4-Place Super Cub

[Acd17931]

I bought a project and she's painted home depot orange.

(4 Place PA-18 Fuselage, includes Pilot & Passenger Doors,Metal Tube Stringers, Floor Tie Downs, L-21 Window,
UpperBaggage Door, X Brace Arch, Last 4 Feet Metal Belly Tabs,Removable Rear Seat Cross Bar, and 2 Lift Handles)

I'm looking for opinions and ideas in this build. Not focusing on budget at the moment. Tell me what you think she needs.

As I develop a game plan and build sheet this month, I will update everyone on the goals and progress.

For now she looks pretty good, but maybe I'm bias because my names on it.

Take care, Happy Holidays

-Dyer
Palmer Alaska

 

[DENNY]

Sliding front seat tracks on the floor, because you do not have a sill to sit on when getting in the front Yokes instead of stick will also help. Longest Javron wings you can get. big tanks. DENNY

 

[wireweinie]

It's still a Cub type airplane. Keep it light.

Is this certified or experimental? Can you make it left seat pilot only, or do you need controls at left and right? What's it's 'job'? Just a fun flyer or are you going to work it?

Web

 

[Acd17931]

Noted Denny, Thank you.

Web,
Experimental.
Job is to take 2 passengers, or a load on some expeditions and some cross country flights in the future. Also cargo flights for a couple camps I have friends at.
Left seat PIC is fine. I do think a RH set of pedals would be nice to have, but not necessary.
It has to be a jeep if its going to stick around in my life. Preferably like a CJ or YJ.

I'm up for new ideas and thoughts.

-Dyer

 

[stewartb]

If I was dreaming? I’d increase AOI. Big elevators and rudder. Big baggage door. Lowered engine mount. Move ailerons out to the tips and use long Pstol flaps. Max performance without adding a bunch of weight. What are you planning for the engine and prop?

 

[wireweinie]

Center stick and all instruments on the left panel will simplify things. Use a CGR 30P or JPI 900 series for the engine instruments as they are all instruments in one hole on the panel. Do you 'need' a screen for the flight instruments? If not Winters altimeter and airspeed indicators are the lightest weight instruments available. One com (Becker or Trig) and a good four place intercom such as PS Engineering or NAT will work for the avionics. For GPS, just use a portable on an external mount, as it will be replaced from time to time.

All lights LED. Light weight starter and alternator on accessory case. EarthX battery.

Keep the floor light (maybe plywood?) and thin Kydex side walls. That will give you some durability with light weight.

Web

 

[frequent_flyer]

If I was dreaming? I’d increase AOI. Big elevators and rudder.

Be careful what you wish for. The FX-3 Carbon Cub has a bigger rudder than the Super Cub. It has no preference for flying straight and would just as soon fly sideways. The slightest error in rudder pedal pressure results in an annoying ball displacement. The XCub increases the size of the fin and hopefully it behaves better. I'd far rather have some "feel" in the rudder.

There have been a few times that I was glad to have the big rudder so maybe have to accept the downside for the very few times it is needed.

 

[stewartb]

That sounds familiar. Try adding some ballast in the way back.

 

[DENNY]

Javron just built up a set of wings for my 30 gal Attlee Tanks, 90 inch PSTOL flaps, full length square end spars added 7 or 9 inches to the aileron length. If you want to haul a load big wings and big fuel are nice to have. Go to Birchwood and look at the 4 place cubs kirk has been building. He has a lot of great ideals. DENNY

 

[Crash Jr.]

First stop, call Kirk Ellis at K-air to see what he recommends. Kirk is the god father of the 4 place so he knows what mods work and which ones don't.

I'd recommend building it just like it is with the center stick and leave the option of adding right hand pedals but just don't put them in if you want to save weight. Light is the key with these planes. Even though they are physically larger it's mostly empty space inside so you can get pretty close to regular cub weights and they fly great that way. Understand that you likely will not ever be able to fill both front seats and stay within CG so leaving the right seat out lowers your budget (the 4 place right seat is pretty spendy) and opens up a big space that you can access the rear for loading cargo. Wings I'd go with Javron like Denny says but no need for 30 gallon tanks, 24's are lighter and work fine. Lots of cargo room to carry extra gas if need be. Regular old O-360 with some powder mods for an engine. Kirk likes those strakes on the tail and square tail feathers on the 4 place.

