Tempest-RCU

My Feedback: (98)

Hi Dave!

I love your cowl flap mechanism. I guess great minds think alike. Your design looks very similar to some pictures I posted of my Don Smith Hellcat several months ago.

Have you figured out how to attach the actuators to the flaps, while still facilitating removal of the cowl? This is the part I am up to. I have an idea in mind but any other ideas would be welcome.

Regards!

Paul

Longlake

Hi Dave,
Sorry my stupid Post for info and a search for airplane in Fla I could buy got mixed in with your, " I know it's not personally owned by you" thread on this beautiful Bearcat project. I wish you were my neighbor! your genius is taken for granted by yourself I believe. Anyway, I just wanted to let you know that in the quiet of this Sunday AM before church, I read the entire story. That is why a person like me ends up giving away kits, because I see a person of you stature and think I can get round to it!, keep up the great work and photos and let me know if you want to build a Hellcat. I might sell a child or something!, :stupid: Kindest Regards,

Dave G

My Feedback: (1)

Paul, As a matter of fact, I think it was your photos that led to my "system" for the actuator. The difference being my cowl flaps are part of the fuselage, hence I'll attach the actuators to the firewall with a pair or short links to the cowl flaps. Look at the picture in post #20.
On yours, I can see (in my mind) a 1/4" plywood "lifesaver" bonded to the inside of the cowl that the actuators are attached to so the system stays with the cowl when the cowling is removed. The only other way I can see it working (with out putting the situation to a committee) is to have the cowl sectioned. You know, the cowl flaps would stay attached to the portion of the cowling but the rest of the cowl could be removed.
And yeah, I'll stick with the line "Great minds think alike".

Lee, Thanks for the kind words. I'm not a special builder... I just like building. It must be in my blood. Like I mentioned before, this has been a dream project of mine for years and is my 37th "scale" r/c model. Some things get a little easier with repetition. Pick a kit you like and start it. You may put it away for a while, but it'll be there when you want to work on it again.
As for trading a build project for a youngin'... Send me a scan of their hands. There's all sorts of spots where tiny fingers are required! LOL

Tempest-RCU

My Feedback: (98)

Thanks Dave for the ideas. My preference is to have the flaps remain attached to the cowl only because with the flaps attached to the fuselage, I can envision the hinge line not always lining up every time I put the cowl back in place.

Similar to your "lifesaver" idea, I was thinking of fashioning some form of slotted track that the actuator pin can engage allowing the cowl to be slid on and off.

By the way, I love the various parts you have machined for your Bearcat! You are doing a beautiful job...

Who's retracts are you using? I know Darrell Tinney (of Sierra) is working on a set of Bearcat gear.

Regards!

Paul

Dave G

My Feedback: (1)

Paul, The scale articulating gear are being done by Gene Barton. They're do to be shipped at any time! I've built Bearcats with fixed gear and a couple with the "too short" retracts, so this'll be a first with scale gear. I'm aching with anticipation.

I had talked with Darryl from Sierra about the gear but he was busy getting ready to do the Cactus Bear and wouldn't be ready to get into the Bates gear for quite some time.

Gene had done the Bates Bearcat before and the new gear incorporate some improved locks and features. I can't wait.

I'm going out of town for work (in a week) for a week. I sure hope they show up before I leave!!!

k_sonn

My Feedback: (32)

Dave:

Have you made any more progress on the Bearcat build?

Dave G

My Feedback: (1)

Kirk, Thanks for keeping tabs on the project.

I'm still building and have been accumilating photos of the work to post.

I've decided that I wouldn't post any of the wing construction until the gear show up. My last report from Gene was that the gear have been cycled with air and should be in my hands next week!

I should be posting more often than I have been, but there aren't too many replies so it's easier to post several pictures on the progress at once.

Are you building or planning on building one of Jerry's designs?

