Cox Engines Forum
You are not logged in! Please login or register! Guests are limited to posting in the "General Questions (Guest Posting Allowed)" section only. Becoming a member is fast, easy and FREE!


Log in

I forgot my password

Search
 
 

Display results as :
 


Rechercher Advanced Search

Cox Engine of The Month
December-2018
Dave P.'s

"RC Tee Dee 049"



PAST WINNERS
Speed Contest 2018
CEF Traveling Engine

Win This Engine!
The Traveling Prop
Gallery


World of Aviation

P-38 Lightning-Roddie style..

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

Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Thu Feb 15, 2018 10:38 am

rsv1cox wrote:You sure have put a lot of time, thought, and effort into that model roddie.  It's going to turn out wonderful.  I can't wait to see your paint scheme.  As I have mentioned before and you alluded to, everything from solid to quite involved.

Bob

A lot of time in thought Bob.. but not all that much in actual fabrication. Probably between 8-10 hours so far. I'm still undecided concerning a paint scheme. The dark/blue-gray "base" is pretty much definite. Maybe a lighter-grey on the bottom..
avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  rsv1cox on Thu Feb 15, 2018 10:50 am

Standard European WWII paint scheme with invasion stripes...................

That's what I'm thinking for my "copy everything roddie did" profile P-38. Imitation is the sincerest sort of flattery. It's been 40 years since I built mine so it's time for another. Scoping out my balsa stash now. Engines are never a problem. Gotta get started soon, 70 degrees here today, Spring is coming and the MG is waiting.

Bob
avatar
rsv1cox
Top Poster
Top Poster

Posts : 3348
Join date : 2014-08-18
Location : West Virginia

View user profile

Back to top Go down

fillets..

Post  roddie on Thu Feb 15, 2018 11:15 am

Here's what my fillets look like after sanding-out with some crocus-cloth.




The crocus-cloth is nice.. in that it cuts the spackle quickly and is "cloth-based".. so it does not crease easily when curled into a tight radius.



I should do a 2nd app... but I'm not going to go crazy here. I also have more work to do on the controls.. so there's the possibility of some "dings" happening.
avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Thu Feb 15, 2018 11:27 am

rsv1cox wrote:Standard European WWII paint scheme with invasion stripes...................

That's what I'm thinking for my "copy everything roddie did" profile P-38.  Imitation is the sincerest sort of flattery.  It's been 40 years since I built mine so it's time for another.  Scoping out my balsa stash now.  Engines are never a problem.  Gotta get started soon, 70 degrees here today, Spring is coming and the MG is waiting.  

Bob

I would LOVE to see you build one Bob!!! This one has been really enjoyable for me. My other Lockheed models' "wing" looks a little better after sanding-out too..




and the little "Flying-Blind" speed-model got some fillets..




avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Thu Feb 15, 2018 5:21 pm

I bought the rattle-can paint today, that I'd been procrastinating over..




I don't know how the "satin" will work out.. but that's the finish I want. I'll have to test-spray a few pieces of wood.. let the paint cure for a couple of weeks.. then subject it to some glow-fuel and see what happens.

avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  getback on Thu Feb 15, 2018 6:11 pm

You got any lustercote coat CLEAR you can cover with ? I don't think that Saitan by itself will do even 25% nitro  ,, But will depend on how much it is flown Laughing   Looking good!!, the plaster job done pretty good after the fact Shocked I am going to bee the Ass i am and ask >>. Why did you not round the engine block mounts ?!? Two Cents
avatar
getback
Top Poster
Top Poster

Posts : 5152
Join date : 2013-01-18
Age : 61
Location : julian

View user profile

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Fri Feb 16, 2018 9:27 am

getback wrote:You got any lustercote coat CLEAR you can cover with ? I don't think that Saitan by itself will do even 25% nitro  ,, But will depend on how much it is flown Laughing   Looking good!!, the plaster job done pretty good after the fact Shocked I am going to bee the Ass i am and ask >>. Why did you not round the engine block mounts ?!? Two Cents

I "do" have some Lustre-Kote.. but it's gloss. Maybe Lustre-Kote can be made "matte" once cured, by rubbing-out with fine steel-wool? I actually saw some rattle-can satin-clear Krylon where I bought the blue paint.

