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Goldberg Extra 300

Old 09-21-2006, 05:22 AM
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Default RE: Goldberg Extra 300


Great info. You folks have all been a great help. I will make enough mistakes without repeating things that you have found out already.

Thank you all again for your inputs.


Frank
Old 10-04-2006, 10:19 PM
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Default RE: Goldberg Extra 300

i have a great planes .60 extra, almost done (for about 4 months now). in the last year i have found quite a few aircraft (arf's) are now built w/2 pc wings. i have a pacific aero edge 540 and funtana 90 w/an alum wing tube, and i have gotten to like the portability of the 2 pc wing. i've considered building either a great planes or goldberg extra w/a 2 pc wing. cut new fuse sides, eliminate the wing saddle cut out, build the wing w/tube sockets, create a hatch w/the canopy, set the top surface of the wing level (no dihedral), taper the bottom of the wing and set the wing at the mid height of the fuse. build it as light as possible, install a saito 125. i like the goldberg because of the larger scale and longer wing.
any ideas?
jon b
Old 10-06-2006, 01:41 PM
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Default RE: Goldberg Extra 300

Sounds like a fun project, just make sure that the modification does not in any way compromise the structural integrity of the wing and fuselage. Keep us posted on how it all turns out.

Karol
Old 10-10-2006, 10:36 PM
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Default RE: Goldberg Extra 300

I can appreciate that aluminum or carbon fibre landing gear looks more scale-like than the bare stock wire landing gear, and that carbon fibre gear may be lighter, but aside from this are there any shortcomings of the stock gear?

In addition to using the stock gear, has anyone built and installed the plywood and balsa fairings? If so, did they last? My impression is that they would be too flimsy, but there is nothing like direct experience.
Old 10-11-2006, 01:06 AM
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Default RE: Goldberg Extra 300

I did use the stock wire landing gear with the built up balsa skirts which worked okay for awhile, but the added stress of flying from a grass field as I do weakened the gear mounting assembly and so I replaced the wire gear with an aluminium one....no further problems.

Karol
Old 10-24-2006, 07:44 AM
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Default RE: Goldberg Extra 300

I am also going to use the Bisson Pitts style muffler on the 91 FX. Fibreglass Specialties indicates they no longer make the cowl which is extended for the Slimline Pitts style muffler. Did you use the "satnbdard" Fibreglass Specialites cowl with your Bisson?

Thanks,

Frank
Old 10-24-2006, 03:34 PM
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Default RE: Goldberg Extra 300

Good thread. I ended up with the CG Extra when I bought A SkyBolt kit at auction, only the top of the box was A SkyBolt, the kit inside turned out to be the Extra. I already have one in 1/4 scale but it's seen it's better days so I will be building this kit sometime in the near future. Reading these build threads is always good no mater how many planes you have built. I always make up my own pull/pull systems using 30Lb stainless wire fishing leader, I really liked how solid that CF rod looked in one photo, I'm thinking of giving that A try. I just wonder about the extra weight but there sure wouldn't be any streching of the wire with that system, looks very solid. Thanks for the idea.
Old 10-26-2006, 09:12 PM
  #108  
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Default RE: Goldberg Extra 300

I used a cowl from AEROGLASS in Candada... Think it is out of business now. Was almost identical to the plastic cowl that came with the kit, except 1 piece. Had to cut some holes and cut off the ends of the muffler, then once on, added some extensions from silicon. Used lite hose clamps to hold them on. Have had no problems with the extensions coming off. Think I mentioned above that I plugged one of the exhaust pipes with about a 1/8 hole in it. Increased the back pressure without having to go to a pump. Seems to have not bad power.

Bruce
Old 11-21-2006, 02:10 PM
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Default RE: Goldberg Extra 300


Folks: I am in the process of attaching the canopy to its frame. Getting the canopy to conform to to shape of the forward bulkhead on the frame is a problem. I am using Super RC Z 56, and clamps. Because the glue is in tension and there is a lot of force, the canopy just pulls away from the round bulkhead. I am in the process of supplementing glue in this area with servo screws. Is there an easier way?

Thanks.

Frank
Old 11-21-2006, 05:58 PM
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Default RE: Goldberg Extra 300


ORIGINAL: frdeluca1


Folks: I am in the process of attaching the canopy to its frame. Getting the canopy to conform to to shape of the forward bulkhead on the frame is a problem. I am using Super RC Z 56, and clamps. Because the glue is in tension and there is a lot of force, the canopy just pulls away from the round bulkhead. I am in the process of supplementing glue in this area with servo screws. Is there an easier way?

Thanks.

