Goldberg Extra 300
#1802
Thanks karolh , i most certainly modify the lg . I have hade to modify warbird retract the same way and what a difference it made ! And i want to say thank you to all for your thoughts and suggestions . This bird is a little bit before my time , but as i have gained experience in flying different models i have had increased respect and appreciation for some of the older designs the carl goldberg designs especially. So far i have the cg ultimate, piper cub , super decathalon and the extra 300 , oh and the cg eagle 63 , my first glow plane . A question however; was the older extas shoulder wings or was it the way cg designed them ? The only reason i choose to modify this is to be scale to the real Goodyear extra .
Last edited by karolh; 01-04-2018 at 05:52 PM.
#1803
Join Date: Nov 2016
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You echoed the same thing i have been thinking myself . I have taken measures to make sure the wing incidence remains the same , but i wonder how the wing wlll react in its new position relative to the thrust line . I guess there is only one way to know , lol ! I also want to keep the wing as a one piece wing because i feel that it is stronger and lighter as such and it looks like i will be able to mount the batteries inside of the fuselage on or close to the cg . There will be two servos in the wing , elevator servo behind trailing edge of wing and rudder servo wherever it will balance the bird . The electric set up i am using delivers more power on the bench than my ys 140 without the vibrations or oil mess . I love the convenience of electric and the broad range of power and prop ranges that it affords but i still love the sound and smell of glow ! However i will be flying this plane throughout this winter to practice as much as possible by myself and so for the sake of having warm fingers and safety i feel e power is a good choice for now . But if the bird flies as well as i am hoping it very well may end up as a glow plane before Cleaveland or i will build another one , lol!
#1804
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You echoed the same thing i have been thinking myself . I have taken measures to make sure the wing incidence remains the same , but i wonder how the wing wlll react in its new position relative to the thrust line . I guess there is only one way to know , lol ! I also want to keep the wing as a one piece wing because i feel that it is stronger and lighter as such and it looks like i will be able to mount the batteries inside of the fuselage on or close to the cg . There will be two servos in the wing , elevator servo behind trailing edge of wing and rudder servo wherever it will balance the bird . The electric set up i am using delivers more power on the bench than my ys 140 without the vibrations or oil mess . I love the convenience of electric and the broad range of power and prop ranges that it affords but i still love the sound and smell of glow ! However i will be flying this plane throughout this winter to practice as much as possible by myself and so for the sake of having warm fingers and safety i feel e power is a good choice for now . But if the bird flies as well as i am hoping it very well may end up as a glow plane before Cleaveland or i will build another one , lol!
#1805
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Thanks Karol
Like i said i was having a brain cramp and spaced putting the main gear on a slight angle.
i just made the mods to angle the gear plate W/O any shims, but either way works well.
Tim a young man and i mean young designed the extra if memory serves me his name is Dave Patrick. I think he was 16- 18 yrs of age at the time.
The GB co. Picked it up and of course mass produced it from there.
the 300 and 260 are both shoulder wing planes and in fact are the same with the 300 being a 2 place where as the 260 is a single.
The 260 sort of lost favor with the early rc crowd but the 300 was a huge hit.
Now yrs later the 260 has made a huge comeback and is very popular with todays modern day RC crowd. Of course theres been many changes so the plane will do 3-D but the wing s still on the shoulder.
The 300 -S is where Walt Extra dropped the wing to the lower position as well as all of the misc models that followed. So the manufacture must have felt the full scale was improved from it.
Myself my 300-S is a great flying plane just takes more stick to hold it level while inverted.
you mentioned the thrust line, i feel that you will be fine as long as you maintain the correct incidences on the plans. Which i believe are all 0 degrees with 2 degree right engine offset. I have the plans and can verify that if need be.
its been a few yrs since i built one but i made sure i had rib templates and fuse templates and a couple sets of drawings in case i want to scratch one.
it does my heart good to see that theres still intrest in this plane that has been long forgotton by most.
keep up the good work i cant wait to see it all finished.