Regarding my engine-mount blocks.. Laughing I suppose I could round the back edges with a dremel drum-sander. They're hardwood blocks. Just about all of my designs for radial-mount engines use them. I know they look a bit fugly.. and most profile kits for radial-mount engines use balsa "cheeks" faired-back toward the wing's leading-edge. The issue with cheeks for me is; they take up nose real-estate for mounting an external fuel tank. I like to mount my tanks as close to the engine as possible.. using the shortest possible fuel-line. Engine cowlings would take the curse off the bare-blocks look.. but a cowling on a profile-model is tough to make look good.
avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  getback on Fri Feb 16, 2018 9:38 am

Well its up to you i was just wondering and as you said : ; Engine cowlings would take the curse off the bare-blocks look.. but a cowling on a profile-model is tough to make look good.




Unless you were to make some fairing that would make things better But a lot of extra work  Doh!
avatar
getback
Top Poster
Top Poster

Posts : 5152
Join date : 2013-01-18
Age : 61
Location : julian

View user profile

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Fri Feb 16, 2018 5:36 pm

getback wrote:Well its up to you i was just wondering and as you said : ; Engine cowlings would take the curse off the bare-blocks look.. but a cowling on a profile-model is tough to make look good.

Unless you were to make some fairing that would make things better But a lot of extra work  Doh!

Yea buddy.. about that "extra work"... I honestly need to be committed for some of the thoughts that I put into my models.. and "this one" is no exception. My aim was to install a bellcrank using a machine-screw and lock-nut.

This is a Sig #234 1/2A Nylon bellcrank.. with its' "bearing" drilled-out to accept a 3-48 machine-screw.



Look at the photo for a bit... because I spent WAY TOO LONG making this assembly.. (thanks...) The brass tube/bushing is a standard 1/8" OD tube that I cut to length using my X-Acto mitre-box. The models' sheet-wing is thinner than 1/8" after sanding. It's actually under .100"... so the bushing needed to be thinner than 1/8".

Lately.. I tend to build my flying-models with hardware designed to test time. It's kind of silly I know... but if someone takes possession of my models after I'm gone.. I'd like them to know that I meant for them to last as long as possible.
avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Sat Feb 17, 2018 11:08 am



..lead-out guides today.. maybe..
avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  rsv1cox on Sat Feb 17, 2018 12:54 pm

It's looking great roddie and coming along quickly now. Not too long before prime and paint. I'm sure all those attachments will be removed first.

You must have wrestled with the cockpit detail, painting it on correctly can be a make or break. I made a mess out of the cockpit on my profile Mosquito. The way that Jim did his was so much better. I hope you kept a picture of Jims.

Thinking about my prospective profile P-38. Twin .049's, been there. Twin Enya 09's, been there on my Mosquito. Done twin Enya .15's in the past. But, twin ganged third line throttle controled Enya 19's, that's different. Will need to double up on the profiles which means a new order from SIG.

Bob
avatar
rsv1cox
Top Poster
Top Poster

Posts : 3348
Join date : 2014-08-18
Location : West Virginia

View user profile

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  getback on Sun Feb 18, 2018 7:00 am

lol! lol! lol! Well i looked at the Fine looking job you did on the Bellcrank leads for like 5 min.s or at least till i stopped laughing when you said it TOOK WAY TOO LONG !! Laughing Hell i am still smiling < Thanks , the plane is coming along nicely Roddie Popcorn O hea i am in the process of cleaning that want to bee a work (hobby) table , little more organizing am i will bee ready to make a Mess ! tongue
avatar
getback
Top Poster
Top Poster

Posts : 5152
Join date : 2013-01-18
Age : 61
Location : julian

View user profile

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  balogh on Sun Feb 18, 2018 7:27 am

Nice job, Roddie,

when will you maiden it and with what engines?
avatar
balogh
Diamond Member
Diamond Member

Posts : 2002
Join date : 2011-11-06
Age : 60
Location : Budapest Hungary

View user profile

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Sun Feb 18, 2018 8:42 am

rsv1cox wrote:It's looking great roddie and coming along quickly now.  Not too long before prime and paint.  I'm sure all those attachments will be removed first.

