 AM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,054 Posts
Hi Savage,

If you can find the same prop in metal, you'll eliminate the flex of the stock prop, giving you a better performance.

In view of the small stock motor, I'd be very careful to use bigger props, as the stock motor has limited torque, bogging it down too much will result in smoke...

Check this thread, where Jordan gets a metal replacement for his boat, maybe your size is also available:
http://www.rcgroups.com/forums/showthread.php?t=1717604

Regards, Jan.
pompebled is offline Find More Posts by pompebled
Reply With Quote
Old Sep 09, 2012, 07:29 PM
Registered User
Joined Jun 2012
73 Posts
Hi, Jan! Thank you very much for your input! What are the benefits of 3 blade props? 2 blade or 3 blade prop, which one is better? Thank you again!
savage0102 is offline Find More Posts by savage0102
Reply With Quote
Old Sep 09, 2012, 08:38 PM
Registered User
Joined Sep 2012
6 Posts
2 blade speed up faster than 3 blade. But 3 blade offer more torque than 2 blade. It your boat is original motor 700W and 75A ESC. Try 438 2 blade (CNC/Bass).
Sure if you upgrade your ESC to 80 / 90A. It will faster also.
cablecar is offline Find More Posts by cablecar
Reply With Quote
Old Sep 10, 2012, 12:24 AM
Registered User
Joined Jun 2012
73 Posts
Hi, Cablecar!

Thank you for your response!

My boat is the stock setup. For a while, my little daughter and I will run it with the stock setup, so that we are wondering which prop would be better with the stock motor & ESC than the stock prop.

Is this a good one? Here is the link. http://www.hobbyking.com/hobbyking/s..._P1_4_M4_.html

I want to figure out the shaft hole diameter of this prop, but it says "M4".What does this mean? Does this need balancing and sharpening?

If you don't mind, could I ask one more question, please? Does a 2 blade prop with a little more pitch but in the same diameter as the stock 3 blade prop hurt the ESC & the motor?

Thank you again for your attention!
savage0102 is offline Find More Posts by savage0102
Last edited by savage0102; Sep 10, 2012 at 01:13 AM.
Reply With Quote
Old Sep 10, 2012, 03:01 AM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,054 Posts
Hi Savage,

Basically a three blade can be smaller to have the same blade surface as a two blade, depending on the propdesign, a threeblade generally draws slightly more current in my experience.

Usually M4 means the prop is meant for an M4 threaded shaft, but twith the Chinese, you never know until the prop arrives at your doorstep and you can see for yourself...

What diameter shaft does your boat have? (the smooth section).

Regards, Jan.
pompebled is offline Find More Posts by pompebled
Reply With Quote
Old Sep 10, 2012, 11:39 PM
Registered User
Joined Jun 2012
73 Posts
Hi, Jan! Thank you very much for your advices! I always appreciate your kind advices!

The shaft diameter is 4.0 mm.

Could I ask a question, please, as usual? Can this Shark 650 ep's stock motor & ESC handle 3-cell li-po with a smaller prop? If so, what prop would be good? If it is available from Hobby King, it will be convinient for me, since I am going to order some things from them. If you know any proper smaller prop, please let me know (But I doubt that it can handle 3-cell with a smaller prop. Anyway, you can give an advice.)

Once again, thank you very much for your attention!
savage0102 is offline Find More Posts by savage0102
Reply With Quote
Old Sep 11, 2012, 03:06 AM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,054 Posts
Hui Savage,

With 4120Kv, it's a 'typical' 2S set-up giving you 30.000 rpm unloaded.

On 3S that would result in 45.000rpm unloaded, which is rather hard on the bearings of both motor and drivetrain.
Also metal props would be mandatory, as the plastic and carbon filled ones will shed their blades...

The 36 mm prop if fitting for the hull size, going smaller will result in an 'endless' run untill the boat gets on the plane...

Not my favourite option.

