RE: 1/5 Pepsi Chipmunk - Build  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       

All Forums >> RC Airplanes >> Kit Building >> RE: 1/5 Pepsi Chipmunk - Build
Page: <<   < prev  1 2 3 4 [5] 6   next >   >>  

Login
Message << Older Topic   Newer Topic >>
RE: 1/5 Pepsi Chipmunk - Build - 9/7/2005 11:27:23 AM   
ronaldh


 

Posts: 51
Joined: 12/11/2003
From: HorncastleLincolnshire, UNITED KINGDOM
Status: offline 		Same thing here Randy. CG on main spar would appear to be too far forward and, as you say, running out of elevator in the flare. Especially noticeable on the bottom of loops.
Ron

(in reply to V2PLUS10)
       Post #: 101

RE: 1/5 Pepsi Chipmunk - Build - 9/15/2005 9:43:36 PM   
frankfearn


 

Posts: 70
Joined: 10/26/2004
From: nottingham, UNITED KINGDOM
Status: offline 		Hi Randy, when you say you had the rates set to low throws,do you mean the rates the manual advises?

(in reply to V2PLUS10)
       Post #: 102

RE: 1/5 Pepsi Chipmunk - Build - 9/16/2005 2:21:54 AM   
V2PLUS10


 

Posts: 654
Joined: 5/31/2003
From: Boise, ID,
Status: offline 		Frank,

I just checked the transmitter settings and I see that I have low rate set up at about 70% throw give or take a little for all the controls, and high rates are set at only 90%. I have expo on all surfaces at 20% to 30%. When I get the airplane down and assemble it I can measure the throws. It's been a while but I expect I set the inital values to the manual recommended settings. I fly on low rates unless I want to do something tricky and then I go to high. I use high rate on the elevator during taxi on the grass to keep the tail down, but use low rates in flight for normal maneuvers. Most of my flying is with scale type biplanes (Tiger Moth etc) so I'm not used to fast low wing models, even though the Chipmunk is not real fast, it is fast for me...

Randy

(in reply to frankfearn)
       Post #: 103

RE: 1/5 Pepsi Chipmunk - Build - 9/16/2005 5:32:42 PM   
frankfearn


 

Posts: 70
Joined: 10/26/2004
From: nottingham, UNITED KINGDOM
Status: offline 		hi Randy, thanks for your response, i will start with the rates the manual suggests, and like you say,add expo to soften things if need be. It would be very good of you if you could measure the throws,i would appreciate it. Many thanks Frank

(in reply to V2PLUS10)
       Post #: 104

RE: 1/5 Pepsi Chipmunk - Build - 9/16/2005 6:16:28 PM   
V2PLUS10


 

Posts: 654
Joined: 5/31/2003
From: Boise, ID,
Status: offline 		Hi Frank,

Checked the throws, these are all low rate, which is where I normally fly:

Aileron...1/2" up and 3/8" down travel.....25% differential

Elevator....1" up and 1" down.

Rudder....2" left and right

Flap... 3/8" first notch....3/4" full travel.....wish I had more. Coupled with a little down elevator..6% and 9% respectively.

As before all controls have about 25% expo. Also I checked the CG which is still about at the front spar, checked with the model inverted. I have a 24oz (!!) fuel tank which is too large, but with it full I must be very nose heavy....time to shift more weight..

Hope this helps. I think that you will find the ailerons to be very effective....

Randy

(in reply to frankfearn)
       Post #: 105

RE: 1/5 Pepsi Chipmunk - Build - 9/16/2005 6:26:37 PM   
V2PLUS10


 

Posts: 654
Joined: 5/31/2003
From: Boise, ID,
Status: offline 		Hi again frank,

Well, I found the manual and see that the low rate throws I have are nearly as recommended. I do tend to set up my airplanes with quite a lot of throw mechanically, and then limit them with the tx settings. Saw one local fellow test fly his 1/4 scale Marchetti and after takeoff it just slowly rolled over and that was the end of it.....not enough aileron throw to compensate....

Randy

(in reply to frankfearn)
       Post #: 106

RE: 1/5 Pepsi Chipmunk - Build - 9/16/2005 8:27:09 PM   
frankfearn


 

Posts: 70
Joined: 10/26/2004
From: nottingham, UNITED KINGDOM
Status: offline 		hi Randy,cant thankyou enough, absoloutly first class, Chippie just in need of fuel proofer, fit radio,engine and she,ll be ready.Excited and apprensive about maiden flight,sure all will be well.Im always the same with any model on test flight, sometimes i think you can think to much about it. Currently having lots of rain,so i will wait a few weeks untill the frosts develop, usually get a calm ,but cold daytime. Again thankyou very much,Frank

(in reply to V2PLUS10)
       Post #: 107

RE: 1/5 Pepsi Chipmunk - Build - 9/25/2005 6:11:56 PM   
ronaldh


 

Posts: 51
Joined: 12/11/2003
From: HorncastleLincolnshire, UNITED KINGDOM
Status: offline 		Flown the chippie yet, Frank?

By the way what fuel proofer do you use? I find that the synthetic oil glow fuels are hard on paint work!

