Wattflyer RC Network: RC Universe :: RCU Magazine :: RCU Forums :: RCU Classifieds :: RCU User Reviews :: RCU YouTube
Home Who's Online Calendar Today's Posts RealTime Post Spy Mark Forums Read
Go Back   WattFlyer RC Electric Flight Forums - Discuss radio control eflight > Electric R/C Airplanes > Beginners
Register Members List Wattflyer Extras Articles Search Today's Posts Mark Forums Read Social Groups

Beginners New to e-power flying? Get the low down in here from experienced e-power RC pilots!

Thank you for your support (hide ads)
Reply
 
Thread Tools Display Modes
Old 02-04-2011, 04:26 PM   #1
JBdiver
New Member
 
Join Date: Jan 2007
Posts: 13
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default Standard to 3-Blade Prop

I'm running a 9x4 prop, what would be a good 3 blade replacement for this prop. I would be doing it for the pure look of the prop only.
JBdiver is offline  
  Reply With Quote
Old 02-04-2011, 04:45 PM   #2
rcers
Community Moderator
 
rcers's Avatar
 
Join Date: Jul 2005
Location: Trophy Club TX
Posts: 6,147
View rcers's Gallery57
Thanked 498 Times in 488 Posts
Awards Showcase

WAA-08 Pilot 
iTrader: (4)
Friends: (9)
Default

8x4 to start. GWS makes owe in that size.
rcers is offline  
  Reply With Quote
Old 02-06-2011, 12:30 AM   #3
Bomb Dropper
The Reaper!
 
Bomb Dropper's Avatar
 
Join Date: Jan 2011
Location: Rochester, NH
Posts: 120
Thanked 4 Times in 4 Posts
iTrader: (0)
Friends: (0)
Default

GWS 8040X3 <-- 8 inch 3 bladed prop

GWS 9050X3 <-- 9 inch 3 bladed prop

What plane is this on? And what motor are you using?
Bomb Dropper is offline  
  Reply With Quote
Old 02-06-2011, 12:35 AM   #4
Catalina
Member
 
Join Date: Jul 2009
Location: Sydney, Australia
Posts: 185
Thanked 10 Times in 10 Posts
iTrader: (0)
Friends: (0)
Default

I think I heard a 3 bladed prop was less efficiant than its counter part 2 bladed type. I may be wrong here, but you may need to go up a pitch or 2.
Catalina is offline  
  Reply With Quote
Old 02-06-2011, 12:49 AM   #5
JBdiver
New Member
 
Join Date: Jan 2007
Posts: 13
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default

I have a slowfly 28 that I think would look good with a 3 blade instead of a standard prop.
JBdiver is offline  
  Reply With Quote
Old 02-06-2011, 02:15 AM   #6
Bomb Dropper
The Reaper!
 
Bomb Dropper's Avatar
 
Join Date: Jan 2011
Location: Rochester, NH
Posts: 120
Thanked 4 Times in 4 Posts
iTrader: (0)
Friends: (0)
Default

Your SloFly 28, does it look like this picture below?

Also, what motor are you running on it?
That way I can better say if the 8 or 9 inch would be better for you.

And Catalina is correct, the 3 bladed props are usually less efficient than the 2 bladed ones. But if you aren't maxing out on your brushless, the difference isn't going to hurt you.

Ex: HeadsUpRC 400 (sport)

GWS EP8040:24 ounces of thrust at 10 amps.
GWS 8040 3-blade:25 ounces of thrust at 12 amps.


So in this case, you gain 1 ounce of thrust at the price of 2 more amps drawn.


The question is.. Will YOUR motor still maintain the performance that you're getting with the 2 bladed 9X4 prop? And, if you go up an amp or two, is that going to kill your motor? Because you would probably want to consider the 9050X3 prop as long as you aren't going to over-amp your motor, esc or battery.



That's what we need to figure out. That's why I want to know what motor you're using with that model.



Attached Thumbnails
Click image for larger version

Name:	Mini28BigWing2.JPG
Views:	45
Size:	92.9 KB
ID:	142928
Bomb Dropper is offline  
  Reply With Quote
Old 02-06-2011, 02:24 AM   #7
JBdiver
New Member
 
Join Date: Jan 2007
Posts: 13
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default

Yes, my slofly looks like those...

Brushless Motor Specs:
--------------------------------------------------------------------------------

No. Of cells:2-3 Li-Poly, 6-8 Ni-Mh/Ni-Cd
RPM/V:1800 RMP/V
Max. efficiency current:8-20A (>80%)
No load current / 10 V: 0.8 A
Current capacity:24A/60 s
Internal Resistance: 90 mO
Dimensions:27.5x26 mm
Shaft diameter: 3.17 mm
Weight:36g /1.27 oz
Recommended model weight: 600 - 1000g
JBdiver is offline  
  Reply With Quote
Old 02-06-2011, 02:55 AM   #8
Bomb Dropper
The Reaper!
 
Bomb Dropper's Avatar
 
Join Date: Jan 2011
Location: Rochester, NH
Posts: 120
Thanked 4 Times in 4 Posts
iTrader: (0)
Friends: (0)
Default

Do you use a 3 cell Lipo? Or a 2 cell?

I would recommend a 2 cell with the 9050X3 prop if you have one handy. But if you have a wattsup meter, you could see exactly whats going on with both props on a 3 cell pack, and then determine if you NEED to go to a 2 cell pack when using the 9050X3 prop.

I'm assuming you're using something equivalent to the "blue wonder" (CDRom style brushless) motor? If so, at 1800kv, I would DEFINITELY go 2 cell with the 9050X3 prop.

There ARE 2 different versions of it 1300kv and 1700kv

I would go with the lower kv version if you want to use a larger (9050X3) prop on 3 cells.



Hope this helps you out somewhat.
Bomb Dropper is offline  
  Reply With Quote
Old 02-06-2011, 03:07 AM   #9
Bomb Dropper
The Reaper!
 
Bomb Dropper's Avatar
 
Join Date: Jan 2011
Location: Rochester, NH
Posts: 120
Thanked 4 Times in 4 Posts
iTrader: (0)
Friends: (0)
Default

But, if you're just in this for the looks of the prop, then I would just grab a GWS 8040X3 and go for it!
Bomb Dropper is offline  
  Reply With Quote
Old 02-06-2011, 03:24 AM   #10
JBdiver
New Member
 
Join Date: Jan 2007
Posts: 13
Thanked 0 Times in 0 Posts
iTrader: (0)
Friends: (0)
Default

I'm real old school and have an 8 clerk NIMH pack.
JBdiver is offline  
  Reply With Quote
Old 02-06-2011, 03:31 AM   #11
Bomb Dropper
The Reaper!
 
Bomb Dropper's Avatar
 
Join Date: Jan 2011
Location: Rochester, NH
Posts: 120
Thanked 4 Times in 4 Posts
iTrader: (0)
Friends: (0)
Default

Yeah... just go with the 8040X3 prop then.

Actually, seeing that a 3 cell Lipo is 11.1V, and you're only using 9.6V with your nimh battery, you could probably use the 9050X3 prop without worrying about a thing.

But I would definitely recommend using a wattmeter to properly test output and amp draw while cranking it at WOT. Nothing beats being sure.
Bomb Dropper is offline  
  Reply With Quote
Old 02-06-2011, 03:38 AM   #12
Bomb Dropper
The Reaper!
 
Bomb Dropper's Avatar
 
Join Date: Jan 2011
Location: Rochester, NH
Posts: 120
Thanked 4 Times in 4 Posts
iTrader: (0)
Friends: (0)
Default

PS: I don't blame you about having the nimh batteries. Lipo batteries can get pretty darn pricey. I've probably invested over $500 in Lipo batteries over the past few years. And that's doing it in moderation, lol.
Bomb Dropper is offline  
  Reply With Quote
Old 02-06-2011, 12:37 PM   #13
rcers
Community Moderator
 
rcers's Avatar
 
Join Date: Jul 2005
Location: Trophy Club TX
Posts: 6,147
View rcers's Gallery57
Thanked 498 Times in 488 Posts
Awards Showcase

WAA-08 Pilot 
iTrader: (4)
Friends: (9)
Default

Originally Posted by Bomb Dropper View Post
PS: I don't blame you about having the nimh batteries. Lipo batteries can get pretty darn pricey. I've probably invested over $500 in Lipo batteries over the past few years. And that's doing it in moderation, lol.
While this used to be the case it is no longer true. LiPo batteries are the cheapest, lightest and highest energy density of all our batteries.

We can thank they influx of Chinese vendors selling for much lower rates. There are a number of US business that carry those packs for budget prices as well.

Mike
rcers is offline  
  Reply With Quote
Old 02-06-2011, 03:19 PM   #14
Bomb Dropper
The Reaper!
 
Bomb Dropper's Avatar
 
Join Date: Jan 2011
Location: Rochester, NH
Posts: 120
Thanked 4 Times in 4 Posts
iTrader: (0)
Friends: (0)
Default

Originally Posted by rcers View Post
While this used to be the case it is no longer true. LiPo batteries are the cheapest, lightest and highest energy density of all our batteries.

We can thank they influx of Chinese vendors selling for much lower rates. There are a number of US business that carry those packs for budget prices as well.

Mike
True.. thanks to hobbycity.com and a few others.. otherwise, prices would still be a bit overwhelming to a lot of folks out there on a tight budget, myself included. Especially when having to often buy packs from 2200mAh and up.

But yes, it could be a lot worse.
Bomb Dropper is offline  
  Reply With Quote
Reply

  WattFlyer RC Electric Flight Forums - Discuss radio control eflight > Electric R/C Airplanes > Beginners

« Previous Thread | Next Thread »

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
100+ MPH Club CHELLIE Hi-Performance and Sailplanes 1947 06-21-2014 11:36 PM
Scratchbuild of an Extra RC Fan Chris Scratch and Kit Built Aircraft 36 07-31-2012 07:21 PM
Hacker A60 18L Prop? gdwyer General Electric Discussions 5 01-18-2011 04:36 AM
What does a motor's watt rating represent? starfire73 Beginners 28 12-22-2010 05:54 AM
Best motor / prop for HL F18 conversion foamjetpilot Pusher Park Jets 3 12-21-2010 04:04 AM


All times are GMT +1. The time now is 04:51 AM.


Powered by: vBulletin
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2005 WattfFlyer.com
RCU Eflight HQ

Charities we support Select: Yorkie Rescue  ::  Crohn's & Colitis Foundation



Page generated in 0.31208 seconds with 48 queries