Joystick TX

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<input class="windowbg" type="checkbox" style="border-bottom: 0px; border-left: 0px; display: none; visibility: hidden; border-top: 0px; border-right: 0px" name="del0" value="0" /> Got the fuselage plans scaled up to full size, just used dividers to measure points on the magazine plans for the 40" model and used them to mark the same points at double the size for the 80" version.

Nothing critical here except the gas engine bulkhead. Had to decide if the nose should be shortened due to the gas engine weight difference from the electric motor. Decided to leave the nose alone, just add a 3/8" bulkhead and build in 2 deg. down-thrust.

Bought some 12" x 180' masking paper at Home Depot to lay out the full sized plans.

BMatthews

Likely shorting the nose is a good idea. But it'll depend on how the model already looks and how light or heavy you figure on the tail coming out.

Keep in mind too that going double size means that the entire structural plan will need changing. Things like you'll need twice the number of ribs and likely the wing spar will need complete redesigning and the tail surfaces will likely need redesigning. If you just double all the wood sizes and leave the rib spacings alone the model will come out too flexible and weak. It really does require a full structural work over when going up this much bigger. You end up with a whole new design that just happens to share the same look as the small model.

Joystick TX

Good input.

I have a few other challenges that are unique. None of the internal structure will be the same.

My plan is to keep the basic outline and moment arms the same.

The main fuselage structure, the tail surfaces,and some of the wingwill be built from expanded PVC foam, AKA "Klegecell." It requires a lot of thought and planning to get it to work on aircraft. It has no grain and is not very rigid. It is also heavier than balsa or lite ply. This is my second "big" aircraft that will use it. The wing loading will be about one-third heavier than thekits of this size.

I completed the lofting of the fuselage side and topand havemarked thefirewall andbulkhead locations using the TLAR method.

The Klegecellfuselage sides will be skinned with 1/16" balsa. Now I need to determine if I need to bother with lightning holes at this point to meet my design weight goal of 15 lbs.

For those of you who never saw this plane, here is the picture from the magazine:

kdc

This seems the least likely model to double in size. The original 40 inch is a very lightly built electric model weighing just 20 ounces.. thats one and a quarter pounds! There is nothing in the construction that looks very substantial, it is all lightweight rather like a vintage model.

Double the size! 30cc engine!..........= accident waiting to happen!

Joystick TX

I don't plan ontrying to double the size to come up withan 80" wingspan, 30 cc gas engine, 40 oz. model.Sorry for the confusion.

I thought the design goal of 15 lbswas a clue that the internal structure will be a tad bit stronger than the electric version. I am not attempting to keep the weight down to 2 1/2 pounds; my engine alone would eat up that by itself.

Klegecell is another clue, it is a structural foam material, nothing like the foam cups used for drinks.Itis available in manysizes and weights. It can bedense enough to drill and tap; so it can evenbe used for motor mounts or firewalls. I figure if it is good enough for the hull ona 26' long sea-going boat, it should be okay for the fuselage on a model aircraft. I don't expect this plane to fall apart unless I dumb-thumb it into the ground.

This is also not my first plane. I've been building since 1948, designing since 1955 and flying RC since 1971.

kdc

Why start from the Bell Hop rather than a model already designed for this size? Why use such a large engine? A similar size model such as the Bandito Grande 82 inch span 15 inch chord weighs 12 pounds and uses a .90 twostroke (15cc) ( just the first example I came across ) Surely 30cc is too much power and 15 pounds is too heavy? I would have thought lite ply and balsa would be lighter.

For the benefit of those who have not seen the Bell Hop plan its an 8.5 inch root chord and 6.25 inch tip chord at 40 inch span for about 100 watt electric.. So doubling to 80iinch makes this 17 inch with 12.5 inch tips

optech

My Feedback: (9)

Kadzooks!!!! Just let the guy do his thing. This is obviously not his first rodeo. Have you ever seen a Bandito Grande sized plane on a .90 two stroke..... Boring!!!! After about two passes over the field I'm ready to go watch grass grow instead. My RC Guys Agwagon ARF was about 16-17lbs with a 32 gasser and was alot of fun. So much so that my next one will have an even bigger engine.

I applaud the ingenuity. Finding something you like and making it your own is a very lost art in model aircraft these days and will be watching this build with interest.

Mike

Joystick TX

The answer to all the "whys" is because I like the basiclooks of the Bell Hop; I want a tough plane with a little higherwing loadingfor windy weather and rough short-field use; I like Klegecell because I have a lot of it, it is a challenge to usein an airplaneand it's free; I like the 30 cc gas engine and with a 30 cc, the weight will not be a problem; I don'twant to use lite plybecause it is expensiveandthis will not be a 3-D plane so there is no need to build a super-light structure.

You may not be aware of this, butsome of the Bandito's are powered by 30 cc engines. We even have some people in our club that put 30 cc engines in 10 lb planes.

Joystick TX

Got the flat part of the fuselage sides done with the doubler's and the bulkheads drawn up.

Joystick TX

Joystick TX

Got a good start on the fuselage. It goes together pretty quick. I'm using Gorilla glue for a lot of it since weight is not an issue. Still need to decide if I want to use a built-up wing or foam. I'm leaning toward built-up right now.

