Cox Engines Forum
You are not logged in! Please login or register.

Logged in members see NO ADVERTISEMENTS!


P-38 Lightning-Roddie style..  - Page 8 Cox_ba12




P-38 Lightning-Roddie style..  - Page 8 Pixel

Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Latest topics
» "Me and Crazy Horse...Our Anniversary"
by Kim Today at 10:23 am

» Project Cox .049 r/c & Citabrian Champion
by balogh Today at 7:55 am

» Original Box for P-51 Bendix Trophy Racer Value
by Wayne Brown Today at 6:09 am

» Cox P-51 Bendix Trophy Racer
by Wayne Brown Today at 12:39 am

» thread measurements
by MauricioB Today at 12:33 am

» Cox Thompson Trophy Winner
by Jerry Today at 12:20 am

» COX 010 TeeDee with RC carb, courtesy sosam 117
by rdw777 Yesterday at 10:08 pm

» a cheap sport muffler
by robot797 Yesterday at 8:34 pm

» OS 10FSR Carb Needed
by Cougar 429 Yesterday at 8:14 pm

» AP .061 Hornet
by F4D Phantom II Yesterday at 5:01 am

» dozens of old .049 TeeDee's, Medallions and a few others
by rsv1cox Yesterday at 2:46 am

» Re-manufactured Enya .06-II for Boats13
by Boats13 Yesterday at 2:32 am

Cox Engine of The Month
March-2024
balogh's

"COX Budapest" .049 engine



PAST WINNERS
CEF Traveling Engine

Win This Engine!
Gallery


P-38 Lightning-Roddie style..  - Page 8 Empty
Live on Patrol


P-38 Lightning-Roddie style..

Page 8 of 9 Previous  1, 2, 3, 4, 5, 6, 7, 8, 9  Next

Go down

P-38 Lightning-Roddie style..  - Page 8 Empty lead-outs.. and guides..

Post  roddie Thu Jun 07, 2018 7:59 am

Hey CEF'ers.. I haven't posted much with this build in the last several weeks.. but you know;.... that doesn't mean that I haven't been thinking about the airplane.. and how to apply the finishing-touches to the controls.. with hopes to get the balance close.

To re-cap; this model is my own design, therefore.. the "moment-arms" aren't proven. So far; the U-Control/profile-structure seems to be good.. for a 1/2A model.

I want to fly this airplane.. but I need to be patient.. and get some "air-time" with other models that I have flown before. It's been too long since I've flown; to risk a maiden with an un-proven design.

My "wingtips" continue to be a problem with breaking-off..  Rolling Eyes  I'll definitely need to redesign that part of the wing.

Here's some photos of how I did the lead-outs.. and guides. I'd been wanting to get this done.. but have been very busy working at a new job.

P-38 Lightning-Roddie style..  - Page 8 Dsc05823
P-38 Lightning-Roddie style..  - Page 8 Dsc05824
P-38 Lightning-Roddie style..  - Page 8 Dsc05825
P-38 Lightning-Roddie style..  - Page 8 Dsc05826

She looks pretty good; hanging from her lead-outs; a slight "nose-out" attitude.

P-38 Lightning-Roddie style..  - Page 8 Dsc05830

As previously mentioned.. both wing-tips need to be reattached..  Rolling Eyes They keep breaking-off with discouraging ease..

P-38 Lightning-Roddie style..  - Page 8 Dsc05828
P-38 Lightning-Roddie style..  - Page 8 Dsc05829
roddie
roddie
Top Poster
Top Poster

Posts : 8119
Join date : 2013-07-18
Age : 64
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  balogh Thu Jun 07, 2018 8:08 am

Roddie the plane is very nice.
As for the wing tips I would reinforce them by gluing a flat carbon strip along the "spar" or 2 along the leading and traveling edges both. Flat enough not to bother the aerodynamics, the carbon strip would definitely make the tips stronger and resist snapping.
balogh
balogh
Top Poster
Top Poster

2022 Supporter

2023 Supporter

Posts : 4724
Join date : 2011-11-06
Age : 65
Location : Budapest Hungary

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  roddie Thu Jun 07, 2018 9:07 am

balogh wrote:Roddie the plane is very nice.
As for the wing tips I would reinforce them by gluing a flat carbon strip along the "spar" or 2 along the leading and traveling edges both. Flat enough not to bother the aerodynamics, the carbon strip would definitely make the tips stronger and resist snapping.

