I just made a trade for a NIB Seagull Texan 120 (82" WS). I plan to install my Zenoah G20 on it. All up weight is supposed to be around 13 lbs and the G20 should pull it in fine style. I'm in contact with a guy in East Texas who has the same plane with the same engine and he says it does very well.
I also plan to install the 60-120 size Etracts on it and decent digital servos. However, it will be a while before I get "roundtoit" because I still haven't finished my GP Ulimate 160 yet.

Garry

I flew the Chipmunk again today and had 3 good flights and experimented with the flaps on landing. It crawls right along with the flaps down and will land nicely if you don't drop her in from 2 feet like I did today. I broke the left side repair I had done on the gear mount and that ended my Chipmunk flying for the day.
I handles well but, I'm beginning to think it's a bit too heavy for the landing gear arrangement. I beefed it up more tonight and also removed the smoke tank and servo from the center section. It made it a bit lighter but, it's still a heavy bird with a fiberglass fuselage and wing center section. I hope I can avoid another broken gear tomorrow (actually today ... it's 2:30 AM) when I fly it again.
I'm still working out my control throw preferences and they felt good today. Roll rate was nice on low and fairly quick on high. I may increase high rates for a faster roll but, I don't think it's meant to handle like a Yak or Edge 540 so, I may just leave it alone. It has lots of wing and rather short fuselage. Controls have plenty of authority but, not like the aerobatic models I mentioned earlier. Aileron throws are currently at 50% on low rates compared to 20% on my Edge. Big difference.
The engine runs well but, it's balky to start and it has an occasional miss at high rpm. It seems to be getting better as I fly it. It transitions well and It spools up to a fairly high rpm ....I need to remember to tach it to see what it's turning. I have an 18x8 wooden Xoar on it now but, I think it will do better on an 18x10 and bring the RPM down so the engine isn't screaming. That little G38ei is working it's butt off at full throttle but, vertical performance isn't what I expect. Maybe a change in prop will help it.
It's a fun airplane to fly and will do most all of the aerobatic maneuvers. The engine/airframe combo seems to be a good match. It's fairly docile and forgiving and will be a relaxing plane to have fun with once I get more comfortable with it.
I hope I'll be able to re-install the smoke equipment when I figure out which prop gives the best performance.

Garry

It's been too hot for this old man to fly so, I've been working on the completion of my Ultimate Bipe. I've mounted the fuel tank and plumbed the lines to the carb, etc, and mounted the Smart Fly regulator, receiver, CDI box, and switches. I still need to assemble the servos and mount the top to the cabane struts and tidy up the wiring inside so it won't resemble a rats nest. I also need to rig a manual choke and cut the cowl to fit.
I'm waiting for two new LIFPo batteries to come in so I can test the mounting positions for CG.
I'll keep working on it until it's finished now so I can start assembly of my next project ....a Seagull AT-6 Texan 120 with 82" span.

Garry

I assembled the upper wing today after installing the ailerons, servos, and linkage. The instructions push you to hurry while joining the wing halves so the epoxy doesn't dry until after you mount the upper wing and join it to the lower wing with the "I" struts. I managed to get it all done in plenty of time and carried it out to the yard for some pictures. The epoxy is still curing so I carried it by the fuselage and gear. I'll let it cure over night before I remove the wings and finish the servo leads to the receiver. I'm still waiting for my batteries but, it should be ready to fly some time next week. Waiting for the batteries will give me a chance to mount the cowl, canopy, and check it over closely.

Garry

Well, the Ultimate is finished with the exception of CG balance and mounting the pilot and canopy. I'll install the wings tomorrow and test run the engine to see what it needs after setting up for a few months.
I'll post some pics tomorrow when it's assembled ...and maybe a little video of the engine run.
The weather folks are predicting cooler weather and decent winds next week and if they're right, I might be able to get the first couple of flights on it.

Garry

Update on the Ultimate 160 ....
CG check was right on the factory spot without adding any weight or shifting anything around. I'm very fortunate in that area. Hope she flies well at that CG station.
I haven't weighed it but, it feels light even with 1/2 tank of fuel. The fuselage is not double boxed framed which saves some weight but, it's built well and strong. It's actually surprisingly light for a Great Planes model. I'll try to find an accurate scale large enough to weigh it.
The engine (Turnigy 52cc w/approx. 4.5hp) run went fine after replacing the crankcase vacuum line. The first tubing I tried was a bit too large in diameter and kept slipping off. I replaced it with smaller tubing and it's working fine now. The engine tuned up fine and I ran it for about 30 or 40 min. at various power settings while tweaking and trying to eliminate the four stroking. I got it real close but, this engine is spitting a bit of oil as if it's not quite broken-in yet. On the other hand, I think I remember adding a bit too much oil to this can and that may be causing it to spit a bit out.
It's running smooth with a 20.5x8 (modified) Biela prop (thank you Benny). By the time I quit tonight it was too dark to use an optical tach so, I'll have to do that another time. It pulls fine but, I'll try other props to find the optimum performer. I think a 20x8 or 21x8 will be best but, I need a brand of prop with a broad hub as this engine has a 3 bolt prop bolt pattern and I've found that some prop hubs are just too small. The holes drill out very close to the edge of the hub of some brands. The Biela has a wide hub and I think RCG props from BP hobbies do too. I've tried Zoar props (my favorite woodies) with this engine but, the hubs are too small. I'll keep checking.
I found something odd when I connected all of the servos and function checked them. The servo in the top right aileron of the upper wing is backwards. It's mounted and connected the same way the other 3 servos are but, it functions in reverse. In other words, when moving the stick to the right for a right turn, the bottom servo moves up but, the top servo moves down. All four servos are HS-625MGs. It's not marked any different than the others, it just operates backwards. So, the first flight will have to wait until a new servo arrives.