Richard.
Like i said i was having a brain cramp and spaced putting the main gear on a slight angle.
i just made the mods to angle the gear plate W/O any shims, but either way works well.
Tim a young man and i mean young designed the extra if memory serves me his name is Dave Patrick. I think he was 16- 18 yrs of age at the time.
The GB co. Picked it up and of course mass produced it from there.
the 300 and 260 are both shoulder wing planes and in fact are the same with the 300 being a 2 place where as the 260 is a single.
The 260 sort of lost favor with the early rc crowd but the 300 was a huge hit.
Now yrs later the 260 has made a huge comeback and is very popular with todays modern day RC crowd. Of course theres been many changes so the plane will do 3-D but the wing s still on the shoulder.
The 300 -S is where Walt Extra dropped the wing to the lower position as well as all of the misc models that followed. So the manufacture must have felt the full scale was improved from it.
Myself my 300-S is a great flying plane just takes more stick to hold it level while inverted.
you mentioned the thrust line, i feel that you will be fine as long as you maintain the correct incidences on the plans. Which i believe are all 0 degrees with 2 degree right engine offset. I have the plans and can verify that if need be.
its been a few yrs since i built one but i made sure i had rib templates and fuse templates and a couple sets of drawings in case i want to scratch one.
it does my heart good to see that theres still intrest in this plane that has been long forgotton by most.
keep up the good work i cant wait to see it all finished.
Richard.
#1806
The Extra's incidences are exactly as Richard mentioned and even though the plans shows approximately a 3/4" wide range for the CG I found mine to be quite nose heavy if balanced at the front of the range. My model started out on glow power with an S.T.60 then .75 and then a .90 and finally a Zen G23 initially on magneto ignition but now converted to CD ignition by Ralph Cunningham. Even at approx. 11.5 lbs with the G23 on magneto ignition the model had no bad flying habits and flew just as sweetly as when glow powered. With the reduction in weight of the G23 from mag to CD ignition and removal of 10 ozs. of lead ballast the Extra now has an AUW of approx. 9.75 lbs. it is a dream to fly. With its gas power I do miss the smell of burning castor but not the mess to clean up after flying.
#1807
Join Date: Nov 2016
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CG extra 300
Thanks so much Richard , i was wondering what the incidence on the wing was supposed to be as per plans . I sort of figured it would be 0 but i do not have a set of plans with this bird .
The reason i choose this plane is it happens to be American made , works great for our field size , and has a great reputation. The canopy will be cut and modified to resemble the extra that i am modelling , as well as creating aerfoile tail surfaces . I hope that no one takes offence to all the mods i am making on this bird because i am sure that this plane was fine before i began , it is just that i am a stickler for details and i love to build but have limited time between work and family. I do not want it to fly 3d as it must seem , i just want it to be very capable and aggressive ! Thank you again !
The reason i choose this plane is it happens to be American made , works great for our field size , and has a great reputation. The canopy will be cut and modified to resemble the extra that i am modelling , as well as creating aerfoile tail surfaces . I hope that no one takes offence to all the mods i am making on this bird because i am sure that this plane was fine before i began , it is just that i am a stickler for details and i love to build but have limited time between work and family. I do not want it to fly 3d as it must seem , i just want it to be very capable and aggressive ! Thank you again !
#1808
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CG extra 300
Karolh , do you remember exactly where the cg is on yours ? I like to build to the cg as much as possible because i HATE having to add lead , lol .And i hope i am not bugging you guys to bad but since this bird is now a mid wing i can balance it inverted , right ? Thanks
#1809
Ask away no problem at all, in fact that helps to keep this thread alive. After playing a bit with the CG I settled with it at 5.25" from the leading edge where it meets the fuse. With my model at that setting it only required the tiniest bit of forward stick for level inverted flight.
