RE: 4*120 Build Thread
 

I had 2 of my fellow club members tell me that they could cover a 4*120 wing in "about an hour". :eek:

I spent about 9 hrs covering my wing. I did add the other 2 stripes. It's all done.

I told those guys, "Maybe YOU could cover it in an hour, but I don't want it to LOOK like I spent an hour covering it. I want it to look like I spent 9hrs covering it."

I don't see how you could cover this wing in an hour. Maybe 2 hours if you just didn't care at all what it looked like.

The fuse is going to take DAYS at the rate I'm going.

RE: 4*120 Build Thread
 

I'll tell you what, it takes a long time to cover a plane. I'm basically done with my 85" Ultimate, but man, it took forever! I'd spend three hours in the garage and it would seem like nothing would get done. I don't see how these China factories produce these so quick.

RE: 4*120 Build Thread
 

RC: I know what you mean about time! I spent about 6 hrs on the fuse. It takes me an hour to get the wrinkles out of an ARF! If someone could cover a plane using 4 rolls of iron on covering...they're way ahead of me! This evening I finished sanding the Horizintal and Vert stabes and surfaces...they're ready to cover. I also glassed the wing center section with 4" and epoxied the firewall and inside of the cowl cheeks.

When we're finished, I may have to drive down to Pueblo and fly around the pattern once or twice with you!

Murphey (as in Murphey's Law)

RE: 4*120 Build Thread
 

Come on down!! Your always welcome. Would love to fly the 4*120 airplanes together.

I ended up buying 9 rolls of covering for my plane. I'm only using 3 colors. It takes 4 rolls for the wing panels. 2 rolls for the fuse. About 3/4 roll for the tail surfaces. And then the black on the bottom of the wing--that was about 1/2 a roll. I'm using monkeykote redon top of the wing for my graphics.

Probably a big red bullseye on the right wing and the letters RYOBI 31 on the left wing, also in red.

RE: 4*120 Build Thread
 

Top of the wing is done. Still need to do the left aileron and hinge it. Right aileron is done.

A measly 4 hours to do this. This covering don't take any time at all.:eek:


Pics of top and bottom:

RE: 4*120 Build Thread
 

Looks Great! How did you do the graphics?
I'm glad to see that the covering between the ribs doesn't draw in too much...I call it the "starving horse" when the ribs show!
I'm out of town on business and won't be back to Denver 'till the end of the week so no progress this week. On Saturday I'll at least get the tail surfaces covered and attached. If I can stay at home it shouldn't be too much longer!

Looking Good RC!

Murphey (As in Murphey's Law)

RE: 4*120 Build Thread
 

The graphics are just red monkeykote.

For the bullseye, just used a compass and drew a couple circles. Cut them out with scissors and ironed them on. There is 1.5" spacing between the rings. Center ring is 3" diameter and outer ring is 14" outside diameter. I did get a few blister bubbles on the bullseye rings, but it looks fine from 3' away. You can't see them until you get 12" away. Works for me, I don't build hanger queens anyway.[:-] I build them to FLY!!!

For the letters, I used Microsoft Word and increased the font size untill the letters were about 8" tall. Then I printed them on seperate pieces of paper and cut them out. Instant templates.:D I traced them on the monkeykote and cut them out. Ironed them on with a low heat setting on the iron.

I sealed all the edges with monkeykote trim solvent.

RE: 4*120 Build Thread
 

Looks good RC. I,ve been building like crazy lately:D and I'm just finished the fuse tonight. I think though I'm going to beef up the landing gear mount by making another FBF light ply piece that's 2" longer so it will be 1 continuous piece that goes right over the landing mount and existing FBF. I figure if I epoxy the begeebers out of it , it should strengthen the mount and front end up alot. Thats a big heavy landing gear hangin on that little mount. Not to mention a few rough one's.




Ken

RE: 4*120 Build Thread
 

What does a Robi way?