Thank You for the "tip" Andras!!! I will reattach the wingtips with some sort of thin over-lapping reinforcement material.. possibly "carbon-veil". So far; cyanoacrylate just keeps breaking-off at the joint.
roddie
roddie
Top Poster
Top Poster

Posts : 8119
Join date : 2013-07-18
Age : 64
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  balogh Thu Jun 07, 2018 9:10 am

Hobbyshops sell thin glass fibre hinges to be soaked in CA glue. That is also a thin material and provides strong overlap without compromising the airfoil.
balogh
balogh
Top Poster
Top Poster

2022 Supporter

2023 Supporter

Posts : 4724
Join date : 2011-11-06
Age : 65
Location : Budapest Hungary

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  rsv1cox Thu Jun 07, 2018 1:50 pm

Darn it roddie, I spent countless hours on my scale P-38, measuring, doing the math, cutting, trying, moulding, sheeting, constructing and adding all the little bit's and pieces, then went out and flew the thing. Time for procrastinating is over.

Just fly the thing. It's only balsa.

In the best possible spirit.............

Bob

PS - Same for my MG, many agonizing hours spent. Not for looking. When I'm finished I going to drive the crap out of it.

P-38 Lightning-Roddie style..  - Page 8 Midget23

P-38 Lightning-Roddie style..  - Page 8 Midget24

P-38 Lightning-Roddie style..  - Page 8 Midget25
rsv1cox
rsv1cox
Top Poster
Top Poster

2022 Supporter

2023 Supporter

2024 Supporter

Posts : 10398
Join date : 2014-08-18
Location : West Virginia

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  JPvelo Thu Jun 07, 2018 2:42 pm

Butt sand the wings where tips break off.

Make new tips.

Attach with epoxy.

Go fly airplane.
JPvelo
JPvelo
Diamond Member
Diamond Member

Posts : 1963
Join date : 2011-12-02
Age : 56
Location : Phoenix

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  KariFS Thu Jun 07, 2018 3:50 pm

... or leave the tips off completely. Some racer Warbirds had clipped wings for greater speed:

P-38 Lightning-Roddie style..  - Page 8 12555L
KariFS
KariFS
Diamond Member
Diamond Member

Posts : 1992
Join date : 2014-10-10
Age : 52

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  JPvelo Thu Jun 07, 2018 5:27 pm

KariFS wrote:... or leave the tips off completely. Some racer Warbirds had clipped wings for greater speed:

P-38 Lightning-Roddie style..  - Page 8 12555L

I was going to suggest that as well. Whatever you do get that thing in the air!!!
JPvelo
JPvelo
Diamond Member
Diamond Member

Posts : 1963
Join date : 2011-12-02
Age : 56
Location : Phoenix

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Threadjack by the British Invasion crew

Post  944_Jim Thu Jun 07, 2018 6:45 pm

Roddie,
It is your plane. I find when I get stuck in details, sometimes a quick shakedown run clears the head.
Wings can get cleaned and fixed.
Fly it on your terms.
Sometimes you gotta run ugly so you don't sit still pretty.
We are all standing behind you...even if we seem pushy.
P-38 Lightning-Roddie style..  - Page 8 Img_2075
P-38 Lightning-Roddie style..  - Page 8 Img_2076
944_Jim
944_Jim
Diamond Member
Diamond Member

2022 Supporter

2023 Supporter

2024 Supporter

Posts : 1936
Join date : 2017-02-09
Age : 59
Location : NE MS

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  rsv1cox Thu Jun 07, 2018 7:29 pm

Pushy? I'm about ready to climb in that half built MG and head for RI with my flight box and be roddies pit man. Eight pages and still thinking. Enough already! Vintage Triumph on the go. Thumbs up.