Some pictures. I made full sized paper templates for the bulkheads and glued them onto the material and cut them to rough shape with a band-saw and jig-saw. Final sanding was done on a 12" disk sander.

One reason I liked this design it because it has no curves, that makes the parts easy to sand to shape.

Joystick TX

Despite the 100+ temps in the workshop, the fuselage construction is almost complete. These pictures show the bulkheads installed, sheeting put on, the main and tail landing gear mounts installed, and the cockpit cutout completed.

Joystick TX

Got the 14 wing rib patterns drawn up along with the jigs to hold the building rods for the correct washout.

Next step is totack glue them onto the Klegecel material and cut them out. I have a lot of the green stuff so I'm going to use it up, it is a little heavy, but that will not be a problem with this plane.

Exhaust3

Joystick,
How's the build coming, any updates? I've been itchin' to see this thing through!! Keep us posted!!

Joystick TX

Right now the weather has been too good to build, so I spenda lot ofmy time flying. I figure our bitter cold winter building season should hit for a couple of weeks in January and maybe a couple in February, that may ground me long enough to get the wing build.

I have felt guilty about not working on it lately, so it is possible that I may get out to the shop and do some work on the wing.

I'm happy with how the fuselage came out. Hope the wing comes out okay.

Joystick TX

I managed to get in an afternoon's work on the plane today.

Got all 28wing ribs cut out. I rough cut them on the band-saw and sanded them to shape.The reason the rib template lines are so thin is to help make them as accurate as possible when they are sanded.

The total weight came out to be7 oz. which is not too bad for the material used. They are 1/4" thick Klegecell,same material as the fuselage. I used hard for the inner ribs and tips, with soft for the ones in the middle. I decided not to use any lightning holes.

I also decided not to use the green Klegecell, it was just a shade too heavy according to my TLAR calculations. Also, I think the brown looks better.

Iused the rod holding jigsas a template for drilling the holes for the building jig rods and cut all the notches cut for the wing spars.

Now all I need is another burst of building energy to get the parts glued together to make something useful looking

Joystick TX

Almost finished with one wing half. Got to cut out the ailerons and do a lot of sanding.

The wingweight is 12 oz right now. It will go up a little with the addition of the ailerons and wing tubes. The wing span will be a little over 86". I will be happy if the weight comes in under two pounds.

The fuselage is about 90% complete. Right now, it weighs 1 lb - 9 oz, which is not too bad considering the material I'm using.

So far I have used Gorilla glue for almost all of the construction because of the PVC foam, I need the expansion characteristicsof the Gorilla glue.

Joystick TX

Got the aileron cut out. They are way more work than I remember. Now I know why I used the barn door type for 40 years.

I need to make the mounts for the Robart hinges and put in some trim wood to fill in the open bays. That will take a while.

Joystick TX

Got the hinge pockets finished. They are made with 1/16" balsa and hardwood. They will be glued to the wing and aileron ribs with Gorilla glue. I don't like to drill the pockets for hinge points on big planes. The hinges will be glued in place after the wing is covered.

Dave Hancock

Hi Steve, I'm building Sid's 40inch Bellhop as my first build. Sid's a member of my local club and has been really helpful but that hasn't prevented me making a right mess of it so far. We are dying to see your finished plane but it has been ages since your last post. Have you made any progress? If so, it would be great to see some photos.

Joystick TX

It appears that I like flying a lot more than building. Our building season here is only a few weeks long and it is hard to get much done in such a short amount of time.

I've also had quite a few interruptions to building the plane. I need to get back to it again before the weather gets too hot in the barn.

Say hi to Sid for me, I love his design.

Joystick TX

I started work on my Bell Hop again. Noticed that I put the Robart hinge point sockets in on the bottom of the left wing instead of the top. Bummer. Now I have to make four new sockets. I also couldn’t find the full-sized plans for the wing, I finally figured out that I never made any. Guess I’ll just use the left wing as a guide and hopefully make a good right wing. Having the second engine has given me a little building boost.

Joystick TX

After watching the Red Green marathon for the last two weeks. I think I discovered THE SECRETs to build or repair an airplane so fast.

I've been using the wrong tools. That's why it takes me years to build a plane.

Here is a picture of me using one that I thinkRed would use to get a nice rounded leading edge.

No, no, no, this is NOT to get the leading edge to a rough shape, this is the "final finishing". I used an Axe to get the rough shape.

Okay, not really. But if you must try this at home, check with your doctor first, make sure your life insurance policy is up to date and please wear proper protection, especially a cup. Don't ask me how I know that last part, it hurts just to think of it.

Joystick TX

Got the hinge points glued in on the ailerons. Slow and tedious work. Got to get them closed up after the glue dries. The wing joiner tube will be the next "hard" thing to install. I should have drilled the holes before I installed the ribs, but I didn't get the tube early enough, so the correctsize was a question.I think I'll make this a one peice wing. Transporting a big wing is not a problem for meand it will be stronger.

Joystick TX

Got the wing tube holes cut. It was not too hard. At least the wing fits together okay.I did manage to accidently poke a hole in the covering, the wood there was too soft anyway, so it needed to be replaced. That's my story and I'm sticking to it.

Got to figure out how to fasten the wing to the fuselage. I'm not fond of wing dowels, may go with four 1/4" plastic bolts, got to do some thinking on that one.

This wing is almost too big for my little shop.