If you go into stripping the powder coating and welding on it then all bets are off. At that point raise the AOI like mentioned, perhaps go with dual front sticks, add Kirk's big baggage door, and get crazy with it. My mind is always on budget so if it was mine I'd take the easy route and build it as-is. Powdercoating on a 4 place is $2100 alone.

 

[Acd17931]

Calling Kirk is already in the works. I stopped by to check out his "hulk" parked out at Birchwood last week. I've been contacting him through Airframes Alaska with questions on the certified style frames, but will stop by to see him probably the 1st week in Jan.

I haven't decided on the engine and prop combo yet. Most options are pointing towards a tuned 360 and a ground adjustable sensenich or whirlwind. The Titan x340 or x370 I was quoted on last week had a 10 month lead time and I'd like something sooner than that.

On the next build I'll modify frames. For now I'll stick with the powder coating and color and see where I end up.

Already had talks with Randy at Carbon Concepts about some ideas.

As always, thanks for the help.

-Dyer

 

[Steve Pierce]

Buy an hour or so of Kirk's time at his shop rate. Will pay dividends as you build.

 

[stewartb]

I wouldn’t like a center stick. The controls decision is the only head scratcher. After that it’s just a fat Cub. Put parts together until you’re finished. Enjoy the build.

 

[Crash Jr.]

I'm not sure about the center stick either but it's the most tidy way to deal with the controls. I'd like to see someone do a Y shaped stick like a Zenith in one as I think that would make it a little more user friendly. I guess it's one of those things you get used to like any plane.

The dual front sticks are like a -14 with the torque tube sideways. It adds a lot of structure (and weight) to the floor to handle the torque tube mounts and a ton of pulleys added to get the cables to go the right places. Yokes are another option but you basically have to find a wrecked Pacer or Maule and cut the whole control setup out of them and graft it in.

 

[tempdoug]

the babes can kneel beside you when your flying.

 

[jnorris]

I wouldn’t like a center stick.

You'd be surprised. I know I sure was. I never thought I'd like a center stick arrangement, but then I was tasked with flying an airplane from WI to FL, and about 10 minutes into the first leg of the trip I was completely convinced that the center stick is a good idea! Very comfortable to fly, and your lap is totally clear so you can put your chart, your GPS/iPad, your lunch, or whatever you want in your lap and it won't get in the way of the controls (or vice versa). I'd certainly go that route on a plane such as the one being discussed here!

 

[jnorris]

I'd like to see someone do a Y shaped stick like a Zenith in one as I think that would make it a little more user friendly.

For what it's worth, I have flown center-stick airplanes with and without the "Y" on the stick and I prefer the non-Y version. The "Y" seemed to be in my way somehow. YMMV of course, but I'd go with the straight stick if it were mine.

 

[DENNY]

The one problem I see with a center stick is trying to locate engine controls so it is easy to fly from both right or left side. That is why dual yokes works well easy to fly from either side with engine controls in the middle. If you are going to do dual controls include brakes!! DENNY

 

[Olibuilt]

I would:

- Keep it light, but....

- Single front seat, center stick

- Go with big deep flaps:




-Slats

-CarbonFiber everything

-Lowered engine mount with SQ style cowling

-Electronic fuel and ignition

-EarthX battery

-Electric trim

-Minimum instrument panel

-Overhead flap handle

-Over sized elevators

-extended landing

-409 engine using AC-Aero Components:

• Same foot print as the O-360 Parallel valve engine,
• Uses Standard bore Lycoming or Lycoming clone 0-360 wide deck cylinders (or for additional costs, lightened Cylinders [- ~ 8lbs]).
• New AC-Aero counterweighted stroker crankshaft, new light weight rods, pistons, rings, wrist pins, clips, and conrod bearings. Although Pistons and conrods are lighter, the stroker crank is heavier. The combined components increase engine weight by about 19 lbs ( light weight cylinders could reduce that increase by 8lbs for a total increase of 11 lbs).

 

[DJ]

What about Steve Wittman's solution?

Sent from my SM-G965U1 using SuperCub.Org mobile app

 

[Crash Jr.]

Unfortunately the 4 place isn't set up to be able to fully fly from both sides. You can add brakes and rudder pedals to the right but the throttle and mixture brackets are all on the left end of the instrument panel.

Don't get carried away with power offerings. You can get very nose heavy very fast with a 4 place.

 

[DENNY]

It is not that hard to move the nose maker knobs, I saw that pretty power coat job two weeks ago. Someone should just take a grinder to something so they don't have to worry about it anymore. DENNY

 

[DJ]

Everyone has their priorities but two would stand out for me in a four place build.

