youngun

You would be right ... IF the plane has right thrust. Many do not.
You are wrong about using the tailwheel. Most tailwheels are below the thrust line. That is one reason why I suggested using a rudder hinge. there is usually one very close to, if not on, the thrust line. At least much closer than the tailwheel.

The point being to use the thrust line of the plane.

A plane should be balanced fore and aft, and wing tip to wing tip (lateral balance) to perform as it should.
If it is not, it may still fly, but it's performance will not ever be what it could have been if balanced properly.

Many do not bother with the balance. And many planes never fly right. And some crash.

Just from observation; Balance is important.



Back to the side mount vs inverted mount issue:

The inverted engine should make it easier to balance laterally.

Also important would be carburetor vs tank centerline placement. If the plane was designed for a side mount engine, would mounting it inverted make it necessary to change the fuel tank height? Maybe. If a 2-stroke were used, probably.

Another item would be throttle linkage. How would that need to be changed to go with an inverted engine?

All in all, more to think about than just rotating the engine 90 degrees.

This plane is a beauty and if I can swing it to get one, I will want to make it as 'right' as I possibly can. The better they fly, the more enjoyment gained for your investment.

youngun

[drool]

Jim Schwagle

My Feedback: (1)

Also available at Chief....

http://www.chiefaircraft.com/rcmsec/...ltimate90.html

daveopam

My Feedback: (9)

A few more points about making it right. I have done a little more work on mine. First no place in the manual does it say to level the stab when you mount it. I had to sand the left side down a little to make mine level to the lower wing. Most ARFs include this step. If a person has built several they should catch it but some will not. Second when I mounted the cabanes and the center section of the top wing it was not straight. I put a 36" straight edge on the center and it was 2" off at the fin. Mine required twisting the cabanes with Channel locks to get this straight.

Youngun, most pilots will never notice if the plane is latterally balanced or not. I'll bet more than 1/2 the guys I have flown with cant make a low pass over the runway in the same spot 3 times in a row. Not that I am recommending against it. I just don't think the average Joe can feel it in the plane. I also did not realize the thrust line was that important in the side to side. I assumed that just like the fore and aft balance as long as the thrust line was below your balance fixture it would wash out. My bad I guess.

David

jpe

My top wing required a bit twisting also to make it fit. Also my rudder was not straight and needed some heating.
As i said earlier this plane needed a lot of trimming before flying "hands off". Very much down elevator and quite a lot ailerons also.

youngun

Good info like this helps us all. THANKS!!


The people that took me "under their wing", so to speak, and taught me, not only how to fly, but also much about building and trimming out aircraft kept beating it into my head all the fine points needed to "make it right". The goal then was pattern flying. And pattern flying with precision placement of the aircraft in the air. "Stick jamming" was frowned on as was "hanging it on the prop". These early influences are still with me and linger on.

It's not your "bad" at all. You've helped others. And I try to help too.
For me , it's just passing on my experience and what I've learned so that others might learn and learn quicker. Also there's the thing of trying to prevent crashs and people leaving the sport in frustration.

Again, Thanks for the info.[sm=thumbs_up.gif]

youngun

The things to watch for are good to know.

Interesting is the "very much down elevator" needed. That might go back to the stab saddle needing some work as in daveopams post above.

I have another asian made arf that also needed many, many "beeps" of down elevator to level out. This ended up with roughly 10 degrees down elevator for level flight. At first I thought it was a mistake that I missed during the assembly. Now, with another arf showing the same signs, it makes me wonder if this is something in their design philosophy of aircraft.

I guess the point would be, we need to check their work to see if the plane is built straight and true. And then correct any mistakes found. [&o]

youngun

I finally found one of these at a hobby shop.

When I opened the box to take a look, two things came to mind.

First; A very good looking plane that is well packaged and padded and looked like "quality". (I know looks can be deceiving)

Second; It was smaller than I expected. It looks like, to me, a .60 size airplane.

