Questions and Answers If you have general RC questions or answers discuss it here.

Prop. Pitches

Reply

Old 10-16-2006, 07:01 PM
  #1  
fzeller
Member
Thread Starter
 
Join Date: Aug 2006
Location: Jeddo, MI
Posts: 45
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Prop. Pitches

Howdy Folks

I think I have this right. If you have a 10-6 prop. and want more pull to get off the ground faster. You should go to a 11-5 prop. But I can not use a larger diameter because I am cutting grass with the prop now. So, I have to stay with a 10 inch prop. should I go with more pitch or less pitch? 10-5 or 10-7 or some other pitch.? As always, thanks for your help.
P.S. It is on a 40 O.S. Max. It that makes any difference.
Fred
fzeller is offline  
Reply With Quote
Old 10-16-2006, 07:48 PM
  #2  
Geistware
Senior Member
My Feedback: (16)
 
Join Date: Apr 2002
Location: Locust Grove, GA
Posts: 12,942
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Prop. Pitches

You have it right and you can go to bigger tires to get more ground clearence.
a 10-5 will give you more RPM and more pull due to the higher RPM of the propeller.
Geistware is offline  
Reply With Quote
Old 10-16-2006, 09:49 PM
  #3  
da Rock
Senior Member
 
Join Date: Oct 2005
Location: Near Pfafftown NC
Posts: 11,511
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Prop. Pitches

If you really like the airplane, think about retrofitting taller landing gear.

Going to an 11" prop from a 10" prop only moves the prop tip 1/2" closer to the ground. To get that 1/2" back from larger tires, you're going to have to put 1" larger ones on the airplane. It's real easy to get a couple of inches from taller gear. And you get almost no more drag from longer gear whereas tires that're one inch bigger on a 40size plane are going to be obviously larger. Will you feel the difference? Probably not. But on a 40size airplane....... it's worth thinking about. You're already wanting more pull. So why do something that can get it but costs some of that pull getting it?

What's the airplane?

Have your gearlegs bent over time? You might get the height just by bending them down some. Even if they haven't flattened out from use.
da Rock is offline  
Reply With Quote
Old 10-16-2006, 10:23 PM
  #4  
Geistware
Senior Member
My Feedback: (16)
 
Join Date: Apr 2002
Location: Locust Grove, GA
Posts: 12,942
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Prop. Pitches

Bigger tires on grass will make the plane roll easier.
Bigger tires are not always more drag while on the ground.
From a weight standpoint, you can go with some of the foam tires which are very light.
Geistware is offline  
Reply With Quote
Old 10-16-2006, 11:14 PM
  #5  
fzeller
Member
Thread Starter
 
Join Date: Aug 2006
Location: Jeddo, MI
Posts: 45
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Prop. Pitches

The plane is a Tower Hobbies trainer 40. I would like to make it a tail dragger, and throw the rubber bands away, and bolt the wing on. That being said, I read in another post that that is what another guy wanted to do, but he was told that because the rudder is above the elevator. It is very hard to mount a tail wheel on it. He was also told that because of the way the plane is built, it is also very hard to bolt the wing on. I guess I will have to live with it the way it is. Thanks Guys. Fred
fzeller is offline  
Reply With Quote
Old 10-17-2006, 03:02 PM
  #6  
carrellh
Senior Member
 
carrellh's Avatar
 
Join Date: Mar 2003
Location: Garland, TX
Posts: 6,544
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Prop. Pitches

I don't have any photos but my brother and I assembled my Big Stik 60 as a tail dragger; and it has the same "rudder above the elevator" issue as your plane.

I didn't come up with this solution. I saw a description, and photos, somewhere on RCU.

I bought these pushrods at the LHS:
http://www2.towerhobbies.com/cgi-bin...?&I=LXK059&P=0
I have a 3/16" drill bit that's about a foot long, from Home Depot.

We attached the tail wheel bracket, determined the path for the pushrod, and used the long bit to drill an angled hole for the pushrod tube to exit the fuselage. Inside the fuselage we drilled a 3/16 hole in the former behind the rudder servo, next to the existing rudder pushrod tube. It took several tries to get the pushrod tube installed, then we ran the rod through the tube and hooked it up. The pushrod tube is only attached to anything at the ends. This would not be ideal for a control surface but it has not presented any issues just turning a wheel.

I don't know enough about the structure of your wing and fuselage to comment on converting to wing bolts.
carrellh is offline  
Reply With Quote
Old 10-17-2006, 05:58 PM
  #7  
lrtx1
Senior Member
 
lrtx1's Avatar
 
Join Date: May 2006
Location: Alachua, FL
Posts: 188
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Prop. Pitches

I just made a set of gear wires for a tower trainer 40. Used 5/32 music wire. Installed bigger wheels, 3 1/4" rear 3" front. The stock gear is real flimsy and has probably bent on you over time. I used 11 X 5 the way it was stock off grass with no problems.

Layne
lrtx1 is offline  
Reply With Quote

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