Kidding a bit roddie. Different strokes for different folks.

Bob
rsv1cox
rsv1cox
Top Poster
Top Poster

2022 Supporter

2023 Supporter

2024 Supporter

Posts : 10398
Join date : 2014-08-18
Location : West Virginia

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  getback Fri Jun 08, 2018 8:31 am

wonder were all those greenies are coming from.
getback
getback
Top Poster
Top Poster

2022 Supporter

2023 Supporter

Posts : 10009
Join date : 2013-01-18
Age : 66
Location : julian , NC

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  roddie Fri Jun 08, 2018 3:53 pm

I'm going to "redo" the lead-outs. I made the terminations at the wingtip; without the wingtip being glued back on. A dumb mistake.

(Sorry for the blurry image.. it's in tune with the night I did the work.  Rolling Eyes  )

P-38 Lightning-Roddie style..  - Page 8 Dsc05831

There's a risk of the crimp-tubes snagging on the wingtip.. once it's glued back on.

I'm keeping the wingtips on the model. I like the contour.. and also want to keep the span at 26" (1/2" scale)
roddie
roddie
Top Poster
Top Poster

Posts : 8119
Join date : 2013-07-18
Age : 64
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  KariFS Fri Jun 08, 2018 5:24 pm

Good point about the span. If you want to stay traditional, you could use tissue as a reinforcement for the wingtips. If you cover the tip entirely and overlap to the main wing by 1/2” or so, you’ll get a stronger joint and also protection against little dents and dings.
KariFS
KariFS
Diamond Member
Diamond Member

Posts : 1992
Join date : 2014-10-10
Age : 52

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  944_Jim Fri Jun 08, 2018 9:32 pm

roddie wrote:I'm going to "redo" the lead-outs. I made the terminations...

Hi Roddie,

Are you using brass tubing for your crimps?
I just got back from Hobby Lobby. Their 3-pack of copper tube had two sizes I can use, and one I have no use for.
Their 4-pack of really small diameter brass is the size I wanted for crimping lines...but it is brass.

I saw only one online reference saying brass was useable. All other sites mentioned copper, aluminum, or "soft metal tube."

Thanks in advance!
944_Jim
944_Jim
Diamond Member
Diamond Member

2022 Supporter

2023 Supporter

2024 Supporter

Posts : 1936
Join date : 2017-02-09
Age : 59
Location : NE MS

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  Ken Cook Fri Jun 08, 2018 10:11 pm

3/32" copper tube works perfectly fine for .018" lines which is the correct size wire for 1/2A leadouts. MBS model supply sells crimp tubes as well. I have been experimenting with wrapped line sets vs  crimped and purposely breaking them to see where they failed or slip. Here's my latest crimp with ratcheting crimpers.
   

       I pulled this crimp last evening to indicate slippage but the line broke prior.

Not sure why the pic didn't post, I will try again later


P-38 Lightning-Roddie style..  - Page 8 Dscn2710

This was a experimental test here as I don't leave the frayed wire or the looped tag out of the back of the crimp tube. I found that if I used the brass, I had to anneal it first in order to prevent cracking. These new crimpers support the looped wire on the sides of the tube vs crushing them. This is why crimps are generally not preffered due to the fact the wire is damaged internally.


Last edited by Ken Cook on Sat Jun 09, 2018 2:48 pm; edited 2 times in total
Ken Cook
Ken Cook
Top Poster
Top Poster

Posts : 5408
Join date : 2012-03-28
Location : pennsylvania

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  944_Jim Sat Jun 09, 2018 12:22 am

Thanks Ken,

I'm trying to make up a couple of sets of lines.
27, 30, 32, 35, 40, 42, 45, for 1/2A models, and 50. All of them but the 50'  will be .008" stranded.