#1811
Join Date: Jun 2017
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Hi everyone !
Sorry for the delays ! I got a little overrun by work in the end of last year. But now that it's calmer, let's get back to serious business !
So, a quick update on the Extra. Haven't done much I'm afraid. But here's what's left to do : I need to finish the cowl, gas tank is ready to be installed, I need to do the cockpit and finish the oracover + a bit of extra reinforcements here and there. Today weight is 3.7kg so my guess is it will stay under the 4.0kg limit.
As always, I'll keep you posted ! End of work should be around April if my main job doesn't take me too much of my time !
Sorry for the delays ! I got a little overrun by work in the end of last year. But now that it's calmer, let's get back to serious business !
So, a quick update on the Extra. Haven't done much I'm afraid. But here's what's left to do : I need to finish the cowl, gas tank is ready to be installed, I need to do the cockpit and finish the oracover + a bit of extra reinforcements here and there. Today weight is 3.7kg so my guess is it will stay under the 4.0kg limit.
As always, I'll keep you posted ! End of work should be around April if my main job doesn't take me too much of my time !
#1812
Your Extra is looking very nice and it seems like you will end up at a very good flying weight. It is said that 'lighter flies better' but most of us have found that this Extra seems to shine best when in the 9 -10 lb. range. No need for an apology for delays in building as it happens to us all at sometime or the other plus taking one's time and not rushing tends to hopefully lessen the mistakes we make.
#1813
Join Date: Jun 2017
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Right! Thanks for the tip and encouragement! I just really hope the Dle 30 will not literally desintegrate the frame. I added reinforcements with 0.2mm thick wood on the whole front of the aircraft. And added a few beams goings all the way along the fuselage. Also changed a few things on the wings and used the two servos ailerons system.
In the end I'm actually quite surprised to be under 4kg with all that extra wood!
In the end I'm actually quite surprised to be under 4kg with all that extra wood!
#1815
Hopefully Gryphus31's Extra with it's revised wing location will be just as well mannered as the original CG design. For a model that was originally designed to fly on .60 glow power that DLE 30 is certainly going to haul it around with lots of authority. I'm keeping my fingers crossed that he will be able to share a video of the maiden flight with us.
#1816
Join Date: Jun 2017
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You're joking right ? Of course I'll provide you all the video of the very first flight ! And probably a few others ! I've been on this beauty for 8 freeking years now, there is no way I won't publish it's first flight on every available social network haha
#1818
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Greetings everyone !
Here I come again with some updates !
So... I just finished the fuel line and the full exhaust line. Also I added the canopy.
Electronics are in place. I just need to add a couple more reinforcements to the wings screwing region and the throttle command. Also I need to put some foam on receiver and rx battery. Ignition and ignition batt are in place.
First engine start should be withing the next days.
Total weightis (without fuel) around 5kg / 11lb.
First flight is scheduled for May the 1st !
Here I come again with some updates !
So... I just finished the fuel line and the full exhaust line. Also I added the canopy.
Electronics are in place. I just need to add a couple more reinforcements to the wings screwing region and the throttle command. Also I need to put some foam on receiver and rx battery. Ignition and ignition batt are in place.
First engine start should be withing the next days.
Total weightis (without fuel) around 5kg / 11lb.
First flight is scheduled for May the 1st !
Last edited by Gryphus31; 04-07-2018 at 05:46 AM.
#1819
Your model is looking good and coming along quite nicely. It's always great to see a model come together like yours is doing. I guess you can't wait to have her finished and to take her up into the blue yonder.
#1820
Join Date: Jun 2017
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Greetings !
Well, here I come again with some questions... Yesterday I tried to fire up the engine for the first time (I wanted to check if everything was ok with the structural frame and so on, not fly).
First problem : impossible to get it work Apparently, guys at my local airfield told me I was using the wrong gasoline.
