ZX11

I just purchased a PNP version of the 1/4 scale H9 cub. My previous experience is the 450 Trex heli, the eflite 25e cub, and the Mini Pulse XT. I have enjoyed going thru most of the pages on this thread. The PNP isn't real clear on some things about the cub that the thread cleared up, like removing the cowl. It took me awhile to locate the ignition battery. At least I think I know where it is since I have not actually seen it yet.

The recommended motor and servo set up from H9 have worked great for me with the 25e cub and the Mini Pulse XT. My question is whether the PNP stock motor powers the cub like the bush pilots in "RC Bush Flying #5" on you tube video (skip to 3:30 to see the PNP version of the three cubs).

http://www.youtube.com/watch?v=s_nv0xBMMaY&feature=fvst

Or does it struggle to gain speed like Fishkillbill's aircraft on page 40 of this thread. I hope it was just a tuning the engine for max power issue.

Also, on the PNP does not have washers on the ball links for the tail feather servos or throttle. Doesn't it need them? How are people modifying the throttle arm for more resolution?

ZX11

Nice pics, Flycolorado. It looks good as a supercub.

SkyPilot101

ZX11 To get more throttle resoulition you can replace the stock throttle arm on your carb with a longer one, set up yout throttle linkage so at idle the servo arm is paralell to the linkage rod (to achieve less mechanical advantage thru zero to half throttle) or use a Tx that has throttle curve programing.

one vendor for throttle arms is: http://www.pspmfg.com/WalbroCarburet...ChokeArms.html

mobyal

You're talking about the stock throttle setup on the Zenoah 20 as supplied w/ the PNP version? Mine has almost no throw from full closed to wide open. If your suggestion'll deal w/ that, then I'm gonna try it!
Thanks
Al

SkyPilot101

Al, these small gassers with walbro carbs do not have a linear throttle response to the carb butterfly opening, at half throtle (half butterfly open) it's like 80% throttle compaired to a glow barrel throttle. (80% throttle range happens within the first 50% of throttle opening) To deal with this you need to slow down (reduce) the 0 to 50% response compaired to stick movement of your Tx (at 50% throttle stick you only want 25% butterfly opening) You can solve this by using a smaller servo arm & larger carb arm and setting your control arm's positions so the first half of your Tx throttlre stick only moves the carb arm roughley 25% Hope my febel explanation helped!

Also realize that this will involve repositioning the throttle pushrod and it's exit point thru the firewall...no big deal really, but since you went with the PNP, you probably wanted to avoid such re-workings....it's just not the case....the PNP throttle is more like a on/off switch as supplied. Another approach is to re-learn the use of the Tx throttle stick & get used to the fact that the bottom half of stick movment controls 100% throttle.

ZX11

Good info, thanks. That would explain the videos where the pilot is either full on or throttle chopped. It is interesting that the throttle cable is attached to what is essentially the throttle stop plate. It looks like where a weed wacker trigger type throttle cable would attach. I can see the advantage of moving the cable to where it reaches the choke side of the carb.

ZX11

The posts by Edchristian mentioned that the G20's ignition system is mounted with the "D" side against the firewall on the PNP. His engine was missfiring when airborne but not on the ground. The G20 instructions state that the "D" side is the high temp side and should have air flow. Flipping it over on the firewall would place the ignition sensor wires closer to the muffler. Damned if you do and damned if you don't.

Edchristian never posted what the fix was. He stopped posting when he got a new ignition box. Guess he crashed

krokko

Hi all!
Interesting reading, been in front of the Mac all morning. I have a H9 1/4 cub in the box, also purchased a DLE30! Now I'm hesitating because of all comments on engine size for the cub. Is the DLE30 too much??

Thanks for all help!

Couldn't wait for an answer. Measured, drilled, opened up the firewall. See the pic's......if they went to the right place......cant see them in the edit mode......[]

krokko

Now, how doas the silencer fit in?? It looks like the standard is just inside, need to look at a pitts. Any idea?

ZX11

Does it fit the same as the PNP version? There is lots of pic of those on the net. How much weight does that motor add to the plane over the 20cc motors? If it fits and the plane balances it is all good.

I am thinking of leaving the seats and pilot out to keep the weight down. Also switching to lipo batteries for lower weight. I like slow landings and flight.

krokko

DLE30 910gr, DLE20 650gr, difference = 260gr, shouldn't be any problem to balance! The by H9 recommended SAITO 1.80 weighs 880gr!

Do you meen PnP as in Plug and Play? Cant understand what it got to do with the muffler size? Anyone else having a DLE30 on the H9 J3 1/4 scale Cub? What silencer have you used?

harttvboy04

My Feedback: (32)

Hi all!

I have the Saito 180 installed on my cub, swinging the Xoar 18x6 Laminate. I get 8100 RPM on CoolPower 15% fuel. If I go the 30% Heli (which I can only do during the summer due to the excessive lean condition created by the cold air) I'll get 8800 RPM. I am considering propping up just to limit the high RPM's.

