BLUEGOOSE2

What is the best set-up for the Goldberg Obsession 3D. Open for opinions here. Gimme the good, bad and ugly about the plane too. Any expected areas that should have attention during assembly, weak areas, bad habits etc etc.

Thanks in advance for your input.

Sam

BLUEGOOSE2

No one enjoying these planes? They seemed so good in other areas I've read.

Flyrite

My Feedback: (73)

I am getting ready to complete one of these, what a great kit and about as easy as they come to assemble, it is a lot bigger than the pictures look. If I had the additional $$$ I would have upgraded the hardware in the kit especially the rudder tiller for the tail wheel and If I had to do it over I would entertain using a pull/pull and a single servo for the rudder to cut the tail weight down, I used a litte heaver engine so it may even out, I am installing a YS 160DZ with a performance specialty muffler, I am going to start break in with an APC 17-10 prop and I think I will use the Power Master YS blend 20/20 to start and work up to the 30% heli fuel after break in, I installed Hi-tec HS645MG's all the way arounf except the throttle which I used a standard servo. I only lack installing the cowl and canopy and final balance then off to the field. I will let you know how it goes but if 160 runs like other YS's I own if should have umlimited vertical!!!!

dkosters

I have one as well--I'm thinking a Saito 125, 150, or 180.........

The Saito 125 is 8 ounces lighter than a 150--If I have to add weight to the tail it could make it almost a pound lighter.

Any data from those who are flying one? Am I better off with a lighter engine or heavier (will I have to add weight to the nose with the 125)?

Thanks,

Dave

FLYINMIKE-RCU

My Feedback: (25)

I HAve A Saito 150 Mounted On Mine. Plane Is Pretty Light So It Should Easily Perform Up To My Abilities Which Aren't Nearly As Good As I'd Like. Have HS625 Servos On Everything But Plan To Use A 645 On The Rudder As Soon As I Can Make An Order And Get One. Really Nice ARF For The Money And A Large Plane For 78" Span. Probably Be A While Before I Fly It. Have Too Many Irons In The Fire To Keep Warm.

John_RedSox

My Feedback: (75)

I have a Saito 180 in mine and have no problems with power or cg. Use a 6.0 volt battery. You will need it to get the power to the rudder. It's a long way down the narrow fuse.

John

mass balance

Could I ask someone that owns an Obsession for the approximate firewall height and width measurements? I've been considering this plane for some time, and I'm thinking about bolting my little BCMA SPE 26cc gasser on the nose. At least one RCU member has wedged one of these motors into a Showtime 100, but it required a lot of cowl surgery, so I'm hoping there may be more room in the Obsession.

FLYINMIKE-RCU

My Feedback: (25)

Firewall Is 4 5/8" Wide And 6 1/4" High At The Highest ( Tallest ) Point. Hope This Helps.

mass balance

FLYINMIKE,

Thanks for the quick response! The BCMA 26 is 5 1/2" wide with the stock muffler, but a lot of the width is because the carb sticks out. The vertical dimension should be ok. I suspect that when I was done cutting, the carb would hang out one side and the muffler the other. But with the reasonable cost of this ARF, I might not care!

Engine weight might be a more important consideration. The 26 weighs 2.4 pounds, a little more than an OS 1.60 that I don't have, for comparison.

Regards,
mass balance

FLYINMIKE-RCU

My Feedback: (25)

Wish I Could Be Of More Help But I Haven't Reached The Balancing Stage Yet. Have About 5 or 6 Projects Going Here At The Same Time And It May Be A While For Me. Just Happened That Mine Is Within Arms Reach When I Read Your Post And Thought I Could Help. No Problem At All.

aatiger

My Feedback: (26)

Hello All,

What do you think of a G26 for the Obsession? Any thoughts/ thanks

Allan

fancman

My Feedback: (16)

I just bought a RCS 140SE on EBAY for $300 to use on mine. Should be a sweet mix and really good on fuel. I've got an RCS 140 in a Lazy Ace Biplane that I changed out years ago to get rid of gas guzzling 150 four stroke. All I need is an 8 oz tank for more than 10 min of flying.

aatiger

My Feedback: (26)

Hello Fancman,

Please let me know how it flys with a 1.4 gasser, I have a RCS 1.4 already, didnt think the 1.4 has enough power.
Love to chat more after. Thanks

Allan

fancman

My Feedback: (16)

I'll let you know. I think it will be fine if I keep the weight down around 11 or 11.5. May not be ulimited like my other pattern plane but I'm sure it will be good enough to get in some very cheap practice. I have a 16 oz tank on my 1.4 and I never refuel until I do two flights and I still have fuel in the tank when I do that.

fancman

My Feedback: (16)

Got the 1.4 RCS installed and saved about 6 oz's by using the supplied motor mounts with rubber well nuts opposed to using the Dubro Vibration isolation engine mounts. I found out that with the muffler I have I won't have to cut out the cowl on the side either, which is very nice.