You must have wrestled with the cockpit detail, painting it on correctly can be a make or break.  I made a mess out of the cockpit  on my profile Mosquito.  The way that Jim did his was so much better.  I hope you kept a picture of Jims.  

Thinking about my prospective profile P-38.  Twin .049's, been there.  Twin Enya 09's, been there on my Mosquito.  Done twin Enya .15's in the past.  But, twin ganged third line throttle controled Enya 19's, that's different.  Will need to double up on the profiles which means a new order from SIG.

Bob  

Thank You Bob! Yes.. the control-system parts will be removed prior to painting.. but I'll probably just cover the gear-struts rather than remove them.

Below is the link 944jim's BMH Mosquito-build. The fuel tank location seemed to be an issue.. Huh... I wonder how/if he found a solution.. Very cool paint/trim on that model!

https://www.coxengineforum.com/t10666-bhm-mosquito-in-ms-build?highlight=mosquito

Twin throttled Enya .19's sounds ambitious! I didn't know that you had any Enya engines.. Laughing Laughing Laughing

avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Sun Feb 18, 2018 9:09 am

getback wrote:lol! lol! lol! Well i looked at the Fine looking job you did on the Bellcrank leads for like 5 min.s or at least till i stopped laughing when you said it TOOK WAY TOO LONG !! Laughing Hell i am still smiling < Thanks , the plane is coming along nicely Roddie Popcorn O hea i am in the process of cleaning that want to bee a work (hobby) table , little more organizing am i will bee ready to make a Mess ! tongue

Thanks Eric! yea... I had to mess around EVEN MORE with that bellcrank yesterday. I had drilled-out (enlarged) the nylon bearing's hole for the 3-48 machine-screw. The assembly was binding.. so I had to open-up the hole a little more. Then I had to shim under the bellcrank with a few flat-washers to allow my pushrod to move freely. It attaches via an "L-bend" which created another binding-issue against the wing. That was probably the actual cause of the assembly binding.. Rolling Eyes Because of having to shim the bellcrank, this required me to cut a longer screw to compensate. blah blah blah... Rolling Eyes

Keep up the work on the table/bench Eric! Soon you'll be cutting-up some balsa. It always make me feel good!

avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Sun Feb 18, 2018 9:52 am

balogh wrote:Nice job, Roddie,

when will you maiden it and with what engines?

Thanks Andras! If I started the paint-process today.. the model wouldn't be ready to fly for at least another month. We're looking at sometime in "April".

Planned-engines are Cox .049 reed-valve, configured as "product-engines" (Sure-Start type horseshoe backplates/carbs.. except without choke-tubes) and probably #1 cylinders. That's the "plan".. but if I encounter a severe tail-heavy condition after painting.. I drilled the engine-mounts to also accept Bee-style engines.. and have a pair of Golden-Bees that I could try. I'm counting on the former option though. Whichever.. I want them to be fuss-free/easy-starting.. at least for the maiden-flight and until I get used to how it fly's. I also plan to run those DAL 5 x 4 L/H props on both engines.
avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  balogh on Sun Feb 18, 2018 11:39 am

I was always fascinated by twin COX engine powered planes!

The L/H props is really a good idea to have the gyro torque pull the bird outward from the CL circle. I am looking forward to hearing/reading from you.
avatar
balogh
Diamond Member
Diamond Member

Posts : 2002
Join date : 2011-11-06
Age : 60
Location : Budapest Hungary

View user profile

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Sun Feb 18, 2018 4:04 pm

balogh wrote:I was always fascinated by twin COX engine powered planes!

The L/H props is really a good idea to have the gyro torque pull the bird outward from the CL circle. I am looking forward to hearing/reading from you.