RE: 4*120 Build Thread
 

It weighs about 4.25 pounds after you lighten it up with an aluminum muffler. I have electronic ignition on mine--haven't weighed it since installing that. Maybe a 4--6 oz weight savings.

RE: 4*120 Build Thread
 

Guys:
I'm having troubles with my digital camera. I am taking pictures, but the card either isn't storing the pics, or the reader won't recognize them. It's all fouled up and I'm NOT happy about it. I think I need a new digital camera. I've tried formatting the smart media card. Reloaded the drivers for the external card reader. Nothing is working.

I've done a little work on the fuse. since the last pics. I never installed the turtledeck stringers before, because I was worried about hanger rash on those sticks while I was building the rest of the plane. I finally installed those stringers.

If you look back in this thread, you will notice that the sides of the fuselage in front of the firewall stick out quite a bit. These "cheeks" are going to flop around and vibrate if I don't do something to reinforce them. They stick out past the firewall by 7". I just put some balsa sheeting in there and rolled it around the front curve on the cheeks. It goes down under the plane about 2" past the crankshaft. I stopped there, because the cylinder head is in the way. Looks pretty good.

I finally installed the 1/8" top sheeting on the fuse from the cockpit up to the firewall. I blended it all into the sheeting that I put between the cheeks, so that it's all solid on top. I'll just have to punch a couple holes for acess to the carb needles from the top. Remember, the engine is mounted inverted.

I'm trying to talk my wife into either a new camera, or at least pop $25 for a new smart media card and see if that fixes it. I suspect the card, because the software is proven and I have a new and clean computer.

I'm afraid that I may be finished covering the plane before I can get this problem with the camera figured out. I'll keep taking pics, and try get them transfered to my hard drive, but right now it doesn't look to promising.

SORRY!!!!![:o]

RE: 4*120 Build Thread
 

I don't know what happened, but the camera is working.[sm=spinnyeyes.gif]

Here's some pics of the engine after mounting it for about the 10th time.:eek: It takes 45 minutes to bolt the engine in. My engine and mount all have to be bolted on as a unit. The carb is in the rear, and it makes it REALLY REALLY hard to get an allen wrench in there to run the bolts into the firewall. I'm NOT taking it off again.

I managed to stuff my ignition unit and my smoke pump down in the front, right behind the firewall. Took a small sledgehammer and a lot of axle grease to get it all in there. I even jumped up and down on it a little.

The smoke muffler is tapped with a Bisson smoke injector nozzle that is reduced to .040" at the spray nozzle.

RE: 4*120 Build Thread
 

Covering pics.

I always cover the top and bottom first. Then I do the sides last.

I started out with the bottom, behind the wing saddle. Then I worked up to the turtledeck. Next I covered the top hatch area and the front of the plane where I added 3/32" balsa sheeting to tie my cheeks together.

After that I went down to the bottom of the fuse. and worked on the area in front of the wing saddle.

I just finished covering the right side and I need a brake. I'll try and work on the left side either tonight or tomorrow.

RE: 4*120 Build Thread
 

Glueing the tail on.

This is the first time I've had it all put together. She looks GOOOOOOOD!!!!!!!!! Oh Man, I can't wait to fly this baby!!

I put the LG on today. I was about to put the wheelpants on--but my senses got the better of me. I'm going to fly it 1/2 dozen times before I put the pants on.

Everything lines up perfect. I can't believe it. I just built this plane without even really trying very hard, and it came out just about as perfect as they get. My intention was to just slap it together and get it off the bench. I wasn't going to worry about making everything perfect. And, it just turned out that way. This is the straightest plane I've ever built, and I wasn't even trying.

I got the stab glued on first and checked it with a tape measure and some string. The wing is straight on the fuse closer than 1/32" from 1 tip to the other. So, for me--thats good for an 83" wing.

When I put the stab on--it's perfect. Not even 1/64" off. This thing is gonna either fly perfect off the board without any trims--or it's gonna snap in on take off and instantly get re-kitted.[sm=bananahead.gif] Who knows?

