Go Back  RCU Forums > RC Airplanes > RC Warbirds and Warplanes
Reload this Page >

P-40 flying characteristics question.

Notices
RC Warbirds and Warplanes Discuss rc warbirds and warplanes in this forum.

P-40 flying characteristics question.

Old 05-16-2020, 10:42 AM
  #1  
the Wasp
Thread Starter
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,523
Likes: 0
Received 13 Likes on 13 Posts
Default P-40 flying characteristics question.


OK guys, I have a problem. so I have a question about how a P-40 responds to "stick inputs". I seam to have a long delay between the time my plane responds to Aileron stick inputs.
is this a common characteristic trait to the shape of the P-40s wing ?? and how do I get around it ??

my friend has an 88" span P-40 and he says mine flies like a P-40 does. but I have never had a plane that has this delay to stick inputs, it's so long it's hard for me to stay ahead of the plane. I have had other planes with this delay but this delay on this P-40 is so long I almost crashed 5 times on my first flight with it.

Servos are Hitech Hs-6635HB Digital, speed .18, torque 69oz @ 4.8.. 8.

now guys, LOL here's the thing. my plane is the World Models P-40, I know it's junk but I had an engine so I bought the plane just to zip around with once in a while. on that I do have a VQ P-40 but it's not ready to fly yet.

thanks guys !!
Jim
Old 05-16-2020, 12:10 PM
  #2  
nswords
Junior Member
 
Join Date: Apr 2020
Posts: 12
Likes: 0
Received 1 Like on 1 Post
Default

I have a TF P40 and it responds like all my other war birds.
Old 05-16-2020, 04:48 PM
  #3  
the Wasp
Thread Starter
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,523
Likes: 0
Received 13 Likes on 13 Posts
Default

Originally Posted by nswords View Post
I have a TF P40 and it responds like all my other war birds.
ok, but how is it they respond ?? do they have a delay to stick inputs ??

Jim
Old 05-17-2020, 05:01 AM
  #4  
carlgrover
 
Join Date: Jan 2002
Location: Decatur, AL
Posts: 724
Likes: 0
Received 6 Likes on 5 Posts
Default

I flew a guys Mustang once that had a real slow response to control inputs. I believe the issue was the control linkages were real sloppy and there were fairly large gaps inbetween the control surfaces and flying surfaces. You might start looking at those items on your plane.

carl
Old 05-17-2020, 08:41 AM
  #5  
the Wasp
Thread Starter
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,523
Likes: 0
Received 13 Likes on 13 Posts
Default

Originally Posted by carlgrover View Post
I flew a guys Mustang once that had a real slow response to control inputs. I believe the issue was the control linkages were real sloppy and there were fairly large gaps inbetween the control surfaces and flying surfaces. You might start looking at those items on your plane.
carl

thank you for the reply !
now that I have read about Vertical Balance I am wondering if the fuse is too top heavy, because the battery is just under the top of the cowl. I will "try" to move the batter lower and test that in flight.

thanks !
Jim
Old 05-17-2020, 01:04 PM
  #6  
dryverman
My Feedback: (2)
 
dryverman's Avatar
 
Join Date: Feb 2005
Location: Proctor, VT
Posts: 210
Received 2 Likes on 2 Posts
Default

Did Brian notice this problem when he flew it?
Old 05-17-2020, 01:10 PM
  #7  
the Wasp
Thread Starter
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,523
Likes: 0
Received 13 Likes on 13 Posts
Default

LOL yes, he said quote> "it does not respond, it flies like a P-40"

Jim
Old 05-17-2020, 06:24 PM
  #8  
RCFlyerDan
My Feedback: (53)
 
RCFlyerDan's Avatar
 
Join Date: Apr 2002
Location: Cape Coral
Posts: 1,671
Received 7 Likes on 7 Posts
Default

Originally Posted by the Wasp View Post
OK guys,

Servos are Hitech Hs-6635HB Digital, speed .18, torque 69oz @ 4.8.. 8.


thanks guys !!
Jim
IMHO...too slow of servos with the wrong voltage battery. May even have blowback due to being too week.
Old 05-17-2020, 07:02 PM
  #9  
the Wasp
Thread Starter
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,523
Likes: 0
Received 13 Likes on 13 Posts
Default

Originally Posted by RCFlyerDan View Post
IMHO...too slow of servos with the wrong voltage battery. May even have blowback due to being too week.
Dan, thanks for the thoughts.
I understand what you are saying. but that's hard for me to believe, because I had the same servos (but analog) "Hitect HS 635HB" (speed 18, torque 69 @ 4.8) in my 82" span PA GeeBee Y with a MVVS 35cc Gasser and it flew fine with no lag to respond !! and this P-40 is around 9 pounds lighter with a wing span of only 57 inches. plus I get this lag to respond at low speeds too.
too add, my 60size GP ShoeString has this lag too, but it's nowhere as bad !

I called my friend tonight that flew my P-40. and again he tells me the plane responds like a war bird.