Still assembling everything but this plane is very easy to assemble so far. I did take note of the warning in the instruction manual and everyone needs to do the same. This is a very lite airframe and I believe when they warn about power management, they ain't just whisteling dixie. If anyone tries flying this airframe at high speed they better be ready for some flutter or worse. The control surfaces are no way near heavy duty and I can see their point on power management. I will fly mine at the lowest throttle settings I can get away wiith at all times.

I'm looking froward to getting this plane in the air soon to see what the 1.4 RCS will do. Given the huge control surfaces on this plane I don't think there will be a problem.

NM2K

My Feedback: (14)

----------------


I've often that that the 1.4 should be updated to a 1.6 or 1.8. Yeah, I know that RCS has a 1.8, but it is heavy and not that powerful.

I'm going to consider using a Moki 2.1 in my Obsession. I hate underpowered models.


Ed Cregger

fancman

My Feedback: (16)

With the MOKI you'll likely pull the wings off this bird. You certainly won't lack for power.

aatiger

My Feedback: (26)

I think you are right Fancman about a Moki 2.1 will do to the Obsession,
the airframe very light, many guys putting a OS 1.6 doing 3D with it,
I just not crazy about the mess of the glow engines.

How are you doing with your RCS 1.4, love to know how it performs.

Al

fancman

My Feedback: (16)

The OS 160 or something like a Saito 180 would probably be the most perfect match but I think the RCS 140 will have enough power for most manuvers. I plan on using mine for more pattern practice than anything else. Not sure what prop will get the job done but this airplane is very lite. Thinking of using APC 17X8 for starters. I know this prop pulls my 15 lb biplane pretty good. Should work great on this 11 1/2 lb bird. I'm still putting it all together but will have it done within the week. Only have an 8 oz fuel tank on the CG wich will give me more flying time than a 18 oz tank with the OS 160. Nice and clean, very cheap on fuel and should still fly great.

aatiger

My Feedback: (26)

That engine looks really nice, I was using 16x8 wood prop on mine 1.4 before, you could go up to 17x8 with a APC prop.
Looks like you have the fuel tank way back there in the fuselage, how's your CG coming out? what servos are you going
use in the obsession.

fancman

My Feedback: (16)

Looks like I will have to put the radio battery as far back as I can get it and move the ignition batt back away from the firewall where I have it now but balance shouldn't be a problem. There is a lot of room in this plane to stuff things. The ignition batt will go beneath the fuel tank just in front of the wing tube. that should solve any balance problem. Using Hitec 6635's on all surfaces except rudder where I'm using a 5945 Hitec.

WheelPantz

I have this airframe I have yet got started on it yet do too other projects. I am trying to decide on engine and interested in the new OS four stroke when it's available. Anybody heard anything about it yet?

http://www2.towerhobbies.com/cgi-bin...&I=LXPRL4&P=ML

Thanks

Rich

rustypep

My Feedback: (6)

Thanks for the post. I have been waiting to see the weight of this new engine. That is lighter (29.3 oz) than a Saito 180 (32 oz) assuming the figures are accurate and a heck of a lot lighter than a Saito 2.20. These figures are without the muffler of course. It will be interesting to see what numbers it produces on which prop and how thirsty it gets. It ends up between the two in displacement but lighter than both. Same price as the 2.20 though. So far I have not found a gasser that will fit. The fuse is only 5 inches wide nar the front. The Brillelli 36 is close but the carb will stick out a lot and the firewall will have to be modified to clear the muffler. Plus you still are looking at over 50 oz+ for the setup.

fancman

My Feedback: (16)

I finally got the plane out for it's maiden fligt today. To balance with the RCS 1.4 I had both the ignition and reciever batt's behind the wing tube. The first flight was great. The RCS pulled the plane pretty good. No unlimited verticle but enough for great big pattern loops and such. I didn't push it to hard because I wanted to trip her out a bit. Just a couple clicks of elevator is all it took.

This thing lands like a dream, slow and stable. I was surprised because the wind today was kind of erratic. The plane locked in and settled down nicely. Time for flight number two! Gassed her up and took off. Proceded to try the sportsman pattern with a friend calling for me. After about the third manuever we watched with horror as the tail on this bird began wiggling. I was at maybe half throttle and that was all she wrote. The tail began to flutter and I had just a little elevator. I didn't think to switch to high rates at the time but what I found when I went over to the plane was that the fuse had broken almost in half just in front of the horizontal stab.

I was 2 miniutes into the second flight and not stressing the airframe in any way when it just broke. Here is what it looks like. Be very careful with this plane. It's built very light. I knew that but never expected this to happen. I never even got to check out high rates or any 3D.

rustypep

My Feedback: (6)

I saw your other thread first. Now I am rethinking the gasser part. This is shocking given what you were doing.