Gray Beard

My Feedback: (-1)

Karol asked me about the servos I have in my Extra, I don't know?? They aren't the old 48 in lbs and I think they are digital? Maybe not all of them? Pain in the hinderpoo to open the hatches to see. The old 48 in. lbs Futaba was what we used originally and they work very well. Today you will be told that you must have some big high dollar digital servo in any stunt plane. Fact is I understand why 3-D pilots like the biggest and best but most sport pilots wouldn't be able tell the difference. Every nimrod will tell you you must have these big servos. My stock reply when someone asks me about servos is to buy the best you can afford, they will be with you for a lot of years and can be used from plane to plane. I bought some of the first digitals that High Tech offered, 70 something inch pounds? They are still with me and being used, they were about $25.00 back then, now about $30.00. I think there is just too much over thinking and spending on servos. A friend bought an Aeroworks YAK 90 size, AW said to use some massive servos in the plane. Aeroworks sells servos, give it some thought. The guy still can't fly inverted so why would he need servos as big as I use in a 40% plane?

Cyberwolf

My Feedback: (4)

When choosing servos I look at the overall picture, what type of plane are they going in,what engine will be used, what type of flying will the plane be used for and how large are the control surfaces, AUW of the plane and so forth. Both the GB Extra and Sukhoi called for S-148 which worked ok in stock form and the smaller end engine's. But add more engine and see what happens.
The extra speed and air going over the control surfaces play haveck and a person finds out real quick the plane no longer flies as it did. An up grade is necessary to the servos to get it back in shape to hold the extra pressure and maybe even the control rods.
There are way to many cheap good hi-torque servo's on the market now for a person to skimp if there is a question about servo's, it is not like it was when both of these plane's was introduced.

Gray Beard

My Feedback: (-1)

Only time any of my planes are at full throttle is when going vertical or doing a high speed pass. Other then that there is no added speed just because I have the added power.
On something like a loop I add power as needed, sort of like driving a car up a hill, it's rolled on as required. Doing things like snap rolls at full power is a good way to fold the wings. Been there and done that. I went to bigger engines for more vertical power, not high speed. That's another reason I usually have a longer prop with a small pitch, I like a slower plane with more power, not speed. Almost any servo in this plane will work very well, it's not a racer getting yanked around a pylon. It's designed as an IMAC plane and was used for that before the judges eye site failed and they need 40% planes to see them. Servo selection can be what ever you want.

OldScaleGuy

My Feedback: (2)

Took my CG Extra out to the field today and had a great time with it. It is such a great flying plane. It was a great day for flying here for a change, warm, sunny and not too windy. As far as servos go, the old rule of thumb of one ounce of torque for every square inch works fine for this plane.

karolh

That's a very nice looking model.

Cyberwolf

My Feedback: (4)

Do as you wish Grey Beard but your analogy is incorrect, your not considering the weight factor or prop blast against the control surfaces due to the larger props from a larger engine no matter what pitch you use. Like I said there is no sense in using a inferior servo with today's good cheap servos at hand for not much more money. The day's of the S-148 or the very high dollar servo is over were not living in the 70's anymore.
I suppose you have never heard of or even thought of Preventive Maintenance.

karolh

Wether it was preventative maintenance or maybe just plain ole common sense I upgraded the servos on my rudder and elevator to 100 oz. in. units, while both ailerons and throttle remain with top cover BB S148's.

EscapeFlyer

My Feedback: (1)

A 10cc class engine that will actually WORK for the Goldberg Extra!!!!

Check it out-

http://www.smtdistributing.com/SMT-E...61SPEED-13.htm For the black case version.

OR

http://www.smtdistributing.com/R61F-R61F.htm For the natural aluminum, version.

You can choose between the 9mm carb with the inflight air mixture adjustment, OR the 10mm carbon maker with no in flight adj.

(Swinging a 11X8 Xoar prop {as good as an APC} at 14,800rpm with a Hatori pipe. The NovaRossi pipe is an almost identical replica of the Hatori.)

Brian

Dauntae

Nice engines but a 11 inch prop would make it look like one of those kids rides at Walmart LOL Originally it had a 60 size but slower rpm than those beasts but had larger props.

Dauntae

EscapeFlyer

My Feedback: (1)

Can always go to a 12X6 or a 12X5....

These engines are long strokes, but are timed for high rpms.... They are happiest when they are screaming! The 12X5 should do that.