1. Great performance empty (lightweight)
2. Plenty of useful load when I just want to move stuff in that big cabin.

For number one I would shoot for the 1200 lb empty weight that Kirk says is possible. I would follow Steve's advice and pay him to tell me how.

For number two, Javron's extended wing with higher gross.

Sent from my SM-G965U1 using SuperCub.Org mobile app

 

[skywagon8a]

- Go with big deep flaps:

View attachment 58721

Oli, Is that the wing you are flying now or one you are building? Those are interesting flaps with the built-in slots.

 

[Olibuilt]

Oli, Is that the wing you are flying now or one you are building? Those are interesting flaps with the built-in slots.

None of both.


They are pic of Rev3 wing I found on the net, can't remember where.


I would love to try a set on my red Cub!!

 

[stewartb]

I believe that’s MCS Mike’s shop. He’s had a pair of Rev 3 wings in there since soon after we rolled my plane out. They’ll go on a locally built custom 2-place Cub airframe. It’s impossible not to notice the chord of the ailerons and flaps. Very interesting wings.

 

[skywagon8a]

This picture of a wing which Oli found gives me an idea. Notice the flaps appear to be three sections held together with clamps. I found during some airflow yarn tuff testing, the inboard section within the propwash generates a considerable amount of turbulence. The section outboard of the propwash maintains smooth airflow even when the flaps are at 56 degrees. This is telling me, the outboard section is providing considerable lift at full deflection while the inboard section is providing drag. My idea is ... develop some flap control mechanism which will split the flaps so the inboard section only goes down about 30 degrees while the outboard section goes to the maximum. This ought to improve the efficiency of the inboard section in the lift department. Perhaps just changing the geometry of the inboard bellcrank will reduce the travel of that section?

 

[stewartb]

The Rev 3 flaps are ineffective past 30°, or so I’m told. They’re known to provide more lift and less drag than Pstols of the same length.

 

[1934A]

This picture of a wing which Oli found gives me an idea. Notice the flaps appear to be three sections held together with clamps. I found during some airflow yarn tuff testing, the inboard section within the propwash generates a considerable amount of turbulence. The section outboard of the propwash maintains smooth airflow even when the flaps are at 56 degrees. This is telling me, the outboard section is providing considerable lift at full deflection while the inboard section is providing drag. My idea is ... develop some flap control mechanism which will split the flaps so the inboard section only goes down about 30 degrees while the outboard section goes to the maximum. This ought to improve the efficiency of the inboard section in the lift department. Perhaps just changing the geometry of the inboard bellcrank will reduce the travel of that section?

I think you might be on to something... Easy enough to do, too.

 

[Acd17931]

Updates.

Univair parts are heading to the site. One of many shipments.

Frame is sitting in the garage on a rotisserie next to a set of 35's to keep me motivated.

Spoke with Kirk Ellis and was grateful to have that line of communication open.

Still on the wing search. I've got 2 request for quotes out there to dakota and Javron for squared tips. Just waitin on final weight numbers and price. Looking at 18 gallon tanks, and ailerons to tips. Tested weight is also a consideration of mine. Only 18 gallons because randy at carbon concepts has a 23 gallon tank that fits in a 18 gallons size hole and is lighter than original.

P-stol flaps are in the budget but with Airframes Alaska becoming an ice rink last month I know they will be delayed.

Engines quotes are coming in and I'm down to 3 options. X340 or 370 with low or high compression. (Main difference being fuel options, hp, and counterweights) Vs older 360 with ACAeros legion package. Prices are in the 30-38k range and power between 180 to 200hp. ACAero water cooled cylinders sound cool on paper but I imagine a weight gain I can't afford. Their Falcon 200 is also really cool to see.

Not set on a particular prop right now.

Spoke with Randy at carbon concepts and a CF interior will be coming. He'll even do the back seats, underseat box and fuel tanks.

No decisions made yet on brakes. Berringer, Groves, or Dakota cub. Im still looking at info.

I will probably do Stewart Systems Fabric exterior. Unsure how the tips are getting finished off but ill figure it out.

LEDs all around. No ADSB. No lights in the wings but rather on the gear.

Still researching fuel system needs.

I'll build a removable RH seat but leave it out most times. 3 place sounds like it fits my mission better.

Manual trim because she's already set up that way.

Kirk did say using a round horizontal Stab with square elevator may look funny but its free surface area. So thats probably going to happen.

Baby bushwheel tail.

Yeah. Thats about it for now.