With some things I've read of people wanting to put an engine bigger than a 1.25 in it - I guess it "grew" bigger in my mind.

After seeing it in the box - My thoughts were - Probably a 1.25 would be too much engine. But that's just my thoughts.

Horizon Hobby shows several engines for this plane; the 1.25 being the largest of these.

jpe

Yes it looks small in box, but it starts to grow rapidly when you build it. Take a look to rudder, it tells you the real size of this one. It's bigger than in my 25% Cap

daveopam

My Feedback: (9)

The size looked normal to me but I have 10+ years flying the Goldberg. The Seagull seems to be a knock off of it. I think the cowl would interchange they are so close. I really don't think the 1.25 is going to be to much. This plane is going to be heavier than the GB. I think I have flown 10 or more GB's over the years. The best one was YS 1.20 powered. My buddy had three with Enya 1.20 four strokes and smoke. These also flew great under power. If one of them died hang on. Both of mine were Super Tigre 90 powered. This was a good combo unless you wanted to hover. When the GB came out nobody really cared about the hover. I guess if a guy wanted to sport fly the 1.25 may be over kill. But it goes back to the old saying. You can always pull the power back.

David

heliheads

I am going to go ahead and put the 120 in it. What do ya'll thing about the Saito 125 verses the OS 120. Looking at the specs, the Saito is stronger, I just have never owned one. The OS seems VERY reliable, is the Saito as good?

youngun

daveopam,

when you said ".....If one of them died hang on....."
Did you mean if the engine died (dead stick) that it didn't glide very well? (was it a flying brick?)
Or did I misinterpret altogether?

I can remember when Goldberg first came out with the Ultimate kit and it was supposed to be a .60 size then.
Do you remember about what the Goldbergs weighed ready to fly?

daveopam

My Feedback: (9)

youngun. Yes I mean it glided like a brike with a parachute on it. Not that any of bipe has a great glide rate. I always caution people about the GB low rate elev suggestion. Even with the 90's I ran on mine. If you have a dead stick and you are on low rate you can not hold the nose up. The only way to save it was to point the nose down and flare at 10'. If there is a bright side it is the plane won't snap. It will however pancake at about a 45degree dive angle. On the GB kit this will put the landing gear wire through the leading edge of both wings and the wheels and or pants through the center of the wing. I think the ARF uses a flat alum gear instead of wire but your still going to get some lower wing dammage.

I don't remember what the GB all up weight is. I built mine 10 years ago. I only just retired it to pull the radio gear out for the Seagull. I am saying the SG is going to be heavier based on the construction. There are several parts of the SG that are built heavier than the GB. For example the landing gear, the flying tail wires, the cabane attachment, the two piece wings, the canopy and pilot bust, and the extra elev servo. There may be more. All of these things together must add a little weight. To add to that I have not seen an area that is done lighter on the SG. I am still hoping it will be a great flyer. If not I have an offer on it already. I can strip everything out and get another GB. I picked the SG based on the larger aile and the overall look.



David

youngun

David,

Thanks for answering my questions.

I hope it flys good for you.

Would you please post your views of how it flys after you get it sorted out?

daveopam

My Feedback: (9)

I should have a few tanks through it this weekend. I may put it up on Monday if the weather holds. I will post here and compare it to my GB. I hope I like it as well but it has some big shoes to fill. It may take a few weeks of tinkering with the CG to really get a good feel for it. I ran the GB about 1/2" behind the range. It would do the best flat spins and Lomceveks of any plane I have flown.

David

daveopam

My Feedback: (9)

A few other small problems have come up. Just wanted to keep you guys up to speed. For starters I am missing some hardware. I have no axles,wheel colars or the ply plates it shows to mount the wheel pants with. I did find 4 round ply washers that are not mentioned in the book. After looking at the pictures in the book. These are doublers for the wing hold down bolts on the lower wing. I pulled the bolts out one at a time then put the washers on and retightend. Then put some thin CA on the washer/fuse joint. These may not be needed but it will spread the load on those plastic bolts.

David

gr8taz nitro

My Feedback: (7)

I've got 2 flights on mine now, and so far I'm totally impressed with this plane. I used all of the stock hardware included except for the tail wheel and jam nuts. I've never liked the wire tailwheel setups included with most of the arf's. I changed it out for a dubro semi-scale assembly and really like it. I also changed out the 3mm jam nuts and used locknuts everywhere in place of, including getting locknuts for the axles. Power is being supplied by an evolution 1.00 with a bisson pitts muffler spinning a topflite 15 x 6-10 prop with a dave brown ulitmate spinner. Controls are being run by JR DS821 servos, with a commonsense r/c 2 cell 1500 rx pack and maxx products 6v regulator. I also installed an expert gyro, but I'm finding that I don't need it like I thought I would. All up weight dry was 9 pounds flat according to the digital fish scale.

The first flight was pretty uneventful. Fed in some power and an easy straight rollout with just a touch of rudder and she was airborne. Got her up to altitude and all I needed was 2 clicks of right aileron to get a level handsfree flight. The plane was suprisingly stable considering the 20mph gusts we were getting. Rolls were very crisp and very axial for a biplane. Brought her in for landing and was a very nice easy 3 pointer. Remeber the gusty conditions? That brings me to the lesson of the day, if you leave your plane on the starting stand on a gusty day, and don't tie it down, it will bite you. My plane lifted off the stand hovered for a second, rolled over and landed on it's back on the concrete. Little rash and some bent cabanes was the cost of my lesson. A little tape and some bending using the mark 1 eyeball for reference, and flight number 2. Pretty much same as the first, I don't know what stall is gonna be like, cause with the wind as high as it was, it never really would stall out, but considering how stable it was, I don't think it's gonna do anything weird or dramatic.

I've never had a biplane before this one because all of the club diehards kept telling me horror stories about the problems with flying a bipe, but I had just as much fun with this plane as my QQ Yak or my funtana x100, and I let one of the guys that kept telling me not to get a bipe fly mine for a while on the 2nd time up, and now he's talking about getting one. All in all a very positive experience with this plane and no problems recommending this one to anyone. Maybe I got lucky, but I didn't run into any of the problems that have been listed in this thread so far. The wings were straight, all the hardware was complete and intact, build time was pretty much 3 evenings for a couple of hours after work.

daveopam

My Feedback: (9)

Well I have two tanks through it. It's time to put the cowl on and do a test flight. Even rich the 1.25 seams like a beast. The only other 1.25 I have flown is on a friends Showtime. Mine is a lot stronger. Although I think he is over propped. His is running a 16x6APC on 15%. We are at 2,000ASL. His motor just never seams to unwind. It sounds like it is chugging all the time. The 15x6APC I have sounds much better. Time will tell I guess when it's airborn. Once broke in I am going to try a 16x4W APC. I'll just have to see how it pulls out after the first gallon.

Flight report to follow soon, David

daveopam

My Feedback: (9)

Ok I put a 4 minute flight on it today. Conditions were terrible. 20mph wind 90 degrees and humid. The 1.25 is running good. To good I guess the 15x6APC is not enough. I borrowed a 16x4W APC for the test flight. I only leaned it for a few seconds and got 9,600. Still a little more than I expected. The 1.25 on my buddys Showtime with a 16x6 APC tached 8,200 right after I ran mine up using the same tach. His must be week or mine is strong.

Any way I taxied out and eased into it and it was airborn in 10' at half power. It had a bunch of climb in it. I soon realized the CG was to far aft. I made about three laps around the field at 1/2 power.Adding down elev until it flew hands off. I did a few aile rolls and then kicked them up to high rate. On high rate roll and it over rolled and got real squirely. The CG was getting worse as it burned fuel. So I flew it in at 1/4 power. The second flight will be another day. I neeed to move the battery up and put the pants on. This will get it into their range of 12.5 to 15 cm. I was at 6-1/4". This is about 3/8" behind the 15cm.

Till next flight, David

gr8taz nitro

My Feedback: (7)

Got my next set of flights in yesterday. Switched to one of the new evolution 15 x 6 props. Tried doing some knife edge passes with it and it pulls really hard to the gear. I think a little bit of mixing on the radio will fix that problem. Locking in to a harrier was extremely easy, a little wing rock but nothing major and pretty easy to control. Just held full elevator and drove it around with the rudder. Snap rolls are quick and violent on high rates. I've got way too much rudder throw, it pretty much broght the plane to a screeching halt everytime I did a snap. Tumbles are very cool and the plane stops when you want it to. Haven't seen any over rotation issues yet.

I tried doing a few basic stall turns and got some interesting results. If I held the rudder hard it would turn, but then do a weird rollout. I've found the rudder is extremely effective, all it takes to get a clean stall turn is bump the rudder hard to start the yaw and then back off to about half and hold it through the turn. Inverted flight is pretty stable and easy, I putted around the field about 1/2 throttle inverted just havin fun with it. I can't do anything more with it because my skills aren't up to the task yet, but I might have a 3d report soon. Have a guy at another club that's pretty good that I'm gonna let wring out the ultimate and see what his impressions are.

daveopam

My Feedback: (9)

Rebalanced mine yesterday but did not have time to put it up. I now have a 15x8MA prop on it to try. This may be to much pitch. It's just all I had in my shop. The LHS is 100 miles each way. I also put the pants on. My CG is right on the 15cm mark now. This thing is a pain to balance. I now have a hole in the center of the top center rib on the CG. I have a string run though to lift for balance. My old GB I just flipped over and held my fingers 3" back on the lower wing.

David

MR.HANEY

My Feedback: (50)

it is a pain to balance,15 cm is right in front of the top wing rear mount,anyway i answered my own question.i asked earlier in this forum about this plane and the zenoah 20ei and got no replys.so here goes,motor was easy to mount,lots of room for ign and batts.with receiver batt in the turtle deck and ign batt mounted beside the throttle servo the plane came out tail heavy,moved both batts to the front and it balanced right on 15cm.first flight it was not amazing,but after 5 tanks through the 20 ei its starting to come alive .the vertical in not unlimited but good,ithink a couple more tanks and it will perform with ease.it seems to get stronger with every tank now,.

outlawjessejames

thank you mr.haney....i just order mine today (will be here friday) and I'm going to put a 20ei in it myself...I'm glad you posted about your plane..i didn't know about a 20ei or a 26. i think the 26 will be to much...can you tell me more about your setup, etc.....and do you have pictures ?? it would be really nice...what kine of muffler did you use...anyway let us know how things are going....you are the first person to post and talk about this plane, with this type of engine...so keep it up..i'm sure there are other that are interested....i know i am.......

MR.HANEY

My Feedback: (50)

i have no pics at this time but i will post some later,i used the stock muffler.i laminated light ply 3/4in thick then cut 4 blocks and used these as standoffs between motor and firewall,i used jr sport 126mg servos on rudder and elevators,hi-tech 645 mg on ailerons and a standard bb on throttle.used stock tank with a gas conversion stopper,plane was set up per manual .you will need more throw on elevator on low rate than what the manual advises,high rates are fine.i also used 4-40 bolts and locknuts on the cabanes and wing struts,also changed to locknut on axles.also be sure to use locktite on all controll horns,when installed the controll horns are very decorative and add apperance to the plane.16-6 prop and a tru-turn spinner.i also tossed the tailwheel and went with a sullivan replacement.also i pined the sides of the motor mount box to the firewall.

outlawjessejames

great pic. of the engine ...how did it fly ?? will it hover o.k. .. did you have any trouble with setup on the C.G.. did you have to add any weight to the the tail? sorry with so many questions...this is my first bi-plane and i looking forward to it....one other question, has anyone used any other hinges then what it comes with??..someone told me that the Dobro pinned hinges are better??? what do you think??? thanks[8D]