(in reply to frankfearn)
       Post #: 108

RE: 1/5 Pepsi Chipmunk - Build - 9/25/2005 7:10:48 PM   
frankfearn


 

Posts: 70
Joined: 10/26/2004
From: nottingham, UNITED KINGDOM
Status: offline 		hi Ron, not flown yet Ron, in the process of breaking engine in. Found that ive had to add alot of lead in the nose to obtain correct c of g.The c of g is 123, millimitre just under 5" from the wing leading edge.I tend to use ripmax fuel proofer applied with my spray gun,not really had any probs with it,apart from the awful smell it produces whilst applying.Hoping to fly this week if weather stays good,will keep you informed, did you have to add nose weight? Thanks, Frank

< Message edited by frankfearn -- 9/26/2005 10:08:51 PM >

(in reply to ronaldh)
       Post #: 109

RE: 1/5 Pepsi Chipmunk - Build - 9/27/2005 10:27:54 PM   
ronaldh


 

Posts: 51
Joined: 12/11/2003
From: HorncastleLincolnshire, UNITED KINGDOM
Status: offline 		Frank,
Mine came out nose heavy with all engine options. With the Laser 150 it balanced just in front of the mainspar and that's with the battery (1700 maH) behind the wing. I have since added a bit of lead to the tail and it now balances behind the mainspar and seems to fly better...elevator is obviously more responsive. I beefed up the firewall a bit when I was considering using the Moki 180...could be the reason it ended up nose heavy!

Break the engine in in the air...more fun that way.

Cheers
Ron

(in reply to frankfearn)
       Post #: 110

RE: 1/5 Pepsi Chipmunk - Build - 9/27/2005 10:40:09 PM   
V2PLUS10


 

Posts: 654
Joined: 5/31/2003
From: Boise, ID,
Status: offline 		Hi Ron,

I flew mine yesterday, and I still need to add weight to the tail. I have the Saito 180 at 880 grams and the Slimline inverted pitts muffler and the EVE's from Apache Products all up front, not to mention the prop and spinner! Been thinking about trying a Saito 120 to reduce weight as I sure don't need the power of the 180. A 150 should be perfect. Batteries are between the cockpits so I'll see if I can put them behind the wing.....Added two ounces to the tail but it is still heavy in the nose. That might contribute to the tail wagging in flight... Did some "slow-flight" practice with it yesterday, and it will really slow down with no wing dropping...would do even better if it were better balanced...

Randy

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to ronaldh)
       Post #: 111

RE: 1/5 Pepsi Chipmunk - Build - 9/28/2005 12:39:13 AM   
V2PLUS10


 

Posts: 654
Joined: 5/31/2003
From: Boise, ID,
Status: offline 		Ron and Frank,

OK. Now I've cut a hole in the aft bulkhead behind the servos, and made a little tray to hold the reciever pack. Even with the 1400ma pack there it only just balances a tiny bit aft of the spar, holding it inverted. I better check and see if I didn't leave a sandbag or something in the nose...

Randy

(in reply to ronaldh)
       Post #: 112

RE: 1/5 Pepsi Chipmunk - Build - 9/28/2005 6:28:48 PM   
ronaldh


 

Posts: 51
Joined: 12/11/2003
From: HorncastleLincolnshire, UNITED KINGDOM
Status: offline 		Randy,

The CG shown on Apache plans appears to be conservative. I feel the model is now flying a bit better with the rearward CG. Some 'up elevator' trim apparent on model at rest. Fish tailing still present and more so when winds are strong(?).

Raking the u/c wires a little bit more forward of the wing leading edge has cured or lessened the tendancy to bend the u/c wires on landing. Moving the CG rearward may have helped.

Ron

(in reply to V2PLUS10)
       Post #: 113

RE: 1/5 Pepsi Chipmunk - Build - 9/28/2005 6:34:41 PM   
frankfearn


 

Posts: 70
Joined: 10/26/2004
From: nottingham, UNITED KINGDOM
Status: offline 		Hello Ron and Randy, all set for flying, engine had a tank or two through,sounding good.As you say Ron will break in properly whilst flying,i hope. Just waiting for the right day now, not looking good for this week, will bide my time. Frank

< Message edited by frankfearn -- 9/28/2005 6:45:45 PM >

(in reply to ronaldh)
       Post #: 114

RE: 1/5 Pepsi Chipmunk - Build - 9/28/2005 9:49:58 PM   
V2PLUS10


 

Posts: 654
Joined: 5/31/2003
From: Boise, ID,
Status: offline 		Ron and Frank,

Flew the Chipmunk again today. Much improved with the 1400ma pack essentially behind the last former at the trailing edge of the wing. Could use a little more weight in the tail though. I have about an ounce of lead attached to the tailwheel bracket also. Need to shift just a little more weight and things will be good. With the airplane upside down and no fuel it will just balance maybe 1/8" (or less) behind the spar if held on the last sheeted wing rib. I had to add a little expo to the elevator as it became more effective but not squirrelly. More fun to fly for sure!!

Randy

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to frankfearn)