Jim

Last edited by the Wasp; 05-17-2020 at 07:44 PM.
Old 05-18-2020, 04:40 AM
  #10  
RCFlyerDan
My Feedback: (53)
 
RCFlyerDan's Avatar
 
Join Date: Apr 2002
Location: Cape Coral
Posts: 1,671
Received 7 Likes on 7 Posts
Default

Originally Posted by the Wasp View Post
Dan, thanks for the thoughts.
I understand what you are saying. but that's hard for me to believe, because I had the same servos (but analog) "Hitect HS 635HB" (speed 18, torque 69 @ 4.8) in my 82" span PA GeeBee Y with a MVVS 35cc Gasser and it flew fine with no lag to respond !! and this P-40 is around 9 pounds lighter with a wing span of only 57 inches. plus I get this lag to respond at low speeds too.
too add, my 60size GP ShoeString has this lag too, but it's nowhere as bad !

I called my friend tonight that flew my P-40. and again he tells me the plane responds like a war bird.

Jim
Jim;
If you fly other aircraft with faster servos and higher voltage, you will notice on another plane that has slower servos. Compounding the issue by using 20+ years ago 4.8v batteries. Digital servos run better on higher voltage. The karbide gear servos are a poor choice for any glow or gas plane, due to the vibration. I used them once and lost a plane years ago due to them. You ask for advice. Change servos or at least come out of the Stone Age with 4.8v battery. With 6v and increase speed by .03 is a big change. Hate guys who try to get by with the minimum. And then wonder why their poor set up doesnít fly right! Good luck to you.

Last edited by RCFlyerDan; 05-18-2020 at 05:19 AM.
Old 05-18-2020, 06:10 AM
  #11  
nswords
Junior Member
 
Join Date: Apr 2020
Posts: 12
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by the Wasp View Post
ok, but how is it they respond ?? do they have a delay to stick inputs ??

Jim
There was no delay with any of my warbirds.
Old 05-18-2020, 06:16 AM
  #12  
[email protected]
My Feedback: (21)
 
Join Date: Feb 2003
Location: pueblo, CO
Posts: 677
Likes: 0
Received 1 Like on 1 Post
Default

Too much exponential
Larry
Old 05-18-2020, 07:38 AM
  #13  
RCFlyerDan
My Feedback: (53)
 
RCFlyerDan's Avatar
 
Join Date: Apr 2002
Location: Cape Coral
Posts: 1,671
Received 7 Likes on 7 Posts
Default

Originally Posted by [email protected] View Post
Too much exponential
Larry
Thatís in addition to the poor setup and part of it.

On a Warbird, for scale set up, if you are using more than 15% Expo on LOW Rates, then your throw rates are too high!

Last edited by RCFlyerDan; 05-18-2020 at 08:41 AM.
Old 05-18-2020, 10:13 AM
  #14  
the Wasp
Thread Starter
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,523
Likes: 0
Received 13 Likes on 13 Posts
Default

Dan, I am not trying to argue with you ! and I thank you for the replies !!

I used the same rx & servo setup but analog at 4.8 on my GeeBee Y that weighed 9 pounds more than my P-40 and I did not have this problem.

the Ailerons have only 5mm of throw, that's less than a 1/4 inch,

I am going to put the wing on and try to check the Vertical balance.

Jim
Old 05-18-2020, 01:13 PM
  #15  
the Wasp
Thread Starter
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,523
Likes: 0
Received 13 Likes on 13 Posts
Default

well, it's not top heavy.
I have no ides why because I did balance it but I found the Lateral balance was off, I had to add 3/4oz to the left wing's servo bay, it's right on now, so it needs to be flown again before I go any father.
if it doesn't fly better I do have some new servos that are rated 50oz stronger than the 6635's, I will mount those after we fly it again.

thank you all for replying !!
Jim
Old 05-18-2020, 02:14 PM
  #16  
allanflowers
 
allanflowers's Avatar
 
Join Date: Sep 2004
Location: San Diego, CA
Posts: 1,671
Received 0 Likes on 0 Posts
Default

Originally Posted by the Wasp View Post
Dan, I am not trying to argue with you ! and I thank you for the replies !!

I used the same rx & servo setup but analog at 4.8 on my GeeBee Y that weighed 9 pounds more than my P-40 and I did not have this problem.

the Ailerons have only 5mm of throw, that's less than a 1/4 inch,

I am going to put the wing on and try to check the Vertical balance.

