Tony Hallo

During slack times on the Super Cub I decided the finish off a Godfrey One Design that I aquired through an estate sale. This is an orginal ready to cover one that was still in the orignal shipping container made for shipping on a bus. This plane was owned by a member of a club I belong to however I didn't know the owner as our paths never crossed. The story in the club was he paid a rather large sum to have the container build, more than the cost of a modern day ARF. This plane was build long before ARF of the size were available. The plane is far from ready to cover. I will post photos of the plane construction, engine mounting, sevro mountng, controls, painting, etc.

I can move this post to another forum if this isn't the right place, this build is closer to a kit build vs. ARF since all the decisions are on the owner.

The plane is small for a 37 1/2% scale model, on the order of 90" WS. It will powered by a ZDZ 80 Super. Photos of the engine mount/cowl fit to follow.

Tony Hallo

The firewall is fit together dry with #4 flathead screws. Absent any instructions I set it at 2 degrees right thrust, zero down thrust. I'm using the the "fit throught firewall" method to mount the engine verses standoffs, these rear intakes engines are somewhat a pain to mount. Depending on how the project works out I may seal off the carb from the engine heat and drill ventilation holes into the fuselage for cool air. I expect this plane to somewhat overpowered so I haven't really make that decision just yet. The engine/muffler combo is is a litlle larger than designed so I had to hack away at the cowl to get the muffler to fit.

After the epoxy sets, I will glass the firewall with 6 oz. cloth back two inches or so on the sides. The screws will remain in place. There was three pieces of 3/4" triangle stock provided for the firewall with the plane. I elected to use hardwood instead at this critical connection.

Tony Hallo

The aileron servo mounting was a challenge, the original location of the horn is right in the middle of the bay. I elected to install 1/4" lite ply mount for the servo, the servo is mounted pararell to the alieron. I didn't provide any hatch, the open bay is fully sheeted on the bottom side to provide the push rod slot and provisions for future servo maintenance. If I need to get into the servo area in the future, I will cut an access hole in the sheeting and cover with a piece of Monokote after repairs are complete.
The pushrod is my own design, 5/32" OD carbon fiber tube, the ends are K&S 3/16" heavy wall aluminum tube 5/8" long, I drill 3/8" deep into one end of the to 5/32" diameter drill, the end is CA'ed to the carbon fiber tube with thick CA, once the CA cures, I tap the rod for 4-40. The aluminum sleeve provides 1/4" of 4-40 threads plus 3/8" sleeve to prevent splitting of the carbon fiber tube. A 1" long 4-40 sockethead is threaded into the rod with red Loctite, the head cut off with a Dremel tool.

Tony Hallo

The canopy that came with the plane was pulling away at the glue joints, I ordered a new one from Precision Aircraft, the replacement canopy has a very nice blue tint, a nice touch, I made a new frame and eliminated the rear former so the the model will look like the full scale plane as shown on the cover of Sport Aviation.

hrrcflyer

Hey Tony,

So far so good. Keep up the good work and keep us posted.

Fly safe and have fun!!
David

Tony Hallo

Tonight I continued on the wings. The plane came hinged for Klett style hinges so I decided to use them. Normally on a foam rib wing I would use Robart pin hinges however the Klett style offer some advantages. You can locate the hinges anywhere along the trailing edge, when I use Robart hinges I add additional foam at the hinge location which is normally near a rib, I may continue using this style in the future for foam rib wings.
I decided to bevel the trailing edge for additional aileron travel, it's 1/4" thick so I beveled it 1/8". I believe this plane was built before the 3D movement, just about every aerobatic today has beveled trailing edges. Put a coat of filler on, hopefully tomorrow I will attack the wings with 150 grit sandpaper, might even get to 220 grit, depends on the quanity of Miller Lites I consume!

Tony Hallo

I got the wings ready to cover so here we go. I start by laying out the patterns on the wing. I am covering this plane similar to the One Design shown on the previous photo, the difference is Royal Blue will be used instead of black for the stripes. Next the white covering goes on, I allow for 1/8" to 1/4" overlap between colors starting with the lighest first.

Tony Hallo

Next the red goes on. I decided to cover the leading edge to give it a little protection while working on the rest of the covering.

Tony Hallo

The final product, one down, one to go.

Tony Hallo

After a summer season of flying this plane I decided upgrade the exhaust system for several reasons. The engine never cooled very well I suspect due to the cowl configuation, muffler location and lack of negative pressure inside the cowl and the Johnson muffler was somewhat noiser than I cared for.
I purchased a JMB canister but the wing tube location didn't allow for satisfatory installation. I just couldn't find a big enough shoe horn. I decided to made my own canister that will fit into the aircraft. The size of this muffler will be somewhere between the JMB and the original Johnson muffler.
The body is 3" OD x .035" 6061 aluminum tube 9 " long, the inlet tube is 1 1/8" x .035" aluminum tube, the outlet is 1" X .049 aluminum tube.