Pilot and canopy are installed and, after servo replacement and aileron alignment, it will be ready to fly. Maybe by the end of next week.

Garry

It finally dawned on me that I can swap my "backward" aileron servo with one from the elevator. I can then reverse my backward servo with the radio. So, tomorrow I'll do that and have it ready to fly when the rain stops ...which I hope isn't for two or three days. We need the water.

Garry

Good plan on switching the servos Garry.........should work perfectly. It's going to look great in the air.

Have you done a range check yet between the TX/RX?

I agree on the rain........glad we are receiving it this time of year. I'm hoping to slip in some flying Tuesday or Wednesday evening if we have a break in the rain.

No range check yet. I'm still trying to get everything working correctly at "close range" right now.

By the way, while browsing Tower Hobby's web site the other night I noticed they have discontinued this great airplane. I'm sad to see it go. I understand it's had a very successful 8 yr. run.

Garry

I swapped out the wrong-way aileron servo with one of the aileron servos and all is working as it should. During the process I discovered a bad servo extension and replaced it. I was getting some odd reactions to the engine run the other day (controls twitching, etc.) and I needed to fix that issue. I hope replacing the bad extension has solved the problem but, will give it a thorough check out before first flight.

Garry

Sadly, I have to report that the Ultimate crashed on the first flight yesterday (Thurs). On approach to my second landing attempt the nose suddenly pitch up slightly and then violently dropped straight down. It crashed in from about 20 ft. up and demolished the airframe and broke the carb mount off the engine. I suspect it was a receiver glitch as the installed receiver had been through a crash in one of my other planes. I knew better than to fly with that receiver as it had glitched on the ground during an engine run. I found and replaced a bad servo extension and thought I had fixed the problem but, intended to change the receiver also to make sure. In my haste, I forgot to replace it and ended up destroying a very nice plane.
First flight was going very well although I thought it needed a bit more prop pitch to increase speed. Take-off was very good and it only required about 3 clicks of right aileron. The first landing was a "one bounce" affair and the gear handled it very well with a very controllable 2nd takeoff from the touch and go roll-out. It tracked straight in the air and the engine ran well and the prop pulled well with plenty of vertical. It handled inverted flight with barely a touch of down elevator. Low rates on aileron were not quite enough but, a flip of the switch to high brought them to life and the roll rate was very nice.
I would definitely buy another one but, Tower has discontinued them within the last two weeks. So, unless I can find a place that has one left in stock I won't be able to replace it.
It appears the gremlins are still with me.

Garry

I've been working on the Chipmunk ....again. Haven't flown it lately because I wanted to replace the main gear and give the engine a tune-up.
I have a Seagull AT-6 Texan (giant scale) ARF that came with nice stout oleo struts and since I plan to install retracts in it, I robbed those struts from the box and installed them on the Chipmunk. I made a small mod to the mounting area in the wings and they fit tight and seem to be strong enough.
I also replaced the spark plug and repaired a couple of bad places in the CDI wiring. While running the engine I noticed the intermittent miss in the engine did not show up. Maybe I did something right?
I also readjusted the carb and she's running much smoother with an 1850 rpm idle and turning 8150 on the top using an 18x8 prop. The Zenoah chart says I should be using an 18x10 that produce 7300 rpm which should bring it down to the best torque range. I haven't run the engine with the new prop yet but, I will tomorrow when I fly it (Wed. 7/31), wx permitting.
If all goes well tomorrow I plan to use this bird in the Sat. IMAC contest on 8/10.

Garry

I recently ordered a small 70" Extra 260 from General Hobby and plan to mount my RCG 15cc engine on it. The plane weighs less than 9lbs AUW and my engine should be a good match for it at 2.1 HP.

In comparison, I had a Seagull Yak 54 (same weight but, smaller plane) with a 26cc engine and thought it was a bit over powered. I had to prop it down to reduce the torque effect in up-lines and it was still tough to keep it straight.

I looked around a bit before I bought this plane and most everything else in this size (70" to 73") weighed 10 + lbs. and called for a 26cc to 30cc engine. So, basically I bought an airplane to fit the engine I have.
I considered the Great Planes Revolver 70" (same weight and size) but, wanted something scale for IMAC. I watched a YouTube video of a Revolver 70" with a 15cc RCG on it and performed very, very well so, I'm confident the engine will fly my new plane through the maneuvers with no problem.

The Post Office says it should be here Monday (8/5) and I'll post a note about the quality, etc. after I take a look at it.

Garry

Looks nice in those pictures. You'll be busy getting it ready this coming week for the IMAC on the 10th and 11th.

Rex,
No, that's too much of a rush. I'll be flying the Chipmunk in the Sat. event and won't be flying the Sun. contest unless I can fly and finish before 11Am ...and that doesn't look promising.
I plan to fly the little one in the Oct. IMAC.

Garry