Andras my friend, "thank You" for the encouragement. It's anyone's guess whether this airplane will fly. Most people don't realize what's involved in designing a flying model. It's probably much easier to design a control-line model.. than it is to design a free-flight or radio-controlled model.. (excluding a control-line precision-aerobatic model)

It's a thrill for me.. to be able to achieve controlled-flight of my designs. If they're capable of aerobatics.. all the better!

I have only designed/built one other multi. My 1st started-out as a "single-engine" self-designed model for Cox .049 reed-valve (Babe/Golden-Bee) power back in the early 1990's. As a single-engine model.. it was terribly under-powered. It had a HUGE plank-wing (1/8" thick x 6" chord x 30" span..) and a sprung landing-gear design and heavy-wheels that probably weighed 2 oz. in itself.. Rolling Eyes

I would later fashion two cheesy engine-mounts attached to the leading-edge of the wing.. to which I would bolt "two more" engines. Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked

and the model was no longer under-powered.... Laughing lol! Laughing lol! Laughing lol! Laughing lol! Laughing lol!

I still have it..  




The central engine-mount (nose) broke-off at some point.. along with the undercarriage/landing gear. It could still be hand-launched and flown as a twin though.
avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  rsv1cox on Sun Feb 18, 2018 4:37 pm

You are at a point now where you could install your engines and get a ball-park idea of where your balance point is, paint or no paint.  

Our two P-38 models are very close in size but probably quite different in weight.  I think I posted pictures of mine sitting on a scale but I have forgotten what the weight was.  Your model should be much lighter.  

My model balances perfectly at the leading edge of the wing, back about a half inch and it becomes nose heavy but not to the point where it does not fly, circles only.

You might get away with the complexity required of those product engines, pegs, bands, remote fuel tanks and all.  But I would recommend your stunt tanked Golden Bees over them in a heartbeat.  Golden Bees have always been my best running, easiest starting, and most reliable Cox engines.  

Looking forward to April

Bob
avatar
rsv1cox
Top Poster
Top Poster

Posts : 3348
Join date : 2014-08-18
Location : West Virginia

View user profile

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  NEW222 on Sun Feb 18, 2018 6:19 pm

Ok roddie. Question time! Unless I missed it somewhere along the way... What is the reasoning behind the leadouts going through the inboard nacel(?) and fuselage and ending up just inside the outboard nacel? In laymans terms, why are the leadouts and control rod on teh outboard edge? Or is there any reasoning, and you did it just because you chose to? Thanks. And looking good, getting closer to teh end of the build!
avatar
NEW222
Diamond Member
Diamond Member

Posts : 1609
Join date : 2011-08-13
Age : 40
Location : oakbank, mb

View user profile

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Mon Feb 19, 2018 10:40 am

NEW222 wrote:Ok roddie. Question time! Unless I missed it somewhere along the way... What is the reasoning behind the leadouts going through the inboard nacel(?) and fuselage and ending up just inside the outboard nacel? In laymans terms, why are the leadouts and control rod on teh outboard edge? Or is there any reasoning, and you did it just because you chose to? Thanks. And looking good, getting closer to teh end of the build!

I did explain why, early-on.. but it wasn't in the form of a topic. Many readers could have missed it.

Because the elevator is "inside" the tail-booms; its control-horn is also on the inside. To mount a bellcrank conventionally (inboard) posed more than one issue. Bellcrank operation would have required a long slot to be cut in the nacelle; compromising the integrity of the wing-joint. The "pivot" point (bellcrank screw location) would fall directly on the nacelle.

Mounting the bellcrank inboard of the cockpit module leaves no means to support the 11.0" length pushrod from flexing.

The Sterling P-38 kit S-17 references installing the bellcrank "backwards" (see below)..




I suppose I could have done it the "Sterling" way.. but it still involves routing the lead-outs through the inboard nacelle.. and I don't like the idea of that lead-out/pushrod intersection. It just seems like an accident waiting to happen.