I don't know how it works in the US, but in Europe we got two kinds of gasoline : 95% Octane and 98% Octane. I initially chose the later for my DLE30 because it is said that 98Octane is always better for most engines (at least for cars and motorcyles). But apparently the DLE only accepts 95Octane. Did you know something about this ?
Then I showed my Extra to the guys at my aeroclub... And here comes trouble...
1. They are not very confident (if not confident at all) about the elevator linkage. I used the original CG system with the wood rod ending with a Y steel rods going to the elevator horns. Apparently it is way to loose to be a safe system. They recommend adding more guidance (like U shaped supports) for the wood rod, and add some carbon tubes on the steel rods.
2. One of them even told me to forget this kind of linkage and use two servos directly at the back of the fuselage for elevator. Problem is : I think this will bring havok to my balancing, as it is very well done right now.
3. They also recommended adding this kind of stuff where the steel rods come out of the fuselage. Opinions ? Will it really help ? https://www.ebay.fr/itm/GUIDE-DE-SOR...0AAOSwbyZZeIm4
4. I used the pull pull system recommended from CG. I welded the clevises to the steel cables with some tin. But they are not very confident about this. What's your opinion ? Also, should both cables be very tight or must I allow some looseness ?
Any way, I'm a bit affraid now to put this baby in the air (if my engine decides to fire up one day)... I don't really want to take any risks with elevator and rudder linkages.. Do you have some pro tips on this issues ?
Thank you !!
Well, here I come again with some questions... Yesterday I tried to fire up the engine for the first time (I wanted to check if everything was ok with the structural frame and so on, not fly).
First problem : impossible to get it work Apparently, guys at my local airfield told me I was using the wrong gasoline.
I don't know how it works in the US, but in Europe we got two kinds of gasoline : 95% Octane and 98% Octane. I initially chose the later for my DLE30 because it is said that 98Octane is always better for most engines (at least for cars and motorcyles). But apparently the DLE only accepts 95Octane. Did you know something about this ?
Then I showed my Extra to the guys at my aeroclub... And here comes trouble...
1. They are not very confident (if not confident at all) about the elevator linkage. I used the original CG system with the wood rod ending with a Y steel rods going to the elevator horns. Apparently it is way to loose to be a safe system. They recommend adding more guidance (like U shaped supports) for the wood rod, and add some carbon tubes on the steel rods.
2. One of them even told me to forget this kind of linkage and use two servos directly at the back of the fuselage for elevator. Problem is : I think this will bring havok to my balancing, as it is very well done right now.
3. They also recommended adding this kind of stuff where the steel rods come out of the fuselage. Opinions ? Will it really help ? https://www.ebay.fr/itm/GUIDE-DE-SOR...0AAOSwbyZZeIm4
4. I used the pull pull system recommended from CG. I welded the clevises to the steel cables with some tin. But they are not very confident about this. What's your opinion ? Also, should both cables be very tight or must I allow some looseness ?
Any way, I'm a bit affraid now to put this baby in the air (if my engine decides to fire up one day)... I don't really want to take any risks with elevator and rudder linkages.. Do you have some pro tips on this issues ?
Thank you !!
Last edited by Gryphus31; 04-16-2018 at 12:06 AM.
#1821
Consider this. That Y linkage has been in this plane for decades, and does work, but it is sloppy. Going the two servo route with proper guided pushrods is a better solution, but does add weight. It gives more linear control, but consumes two channels, or a Matchbox to do right.
By welded I assume you mean soldered with regular solder. This works, it is not as secure as brazing with silver wire though. If you are not an aggressive flyer, it should last, was going to say the life of the plane, but the plane may last half a flight.
As far as Octane, that only matters in racing. The DLE will run fine on the higher octane, but I doubt the issue is the fuel. It may be fuel related though. If this is the first time its been fueled, have you checked that fuel is getting to the carb? The first time I tried to start my DLE20 it would not draw any fuel until I soaked the carb gasket in fuel. If it is drawing fuel then it isn't sparking. If you can smell fuel in the muffler, then go over all the electrical connections to the ignition module. You may want to pull the plug and zip tie it to the side of the head and spin it over a bit to see if you get spark, and only do this with the tank drained and the plane outside.