My 50' will be a set of .015"x60' cut down for my BHM Mosquito. I think I'll be wrapping that set.


Last edited by 944_Jim on Sat Jun 09, 2018 12:29 am; edited 2 times in total (Reason for editing : Remove a goober)
944_Jim
944_Jim
Diamond Member
Diamond Member

2022 Supporter

2023 Supporter

2024 Supporter

Posts : 1936
Join date : 2017-02-09
Age : 59
Location : NE MS

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  Ken Cook Sat Jun 09, 2018 2:17 am

Jim, I will just mention this as others can benefit as well. The .008's are good, they're just a pain in the rear to maintain. I've broken them on many occasions just from flying them. Wrapping .008's is a major pain and I avoid doing so. .012" stainless is very beneficial and will endure the rigors we tend to put the lines through. There's little to no difference in weight not to mention drag. Were not going for speed here and .012's are far more durable than .008's. They don't kink like .008's do. Line diameter is based on weight of model and I feel your Mosquito would do far better on .012's than the weight of .015's .
Ken Cook
Ken Cook
Top Poster
Top Poster

Posts : 5408
Join date : 2012-03-28
Location : pennsylvania

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty lead-out re-do..

Post  roddie Sat Jun 09, 2018 4:46 am

I can't seem to upload any images tonight.. but I removed the bellcrank from the P38.. and cut-off the lead-out cables. I'll be able to utilize those long cables on a single-engine 1/2A model in the future.

I found an unopened package of K & S copper-tube 3/32" x 12"L x 3 pieces.. that I didn't realize I had. I cut a pair of 24" length .015" 7-strand stainless cables.. and "re-did" the connections at the bellcrank.. and will post some photos when the image-server is back on-line. Until then; I need to get those wingtips straightened-out..
roddie
roddie
Top Poster
Top Poster

Posts : 8119
Join date : 2013-07-18
Age : 64
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  roddie Sat Jun 09, 2018 3:49 pm

These are much better than the first attempt. I also have to remember to "stagger" the outboard terminations when I make them, so they don't get caught on each other. The guide-eyes are about 1.0" apart.

P-38 Lightning-Roddie style..  - Page 8 Dsc05810
P-38 Lightning-Roddie style..  - Page 8 Dsc05811
P-38 Lightning-Roddie style..  - Page 8 Dsc05812
P-38 Lightning-Roddie style..  - Page 8 Dsc05813
P-38 Lightning-Roddie style..  - Page 8 Dsc05814
P-38 Lightning-Roddie style..  - Page 8 Dsc05815
roddie
roddie
Top Poster
Top Poster

Posts : 8119
Join date : 2013-07-18
Age : 64
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  944_Jim Sat Jun 09, 2018 4:49 pm

Roddie,

Where did you source the tubing?
$2 for the bundle is too good a deal to pass up. I'm finding it closer to $5 plus S&H...that makes it closer to $5/stick!

That bellcrank/elevator pushrod end keeper, is it Homebrew or commercial?
It looks like an easier method than bending cleanly, or soldering.
Thanks in advance.


Last edited by 944_Jim on Sat Jun 09, 2018 10:00 pm; edited 1 time in total
944_Jim
944_Jim
Diamond Member
Diamond Member

2022 Supporter

2023 Supporter

2024 Supporter

Posts : 1936
Join date : 2017-02-09
Age : 59
Location : NE MS

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  roddie Sat Jun 09, 2018 8:36 pm

944_Jim wrote:Roddie,

Where did you source the tubing?
$2 for the bundle is too good a deal to pass up. I'm finding it closer to $5 plus S&H...that makes it closer to $5/stick!

That bellcrank end keeper, is it Homebrew or commercial?
It looks like an easier method than bending cleanly, or soldering.
Thanks in advance.

Hi Jim, The K & S 3/32" copper tubing came from a LHS that closed in 2014. A lot of the prices on items were outdated.