That being said, the 180 is 29. something CC's. In my opinion, I have SAFE power to get out of trouble in a tight situation. I tend to fly my cub hard - I have had to re-patch the wingtips twice already doing one wheeled touch and goes! [8D] I also had to ADD about 6 ounces to the nose to balance....

When I want to fly scale, I put around @ 1/3-1/2 throttle. I have found that, using my DX8 telemetry, the best level flight RPM range for my Saito 180 and my Cub is about 4400 RPM. At this throttle setting, I could easily stretch to 10 minutes flight. I chose normally to do touch and go's, so my throttle is a bit more 'liberal'.

For the weight, I would think that the DLE 30 would be a great match. I may sell my Saito and go that route, or the Syssa 180 (30 cc High Performance gasser).

I also was considering going electric. I found a motor that would be perfect. I fly this motor on my 71" AJ slick, and the thrust is INSANE, pulls like a tractor out of a hover, while being increadibly efficient at the same time. Best of all, this plane could EASILY deal with 10,000 mAh of battery to fly ALL DAY LONG. I currently have the HAcker A60-6xs propped 20x10 @ 85 Amps WOT. If I go 19x8, I imagine that my amps might go down to about 70-75, and cruise throttle might be around 30-40 amps ( just tickling the 2x 6s 5000mAH batteries I'd use).

I can't lie - I am just getting tired of my Saito and it's rich/lean tuning for the winter, and honestly I have put enough money into getting that thing running as great as it does that I could get sick (professional rebuilt after cam gear = 275 in parts and labor, SwitchGlo Pro On board glo system = 65, 4 gallons fuel (mixed 30% and 15%) about 100, Glo plugs 16, 90 degree muffler adapter= 20, Slimline Pitts muffler 90, redrill and reweld for the Pitts so as no to cut the firewall out for the muffler 25, 4500 mAh LiFe pack to power radio and SwitchGlo 35, Vibration dampening equipment 25, prop nuts 15, Props to test 45, and I am SURE I am forgetting something...just sickening [&:]

I know that gas might be a bit more economical, but it is still a combustion engine prone to vibrations, parts coming loose, fuel in the fuselage from the eventual tank failure, ETC. I would be willing to give gas another shot ( I had a G26 that I never got to run right in a Great Planes Stearman - put a bad taste in my mouth with Gas). I may just not have had enough experience with Gasoline to understand it, but I know that I went through my fair share of hardship with my 180 to get it running well. I found that my excessive lean condition was being caused (on 30%) by fuel lines that are too small. I had to convert to 1/8 fuel lines and my lean issues went away (this problem's pricing was left out of the equation above HAHAHA).

Just my $.02

Best,

Chris

krokko

Hi, interesting reading!

A little bit of my experience;

I'm normally a Metanol/Nitro flyer; OS91 FS, SAITO100, OS55, OS40, and so on. A couple of years ago I bought a DL50 for my GP Ultimate, run well, no problems. Installed a ZDZ50 in my Toni Clark Super CUB, very nice and reliable engine (unfortunately I crashed that one due to the wind, or bad pilot, whichever you want to blame). Bought a DA50 for my Toni Clark Ultimate,(still in the hangar).
The other week a fellow came and offered me a Piper L4 from Hobbyking in HongKong, he also sold me a 50CC twin to put in the plane!? Far to powerful, I have a SAITO100 installed an that will be more then enough! I already had a Hangar9 1/4 scale J3 on order, and the other week it landed, beautiful box everything nicely packed, nothing broken. With it I got a DLE30 which is now bolted to the firewall. Everything looks nice except for the muffler, I believe I have to look into some of the Pitts mufflers offered, will see, don't really know right now. Spent the last hour trying to replace one of the blind nuts holding the engine cowling, succeeded finally!!

I agree with you, the DLE30 should be a great match for the H9 CUB. Cant wait to get it flying (have to wait for the spring, it's winter in Sweden today -15)

Will post some pictures when I have something interesting to show!

One comment on the HobbyKing Piper L4, its low priced, so don't expect it to be of high quality, you get what you pay for!

rgds/krokko

ZX11

The kit I bought had the left landing gear suspension strut 7mm longer than the right one. Its the tube with the springs that connects to the wheel axel. It spreads the left gear out more with the wing tilted down on the left. Interesting error. I could cut it downand redrill but it will leave the new bolt hole close to the original hole.

Hangar 9 has the gear parts on back order till the end of the month. They will send me the parts then. Good support as far as I need since spring flying is far off anyway.

I debated buying the plane last week since it is winter and it won't fly for awhile. It is good that I did since this gives me time to work out the bugs and get the optical kill switch. Also, the PNP was on sale for $800. Now it is time for me to build a engine test stand for this sucker.