I'm getting excited now. After the tail dries, I'm going to take the wing off and drop servos. Then I'll drop servos in the tail and fish my extensions up through the fuse to the wing saddle and find a spot for the RX.

I just might fly this thing next week. Local club member and flying buddy RETNAVYCDR has volunteered to get a video of the maiden for me.

Pics:

RE: 4*120 Build Thread
 

I got the tail section control surfaces hinged and glued.

5 CA hinges per surface.

Pics:

RE: 4*120 Build Thread
 

Two reasons it turned out straight- it's a SIG and it's a 4-Star. Just add glue and shake well :D Got in about 8 good flights with mine yesterday. We had our annual winter fun fly at Lost Creek. Hope to make it down your way to fly this summer.

Scott

RE: 4*120 Build Thread
 

I got all the flight control servos installed. I just finished the linkages and control horns.

All thats left to do is glue the canopy on, fit the RX and battery and then balance it.

Might get lucky and fly it tomorrow. We'll see.

RE: 4*120 Build Thread
 

You guys having fun fly contests on skis?[sm=lol.gif]

RE: 4*120 Build Thread
 

gettin close man!

nice work;)

RE: 4*120 Build Thread
 

RC and Scott: On my 4* I added a block aft of the trailing edge to mount floats. Floats are the greatest way to fly from powder snow! And what great touch and go's! I have a set to build as soon as this plane is finished!

Headed down to the basement for a couple hours of 4*120 time!

Murphey (As in Murphey's Law)

RE: 4*120 Build Thread
 

Mine is a touch tail heavy.[&o]

I moved my engine back to much.[:@] 3 servos in the tail doesn't help either.

I hope that I can balance it with a spinner and a prop. It's not that far out of balance right now. Just a teeny bit on the tail heavy side without a prop and spinner.

If I put the wheelpants on--it should be good to go.

I'm going to have to use a 3-blade prop. I've only got 10" clearence under the crankshaft. An 18" prop would only clear by 1"[X(] I was planning on using an 18-8 or an 18-6 prop. I'm going to order a 16-8 3-blade.

With my ignition system and battery as well as the smoke pump and battery up front, I was afraid it would be nose heavy. Would rather have had the problem. Nose heavy is easier to fix.

I'm gonna fire the engine tomorrow in the driveway with an 18-8 prop.[8D]

RE: 4*120 Build Thread
 

Let me re-phrase that, Our annual winter fly-in. No contest, just fun flying on skis!!! We had 3 guys up from Co. Springs- 2 with giant Stingers with G 62's and a cross between skis and floats, and an SNJ Harvard on skis. No, they didn't retract [8D] By the way, this is not the way to land on floats!!!!

RE: 4*120 Build Thread
 

Looks like someone decided to give their OS108 a drink.[sm=lol.gif] Looks like a pelican diving into the ocean for a herring.

Here's some pics of the tail servos and linkages.

I'm using a Hitec HS-77 low profile servo for each elevator. JR 4721 for the rudder. Control horns are DuBro #866 heavy duty. 4-40 pushrods.

I'm using my TX--a JR8103 to run a programmable mix on the number 6 mix. This mix automatically includes trim for both servos. So, when I need to trim up or down elevator, they will both move together. Running my slave servo on #5 gear channel. Set gear travel to 0% when switch is in both positions. This effectively disables the switch. Wouldn't want to accidentally flip it while flying and have 1 elevator move up or down. [X(] Use gear sub trims to center the servo.

Pics:

RE: 4*120 Build Thread
 

Got the canopy attached. I'm using Pacer 560 glue. 4 screws in each side. 1 screw in the top on the center stringer for the turtle deck.

With a tail heavy condition--I elected to forget about the pilot. I thinned some 5 minute epoxy and brushed a thin coat on the inside.

Pics:

RE: 4*120 Build Thread
 

Why not consider longer "legs" so that you can keep a 2-blade prop? Can you get other landing gear that will give you the additional clearance?

BobbyG