Prop questions:help

[b.mcdaniel.2009]

Will someone please explain rc boat props to me. just got into the rc boats and was wondering what size my prop is 1.6x2.5 Formula fastech(in m.m.)?, and if i want more top speed what should i look for. Please explain if i want a bigger or smaller pitch or diameter to achieve more speed.THANKS





I know that own my real boat the higher the pitch the more top end you will have. but lower rpm's.

[b.mcdaniel.2009]

anyone?

[dana]

theres alot to explain. theres alot of info on these forums. my suggestion would be an octura x640 or x642 for that boat. but someone else might have a better suggestion. from what i've gathered, lower rpm (or kv ) motors have more torque and like props with more pitch, and high rpm motors have less torque and like a lower pitch prop. ex. my old proboat had 1500 kv motor so i used a x640 ( 1.6 ) pitch, my aquacraft has 2030 kv and i use x440 ( 1.4 pitch ). as far and diameter i think a good starting point is to go about the same or a tad higher than stock and monitor temps.if temps are good you can move up to a higher diameter. im sure there are more experienced boaters on here that could be more informative but thats my 2 cents. in any case a good copper prop is gonna give you more speed than a plastic prop any day

[BHChieftain]

My son is running a x442 right now and that works great, but we are going to move up to x642 shortly (this seems to be the most recommended prop with this motor/hull).

Chief

[b.mcdaniel.2009]

how do i figure out the total demensions of a prop. Is there some kind of equation?

[dana]

well 1.6 is the pitch of your prop and 2.5 is the diameter.

[lectriglide]

well 1.6 is the pitch of your prop and 2.5 is the diameter.

That is backwards - the Proboat stock prop is 1.6 diameter (40.64 mm) and 2.5 pitch (63.5 mm)
On Octura x and m series props, dana is correct, the first number is the pitch, the last two the diameter.

Check out this chart - http://www.fastelectrics.com/octuraprops.htm

[dana]

That is backwards - the Proboat stock prop is 1.6 diameter (40.64 mm) and 2.5 pitch (63.5 mm)
On Octura x and m series props, dana is correct, the first number is the pitch, the last two the diameter.

Oops hehe my bad... He is correct. I did get that backwards

[b.mcdaniel.2009]

so if i want more top speed do i run a larger diameter, or higher pitch?

[lectriglide]

so if i want more top speed do i run a larger diameter, or higher pitch?

Depends on too many things to make a general statement.
For the Fastech, I believe Darin said in his "race prep" thread to think less diameter and more pitch.

Did you take the advice of multiple posters and get an x642??

[sanyijr]

What temps, too

Also, if you deviate out of the "general" recommendations that have been time tested, you may start gettign to the limit of your ESC and even battery discharge rate.

X642 is much quieter and faster than stock. Keeps things cool and stable. But once you get into larger diameter, even by millimeters, your amp draw starts to go up. Pitch is the same way.

So check out the other suggestion on the forum

http://forums.offshoreelectrics.com/...ad.php?t=14507 and maybe this

http://forums.offshoreelectrics.com/...ad.php?t=12201

But for me, X642 is working great with big Lipos. Very quick, no cavitation and very stable wave hopping at WOT!