I guess the cub will take lots of motors. Those are long wings. Isn't a 180 four stroke one of the recommended motors? BTW, there is a video on youtube of a 20cc gas mounted to a 77inch cub. It is funny because my 72 inch cub takes a 25e (.25 equivalent) electric motor.

arrio

My Feedback: (17)

The Cub is a floater. I really have to get the idle really low for a decent landing.

I have a Saito 150 in mine. Running a 16x8 APC prop and 30% heli fuel. With the Saito 150, take offs are quick and easy, plenty of power. Off the ground in less than 20 feet.

Has almost sustained verticle flight. Can maintain hover but not continuose verticle momentum. Though giant loops are not a problem.

The stock plastic wheel hubs both cracked and and broke apart . Replaced with Dubro 5" balloon style wheels. Lost one of the axles and had to replace with 3/16" music wire stock, as the original 5mm axles where not available at the time.

I would also like to add flaps to my Cub. Not so much as a scale Super Cub thing. I just like the Flap functionality. I am always on the lookout for a spare set of wings to try the mod.

Using a JR X9303, and DS821 servos. 3S liPo with 5v regulator. Servos doing well. I am not hard on the controls and manuevers. Mostly smooth aerobatic stuff.

flycatch

My Feedback: (26)

Maiden the Cub today in a 10mph cross wind and it flew just like a full scale. The last Cub I had was a clipped wing Sig kit about 81" WS. The only thing I have to learn is keep the power up during landing approaches and land on the mains. The stock landing gear does not absorb three pointer to well. The Zenoah EI 20cc provides more than enought power and I took off and flew at 1/3 throttle setting. The elevator felt a bit touchy but I believe that was me trying to harmonize the controls. Hangar 9 again has produced another airframe of quality.

Lifer

My Feedback: (1)

Flycatch,

Same experience as with mine. Ended up installing really big Dubro inflatables and no more issues with the main gear. Six months later it had floats and will likely stay that way. A nice flying plane!

Planejaw

My Feedback: (53)

Congratulations on the maiden. Yes, the H-9 Cub can sure become your favorite very quickly. I've made modifications to the landing gear by removing the springs under the bungee covers, inserting 4/40 bolts, large washers and safety nuts, then wrapped #216 O-rings around the newly created "posts" made out of the bolts. You can adjust the stiffness of the gear and just how much "give" you want it to have. Then, simply get a bicycle innertube (larger diameter innertube), cut a couple of pieces about 3-4" long and Zip-tie the ends around the struts to give you new bungee covers. If you stay with the springs, they'll stretch out quickly and are expensive to replace. I've run a whole season on one set of O-rings. I normally run 4 per side. You can twist them, run post to post or wrap one around 4 posts. Use as many or as few as you want to give you the shock absorbing qualities you want. On my second H-9 Cub, I used some small diameter aluminum tubing over the bolt threads, so they would not cut into the O-rings, but on a whole season on my first Cub, even without the tubing, I had no O-ring failures. A little expo on the elevator will tame out any pitch oscillations you may encounter, as will more flight time on the ship. Look back at posts 590, 651, 791 and 796 for some good photos.

Planejaw

My Feedback: (53)

Yes, excellent idea on the tires. I have 5" DuBro inflatables on mine. Same thing on an Aeroworks Sport cub. The Aeroworks Cub has a spring-loaded scale-type gear, but there is only about 1/4" of travel in the shaft that comes out of the "bungee" tube, so larger air-filled tires are also a good addition to that ship.

Lifer

My Feedback: (1)

I've got the 7 inch inflatables but I let all the air out. Really absorbs the bumps that way!

harttvboy04

My Feedback: (32)

Hi all!

What size are the bolts for the landing gear, and the tubing used to protect the o rings?

And also, WHERE DID YOU FIND 7" tires?! The biggest I could find were the Dubro 1/3 scale tires. Let me/us know- thanks!

Chris

Planejaw

My Feedback: (53)

I think I used 4/40 bolts on my gear. The tubing size, not sure as I'm not at home now. Might be 1/8" or slightly larger. If you've built a few airplanes, you probably have some aluminum or brass tubing laying around the workshop. Again, not a huge problem if you can't find any. The threads on 4/40 bolts, or anything that size, are pretty fine and as I said, I had no problem on my first Cub. I did install tubing over the bolts on my second one, however.

Tx_RcFlyer

My Feedback: (7)

I picked up one of these up at a swap meet last weekend. Partially assembled and they did an ODover gray paint job on it. Firewall was not even drilled for an engine yet. What a perfect home fora spareDLE 30 I had. Not a fan of the ODcolor scheme, I ordered 10 meters of Solar Tex. Plans are to clip the wings by one rib bay, oversize tires and a three bladed prop.

Attached pic is what I am starting with.

The Old Skeptic

I don't see any wing struts. I assume that you have a set? Don't fly this baby without them if you have to make a pair yourself!

Tx_RcFlyer

My Feedback: (7)

I have all the parts, struts included. Those wings were bolted on when I got home so I could see what it looked like and make funny airplane noises.