P-38 Lightning-Roddie style..  - Page 8 Apple_10

The "keepers" on my pushrod (both ends..) are 1/2A spring-style wheel retainers. Cox International had some NOS packages a while back. Sig used to stock them.. but no more. The thing is; you must use 1/16" (.062") music-wire for the pushrod. The "L-bends" really simplify the whole thing.
roddie
roddie
Top Poster
Top Poster

Posts : 8119
Join date : 2013-07-18
Age : 64
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  Ken Cook Sat Jun 09, 2018 8:53 pm

Roddie seeing how you like those so much, I would give them a call. I know they're still made. I looked this up before and they don't list in a search but they did have them SIG SH121... 1/2A WHEEL RETAINERS 1/16

Send a inquiry to Becky Van Dee becky@sigmfg.com with this part listing I posted.
Ken Cook
Ken Cook
Top Poster
Top Poster

Posts : 5408
Join date : 2012-03-28
Location : pennsylvania

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  roddie Sun Jun 10, 2018 9:54 pm

Ken Cook wrote:            Roddie seeing how you like those so much, I would give them a call. I know they're still made. I looked this up before and they don't list in a search but they did have them  SIG SH121... 1/2A WHEEL RETAINERS 1/16

           Send a inquiry to Becky Van Dee   becky@sigmfg.com with this part listing I posted.

Many thanks Ken! Yes.. I use this simple part for many applications.
roddie
roddie
Top Poster
Top Poster

Posts : 8119
Join date : 2013-07-18
Age : 64
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty wingtip bracing

Post  roddie Fri Jun 15, 2018 5:05 am

When I designed this model, I made its sheet-wing from dis-similar wood-types. The "core" is 1/8" (3mm) basswood.. with 1/8" balsa leading/trailing-edges.. and wingtips, butt-jointed to the basswood.

The balsa pieces were all edge-glued to the basswood with CA.. but as previously mentioned; the "wingtips" have broken-off during handling (more than once..) with discouraging ease. I'd "braced" the tips (top/bottom) with 1/64" plywood strips in anticipation of a problem.. but should have made the tips with their wood-grain running span-wise.. rather than chord-wise.  

P-38 Lightning-Roddie style..  - Page 8 Dsc05210
P-38 Lightning-Roddie style..  - Page 8 Dsc05211

So.. I re-glued the joints once-more.. and decided to try an experimental "skin-graft" using strips of "used" laundry fabric-softener (dryer) sheets.. saturated with thin CA glue.

P-38 Lightning-Roddie style..  - Page 8 Dsc05910

Sanding to a semi-smooth substrate went quick and easy.

P-38 Lightning-Roddie style..  - Page 8 Dsc05911

I applied vinyl spackling.. and feather-sanded once it had dried.

P-38 Lightning-Roddie style..  - Page 8 Dsc05912

I won't fuss too much more with imperfections and little surface-dings. The wingtips need to be re-primed/painted, followed by a "misting" of rattle-can clear polyurethane over the entire model.

We're still under 11oz. which isn't too bad for a U-control 1/2A twin.

P-38 Lightning-Roddie style..  - Page 8 P38_we10
roddie
roddie
Top Poster
Top Poster

Posts : 8119
Join date : 2013-07-18
Age : 64
Location : N. Smithfield, Rhode Island

http://www.stilburnin.com

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  Marleysky Fri Jun 15, 2018 5:45 am

Dang! Roddie, that plane looks good enough to FLY! The only thing that should hold you back now is the “Sticker Police “. You gotta have a ⭐️ or stripes or flags or a Cox sticker on it. Go, go, go for it!
Marleysky
Marleysky
Top Poster
Top Poster

2022 Supporter

Posts : 3618
Join date : 2014-09-29
Age : 71
Location : Grand Rapids, MI

Back to top Go down

P-38 Lightning-Roddie style..  - Page 8 Empty Re: P-38 Lightning-Roddie style..

Post  Sponsored content


Sponsored content


Back to top Go down

Page 8 of 9 Previous  1, 2, 3, 4, 5, 6, 7, 8, 9  Next

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum