SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Feb 07, 2009, 07:09 PM
Big gov never Works
St. Martin's Avatar
Skunk Water, Rhode Island
Joined Jul 2002
12,346 Posts
Build Log
Warbirdkits.com Consolidated B-24

It's been 13 months since I did a build thread with a prop on the front. It's been a yr of EDF's. Well, last was with two props. (enlarged Midkiff A-20 Havoc) Now I'm up to 4 props. What happened to the good ole' days of building single engine fighters.. But the sound of a multi engine cruising by is always worth the effort!

This design started yrs ago with David Collins. Tom Jacoby purchased this design from David. It was never finished, by David, and Tom changed some areas for the better. Tom started building one, but it went on the back burner. So, I got the job.

Now..I think I really need to get one of my Guillows kits out of my archive, and build it. Maybe the Hellcat, which I have done atleast a dozen times. The reason? For the first time, I'm finding freeing lazer cutting parts laborious The Guillows will help me apprieciate the lazer parts again. It could be, that I'm just getting old and cranky. A condition I have recognized as Morganitis.

Wing Span is 73.5" with 553Sq Wing area. It has 4 ch of control with retracts. Robarts 600 series mechanical. Interesting, the plans show the belly turrent hooked up the the nose retract. When the gear it retracted, the turrent drops. Neat!

I am considering bomb bay Function and flaps. Power will be 4-Tower Pro 2409-12 mtrs, on a 3s system. GWS HD 9-5 3-blade props. Started preparation of parts about 3 hrs ago. Still have the ply parts to do. Another interesting feature, of this design, is there is no cutting of sq stock to form the fuselage sides. All pieces are lazer cut! If the fit is good, this will be a time savings.

Lazer cutting was performed by Charlie and Vicky Bice @ Manzano lazer works. Always a good job, you two! I will be in and out of this project. I still have a few EDF builds to perform, that are temp on hold. But I see no problem in doing the maiden on a calm early summers morning or eve.

Fuzz
St. Martin is offline Find More Posts by St. Martin
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 07, 2009, 07:17 PM
Big gov never Works
St. Martin's Avatar
Skunk Water, Rhode Island
Joined Jul 2002
12,346 Posts
Forgot to mention: The horizontal stab has two different construction methods. The ribs with the cradles are Davids early design. Tom's change was to use a 1/16" profile with riblets. I will decide the better of the two.

Fuzz
St. Martin is offline Find More Posts by St. Martin
Reply With Quote
Old Feb 07, 2009, 07:40 PM
Oh no, not again!
jhspring's Avatar
United States, LA, Carencro
Joined Dec 2005
5,365 Posts
Nice. I had inquired about this it a year or so ago and was told it was on indefinite hold. I will definitely be following with interest.

Cheers,
Jeff
jhspring is online now Find More Posts by jhspring
Reply With Quote
Old Feb 07, 2009, 07:51 PM
Big gov never Works
St. Martin's Avatar
Skunk Water, Rhode Island
Joined Jul 2002
12,346 Posts
Yes, Jeff, Tom and myself were pretty locked up in other designs and things in life. And lately it has been Jets. I'm not a part of Warbirdkits, other than helping Tom develop designs. As what works in CAD is not always true in real life. I have my work cut out for me. All bucks need to be made for the canopys, etc. And any changes that show up during the progress. One thing for sure, I have yet to work on one of Toms designs, that were not successful. And his openess for input is the best.

Fuzz
St. Martin is offline Find More Posts by St. Martin
Reply With Quote
Old Feb 07, 2009, 10:06 PM
Now in TN!
J Morgan's Avatar
Chapel Hill, TN USA
Joined Apr 2001
24,438 Posts
By the time this build is done, you will have Morganitis.

CB
J Morgan is offline Find More Posts by J Morgan
RCG Plus Member
Latest blog entry: OV-10A Bronco from Palmer Plans
Reply With Quote
Old Feb 08, 2009, 01:50 AM
Big gov never Works
St. Martin's Avatar
Skunk Water, Rhode Island
Joined Jul 2002
12,346 Posts
How true, CB! It's going to take half a balsa forest to sheet it. I'm honestly thinking of Depron. Considering this alternative to wt savings, Depron and glassing VS balsa and silkspan/lacquer, both would equal about the same AUW. Wot's your view on this, CB? Any suggestions on the thickness of the Depron and availability?

Fuzz
St. Martin is offline Find More Posts by St. Martin
Reply With Quote
Old Feb 08, 2009, 04:53 AM
Registered User
alangorham's Avatar
Bedlington, England
Joined Mar 2003
222 Posts
Hi Steve

Just like Jeff above, I asked Tom how this one was coming along some time ago. I was thinking of having a go at designing my own, but I'll hold off now and enjoy watching your progres instead.

Enjoy!

Alan
alangorham is offline Find More Posts by alangorham
Reply With Quote
Old Feb 08, 2009, 06:01 AM
Now in TN!
J Morgan's Avatar
Chapel Hill, TN USA
Joined Apr 2001
24,438 Posts
Quote:
Originally Posted by St. Martin
How true, CB! It's going to take half a balsa forest to sheet it. I'm honestly thinking of Depron. Considering this alternative to wt savings, Depron and glassing VS balsa and silkspan/lacquer, both would equal about the same AUW. Wot's your view on this, CB? Any suggestions on the thickness of the Depron and availability?

Fuzz
I think I would consider 3mm depron. Get it here:
http://rcfoam.com/

But you work so well with balsa that maybe you should just stay with it. Depron would be cheaper though.

CB
J Morgan is offline Find More Posts by J Morgan
RCG Plus Member
Latest blog entry: OV-10A Bronco from Palmer Plans
Reply With Quote
Old Feb 08, 2009, 09:35 AM
Imagine That!
TomJacoby's Avatar
Tularosa, New Mexico, United States
Joined Jan 2003
1,638 Posts
Quote:
Originally Posted by St. Martin
How true, CB! It's going to take half a balsa forest to sheet it.
Fuzz
Steve, it's not really designed to be sheeted. David designed a ton of free-flight stuff and this model reflects the techniques he developed over the years. Plus, when David designed this model, brushless power was still on the horizon. With four GWS-350 power plants, one of his aims was to keep the weight down.

But the electric r/c scale scene has dramatically changed over the years since I acquired the rights to this design (2004, IIRC). We now have extremely economical brushless motors and can handle the additional weight of sheeting. And the B-24 fuselage's slab-sided cross section is so simple that sheeting ought to be quite easy.

The proliferation of really small, light and inexpensive servos over the last few years leads me to believe that the empennage should be redesigned with individual servos for each control surface: two rudders and the elevator. This would eliminate the need for David's pull-pull rudder setup and long elevator pushrod, and eliminate my cable-operated rudders.

By the way, this is why I put my prototype on the back burner. All it needs is the empennage and it's ready to cover!

I would also like to see the empennage made removable. That would have been a real chore with the pull-pull setup, but not so difficult with servos in the empennage.

While we're at it, why not give the retractable belly turret its own dedicated servo.

I like the idea of operating bomb bay doors, and am anxious to see what you come up with! IIRC, the real B-24 had roll-up doors. Flaps would be a nice option, too.

One other area that could use your attention is the wing center section. David designed it for max strength, but it's a challenge to build.

Here's some interesting shots of a B-24:
http://electraforge.com/brooke/fligh.../b24_2005.html

Tom
www.warbirdkits.com
TomJacoby is offline Find More Posts by TomJacoby
Reply With Quote
Old Feb 08, 2009, 05:40 PM
Big gov never Works
St. Martin's Avatar
Skunk Water, Rhode Island
Joined Jul 2002
12,346 Posts
Glad you found the thread, Tom. Yes, I finally figured out that David did not intend the aircraft to be fully sheeted. It was when studying the wing, I noticed only the LE is sheeted on the top, back to the spar. I'll let you decide if you want it sheeted, Tom. This is stand-off scale. And even the Midkiff A20 was open frame. And it was not noticeable. If it is fully sheeted, the center section could be lightened. There is a lot of unneccessary plywood there.

The plans were slightly too large to build on. (not refering to the 6% larger set you sent) Plus the set that was supposed to be used were cut off not showing the fuse nose or necells stab and wing tip panels. I figure the plans were approx 1% too large.

But a tribute to parts fit only requires a 90deg starting point. So far I only found two parts wrong size. F-40 and F-39. Both opposite each other top and bottom fuse. I extended them with 1/8x1/4" scrap, and the fit perfectly. The lazer cut "sticks" for the fuse sides, were a dream. Really speed framing up.

I'm working out the nose gear mounting now, before I cannot access the area. So far, I noticed that the nose gear will need a "yoke" bend in the gear. This to retract the wheel in the fuselage center.

The fuse top view only shows one stab mount. Wich is all that is provided. While the stab and fuse side view shows two. I will design in two mounts. As I agree that it needs this area accessable. The top bulkhead in front of the stab assembly (F-43) will be duplicated so as to have that area above the stab cradle completely removable. I also have finished the numbering of the fuse bulkheads. Some are incorrect. I had to use the process of elimination to find the proper locations. But all is well.

I may just make the bomb bay doors a non-scale affair. Needs more thought. Flaps are a simple thing. They look split type. Rudders, elevators and ailerons were fabric covered. I have 10 yds of very light polyester dress lining material(NO I HAVE NOT TAKEN UP MAKING MY OWN DRESSES!) This material is like silk. Will iron on with Balsa-Rite and simulate these areas. Rib stiching? Maybe, easy enough to do. Last done on Greg Smith's Rittenger 109.

Fuzz
St. Martin is offline Find More Posts by St. Martin
Reply With Quote
Old Feb 08, 2009, 07:44 PM
Imagine That!
TomJacoby's Avatar
Tularosa, New Mexico, United States
Joined Jan 2003
1,638 Posts
Quote:
Originally Posted by St. Martin
Glad you found the thread, Tom. Yes, I finally figured out that David did not intend the aircraft to be fully sheeted. It was when studying the wing, I noticed only the LE is sheeted on the top, back to the spar. I'll let you decide if you want it sheeted, Tom. This is stand-off scale. And even the Midkiff A20 was open frame. And it was not noticeable. If it is fully sheeted, the center section could be lightened. There is a lot of unneccessary plywood there.
Steve, I will sheet the fuselage of my B-24 from the wing cradle forward. It probably isn't necessary, but the CA I used to assemble the fuselage sticks isn't holding well - probably got contaminated.

Unfortunately, the wings aren't designed to be fully sheeted. I suppose it would be easy enough to revise the ribs for sheeting, but it's probably not necessary.

At least it's lite ply in the center section! But lite ply has its own problems: warping, for one. Most of the lite ply in my prototype kit (cut in 2003 or 04, not by Manzano) was very wavy by the time I got around to working on the model four years later.

Quote:
Originally Posted by St. Martin
The plans were slightly too large to build on. (not refering to the 6% larger set you sent) Plus the set that was supposed to be used were cut off not showing the fuse nose or necells stab and wing tip panels. I figure the plans were approx 1% too large.
Staples continually frustrates me on printing. They don't seem to understand or care what "100%" means!

Quote:
Originally Posted by St. Martin
But a tribute to parts fit only requires a 90deg starting point. So far I only found two parts wrong size. F-40 and F-39. Both opposite each other top and bottom fuse. I extended them with 1/8x1/4" scrap, and the fit perfectly. The lazer cut "sticks" for the fuse sides, were a dream. Really speed framing up.
Glad you found those two incorrect formers. I did too, but forgot which ones they were Once you figure out the numbering system for the sticks and formers, it does go together quickly!

Quote:
Originally Posted by St. Martin
I'm working out the nose gear mounting now, before I cannot access the area. So far, I noticed that the nose gear will need a "yoke" bend in the gear. This to retract the wheel in the fuselage center.
It's "standoff scale" - I just left the nose gear strut straight on mine
I must admit that there's a touch of Rube Goldberg in the nose gear retract linkage.

Quote:
Originally Posted by St. Martin
The fuse top view only shows one stab mount. Wich is all that is provided. While the stab and fuse side view shows two. I will design in two mounts. As I agree that it needs this area accessable. The top bulkhead in front of the stab assembly (F-43) will be duplicated so as to have that area above the stab cradle completely removable. I also have finished the numbering of the fuse bulkheads. Some are incorrect. I had to use the process of elimination to find the proper locations. But all is well.
I don't recall any of the bulkheads being numbered wrong, but then it's been a year since I worked on my model. I don't remember what I did yesterday, much less a year ago.

Quote:
Originally Posted by St. Martin
I may just make the bomb bay doors a non-scale affair. Needs more thought. Flaps are a simple thing. They look split type. Rudders, elevators and ailerons were fabric covered. I have 10 yds of very light polyester dress lining material(NO I HAVE NOT TAKEN UP MAKING MY OWN DRESSES!) This material is like silk. Will iron on with Balsa-Rite and simulate these areas. Rib stiching? Maybe, easy enough to do. Last done on Greg Smith's Rittenger 109.
Fuzz
The roll-up doors on the full-scale were probably a great idea, but I bet they jammed regularly. Some sort of positive actuation will be needed for both up and down.

-t
TomJacoby is offline Find More Posts by TomJacoby
Reply With Quote
Old Feb 08, 2009, 07:48 PM
Now in TN!
J Morgan's Avatar
Chapel Hill, TN USA
Joined Apr 2001
24,438 Posts
What's that white stuff outside the window?

CB
J Morgan is offline Find More Posts by J Morgan
RCG Plus Member
Latest blog entry: OV-10A Bronco from Palmer Plans
Reply With Quote
Old Feb 08, 2009, 07:50 PM
Imagine That!
TomJacoby's Avatar
Tularosa, New Mexico, United States
Joined Jan 2003
1,638 Posts
Quote:
Originally Posted by J Morgan
What's that white stuff outside the window?

CB
Not FOME dust, I hope!

-t
TomJacoby is offline Find More Posts by TomJacoby
Reply With Quote
Old Feb 09, 2009, 03:57 AM
Big gov never Works
St. Martin's Avatar
Skunk Water, Rhode Island
Joined Jul 2002
12,346 Posts
Tom, some bulkhead positions were not labled and F-66 was shown both top and bottom. All I remember this morn. I think I will sheet the entire plane. With the exception of the fabric covered areas. I guess it could be a builders option. Not really a massive change of thing for the builder. And the fuselage is quite stiff, even without the stringers.

One point I have been thinking: batt placement. It looks like it may have to have a removable nose piece to slide the batt(s) above the nose retract. The gear takesup all the room. Easy to get built into a corner here. As I have no ideas as how she will require that placement for the CG.

All that white stuff is slowly going away. It's been around since before Xmas. Last days have been warm. Tired of looking at the dirty stuff!

Fuzz
St. Martin is offline Find More Posts by St. Martin
Reply With Quote
Old Feb 09, 2009, 10:24 AM
I eat glue
Canada, NS, Yarmouth
Joined Jul 2006
3,451 Posts
I could send you some of our white stuff, we've had a few relatively warmer days, but still have about 3 feet of it.
baldguy is online now Find More Posts by baldguy
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Anyone done a 90" Jack Stafford B-24 Liberator? Randall Miller Scale Kit/Scratch Built 21 Mar 26, 2010 11:18 PM
Discussion Warbirdkits.com B-24 Tram Scale Kit/Scratch Built 3 Feb 16, 2009 04:23 PM
R/C Guillow's B-24 Flyer103 Power Systems 6 Oct 26, 2007 08:05 AM
Looking for Consolidated B-24 Kit or Plans planefun Electric Plane Talk 8 Nov 21, 2003 05:39 PM
I'm looking for a B-24 dave_lilley Aircraft - Electric - Airplanes (FS/W) 4 Oct 18, 2001 11:27 AM