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-   -   Goldberg Extra 300 (https://www.rcuniverse.com/forum/kit-building-121/2403807-goldberg-extra-300-a.html)

dobra 07-15-2009 12:51 PM

RE: Goldberg Extra 300
 
1 Attachment(s)
Shame the pics are dark. Best I could do.
total weight now with fuel is 10.4 Lbs
Started up today and all is well and ready to go. Too windy to put it up as a maiden, Rubbish English weather.

Jaybird 07-15-2009 01:02 PM

RE: Goldberg Extra 300
 
Wow, very nicely done. The attention to detail is great and the covering looks really well done. I found that a bold color difference between the top and bottom side helps to keep orientation. When I first got mine it was done with a similar color pattern on top and bottom of the wings with the difference being a white section in the middle on top and a black section on bottom. The fuselage was all white, similar to yours, and the first couple of flights kept me on my toes trying to keep track of right side up and banked turns at a distance especially against a hazy or cloudy sky. Just my opinion of course. My only question is, how is the pilot suppose to see through that blue haze under the canopy? LOL.

Best of luck with the maiden!

Jaybird

dobra 07-15-2009 02:38 PM

RE: Goldberg Extra 300
 
He is blind, did I not mention that.
Might take some pics of the inside and post them.
Going to have some lettering on the side and on the bottom will have black stripes on angle on the underside of the right wing only.
Am quite excited about getting this one up. English weather has meant i have not been able to for ages. Seems every time i am off work it is either ranning or blowing stupid speeds.
Oh, just a point about the cowl - it is a pig to make it look ok

Jaybird 07-15-2009 02:46 PM

RE: Goldberg Extra 300
 
Ahhh, I see....well, sort of...

Well, if it's any consolation, here in New England (Maine), it rained for almost the whole month of June and we've had maybe 5 or 6 nice days in July. The wind is here too, but it calms down just as the sun sets...and then thse huge, blood sucking mosquitos descend on you and everybody runs!

The additional colors sound like a good idea. It is a great airplane even with a little OS 61 2-stroke on front. yours should really haul!

Jaybird

dobra 07-15-2009 03:07 PM

RE: Goldberg Extra 300
 
glad we are not the only ones suffering with inconsiderate flying weather.

WestCoastFlyer 07-15-2009 03:40 PM

RE: Goldberg Extra 300
 
Very nice! Great looking airplane! I like the wire stab supports. The canopy is cool, it doesn't look like a stock canopy with the rivets? and the blue tint. I know you'll go with black stripes underneath, mine's massively red underneath.

I hope the weather improves. Everyone should live in the Pacific NW in the Summer, best weather on the planet in the Summer. Just a little secret I thought I'd get out there. The rest of the year sucks with gray sky, but the Summer is heaven.

All the best with the maiden, take your time and fly on the perfect day.

dobra 07-15-2009 03:48 PM

RE: Goldberg Extra 300
 
Stock canopy and small dome screws and tamia clear blue paint on the inside. looks better in the flesh. Was going to dye it but never done it before and was not sure of the outcome.

Gray Beard 07-15-2009 07:54 PM

RE: Goldberg Extra 300
 
Jaybird, it wasn't JYO, I looked at it and was really impressed with the covering and how well it came out, really a great job. I spotted the stark white bottom and gave myself a big OhOh!! I just finished a plane in yellow and red. Figured I had plenty of red on the top so I left the bottom all yellow thinking I would just train my eyes to pick up the top from the bottom. After maiden it ended up with bulls eyes all over the bottom!! You could say I got a mite confused!!:( Being color blind doesn't help me much either. Whit is one of the harder colors for me to pick out. Dobra has a good idea for the bottom though.
My Extra has three inch stripes on the bottom of the wing and works OK but even orange and black throw me once in a while.
The cowl cutting on this one came out really good too. Nice and clean.
I haven't flown in a couple of weeks, my radio was in the shop but it has really been blowing hard and getting hot. Today it was 104F with a 23 mph wind with heavy gusts so I don't care to be out flying. I know, it's a dry heat but so is fire!!!
Outstanding job on the Extra dobra, your going to be flying your favorite plane real soon!!!