Happy Landings

k_sonn

My Feedback: (32)

Dave:

I was building a Bates Hellcat. Had to put it aside for awhile so I could build a couple planes for customers. I hope to get back to it by in the fall. I started a build thread in the User Prodcut Review section: www.rcuniverse.com/showthread.php?s=&threadid=363671&forumid=142. I really want to build a Bearcat in the near future. I have been tettering back and forth between Ziroli and Bates. Did you compare the two? If so, any reason why you chose the Bates? I am having a hard time deciding between the two. Currently, when I have spare time, I am finishing a Top Flite Bearcat that has a carbon fiber fuse..

Dave G

My Feedback: (1)

Kirk, Checked out your thread and all I can say is that's a fine looking project . Jerry should use your thread as a builders manual! Hope you're back on it soon.

As for "Did I compare the two"? You bet. Ziroli's is truely more "scale" but my issue was 2 fold. First was: what made a plane with 6 inches of more wing span weigh 30+ pounds? I figure my project will be right around 16 pounds. I'm trying to "buy" and build light, but I'm not skimping on any of the goodies either... Smoke, lights, cockpit, 10 servos, 4 batteries, and of course the scale articulating gear. I'm a desent pilot, but a bird with a 86" wing at 33 pounds would be a handful for me. I'm not knocking Nick's birds. He's had several designs that have inspired me.

The other issue I had was that "this" Bearcat was going to have scale gear and if I had picked the Ziroli Bear, Century was the only company with this gear (at $900 I believe). Now I know some guys swear by CMJ gear but I wouldn't own a set. When I went searching for gear, Darryl at Sierra was working on the Cactus Bear and Gene Barton, who had built some for Tianno for the Bates Bear was up for the job. I think he said his current price is $500. Then a wood kit by Cornell Michaels, practically fell in my lap, so the decision was made.

I'd still like to do a bigger version. I'd like to do one in 1/4 scale. It would have a 96" wing, and I know it would come in around 30 pounds if I built it from scratch. The situation would be I'd have to machine the gear myself which I have a very complete set of prints for. I should build the gear first!

BTW... Where on God's Earth did you ever find a carbon fiber fuselage for a Red Box kit? I've been building Red Box Bearcat kits for 20 years and have never heard of it. Please tell me it did not come from Top-Flite!

k_sonn

My Feedback: (32)

Dave:

Thanks for the info. I aquired the carbon fiber fuse from a friend who had purchased it many years ago. From what I understand only three were made. Here's a link to the thread where I posted a picture of it: www.rcuniverse.com/showthread.php?s=&threadid=949058. I have purchased a red box kit and used the ribs for templates. I have built the wing. I still need to build the tail feathers. I will try to take some pictures of what it this weekend and post them to the above mentioned thread. If you know anyone looking for a red box Bearcat let me know. I want to sell the one I purchased..

MikeChilson

My Feedback: (2)

Dave,

Thanks for supplying TON's of info on your project. I have been working out a cowl flap mechanism for an upcoming project and after seeing yours it I like the way yours works. I'll be making some mods to mine.

Anyway, Keep up the good work. It's always a pleasure to watch a skilled builder work their magic!

Dave G

My Feedback: (1)

Man Mike. Do you hear that noise? It's my head blowing up like a helium balloon! Thanks for the words.

Guess I'd better post some of the latest work. Soon.

Dave G

My Feedback: (1)

Never let it be said that I can't be corrected. The comments that I made on how I chose this plan to work from was addressed by by Jerry in an email to me and I'd like to take time to set the record straight. Jerry has taken his valuable time to set the record straight for all of us who don't have an idea of what it takes to produce "scale" plans. Below is most of the email from him. I never knew it involved this much work just for the paper I've almost taken for granted for so long. Thanks Jerry.

Dave,

I don't mean to be a hard-nose about stuff like this but it is an issue that I am very sensitive about. Mr. "X's" approach is to develop a model that is easy to build, flies very well, and looks very close to the full scale aircraft. He normally selects a 3-view that 'looks right', then uses it for the basis of his model. His model designs are beyond reproach in our Hobby/Sport. I can only dream about having the success, accomplishments and respect that he has won and deserves.