A metal 36 mm threeblade, or a slightly larger two blade will be more efficient.
Something like this:
http://www.hobbyking.com/hobbyking/s..._1pc_bag_.html

Regards, Jan.
pompebled is offline Find More Posts by pompebled
Last edited by pompebled; Sep 12, 2012 at 11:21 AM. Reason: Addition.
Reply With Quote
Old Sep 12, 2012, 10:53 AM
Registered User
Joined Jun 2012
73 Posts
Thank you very much for your answer, Jan!

You said, "A metal 36 mm threeblade, or a slightly larger two blade will be more efficient.
Something like this:
http://www.hobbyking.com/hobbyking/s..._1pc_bag_.html"

Is this for 2S or 3S?

Thank you very much again for your attention!

Savage
savage0102 is offline Find More Posts by savage0102
Last edited by savage0102; Sep 13, 2012 at 01:55 AM.
Reply With Quote
Old Sep 13, 2012, 01:56 AM
Registered User
Joined Jun 2012
73 Posts
Oh, could I ask one more question, please?

The boat turns to the right very well, but turning left is not easy. Turning left is bouncy and often it flips over. Isn't there any way to improve the left hand turn? Thank you!
savage0102 is offline Find More Posts by savage0102
Reply With Quote
Old Sep 13, 2012, 02:58 AM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,054 Posts
Hi Savage,

I can't get your link to work...

A single shaft boat will always have a favourite direction of turning well, with a counterclockwise turning prop (seen from the rear) this is the right hand turn.

This is a result of the propwalk.
Left hand turns need to be wide and when it has to be a narrow turn, throttle down first, so there's more hull in the water.

Generally, left hand turns at speed are not done, when your boat runs over 30 mph.

Regards, Jan.
pompebled is offline Find More Posts by pompebled
Reply With Quote
Old Sep 13, 2012, 06:41 PM
Registered User
Joined Jun 2012
73 Posts
Hi, Jan!

Thank you for your answer again and sorry for asking many questions!

You said, "A metal 36 mm threeblade, or a slightly larger two blade will be more efficient.
Something like this:
http://www.hobbyking.com/hobbyking/s..._1pc_bag_.html"

Is this prop for 3S or 2S? Thank you again!
savage0102 is offline Find More Posts by savage0102
Reply With Quote
Old Sep 14, 2012, 08:42 AM
Boaters are nice people.
Sneek, Netherlands.
Joined May 2004
5,054 Posts
Hi Savage,

The threeblade 36 mm metal prop with a 4 mm bore from my link is intended as replacement for the stock prop running in stock 2S set-up.

If you want to run that prop on that hull on 3S, you'll need another motor with a lower Kv
Something like 2700 - 2900Kv.
This motor is already on the edge, as it's a 4-pole with a lot more torque:
http://www.hobbyhot.com/LEOPARD-RC-M...ess-Motor.html

This motor will most certainly cause torque issues and requires a sensitive triggerfinger:
http://www.hobbyhot.com/LEOPARD-Boat...ess-Motor.html

Regards, Jan.
pompebled is offline Find More Posts by pompebled
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Exceed "Dragon Snap" 720 EP performance questions - MINI REVIEW JGuilty13 Racing Boats - Electric 105 Sep 23, 2014 03:53 PM
Discussion Dragon Boats, Shark Mono 1 ep won't work when battery is connected _Hammer_ Racing Boats - Electric 14 Jan 11, 2012 10:44 PM
Discussion Prop Adapter for Exceed-RC Motors? theleetbeagle HobbyPartz.com 5 Oct 18, 2011 11:22 AM
Wanted prop adapter for exceed rc monster 32 schnitzelwagen Aircraft - Electric - Power Systems (FS/W) 0 May 17, 2011 11:01 PM
Discussion Exceed RC Dragon Fly 20 - Smoked the Receiver elight50 Mini Helis 0 Aug 13, 2006 03:53 PM