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Goldberg Extra 300

Old 11-09-2022, 10:05 AM
  #2026  
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another question as I am getting ready to join the wing halves
is there Dihedral on this wing
I see there is a 91 degree tool for the spar so does that mean theres 2 degree dihedral total on the wing
also confusing to me is
when joining the halves the manual says to use the tip brace tool and the root brace tool
so does the tip and root spacers take this into account
and cutting one spar from the plan and the other using the 91degree guide just help when joining the halves up

final confusion, when I built the wing halves, I believe I missed the part where it said to join the wing sheets together
I still built them on their on their respective layouts. pinned the 3 ribs that had the breakout tabs, built them and sheeted a per directions
so now I've got the plans together and am fairly sure you flip the wing over so the other side without the sheeting is facing up

is the side thats now facing up the top or bottom

this takes me back to my orginal question of dihedral. which the tip and root ply spacers would take into account
I would guess that the spars that were cut 1 degree out from one another would now match

I 'm going to blame todays stupid spell on getting the "seniors" flu shot and the shingles shot yesterday

hope somebody can straighten me out - going to re-read the wing section of the manual again but I'm beginning to think at this point I'm looking at the bottom side

both wing halves came out great but I'm going to wait until I understand the dihedral and which way is up or down before I join them
Old 11-09-2022, 12:24 PM
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Old 12-13-2023, 07:56 PM
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Did you ever get the thing finished? I built one in like 1990. I snapped the right horizontal in half in a snap roll and made it around to land in a field hitting a trashed box spring destroying the plane. Here's a pic.
d




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Old 12-14-2023, 06:54 AM
  #2029  
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but the plane is finished and waiting for weather and wind to calm down
The fuse sides and bottom are 1/8" marine plywood and the rest is either light ply or balsa
Canopy is from my old extra230 with a modified frame for this plan
engine is a MDS148 and hi speed trials at the field were very good, actually had it a few inches off the ground before throttling down
This engine is a beast.

for some readon I cant upload pictures or links so...
I posted a picture on my QRZ radio page: ve3cga click on the rc plane icon and it will take you there
then click on the extras picture to get a full screen version
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Old 12-15-2023, 08:36 AM
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Has anyone built/flown the cloned CG Extra from Outerzone ?
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Old 12-15-2023, 10:34 AM
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I am still building, unfortunately I got stuck, finished the wings and started the fuselage. I have had little time. I hope to continue building next spring.
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Old 01-03-2024, 07:08 PM
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First time poster here.

I am currently building the Goldberg 300 with plans from Outerzone and the short kit from Balsa Work Bench.

Thank You! to you all who have contributed to this thread. I have learned a lot!

Britflier
I am currently nearing the the final stages of construction - building the canopy. Like you I measured the wing incidence at this point and have the exact same wing gaps you show in your previous post as well as the same -.5 degree wing incidence. I am perplexed. The canopy and laser cut canopy former's fit perfect as is. Anything I do to correct the negative wing incidence will negatively effect the canopy fitment as a result.

I was wondering if you found a solution? Or continued with the build as is, if so, how did it fly?
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Old 01-04-2024, 09:42 AM
  #2033  
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Default waiting for calmer winds

I can tell you that was the best scratch built I've done
Everything was rough cut with a dremel/ hobby saw and knife then sanded to match the outline of the piece
I laser print the part layouts then spray with 3M photo mount so they are mounted on the rough
wood pieces...cut slightly outside the lines then sand so they match
Its not CNC but MNC or "manual"
wing had no incidence, I used the wing braced that were in the plans
and I have a very flat bench
Probably going to have to mount my skis on to maiden it, we just got a bit of snow
I put a MDS148 engine on it and will have to re balance as its too nose heavy. I'll leave it a bit nose heavy for starters
I cover my planes with photocopier laminate, its very thin but was free, commercial copiers toss out part rolls
I paint it later after first flites
The only serious mod was the canopy. Its from my old extra 230. the frame had to be lengthened to fit the extra300 plan
I'll build a fiberglass cowl once it flies good.
That MDS 148 is a monster... the plane shakes like a NHRA fueler at idle then stiffens up after any throttle
I taxiied it several times and it tracks straight and after givin it 1/2 throttle it starts skimming the grass.
It really wants to go
One other mod I did was to move the landing gear forward until the wheel axles were even with the leading edge , I hate nose overs
Looks like the photo is going to work this time, hope so



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Old 01-04-2024, 12:24 PM
  #2034  
 
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I can tell yall that my SuperTigre .90 was perfect fit, but still way more power than needed for the GBE
d
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Old 01-04-2024, 07:40 PM
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Miryan, I ignored the -ve incidence on the wing, went ahead and completed the build. I have only flown it about 10-12 times, Ive been flying my other planes instead. The Extra flew OK, but I was not comfortable with the performance. Since the last flight I have made some changes to the c of g. I have moved it to the forward limit as shown on the plans. I also put some more sidethrust on the engine. I also added some soft material spacer to the front of the wing saddle. The canopy still fits but is tight on the wing.
I will keep you posted on how it flys.
The Outerzone plans show 0, 0 incidence. Maybe the kit cutters files did not translate exactly ?
Or maybe the native Goldberg builds 0, -0.5 ?
Can anyone confirm?
Old 01-12-2024, 03:14 PM
  #2036  
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Thanks for the reply and info Britflier!
ve3cga: Cutting all of that lite ply to plans manually and getting it to fit is a lot of work! My hats off to you sir! Glad to hear your happy with it.