My application simply utilizes the "outboard-nacelle" similar to a conventional profile-model control-installation. It also provides functional outboard-weight. In combination with running left-hand propellers; the model may not require any outboard wingtip weight. There are no offsets built-into the engine mounts or either rudder.

avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Mon Feb 19, 2018 11:49 am

rsv1cox wrote:You are at a point now where you could install your engines and get a ball-park idea of where your balance point is, paint or no paint.  

Our two P-38 models are very close in size but probably quite different in weight.  I think I posted pictures of mine sitting on a scale but I have forgotten what the weight was.  Your model should be much lighter.  

My model balances perfectly at the leading edge of the wing, back about a half inch and it becomes nose heavy but not to the point where it does not fly, circles only.

You might get away with the complexity required of those product engines, pegs, bands, remote fuel tanks and all.  But I would recommend your stunt tanked Golden Bees over them in a heartbeat.  Golden Bees have always been my best running, easiest starting, and most reliable Cox engines.  

Looking forward to April

Bob

Hi Bob, I did get an idea on where the model balanced with product-style engines installed.. but it was far from conclusive at that point. It was a "mock-up" with 3 very heavy wheels on the gear..




The weight in ounces "with engines".. but less wheels, fuel-tanks or control-system.



As usual.. I'm counting on adjusting the models' balance/CG "functionally". One means is through the use of different weight wheels. The 1.375" diameter Perfect-brand wheels (shown) are HEAVY wheels to run on a 1/2A model.. (even with twin-engines)

I will be weighing the model periodically.. and also checking its balance to get an idea of what to expect. It will be interesting.. and I'm not discounting the possibility of running the Golden Bees. I already provided for their mounting if need be. An excessively tail-heavy condition following paint/finish may necessitate their use.
avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  rsv1cox on Mon Feb 19, 2018 12:24 pm

Looking great roddie, balance is about where mine is.  Where are your home-made foam wheel/tires?  Bet they would be much lighter.  

The weight is half of mine which weighed in at about 15.85 oz all up.  I'm seeing a great flyer in your future.  Rock and roll.

Bob
avatar
rsv1cox
Top Poster
Top Poster

Posts : 3348
Join date : 2014-08-18
Location : West Virginia

View user profile

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  NEW222 on Mon Feb 19, 2018 12:49 pm

Thank you roddie for the explanation. I am probably the only one that missed it.... Smile
avatar
NEW222
Diamond Member
Diamond Member

Posts : 1609
Join date : 2011-08-13
Age : 40
Location : oakbank, mb

View user profile

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  roddie on Mon Feb 19, 2018 2:15 pm

rsv1cox wrote:Looking great roddie, balance is about where mine is.  Where are your home-made foam wheel/tires?  Bet they would be much lighter.  

The weight is half of mine which weighed in at about 15.85 oz all up.  I'm seeing a great flyer in your future.  Rock and roll.

Bob

I fab'd-up some of my homemade wheels this afternoon. I had previously CNC routered a bunch of different sizes from 3mm "Dibond"; a rigid material (panel) used in the sign industry. It has a dense plastic core with aluminum facers bonded to each side.

The hub-hole is 1/8" diameter.. because the wheels were routered with a 1/8" endmill. I made a mandrel from a long 5-40 machine-screw and nuts for grooving the plastic-core to fit an O-ring tire. Chucked in my drill-press; I use a 1/8" dia. round rasp to cut the groove.





The larger wheels are 1.375" diameter with the O-rings mounted.

Their weight per pair is 4 grams



and below; the Perfect-brand 1.375" streamlined wheels' weight per pair is 20 grams..



I weighed the model again today with controls installed.. and pretty-much everything except paint and the .5oz. fuel-payload.  

We're at just over 9 ounces.

avatar
roddie
Top Poster
Top Poster

Posts : 6112
Join date : 2013-07-17
Age : 58
Location : N. Smithfield, Rhode Island

View user profile http://www.stilburnin.com

Back to top Go down

Re: P-38 Lightning-Roddie style..

Post  Sponsored content


Sponsored content


Back to top Go down

Page 4 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