Go Back  RCU Forums > RC Airplanes > Beginners
Reload this Page >

what prop for an os 46 la?

Notices
Beginners Beginners in RC start here for help.

what prop for an os 46 la?

Old 08-23-2005, 05:41 AM
  #1  
martno1fan
Senior Member
Thread Starter
 
martno1fan's Avatar
 
Join Date: Jan 2005
Location: blackpool, UNITED KINGDOM
Posts: 11,390
Likes: 0
Received 2 Likes on 2 Posts
Default what prop for an os 46 la?

hi i was flying my trainer with an 11x6 graupner prop and after having crashed it and rebuilt it im nearly ready to maiden her again!!.ive read lots of things about prop sizes and now im wondering if this prop was the right size?,would i be better with an 11x5 or a 10x6 or something else?.anyone know which would give me the best prerformance?.im taking off a grass runway and sometimes she takes a long time to get airborn would a 10x5 give me more speed on take off?.
Old 08-23-2005, 05:52 AM
  #2  
bkdavy
Senior Member
My Feedback: (1)
 
bkdavy's Avatar
 
Join Date: Sep 2004
Location: FrederickMD
Posts: 2,114
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what prop for an os 46 la?

I have the 46 LA, and I've flown a 10x6, 10x7, 11x4, 11x5, and 11X6. By far the best performance is with the 11x5. It turns it at 11,000 rpm. The 10x5 will probably increase your take off roll, since you won't get as much thrust. For comparison, I ran the numbers in Thrust HP. You should be getting about 10400 rpm from the 11x6 prop, for a thrust of about 4.7 lbs. The 11x5, at the same horsepower rating and 11,000 rpm, gives 5.3 lbs. The 10x5 should come in around 12500 rpm and 4.7 lbs. I also like the larger props for landing, since the larger disc gives better braking. Try the 11x5 APC with the 46 LA. I think you'll like it.

Brad
Old 08-23-2005, 06:12 AM
  #3  
SENZA
Senior Member
 
SENZA's Avatar
 
Join Date: Jan 2004
Location: BRADFORD, MA
Posts: 435
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what prop for an os 46 la?

I second that 11x5 apc i use them on my 46fx's and ive tryed them all! ultra stk 40,Aero works edge 540 fly just fine
Old 08-23-2005, 06:38 AM
  #4  
martno1fan
Senior Member
Thread Starter
 
martno1fan's Avatar
 
Join Date: Jan 2005
Location: blackpool, UNITED KINGDOM
Posts: 11,390
Likes: 0
Received 2 Likes on 2 Posts
Default RE: what prop for an os 46 la?

thanks guys ill try the 11x5 thanks again!!
Old 08-23-2005, 08:10 AM
  #5  
britbrat
Senior Member
 
Join Date: Jun 2004
Location: Deep River, ON, CANADA
Posts: 3,299
Likes: 0
Received 1 Like on 1 Post
Default RE: what prop for an os 46 la?

Since you don't need speed, an 11-4 is also an excellent choice for the .46 LA in a trainer -- it will give even more thrust than the 11-5 & let the engine wind up to ~13,000 -- close to its torque peak @ 12,700 & its power peak @ 13,400.

The 11-5, while much better than the 11-6, is still too much prop for that engine.
Old 08-25-2005, 10:09 AM
  #6  
Thor84
Member
 
Join Date: Aug 2005
Location: thornton, nh
Posts: 51
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what prop for an os 46 la?

i use a 10x7 .... of corse i dont have the ground clearence to run the 11s
Old 08-25-2005, 12:51 PM
  #7  
Sarges_heroes2003
Senior Member
My Feedback: (6)
 
Sarges_heroes2003's Avatar
 
Join Date: Jul 2004
Location: El Dorado SpringsMissouri
Posts: 523
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what prop for an os 46 la?

when getting into such large diameter props would it be a good idea to look at possibly getting a 3 blade prop? I to am getting a 46 la and mounting it to a lt-40. just asking is all.
Old 08-25-2005, 03:15 PM
  #8  
Charlie P.
 
Charlie P.'s Avatar
 
Join Date: Feb 2003
Location: Port Crane, NY
Posts: 5,117
Received 8 Likes on 8 Posts
Default RE: what prop for an os 46 la?

I use APC 10.5x6, 11x5 and 11x6 on my .46 and .50 size 2-strokes. Right now they both have 10.5X6 on them.

Your preference will likely depend on your flying style. I started using the 10.5x6 in one plane because the 11" props "ticked" the ice when flying with skis. Liked it so much I stuck with it year-round.

May I point out that while the shallower pitch engines allow you to reduce the load on the engine and achieve higher RPM/torque, you also have reduced "bite" in the air. The 6" moves 17% farther through the air in 1 revolution than the 5". Variations in air temp, humidity, the plane-to-plane of total weight and "cleanness" of profile may give you more thrust with a higher pitch prop. And you, hopefully, ain't always flyin at full throttle. The braking effect of the larger props helps or hinders on slow downward maneuvers at low RPM.

Hook the plane up to a fish scale and see which prop pulls harder at full RPM.
Old 08-25-2005, 03:28 PM
  #9  
RCVFR
My Feedback: (7)
 
Join Date: Feb 2002
Location: Keller, TX
Posts: 2,051
Likes: 0
Received 0 Likes on 0 Posts
Default RE: what prop for an os 46 la?


ORIGINAL: martno1fan

thanks guys ill try the 11x5 thanks again!!
I think you will be pleased. I run an APC 11X5 on a 40LA mounted on a trainer with very good results.

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


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.