EscapeFlyer 07-17-2009 04:24 PM

RE: Goldberg Extra 300
 
Bump- Just to keep the thread fresh. I enjoy looking at this plane! Maybe I should build mine now.....

Gray Beard 07-17-2009 07:19 PM

RE: Goldberg Extra 300
 


ORIGINAL: Ilikebipes

Bump- Just to keep the thread fresh. I enjoy looking at this plane! Maybe I should build mine now.....
Yes you should, it's a really fun kit to build. I would like to build another one for myself with some mods. Before you build, please make up some templates of all the parts, I would like to scratch build another one for myself, mine is getting a little long in the tooth!! If I had the templates I could build them until the cows come home.
Yep, it was one of my all time favorite kits!!!

EscapeFlyer 07-17-2009 08:19 PM

RE: Goldberg Extra 300
 
I plan on making templates. Now if I could figure out how to pull my own canopies and buy some cowls, wheel pants, and a few forward swept landing gears.....


WestCoastFlyer: Was the landing gear you bought for the 60 size kit designed for the 1.20 size arf?

Next question foreveryone who flies this kit:

As I understand, a flat bottom fuse will stall briefely before it transitions into knife-edge flight. This can be tested by putting your bird straight and level and initiating an aileron roll. If the nose drops quickly during the roll, it is because the fuse is stalling out. (I've read this in a magazine recently)

Modern pattern aircraft manufacturers have solve this problem by rounding the bottom of the fuselage.

Can any Goldberg Extra (60 size kit) fliers verify that the nose of your Extra drops quickly during an aileron roll?

If it does, I'm considering a possible modification. Most Extras now days have two stringers running the length of the bottom of the fuse. To do this I wouls have to cut Tw new fuse sides and change the bulkheads a bit to accomidate this change. It is a little "extra" (no pun intended) work, but might just make an amazing kit even better- if possible.

Is this necessary? I plan to compete with it. (Sportsman wouldn't make this mod necessary, but progressing through the ranks with this Extra would - I think.)

Any takers on the idea or question?

Everyone I've talked to said the Goldberg is BY FAR the best extra in this engine class EVER produced.

(If it's not broke, I won't fix it!)


WestCoastFlyer 07-17-2009 09:23 PM

RE: Goldberg Extra 300
 
I'm with Gray Beard. If I wasn't watching my spending I would've already contacted the person earlier in this thread that had a kit in the box.

Regarding the 1.20 gear question I don't know. Do you have specs?

The 60 Goldberg Extra does not drop the nose quickly on aileron roll but I also have this disclaimer: Mine has flown the most beautiful 4 point roll I've ever seen. On rails. Perfect. The caveat is it was a 2-time AMA champ flying it. I'll check with him and get back to you.

EscapeFlyer 07-17-2009 10:57 PM

RE: Goldberg Extra 300
 
Actually, I was the one that was going to sell. Boy, I'm glad I didn't make that mistake.

I might just have to leave it alone.

I've seen a video called Wringing it Out a long - LONG time ago. Dave Patrick is showing how to perform aerobatics. He was flying this Extra and the Ultimate Bipe. I remember the Extra. Dave performed the most perfect rolling circle I have ever seen-with this kit!

WestCoastFlyer 07-17-2009 11:53 PM

RE: Goldberg Extra 300
 
Rats! That was you :-) I seldom look back, it's great that was you.

Ilikebipes, before I read your most recent post I pulled the cowl to get the right and down thrust for you - and anyone else in the future. This setup is the result of test flights flown by the previously mentioned friend. It did not fly perfectly after I built it 12 or so years ago. It needed some down thrust and more right thrust. This is with an Enya 1.20R and 15x8

The setup standing behind the airplane:

Top left...............Top right
5 washers............2 washers


Bottom left............Bottom right
4 washers..............2 washers





dobra 07-18-2009 03:21 AM

RE: Goldberg Extra 300
 
What size washers are they?
can you try and get the degrees of the prop some how?