Tony Hallo

The Johnson muffler weights 13.1 ozs. The JMB canister weights 15.4 ozs and my design is about 8.1 before welding. I have about 13 times the engine displacement for muffler volume, somewhere sometime someone told me 10 times the engine displacement was the minimum required for an effective muffler system, time will tell.
I have a new cowl, canopy and wheel pants on order from Precision Aircraft, shipped today.
I have about $35 in material, if this works out, I might just continue to build my own canisters.

mmattockx

Tony,

Where did you get 3"OD x .035" wall aluminum tubing?


Thanks,
Mark

Tony Hallo

Aircraft Spruce. Get other of material from them, mostly spruce and aluminum.

darrolair

Tony Hallo,

How did that ZDZ super 80 handle your airplane? What did your plane weigh? How were the flight charactistics? Would you change anything else and did you after flying it for awhile? Do you have some finished pics? Nice job of building.

Darrolair

Tony Hallo

Plenty of power, this is not a 3D plane as it was designed and built long before 3D became popular so the control surfaces are scale size rather than 3D size. Never weighted it, I would guess somewhere in the lower 20's, not much you can do once the plane is built, just add as little weight as possible when finishing it off. The main change I am making is for better engine cooling. RC Showcase states engine temperature should be less than 220f, don't really tell you how to measure this, I would taxi back as quickly as possible, kill the engine with the choke and measure the cylinder temperaure near the plug, started out near 290F, added internal baffle and air dam on the muffler, got down to 250f on cooler days, the engine temperature heated up as the day when on to 270f or so.

darrolair

Tony,
I'm sure it's not a 3D airplane, it's a looker. I bet it catches the eye of everyone at your field. Just fly and have fun.

Darrolair

Tony Hallo

It's down for a total rebuilt now, moved the engine to the horizontal position, new cowl and canopy. Hopefully I can get it to run cooler with better flow through cooling, time will tell.
The plane was cursed last year, on the second day out had a dead stick landing in the high weeds, broke the fuselage in half, first rebuild. Later in the year the canopy fell off work bench and broke. I srewed around with carburator for a month until I replaced the Tilletson with a Walbro, problem solved. I decided to redo petty much the whole plane. Only difference this time I will use black strips rather than Royal Blue since I ran out of Royal Blue base coat finishing while finishing off last year. The weather getting nice in this part of the world so I got to get busy!
It's different model plane, not the typical Cap, Yak, or Extra you see at the flight line, that's what I like.
I will post photos as rebuilding progesses.

darrolair

Tony,
Sorry to hear the news. Hope you can revive your plane. Keep posting, I'm interested in your plane. Godfrey has some good designs. I don't fly 3D, but love to see airplanes do certain manuvers that tell me the flight characteristics of the plane. It's also becoming better weather here for flying and I'm getting itchy thumbs. Good luck.

Darrolair

Tony Hallo

Darrolair,
Here the most recent progress. New cowl is mounted and the canopy is finished, waiting for the 560 canopy glue to dry. The turledeck really didn't like the Monokote removed twice, too many heating operations, I'm filling the imperfections with Lite Fill.
Started making the cooling baffle. Laid out the location on the cowl where the baffle will be located , made a tram out of scrap balsa wood, and then trammed the cowl where the baffle is located, measure back to center the depth of tram to develop the cowl shape where the baffle is located.
I cut 1/4" dowel the same distance as tram depth. This layout is then cut out 1/8" plywood, I tried to use the Seetemp shape but it was just too flimsey.

Tony Hallo

I cut a larger hole in the plywood where the engine is approximately located, taped the baffle in place after checking fit and making several adjustments. Made up the engine baffle with Seetemp, great stuff by the way. Put everything together and tape the Seetemp to the plywood.

Tony Hallo

For the baffle I laid up two pieces of fiberglass cloth on a piece of wax paper, I think they may be 2 oz. in weight, not sure. Once cured the baffle will be cut out and glassed into the cowl.

Tony Hallo

For the air exit, I'm making two louver sections out of fiberglass, here is a photo of the mold. One layup will produce open area equaling the air inlet on the cowl. The louves will be located behind the landing gear. Air from the cowl inlets flows through the baffle, around the muffler and out the louvers. At present time I do not plan any additional penetrations in the cowl except for the spark plug, hopefully everthing works as planned???

darrolair

Looking good Tony. Where did you get the idea to create the cooling baffle. Good idea.

Darrolair

Tony Hallo

Most planes today have some form of baffling unless the cylinder is exposed to airflow. My cylinder was exposed but due the shape of the cowl, I don't believe good airflow was established over the cylinder. I checked my temperature against other planes at the field where I fly and mine was the hotest. I did measure as low as 180f on one plane but really didn't care how much of the cowl was removed.
Here are some photos of the finshed baffle installed. I added balsa reinforcement across the top and once final shape is determined I will add 1/8" also. Right now the epoxy isn't totally cured.
The canopy fits better than before, I'm not sad I decided to go over the whole plane.

Tony Hallo

Here's a photo from the original installation, the cylinder head didn't stick out much beyond the cowl. I flew the plane as shown without any baffling, too hot. Added baffle in front and air dam on the muffler, this was maginally acceptable. Due to steep shape of the cowl, I didn't believe I was getting any benefit from suction induce to draw air out, just building high pressure in the cowl.
At any rate stay in touch, there not much action on this post.