Frank

As I recall the canopy in my kit came moulded to match the curved shape of it's frame and fitting it was quite straight forward. I used medium Zap to hold the canopy in place on the frame and then placed a bead of clear silicone as a fillet on the inside to help strengthen the entire assembly.

Now after more than 10 years in service my model is still as good as new.
Old 11-23-2006, 07:11 AM
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Default RE: Goldberg Extra 300

freluca1,
The canopy in a pain! What I have done is to add very thin ply strips that connect the two forward bulkheads. This gives better strength and a large gluing platform. I also add some balsa between the two side stringers for ridigity (I do not use the formed cockpit). I don't even use rear bulkhead as the canopy rests on top of the turtle deck.
Old 11-23-2006, 10:38 AM
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Default RE: Goldberg Extra 300


Great suggestion, especially your idea of connecting the two forward bulkheads. By a combination of screws in the forward bulkhead, clamping and gluing I finally have an acceptable , not great but acceptable, looking canopy/ frame assembly. If I had it to do over again I would definitely have used your approach.

I am getting ready to cover the plane. I was thinking of spray painting the turtle deck and rounded plywood area foreword of the canopy thinking it would better blend with the cowl. It will also be easier than covering that area.

Thoughts?

Thanks,

Frank



Old 11-23-2006, 07:44 PM
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Default RE: Goldberg Extra 300

To cover the turtle deck ,which isn't easy, I use the left over plywood for the turtle deck as a template. I just lay the turtle deck frame over the covering and cut it out, adding extra covering material if needed. I always end up with some wrinkles between the horizontal and vertical stab.'s.
Old 03-23-2007, 09:26 AM
  #114  
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Default RE: Goldberg Extra 300

Hey Skyriter: What prop are you using with your OS 90 two stroke?
Old 03-23-2007, 10:25 PM
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Default RE: Goldberg Extra 300

All I have to say is wow! It seems that there is a little bit of overkill going on here. I know that sometimes you have an itch to just go all out on somthing. Here is some reasonable prespective from a level headed guy. I have had my Goldberg Extra for about two years now. It was given to me by a good friend who while cleaning out his shop found an airplane that he bought a while back as a plane that he was going to build one day. He had decided that he was not going to build it so he gave it to me. I built it as per the plans and instructions. I use a O.S. 61FX for power with a pitts muffler and standard ball bearing servos on everything but the rudder to which I have a high tq servo hooked up to. This plane is the plane that I fly the covering off of. The plane will do anything with the exception of 3-d type manuvers. It is light on the controls but is the most honost plane I have ever flown.

The plane is awesome straight out of the box. So have fun with it.
Old 03-24-2007, 07:57 PM
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Default RE: Goldberg Extra 300

I do agree, the Goldgerg Extra is really an awsome flying model straight from the box. In this case a little extra power can be a good thing, and if built as per the plans and instructions this baby can handle it quite well. Though designed around a 60 size glow motor, this model really comes alive with a 90-1.20 glow or a 23cc gas power and will give countless hours of enjoyment.

Karol
Old 04-02-2007, 07:16 AM
  #117  
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Default RE: Goldberg Extra 300

Folks: Just finshed mine: OS 91 FX, 16X6 APC, Slimline muffler,Fibreglass Specialties cowl, pants and alum gear, 16OZ tank (?), 1400MAH 4.8V batt. Plane weighs 9 pounds and is nose heavy. Looks like I can get it to balance by locating the battery way aft of the wing.

My concern is that when I fill this big tank there will be a significant shift in CG towards nose heavy again, but as I have heard the 91 FX is "thirsty' I believe I need this size tank. Should I be worried about the initial trim with the tank full?

Also, I cut out both air intakes on the front of the cowl plus good clearance around the cylinder and the muffler pipes. The cowl is pretty tight at the bottom though where it meets the gear. Should I expect any overheating problems with the 91FX?

Thanks
Old 04-02-2007, 03:57 PM
  #118  
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Default RE: Goldberg Extra 300