WestCoastFlyer 07-18-2009 11:28 AM

RE: Goldberg Extra 300
 
Dobra, my next door neighbor is a Mechanical Engineer, he works out of his home with a nice shop. I'll talk to him today about measuring the right and down thrust.

I'll measure the washer thicknesses, but keep in mind the motor mount has been off and on many times, re-tightened many times, and some of the washers are more pressed into the firewall than others. I'll see about getting measurements from the mount to the firewall.

Edited to add: It goes without saying I hope you don't wait to maiden for these measurements. Every airplane is different, the torque of engines are much different, and I'm sure you're setting it up per factory specs for the maiden, I'm just mentioning it. It would however be interesting to compare notes with your Extra and mine, and other Extras out there.

You see, it always went like this: I'd be flying it or he'd be flying it, and he'd say, "It needs more down thrust" or whatever he thought that day, I'd go home and make the change... and so on over the course of many years. I haven't changed it since he did that perfect 4 point roll three years ago.

Gray Beard 07-18-2009 12:41 PM

RE: Goldberg Extra 300
 
Mine has almost no drop in the aileron roll. It's CGed a bit to the rear and when I go inverted it takes almost no down elevator at all to fly level. I have built several of these kits and every one of them took two degrees of right engine thrust. I almost never use washers for thrust, I make up an angled hard wood shim and I can slide it in or out to change the thrust angle and have complete support of the motor mount. The engine I have in mine is the YS 1.20NC but I have also used the OS 1.20 pumper.
Last one I built I used the YS 1.40 sport with the JTEC anti vibe motor mount. It was a bit harder to mount and needed some counter sinking of the fire wall for the rubbers. I made up a new fire wall with thicker wood to account for the counter sinking. With this mount and the 1.40 there was almost no vibration at all!! Great mount!!
I had to give it a lot of thought but I now remember the last kit had the canopy so I didn't need a replacement but I did get the LG, cowl and wheel pants from Fiberglass Specialities. It was the LG for the 60 size and a perfect kit.
If you are good enough to send me a set of templates I will build myself another one but I want to make up counter ballanced control surfaces. The plane doesn't need them but I wanted to give them a try and they look pretty cool.
Compared to the GP Extra the CG kit is a bit on the heavy side but that may be why it fly's so much better. It tracks like it's on rails!!
If you need to see how to figure out your engine thrust degrees I can post up some photos as soon as I get new batteries for my camera and show you the easy way.

WestCoastFlyer 07-18-2009 12:53 PM

RE: Goldberg Extra 300
 
That would be great Gray Beard. I noticed my neighbor's car isn't at home. He's a fly fisherman and could be gone for the weekend.

I measured the angle with an adjustable carpenters tool, but I don't have a protractor. Eyeballing it looks to be around 3 degrees to me, and the down thrust looks like about 1 degree. My firewall isn't totally straight at the top, I must have done some sanding at some point.

That's a great idea with the shims, because washers do press into the firewall.

EscapeFlyer 07-18-2009 02:49 PM

RE: Goldberg Extra 300
 
Wow. You guys are great!!! Thanks for all the help. I think I'll keep the kit stock- except for landing gear.

I haven't been this excited about an airplane in a long time!

WestCoastFlyer 07-18-2009 03:43 PM

RE: Goldberg Extra 300
 
My neighbor came home and he brought over a cool little plastic angle gauge. It's articulating, probably used for drafting. We took turns holding two straight edges and also used the carpenters sliding bevel. And I hope Gray Beard is sitting down, the right thrust, according to our crude measurement process of eyeballing with straight edges, is a whopping 4 degrees. But his could be wrong information. From my first measurement with the sliding bevel it's 3 degrees right thrust. Down thrust is 3 degrees, which is 2 degrees more than the factory suggests.

Goldberg has it Right 2, Down 1. Without measuring properly, which I admit, it's safe to say mine is Right 3-4, Down 2-3.