By welded I assume you mean soldered with regular solder. This works, it is not as secure as brazing with silver wire though. If you are not an aggressive flyer, it should last, was going to say the life of the plane, but the plane may last half a flight.
As far as Octane, that only matters in racing. The DLE will run fine on the higher octane, but I doubt the issue is the fuel. It may be fuel related though. If this is the first time its been fueled, have you checked that fuel is getting to the carb? The first time I tried to start my DLE20 it would not draw any fuel until I soaked the carb gasket in fuel. If it is drawing fuel then it isn't sparking. If you can smell fuel in the muffler, then go over all the electrical connections to the ignition module. You may want to pull the plug and zip tie it to the side of the head and spin it over a bit to see if you get spark, and only do this with the tank drained and the plane outside.
#1822
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Right... As for now I'll just add carbon tubes and U supports for the wood rod.
As for the welding part, yes I wanted to say soldered.
As for the engine.. I really don't know what to think... I think fuel is getting to the carb as I'm smelling it (and even getting some drops out of the carb after lots of spins trying to start it). I took off the spark from the engine and tried spinning it, and I hear and see it spark. It actually did start more or less for approximately 30 seconds before dying. Did that a couple of times, but it like 1 start every 50 spins and it doesn't last. I already checked both Low and High screws and reset both to factory default (1,5 turns for Low and 2 turns for High). I'm a bit out of options here
As for the welding part, yes I wanted to say soldered.
As for the engine.. I really don't know what to think... I think fuel is getting to the carb as I'm smelling it (and even getting some drops out of the carb after lots of spins trying to start it). I took off the spark from the engine and tried spinning it, and I hear and see it spark. It actually did start more or less for approximately 30 seconds before dying. Did that a couple of times, but it like 1 start every 50 spins and it doesn't last. I already checked both Low and High screws and reset both to factory default (1,5 turns for Low and 2 turns for High). I'm a bit out of options here
#1823
New engines usually take a bit to start. It tells me that you are getting fuel and spark, but I don't think enough to the carb to stay running. Was the plug wet when you pulled it out?
#1824
Most engines being run for the first time can be a bit baulky to get going even for the experienced operator and the fact that the engine does run but for a short while leads me to believe that the needles need to be opened up some more to increase fuel flow. Try opening the High needle to 2 full turns from closed and see if that helps as most time factory settings are very close to the optimum settings for the carb. Also the use of an electric starter would certainly help to get your engine going plus more than likely save your weary arm.
Last edited by karolh; 04-16-2018 at 10:05 AM.
#1825
Join Date: Jun 2017
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Hello everyone !
So, big news ! Yesterday I was at my local airfield. Some people from my club helped me (a lot) with the engine that aparently needed more than a few tuning. We openned the carburator, everything was sticked together from the last of oil. Anyway, we managed after one hour to get the engine running.
Today was the big day ! I finally (after 8 years of building) managed to get this Extra into the big blue. It flies like a charm ! I haven't tried yet any harsh manoeuver. But the DLE30 really pushes the aircraft. I can easily maintain vertical ascention. Inverted flight also is ridiculously easy. However does this engine suck gas !!! I was empty in 7 minutes (I did went through some heavy trials before take off without putting gas in the tank again but hell...). Did I mention that even though it is a very good flier it does not glide well at ALL. Anyway, now to check if everything is in place and working good !
Also, my local airfield has a grass runway, and this Extra is very very very very (did I say very ?) easy to toggle head first into the grass when taking off. Any tips ? Problem is.. it is well balanced when in flight...
Anyway ! Thank you for your support everyone ! I'll keep you posted in the future once I'll throw more flights into this big boy.