Brian

mrhp

My Feedback: (49)

hi rpm engines no good in these type of planes. save them for the racers

EscapeFlyer

My Feedback: (1)

That is certainly one opinion....


Dauntae-

This would be cool too.
http://www.smtdistributing.com/R91F-R91F.htm



The YS 1.20 is a perfect match. But it is nice to have legitimate options.

Brian

Dauntae

The 91 would certainly give a much better prop for this plane but at higher rpm the airframe would need a low pitch prop, I'm a 4 stroke junkie now so I have a Saito 150 in mine and flies it wonderfully.

Dauntae

Gray Beard

My Feedback: (-1)

Brian, why not finish yours and give it a try? I wouldn't mind seeing how well it works. I didn't care for the plane with a .61 two stroke but it was just an OS. I tend to go under the bench and use what I have on hand so that tends to be the YS 120s. My plan was to build another one and use my RCS 1.40 gas engine but other builds keep getting in the way. At the price of the DLE 20 and the Mintor 1.40 22cc gas engines I don't think I would use a glow engine at all. Mine just happens to have the YS 1.20 and it works so well I haven't changed it other then the OS 1.20 fs. That was OK but lacking a bit.

kalikikopa

I flew mine with a RCG 26cc gas engine. total weight was 11lb. Used 16x8 prop. The 18x6  worked well too, but it was so big it would trim the taller grass when taxing, so the tips of the prop were green.

colmo-RCU

Back to the landing gear discussion, I found this replacement gear at tower, it's just a tad narrow but has worked great for me

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXNCT7

It's cheap and strong, I think it's a good option. I also went with high torque single servos for rudder and elevator, but made myself a Y out of 4-40 rod and I joined the 3 pieces with a ply-glass sanwich. It's there for the long run, I recon. I wish I had reinforced the fuse as many guys say here, but honestly I didnt read through the whole discussion until after it was built

EscapeFlyer

My Feedback: (1)

WOW! SWEET!

Flight report!

Brian

karolh

That is one sweet looking Extra you have there, congrats to you on your build.

OldScaleGuy

My Feedback: (2)

Great looking family too. Looks like wide open space to fly.

colmo-RCU

Thanks, guys, living in the desert has its good things, like every unused piece of road being a perfect runway, although I made the plane too dark and now in summer the paint will start to melt on the cowling after 9 am. Already happened to me the day the pics were taken.

The flight report I guess will be very boring, it's the sweetest, smoothest, easiest plane to fly, yet it does everything up to harriers, no 3D. Unlimited vertical, contrary to what happened at the high altitude of Bogota (8300ft). Hehehe, I sound like one of those "unbiased" magazine reviews, but you guys know better. I had to mix elevator and opposite aileron to have straight knifeedge, cause Im too lazy to keep correcting by hand, but now I can fly nonstop knifeedge and even climb a little.

The exhaust pipe gave me grief, as the flexible metal part, you know the electrical piping they use sometimes, kept breaking after each flight and I kept having to make it shorter. In the end I went to a turning shop, and after hours of trying to explain to a Bangladeshi what I wanted (what a Babel Tower this place is!!), we ended up making a steel replacement out of steel stock, hollowing it and all. It was a great couple of days spent in the industrial part of Abu Dhabi. He even made aluminum lock nuts.

Now everything works properly, and I hope it will for many years. Ill try and take some better pics tomorrow

karolh

Like you, anyone that's ever flown one knows it's the sweetest, smoothest, easiest, most capable and forgiving plane to fly bar none. If in all of that I forgot to mention how sweet it is to fly, forgive me

colmo-RCU

Ok, so here are the pics I got. I lightly sanded the top of the fuse, the blue part between the cockpit and the cowling, and painted it with a light coat of the paint, because I hate the way it looks with the two different shades. Also, I dropped a screwdriver on the wing, so I had to make the new Extra logo, which I think is very cool. The angle of the pipe is very steep, I don't like it, but will have to live with it. It does make for a very clean plane, though

RICKSTUBBZ

While reading through the “NATS NEWS” I just happen to run across this.......All pictures are copied from the “NATSNEWS”

OldScaleGuy-Congratulations..........

karolh

Well done Steve, just goes to show how rock solid that old Goldberg design is, and still kicking the butt off newer whiz bang models.

aits

My Feedback: (3)

Hello All,

I am in need of a set of plans for the Carl Goldberg Extra 300 ! Is anybody willing to part with theirs or willing to make a copy of a set and sell to me?