You know what to do about the gear, but I should mention the cowl because taking mine off yesterday I've developed a few more lengthy cracks behind the spinner that weren't visible with the spinner on. My cowl is a bear to get off/on due to my cutout and the Enya, the valve cover has to come off. The ABS cowl that comes with the kit needs to be glassed, not entirely, although it'd be a good idea, but the inside front of the cowl definitely needs to be heavily glassed.

Over the years my cowl was also burning/melting where my straight pipe runs (not touching the cowl but hot enough) and over the years I'd glassed that length of cowl several times. The glassing that finally worked was when I glassed in a couple layers of aluminum foil that run the length of the cowl with the straight pipe.

You should consider doing a build thread when you build yours. You'd get a lot of backseat drivers in that build bugging you ;) but I think the Goldberg Extra deserves the attention and I know you will love your airplane.

Gray Beard 07-18-2009 04:20 PM

RE: Goldberg Extra 300
 
All the ABS parts need to be glassed after you glue them together. A hard wood nose ring in the front of the ABS cowl glassed in will help out the cracking problem.I will be going to the market in a couple of hours and pick up some batteries for my camera.
I like the extended cowl that FGS makes but but I have used the ABS that comes with the kit after a few mods. Wish someone molded the the inside floor board/canopy that comes with the kit, it would dress up a lot of other planes too.

WestCoastFlyer 07-18-2009 04:45 PM

RE: Goldberg Extra 300
 
The hardwood nose ring is a great idea, and something Ilikebipes should definitely do. Interestingly I'd heard that suggestion all those years ago when I built mine and I wish I would've done it. Quite frankly my cowl is so uneven and ugly with layers of glass in there at this point I'm just going to lay some more in. Maybe even one thin layer on the outside on the nose.

I'm interested in seeing your thrust measuring methodology. But take your time, I hire my neighbor for commercial work and pay him fairly, but for this type of stuff I pay him in beer. That former measurement cost me 1 Drop Top Ale lol. I'm stuck at home this weekend with only a motorcycle, no way I'm running to the store for beer for that guy lol.

Gray Beard 07-18-2009 06:37 PM

RE: Goldberg Extra 300
 
1 Attachment(s)
Well, it's 103 out in my shop and looking a lot like rain so I really rushed things, muggy outside!!. Hope I can write what I'm trying to say so you can understand it. Most the time I take measurements but in this case I just laid things out so you can get the idea. It usually takes about five minutes, I think I did it in 60 seconds!!
I just lay out a line with the center marked and a mark at the 2 degree line and rule the two out. Measure the thrust washer and mark that out up on the top and line that out. The distance at this line will show you how far to the left the engine has to be mounted so the crank shaft is centered in the cowl nose ring. On the bottom line I measured the center of the mount then moved the engine over to the two degree mark and lined out the space between the line and back of the mount. The OS 1.20 shows it needs to be mounted to the left 1/4 inch to center the crank and requires a 3/32 shim to give it a two degree right thrust.
I usually measure things better but this should give you an idea of how easy it is to figure the thrust angle and offset.
Gene

WestCoastFlyer 07-18-2009 09:41 PM

RE: Goldberg Extra 300
 
1 Attachment(s)
Gene, Thanks! You braved 103 degrees with humidity and I braved 82 degree heat and a ride to pick up a protractor. I think I had it better than you. :-) I hope you're keeping cool.

I wanted to get a protractor to check out my initial measurement transfer/drawing I made this morning with the sliding bevel. A picture with the protractor is attached. 3 1/2 degrees right thrust.

Gray Beard 07-18-2009 10:49 PM

RE: Goldberg Extra 300
 
In Portland 82 degrees is pretty warm. Most the time we are at about 6% humidity so it never feels all that hot, it has been hitting 17% and to us that's a lot of wet. Nothing like the sweat I produced in Missouri when I was in the Army but more then I want these days.
Write down your set up on the CG Extra when it is finished and you have it flying just the way you like it. I found that all the Extras I have had set up about the same so I have a starting place on all of them. My 30%er is set up just like my CG and they fly about the same!!
Gene


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