Well, I finally got some time to check and triple check the plans, laser cutting and my work so far, to try and figure out where the issue is.

First off, I went old school and painstakingly transferred the wing center line from the plans to my fuse side to verify it wasn't my gauge. Sure enough, the center of the leading edge of the wing lined up perfectly with my marks. The center of the trailing edge was just over 1/16 high, not quite 3/32. Dang! Same thing my incidence meter was telling me, so at least I know my gauge is accurate,

After much tinkering to see what went wrong, I figured out the error was on my end.

The plans show the wing trailing edge and ailerons at 1/16 thick. I forgot that I had consciously made the decision to taper them to 1/8" thick thinking 1/16 was going to be too thin and fragile. I obviously didn't think that through too well! The thicker trailing edge lifted the back of the wing in the wing saddle Also, it appears I compounded the problem by not getting the trailing edge blocks at the wing root cut square as they are tapered evenly but slightly pointing down, further lifting the back of the wing.

Because the U-Shaped gusset ties into the top of the wing saddle right where it needed to be sanded to correct this. it really complicates things. My fix was to leave everything at 1/8" and sand "saddles" into the wing trailing edge where it contacts the fuse wing saddle, thus dropping the trailing edge down. It worked, I just hope it didn't weaken the trailing edge too much and bite me in the A**.
Old 02-04-2024, 12:01 PM
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thanks, its rewarding to almist whittle out the pieces. these goldberg plans are awesome, the ultimate bipe was excellent to scratch build

anyway if this week is going to stay sunny, no rain ,no winds over 15mph I'll be trying the plane out

I just put 7oz on the rear of the fuse to balance it with just a bit of nose heavy

snows gone here at the moment and with the sun the ground isnt squishy
Managed to fly my new scratch built electric 4' ultimate stick and it was almost boring except it was snowing so hard I didnt dare flying above 50'
Had to land after several passes - looked at the transmitter and it was covered with snow. the plane flew perfectly
Luckily no water inside the controls

Once spring comes along I'll try my ys110fz in it, I tried it this winter but it just wasnt reliable, Ran too rough
Old 02-05-2024, 05:39 AM
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Wishing you best of luck with your maiden flight. It's a Goldberg so I'm pretty sure it's gonna fly awesome. By the way, what does your model weigh ?
Old 02-05-2024, 07:00 AM
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thanks, I hope it does as well. first couple flites are going to be without canopy just in case...

weight as of 10am is 9lbs 6oz
heavier than I wanted but both the 78" models I had were 10-12lbs if memory is working ok


Old 02-05-2024, 10:39 AM
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Over it's now 27 year life span my CG Extra has with different engines weighed from 8.5 lbs with an ST.61 to 11.25 lbs with a stock G23 gasser and the rather extreme weight swings did not in any way affect the model's excellent flying habits. Eventually I had the small engines and Zenoah Guru Ralph Cunningham convert the G23 to electronic ign. which lost it all of 16 ozs. but more importantly I was able to remove the 10 ozs of ballast weight from the tail of the fuse. it needed to balance. Now with an AUW of 9.lbs.10 ozs and with unlimited verticals and with landings as easy and forgiving as a trainer it's a real hoot to fly.

At 9 lbs.6 ozs I'm quite sure your model will be a dream to fly too. Hopefully you meant flying it without the cowl, as attempting to fly it without the canopy in place might actually do more harm than good.....just my 0.02 cents.

Last edited by karolh; 02-05-2024 at 02:37 PM.
Old 02-27-2024, 01:54 PM
  #2041  
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My latest , C/G Extra 300, DLE20RA . Got this kit a year and a half ago at our club's swap meet , came with a glass cowl and pants but the canopy was trashed. was able to get a new canopy and alum. gear from a friend in the club. Built to the plans for the most part except ,put the ele. servos in the rear, throttle and choke in the nose,fuel tank on the c/g and beefing up the firewall and landing gear area with alum. angle stock. Came out a little heavy ,I think, but I haven't weighed it yet.Did the maidan last Sunday, flys
REALLY well, got 2 flights on it and am very pleased.
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Old 02-27-2024, 02:04 PM
  #2042  
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Just went out and weighed the Extra , came out at 10 lbs on the dot with 3/4 tank of gas, so better than I thought. The C/G Extra and the DLE 20 Ra make a great combo.
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Old 02-28-2024, 04:29 AM
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That's a very nice looking model you've got there. At an AUW of 10.0 lb I'm not the least surprised that it flew well, after all its a Carl Goldberg Extra.

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