My philosophy is to develop a model that first, has "exact scale" outline. The construction is based on a time proven one that virtually guarantees a true and straight airframe. It does not depend on the workmanship accomplishments of the individual builder to produce a warp-free model. Minor compromises of the full-scale aerodynamics are often made to extend the "flight envelope" (primarily increase the time between stall approach and full stall) that will produce a model with good flight characteristics.

After deciding on an aircraft to model, I collect all the 3-views and factory drawings available for a subject. I will also collect all model plans of the subject near the scale and size of those I intend to produce. I then photograph and field measure all the full size aircraft I can find. I purchase every book I can find on the subject and study the design, construction, development and service history of the subject. I often interview pilots of the subject and obtain all Flight Manuals, Erection Manuals, and Service Manuals for the subject. This process alone may take as many a 8 years (as it has for my latest subject, the Lockheed Hudson and Ventura). At this point, I will draw a definitive 3-view of the subject, if one does not exist. This must be published before it can be officially used in documentation for judging the model.

Now, design of the model can begin. Often the initial drawings are done full size, at 1 to 1 scale, so field collected dimensions can be added to the drawings without the need of rounding off a multiplier to meet the drawing scale. This help increase accuracy by eliminating mathematical errors during this stage. The object is to produce a "very scale" model that utilizes the fewest amount of parts and simplest means of construction. The primary goal is to produce a very rigid and light weight airframe.

During this time retracts must be developed for the model. I will work with Darrel Tenny, Century Jet and Robart to see that they have all the data to produce a set of scale-like retracts that will replicate the full size version and fit into my plan design. Compromises must be dealt with for retract design as well. All of these manufacturers are capable of building retracts that a virtual miniature duplicates of the full size products. In many cases, this level of scale detail, the price will put the retracts out of reach of all but a very few modelers. The basic product must duplicate the action of the full scale units but the majority of scale detail must be omitted in order to market to the majority. A scale modeler will find it very easy to add the level of detail required for the intended competition class to which they are building.

With airframe design complete, files are developed for use in laser cutting a proof-build prototype model. The prototype
model is used to ensure fit and finish of all cut parts. The model is completed to the point were models can be taken of the cowl, canopy, etc. These parts are developed into production tooling and sent to the fabricators. The model is then flown to proof the flight characteristics.

A construction manual must be written that includes subject history, model construction, finishing, painting, flying, and scale drawings. Then we are ready to market the plans and accessories.

As you can see, there is a lot of time and expense involved in producing a "true scale" plan and accessories. No matter how scale a competition model is, or is not, it will be scored against the documentation provided to the judges. Theoretically, you can build the most not-to-scale P-51 known to man, and still win first place if your model matches the 3-view and other documentation provided the judges. My goal is the raise the bar in providing a model that, in fact, matches the outline of the full scale subject, and if necessary, providing the scale drawings that can be used to judge your model.

Perhaps the Bearcat you saw was highly modified by a very accomplished modeler to produce a more scale outline.

Thank you for your time and allowing me to explain my positions on how scale my plans are with regard to other subject plans on the market.

Jerry Bates

iatemydingo

My Feedback: (1)

back to work!! :-D

Dave G

My Feedback: (1)

Dingo, yeah- breaks over and I'm back at it .

Here's the 1/4" plywood that was used in the firewall mockup, back in post #74. The idea is that this circular ring will be epoxied to the inside of the cowling having alignment pins and attaching holes for hardware into the firewall. If you look back to post #74, you can see it outlined on the print.

Dave G

My Feedback: (1)

Here, a fairly special tool called a "drill jig" is clamped to the firewall with a drill bushing and a 1/8" bit to drill the first alignment pin hole. The jig is then relocated to drill the hole for the blind nut. A 1/8" steel dowel pin is slipped into the first hole and the jig is moved to the 2nd lug on the plywood ring.