OK, almost finished with mine. I built it for A friend so he supplyed all the stuff I found missing in the kit box plus the engine and servos and TX.
The canopy, wheel pants and cowl came from Fiberglass SP and yes, they still have the extended cowl. The landing gear is from Wild Hare and is from there 27% Extra.
The engine is the YS 1.40 Sport so the LG from Wild Hare is A bit longer then FGS, I needed the extra length for the bigger props this engine can throw.
All servos are from HT and are the 645 MG. The RX is A Futaba 9 channel PCM.
I ran A pull/pull rudder system with two elevator servos mounted in the aft section of the fuse. Two aileron servos. 16 oz fuel tank and I have A 6 volt battery. Made up my own remote glow driver from head phone jacks. Engine is mounted with an anti vib mount from Jtec.
The fuel tank is mounted with the center of the tank right over the CG and without any servos in the bay under the wing, I had gobs of room to leave space over the CG for A smoke tank and pump. Being injected the YS and any pumped engine doesn't care where you mount the tank but any other engines you can't do this.
I mounted things the way I did to help out with the CG knowing it was going to come out nose heavy, and yes, it did. About two ounces with this engine and cowl. I have everything mounted behind the CG.
I'm in the process of painting the cowl and pants at the moment and with dry time that will take A couple of weeks. I like to give it at least four days time between colors.
I fired up the engine the other day and this was the first time I have seen A four stroke that didn't vibrate the plane, can't say enough good things about the Jtec mount. It's A bit different to set up but it is one of the better mounts I have used.
Muffler is stock. Waiting for the finished product before I weigh it but it came out very light.
Any questions hit me with an email.
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Old 04-02-2007, 04:46 PM
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Default RE: Goldberg Extra 300

For the first few flights I balanced my model about 1/2" in front of the given CG range to get a feel for the model, and finally ended up having it just about midway the balance range. A 12 oz. tank is positioned as per the plans and the model shows difference in it's performance wether it's full or not.

That 16x6 APC sounds like a lot of prop for the 91. As I recall I used a 13x7 on a ST 90 which worked quite well in the Extra. The FS cowl has adequate sized cooling openings for both intake and outlet, but a good rule of thumb for getting rid of hot air inside the cowl as quickly as possible is to make the exit opening three times the size of the intake opening. Just watch your mixture setting making sure you are always on the rich side of things and you should be okay.

At 10 lbs with its electronic ignition G23 gas motor, my model is an awsome flier with absolutely no bad habits and great performance. I'm pretty sure that you are going to love the way your model performs, and don't forget to post an update when you maiden your pride and joy.

Karol
Old 04-07-2007, 06:53 PM
  #120  
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Default RE: Goldberg Extra 300

I am using a APC 15 x 6 on an OS 91 2stroke. Have a Bisson pits style muffler. Had to plug 1 side in order to get enough back pressure to get it to richen up. Was running about 5 turns out, and it still ran lean. Now with the mufller plugged, it runs good. This gives me good torque without a lot of speed. Think I am getting about 9500 or more for rpm - been a long time since I had a tack on it.

Bruce
Old 04-08-2007, 09:17 AM
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Default RE: Goldberg Extra 300

Good looking Extra's there. Just finished mine with a couple of mods; moved landing gear way forward and used aluminum gear, dual elevator servos, YZ 110 upfront. Yes the turtle deck is a pain!! Have a fiberglass cowl that will be finished later after engine break in. Weights around 9 lbs (without cowl).
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Old 04-08-2007, 09:33 AM
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Default RE: Goldberg Extra 300

skywriter:

Did the engine actualy cut out on you in flight until you blocked one exaust? Also what does your plane weigh? I am actually over 9lbs , probably closer to 10
Old 04-08-2007, 10:21 AM
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Default RE: Goldberg Extra 300

Obviously the lighter you can get a model the better it will be, however don't worry too much about your Extra's weight if it's between 9-10 lbs, because I have heard of similar models at 11+ lbs powered by big Saito's that are nice flying planes.

Karol
Old 04-08-2007, 12:19 PM
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Default RE: Goldberg Extra 300

Don't worry about the weight too much, Mine has a Saito 150 with duel elevator servos and came in at a little over 10lbs and flies great and slows down nicely for landings. This plane seems to handle the weight really well without giving any bad issues to the weight.

Dauntae
Old 04-08-2007, 01:17 PM
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Default RE: Goldberg Extra 300

No, just could not get the engine to run right. Thought 5 turns out was a bit out of line. Had read in some of the other forums where some pit style mufflers did not provide enough back pressure to presurize the tank. Figured I would try blocking one. The suggestions was to pinch off one if the pipes. I uses a 3/8 wood dowl and then drilled a small hole thru the pipe and then fastened the dowl in place with a wire. This allows its removal if I decide to go to a perry pump. This was a cheaper way to go. Not sure if I am getting max power this way, but it flys good. Think I am aout 1 1/2 to 2 turns out now. At least now I can get it to run rich, where before it just was not happening.

Plane weighs about 9.6 on a digital fish scale. Think I am a little on the heavy side. I used the 3/6 alum landing gear. Also moved it forward quite a ways and beefed up the landing gear mounting quite a bit. If it comes out, then a lot of things are going to come out. Used 2 servos on the elev and pull-pull on the rudder. Also used 2 servos on the Ailerons

Bruce

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