jjoos99

My Feedback: (12)

I am building a goldberg ultimate and was wondering what engine choice guys were installing in their planes? I have been building it for a ys120 but have been wondering if it is too much for this plane. Too much weight that it would fly heavy or not balance out right without having to add some weight to the tail.
thanks
Jeff

daveopam

My Feedback: (9)

The YS 1.20 would be a great choice. I am putting one together myself. It is my third one. This one is going to have plenty of power. I am going to use a OS 1.20AX. I have mounted two micro servos in the tail for weight. I like the CG at 3" back on the lower wing inverted. The last one I had was ST 90 powered and needed the battery 6" behing the lower rear wing bolt down plate. To get the CG in the sweet spot. I don't know if the 1.20 is heavier then the .90. Should be about the same. Nice thing about an ULT is it will fly great under power even on the heavy side. I flew one years ago for a friend that had a Enya 1.20 four stroke and a smoke system. If it dead sticked look out. Under power it was great.
Not bragging but I have flown about 20 different GB ULT's over the years. Best one I ever had my hands on was YS 1.20 powered.
You wont be sorry.

David

Crash Campbell

Hi Jeff,

Like David said I'm sure the YS will be great. I have a Saito 125A in mine and it was easy to balance with servos/battery position, no weight needed. The Saito gives unlimited vertcal. I'm sure the YS will be similar.

Cheers,


Colin

jjoos99

My Feedback: (12)

Colin
Did you also mount your servos in the tail? I am building the fuse now so it would be the perfect time to implement the rear servos.
David
Do you have any pics of how your are doing the servos? I have several hitec 81 servos that I could use that came out of another plane. My email is [email protected]
Thanks
Jeff

jjoos99

My Feedback: (12)

Also would you go with a blind nut bigger then the #6 for the engine mount for the 120 size motor. Kit comes with #6 nuts and screws.
Jeff

Crash Campbell

Hi Jeff,

The servos on mine, one for each elevator half, are mounted slightly rearward of the CofG. I balanced mine before covering with the RX battery near the firewall. Since flying I have gradually moved the CofG to the rear by 10mm by moving the RX batteries. This set up suits my style of flying.

You will love how this model flys.

Cheers,

Colin

daveopam

My Feedback: (9)

Jeff I will take a few pics and post them here. I am at work now, may be a day or two. I am using Hi-tec mighty minis but dont know the number of them. The number should show in the pic. This was a very easy instal. I was able to make the slot for the pushron exit taller and use that area.

David

js3

My Feedback: (3)

I've flown GB Ultimate bipes with a YS 1.2 (mine) and a YS .91 (my brother's). I felt my brother's plane with the .91 was every bit as capable as mine was with the 1.2. and being a touch lighter, handled a bit better at slow speed. If I had one now, I'd try the YS 1.1 which is based on the same case as the .91.

daveopam

My Feedback: (9)

Jeff here are a few pics of the servo instal. They are Hitec HS-225BB. These make 54oz each and should be more then enough. As you can see in the first pic I am still setting up the linkage. With the ball link on the servo and and a clevis soldered on the other. It will be an almost straight shot.

David

jjoos99

My Feedback: (12)

David
Are you using each servo to control a separate elevator half.
Jeff

daveopam

My Feedback: (9)

Yes I am. The last two Ult's I have had I used a Dave Brown push rod with a "Y" to run the Elev halves. This is fine for most flying but limits the amount of throw you can have. I know this is not a 3D bird but I plan on doing some 3D with it. I use a 9C Futaba so I have the Elev servos on separate channels. My last Ult would do a decent elevator but could use a little more Elev throw. This set up should give 45 degrees + of throw. The second reason for doing this is CG related. I balance mine 3" back from the LE of the lower wing while inverted. To get the CG in that spot on my last Ult I had to zip tie the battery to the first former behind the lower wing opening area. This is about 6" behind the rear hold down plate. This was a pain to reach and a pain to get positioned to clear the pull/pull.
I should have a lot more freedom to put the battery in the radio bay.


David

jjoos99

My Feedback: (12)

I think that I will go with the tail mounted servos. i have the 225s already and the matching y that I used in an edge. i take it a pull pull set-up for the rudder? since I am going with the ys I am putting the tank over the wing for better in flight balance as the fuel level lowers.
Jeff

NM2K

My Feedback: (14)

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To anyone building this kit - DO NOT USE THE PUSHROD SETUP SHOWN ON THE PLANS! - or you will lose your model. This applies even when the K&B .65 shown on the plans is used. The unsupported 2-56 pushrod ends with a large Z-Bend (where exiting the fuselage unsupported) will fatigue and will go soft, meaning that one day you will not have sufficient up elevator to recover the model from a dive or a spin. How Goldberg let this mistake get through just proves that even one of the best companies can make serious mistakes.

I agree with others who are saying to keep the engine light. It doesn't take much power to manhandle this model, so light weight is more important than absolute power. I had an Enya 1.20R on mine and I would gladly have given up some power in return for more agility.

I like the idea of a hot two-stroke .91 to 1.20. If you already have the YS 1.20, then by all means use it. Just be sure to reinforce the firewall with triangle stock and even fiberglass cloth.

I chickened out and bought the ARF version of the Ultimate Biplane this last time with the intention of using my Saito 1.25. That will be sufficient for the aerobatics that I intend to fly.


Ed Cregger

WacoNut

How about a 26cc gasser in this plane?

jjoos99

My Feedback: (12)

I do already have the 120 ys. I also have a 26cc gasser but I had it in a 1/4 scale cap and it just didnt have the power it needed to pull the heavy plane and engine around. I might be wrong but with this type of plane I wouldnt think that the gasser would have the punch it needs. After loosing the cap to a tip stall due to lack of power I would rather see a 26cc gas in a slow flying plane like a larger cub. If you know anyone who would be interested in a 26cc gasser I have a mvvs that I would sell.
I installed the solid 1/4 firewall and increased the size and strength of the stringers as per harry higley's book for the added strength of the 120 ys. How much heavier is the 120 over say a .91ys? I have considered selling the 120 and picking up another engine. I have the firewall set up with blindnuts for the 120.
Jeff

daveopam

My Feedback: (9)

Don't second guess yourself now. Put the YS 1.20 on it. You wont be sorry.

David

seanucd2000

My Feedback: (1)

I've got one with a YS 1.10, and wouldn't want anything less. Plus, this plane deserves the sound of a four stroker.

NM2K

My Feedback: (14)

The problem is that no one is producing and selling a 26cc gasser that can stay even with a good glow 1.20 engine, two or four-stroke, not to mention dealing with the extra weight of a gas engine.

Yes, you can fly a Goldberg Ultimate Biplane with a gas engine, but its performance will be way down when compared to a good glow engine. However, for some folks, that is adequate power. For many, I don't think it would do.

The extra weight is really going to make landing this model deadstick a real challenge, as if it isn't a challenge when the model is light. Biplanes are different in this sense, but you only get one chance to get it right when that inevitable deadstick shows its ugly face.

The best strategy is to pretend you are landing the Space Shuttle. Drop that nose immediately and dive toward the field. This goes for either glow or gas engine.

I'm not trying to scare anyone. Just be forewarned and work out the landing procedure BEFORE you have to employ it.


Ed Cregger

jjoos99

My Feedback: (12)

Are both wings and stab all set to 0 degrees incidence? so far my bottem wing worked out to perfect 0 and the stab is maybe just a 1/4 degree from 0.
Jeff