These jigs and bushings are indispensable when the only option is to freehand a hole with a hand drill. Try keeping it square to the firewall when it's already at a 4-1/2 degree angle! They can be purchased through Aircraft Spruce, Wicks, ATS, or several other aircraft tool supply stores.

Dave G

My Feedback: (1)

Here the jig has been moved to the 2nd lug and you can see the dowel pin in the first lug and the through hole for the hardware. A blind nut (Tee Nut) will be installed on the aft side of the firewall and the dowel will be bonded in the firewall. 6" drill bits make it easier to keep from binding the bit in the bushing.

Dave G

My Feedback: (1)

Here all the dowel pins and blind nuts have been installed and the ring is being held with 4-40 socket head cap screws. Once the ring is epoxied to the cowling, a nice long, "ball end" hex key will make attaching the cowl to the airframe a snap. The bottom of the ring will be trimmed away after it's bonded in place since the cowling has a built in "cowl flap" molded in the open position.

Dave G

My Feedback: (1)

Here the upper cowl flap actuator is fitted. After making 2 different set ups of this, installing it was easy. A through hole in the firewall still needs to be drilled for the push pull to the control horn. I'll wait until the wing is fitted and the servo installed since the rod that the control horn is mounted, may need to be shortened. (The little pillow block, closest to the control horn, has not had it's attaching hole drilled through the firewall yet.) The whole set-up works so silky smooth and has no free play at the control horn. I may lop off the attaching holes on the 2 pillow blocks at the tank box and install them with a dab of epoxy on the face of the firewall. We'll see...

FliteMetal

Interesting comments and observation of Nick's Bearcat....over Jerry's...considering one has an exact scale outline.

What documentation was used for comparison? The same 3 VU Nick used to draw his planset? ............. ;^)..................

xanaphyst

My Feedback: (17)

Well it's time to put some fire back on this thread...after a long wait to get started on my project i'm finallyat it ! Had to move into the new house and build a workshop first !!!! Here is a shot of the work table with the reference lines drawn out for the formers. All reference lines are marked as measured from
F-1 to keep it accurate. My wife says it just looks like lines on a table but i say it looks like Rare Bear...silly woman !!![img][/img]

xanaphyst

My Feedback: (17)

Here I am getting started .....this is f-2 up to f-13 in place. This jig was constructed " a-la- Dave G. method". The .25" square crutch line stringer sits
perfectly level across all "upright tees". A combo of tight string lines and a laser level aided in lining it all up just right and final shimming completed with pieces of magazine paper.[img][/img]

AirRayInc

My Feedback: (7)

being a Bearcat fan,
I am curious about the excellent progress, any updates?
Ray

ProfLooney

Dave for some nice scale wheels ya can afford in the future goto http://WWW.SCALEWHEELS.COM they are out of the uk and they have tires up to 8" in diameter

Joe

Dave G

My Feedback: (1)

Ray, Thanks for checking in on the projects. As you can see my buddy is finally getting his under-way. Mine's had great progress... If you include that I built the entire wing for the fun of it. Seems there's a wing meant for the "sport" gear, and the mounting points for the scale gear don't match the sport wing.

I had the wing at about 80 percent complete when the scale gear showed up and my heart just sank. A few phone calls to Jerry and some serious measuring took place and the only way to save the wing would have required a major butcher job, and I wasn't about to do that. I trashed the sport wing, Jerry got the scale wing drawings to me and I started another from scratch.

My work load at my job triples toward this time of year, so the progress on the new wing started off slow. I've got most all the new pieces cut and fit and the scale gear will be just fine once I figure out the plumbing with the inner door sequencer. The new wing has more scale flap and aileron hinging.

Pictures will come once assembly has progressed further and I get the hang of the new RCU format. I think for the forums, I like the old way better. More progress pictures soon.



Joe, Thanks for the tip on the wheels. If I can convince the powers "above" (me at work) I'd like to produce "my" wheels and sell 'em cheaper than anybody. I can't give them away, of course, but a fairly scale looking wheel shouldn't cost as much as the engine! We'll see.

Happy Landings