Jim
5mm of movement is obviously not enough. Maybe 10mm would begin to give you decent response. Vertical balance is not an issue.
Old 05-18-2020, 02:50 PM
  #17  
Tony Gag Jr.
My Feedback: (124)
 
Tony Gag Jr.'s Avatar
 
Join Date: Jan 2002
Location: Terryville, CT
Posts: 1,132
Likes: 0
Received 1 Like on 1 Post
Default

That is definitely not a warbird flying characteristic. If your pilot thinks thatís how a warbird flys you might want to find another pilot. Lol. I think the opinions you have seen here could be the issue, too much expo, not enough control throw, weak servos. I also wouldnít use karbonite geared servos in anything other than an electric plane.
Old 05-18-2020, 07:37 PM
  #18  
the Wasp
Thread Starter
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,523
Likes: 0
Received 13 Likes on 13 Posts
Default

5mm of movement is obviously not enough. Maybe 10mm would begin to give you decent response.
if I did that it would roll faster than an Extra or Edge, even the dealer says to use only 6mm of throw..

That is definitely not a warbird flying characteristic. If your pilot thinks that’s how a warbird flys you might want to find another pilot. Lol. I think the opinions you have seen here could be the issue, too much expo, not enough control throw, weak servos.
the friend that flew it is a very capable pilot that has a P-40, you should have seen him land it on it's first flight, he landed it like he had been flying it for 30 years, it was one of the best landings ever.

I agree that the servos are weak, I have some new, stronger ones I will install. but I want to fly it before doing so to test the new balancing.

thanks guys !!
Jim

Last edited by the Wasp; 05-18-2020 at 07:46 PM.
Old 05-19-2020, 07:21 AM
  #19  
[email protected]
My Feedback: (21)
 
Join Date: Feb 2003
Location: pueblo, CO
Posts: 677
Likes: 0
Received 1 Like on 1 Post
Default

I really doubt it is weak servos, I have flown a TF giant P-47 with a g62 engine for 15 years with the same 70oz servos. I think 6mm throws are not enough. I usually set up planes with 3/4 inch up and down on ailerons and more on elevator sometimes. One caveat, I like active planes so that is more active than some others like. I also never use exponential because I learned to fly when there was 4 channels, no servo reversing or end point or dual rate, you learned how to be delicate with the sticks instead of depending on the radio to dampen out the reactions. Not against any of those things, just don't need them. I want my planes to react when I give them input, not feel like there is a rubber band between the servo and the surfaces. Just my opinion.
Larry
Old 05-19-2020, 12:32 PM
  #20  
the Wasp
Thread Starter
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,523
Likes: 0
Received 13 Likes on 13 Posts
Default

[email protected]
I can understand how the short throw of only 6mm can be my problem with the plane not responding as I want it to. but if I do increase the throw the speed rate of the roll will increase too. so if I do increase the throw how can I keep the speed of the roll down ??

Jim
Old 05-19-2020, 01:35 PM
  #21  
Tony Gag Jr.
My Feedback: (124)
 
Tony Gag Jr.'s Avatar
 
Join Date: Jan 2002
Location: Terryville, CT
Posts: 1,132
Likes: 0
Received 1 Like on 1 Post
Default

Jim, to control the speed of roll you either take it easy on the sticks or add expo, thatís the point of expo. Thatís why aerobatic pilots use lots of expo, to make the flight controls less sensitive around the center points of the stick.
Old 05-19-2020, 01:56 PM
  #22  
[email protected]
My Feedback: (21)
 
Join Date: Feb 2003
Location: pueblo, CO
Posts: 677
Likes: 0
Received 1 Like on 1 Post
Default

I would use dual rate and adjust the low to what you like to fly with and add 20% more throw on high, try it and see if it is better. Gradually get used to the higher rate. I see many fliers with war birds who deaden them with expo so they fly smoother. Works great until you need to do something in a hurry. (like eminent ground contact!)
I learned to fly with a light touch on the sticks, makes it easier to let the plane do its own thing and smooth out the fly-bys.
Larry
Old 05-19-2020, 06:07 PM
  #23  
the Wasp
Thread Starter
My Feedback: (1)
 
Join Date: Sep 2003
Location: VT
Posts: 4,523
Likes: 0
Received 13 Likes on 13 Posts
Default

Tony Gag, I have been fly 18 years, I fly Helis too, I know Expo.
Expo does not control the speed the plane rolls at, as Larry said "Dual Rates do"

the problem is that I can move the stick and the plane will fly 70ft before it will even start to respond.

Larry, yes it also rolls faster than I like. I have the low dual rate throw set a 5mm, if I lower them more the slow response time will lengthen.
I don't get this plane at all.

Jim
Old 05-19-2020, 08:50 PM
  #24  
dgiatr
 
dgiatr's Avatar
 
Join Date: Jan 2009
Location: petralona, GREECE
Posts: 305
Likes: 0
Received 0 Likes on 0 Posts
Default

Hello
did you use any differential control on your ailerons; i always use 50% ailerons differential movent on almost of my warbirds, especially in p-40!.

Jim.
Old 05-20-2020, 02:27 AM
  #25  
Tony Gag Jr.
My Feedback: (124)
 
Tony Gag Jr.'s Avatar
 
Join Date: Jan 2002
Location: Terryville, CT
Posts: 1,132
Likes: 0
Received 1 Like on 1 Post
Default

Ok great. Since you have all the answers I guess will stop offering advice. Good luck.

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.