The flap mounts fit inside without modifying anything. Actually stuck with the steel bolts. Why take the chance on plastic breaking?

Here are a couple of pictures.

Wow- you did a great job! Did you paint on the A.S. color scheme?

I used a dubro strip aileron link for the flaps and it worked out a bit short...I had to cut small grooves in the wing mount supports so that they wouldn't bind. Hope I don't live to regret that...

Thanks for the pics...now I want to finish mine! I've heard nothing but good things about this plane.

Why does someone would recommend this TT-91 FS engine while it is 200 g heavier than Saito 91? Common guys, a little bit of extra power doesn’t worth it.

Saito 120 is overkill, but the same weight (50g less) TT 91 FS is OK? Strange to hear it.

If the issue is balance it seems better to add functional weight rather than dead weight.

I don't get it either.....

Like I said, I had to but A LOT of weight on the nose to balance it with the magnum 91.

A heavier engine of the same power is NOT functional weight, it is dead weight.

Bill.

My Chipmunk flew this past weekend for the first time. It is the Goldberg that has been modified into the Pepsi Super Chipmunk. Mine has a SuperTigre .75 with a SlimLine pitts muffler and it had plenty of power. I think it wieghs about 7.5 pounds.

-Bob George

Oh, I wanted to insert a picture of it, but I don't understand how. You use to just click on "insert image"...

Sounds to me like functional weight is a relative term.

If you already had the lighter engine and then switched to the heavier one, then I guess it would be considered dead weight.

But an engine is functional, and it has weight, so aren't all engines functional weight as opposed to just adding weights to the tail that provide absolutely no power, just weight?[:-]

Wings:

One of the main criterions in aircraft design is lowering the weight. If there are two engines of the same power differing only in weight, the lighter engine is better for that application, and the installation of the heavier engine would be considered the addition of dead weight.

The lighter engine is generally more expensive, though, and if the heavier engine gives satisfactory performance the lighter engine could also be considered a waste of money.

Building a scale model or assembling a scale ARF has limitations that do not allow extending the nose for balance with a lighter engine, if nose weight is required the heavier engine, being less expensive, is a good choice. At the same time, a larger more powerful engine of the same weight as the smaller heavy engine could also be considered the better choice.

Bill.

If this Goldberg Chipmunk is balanced right with TT 91 FS it only means that something really wrong with the plane.
She balances dead right with Saito 91.

A Mag 91 doesn't come close to the power of a TT 91. In fact, my TT 91 is stronger than my Saito 100.

Thermodynamics will tell you that efficiency is a function of mass as it relates to the retention of heat energy. Dead weight is an inaccurate label.

Bruiser,

Did you modify the cowl to reflect the cowl cheeks of the Pepsi?
I attach a photo of my 1/5 Pepsi Chipmunk (half built)

Hey Bill,

I'm not trying to be argumentive, but I still don't agree with ya.


An engine produces power, so it is functional weight. Tail weights are dead weight, they do nothing other than adding weight.

The Magnum 91 with my chipmunk (by the way, thanks for recomending that to me) makes the plane tail heavy. Therefore I had to add weight to the nose to balance it. So If I installed a larger engine with the same power and therefore did not need the extra "balance" weight I installed on the nose, the engine would not be considered dead weight no matter how you look at it.

Kinda silly to argue about, but its fun to debate things. I guess we just disagree, lol.


Wings

Thanks for your reply. I have a brand new O.S. I I thought it would be a good idea. I'll going to search for a smaller engine. Thanks for your engine recomendations and.... WOW there is such a button in my keyboard AND IT WORKS !!! this is so cool !!!!!





Is landing required?

Yes, I made a mold for the cowl and laid it up fom several layer of glass. I learned a lot in that process...

-Bob George

Hi Bob,

Beautiful looking Pepsi!! They do look just as good as the Pennzoil or even better !!
I have never ventured into doing my own cowls, ought to try though

Ari

Hello, I built my Chipmunk when i was 14 I think and on its second landing the gear ripped out of the bottom. It wasn't a hard landing I just forgot to put some supports somewhere (duh). So 5 years later and i'm back from college and bored and getting back into flying. I've been cruising around my first plane, an Easy Sport 40, and now I want to get the Chipmunk going again. I fixed and "beefed" up the landing gear. I have a side mounted OS 91 4-stroke, a TME Simple smoke pump installed, and a Slimline smoke ready pitts muffler, and a new cowling on the way. I guess I was just hoping someone could give me some helpful hints about making the smoke system work well. Oh ya, and how to hook it up to an older Airtroincs 6-channel radio? Thanks.

I'm building or more like finishing an old super chipmunk 60 from Carl Goldberg and so far its just been trouble. Since i've heard so many bad things about the landing gears, and the wing is already built, so i can't get to the landing gear block to reinforce them. i'm putting the optional retracts in and they are old unused rom-air's, got them to work with a new robart air kit so thats whats going in. save some money! They arnt nose gears so i have to make my own setup for them to work, not to big a problem. I've gotten a 16oz flex sullivan tank to fit and will put digitals on every control surface. Putting duel aileron servos, and thinking of using pull-pull for the rudder.

The real issue i'm having so far those is that the plane seems to be really heavy. I got a Supertigre 60 ringed for Christmas and plan to send it back in and get a 90 ST for the power. To try and get rid of some weight i plan on using a dremel tool and make my own lightning holes in as many places as i can on the fuse. I'm also ditching the whole pilot and interior cockpit. Figured i'd just tint the canopy.

Is there anything else i can do to loose weight or is this about the extent to what i can do. I really don't have a lot of cash and time to buy and build another chipmunk kit. Im really trying to save money so any helpful tips will be greatly appreciated to help me get this plane to be a nice flying airplane for summer!

Thanks ahead of time!
Darion

My Chipmunk is a bit over 8lbs. it's been crashed and rebuilt a few times. I have a Saito .91 on it and for me, it's a bit under powered. I'd think that the ST .90 ( I have one of those on my Hobbico Sukhoi SU-31) would pull it around nicely!

I'd probably be conservative on the lightening holes. Don't want to weaken the structure of the airframe. Beyond that, I'd say you're headed in the right direction. I love the way this plane flies. I'm quite likely to buy another one if this one has another gravity incident. ;-)

Hey thanks for the info. Glad this post still has some liveliness to it!

I'm not exactly sure but thats were i figured my plane to be at for weight as it is. So knowing that yours weighs in at that makes me feel a bit better but i still plan to lose as much weight as i can because i decided to put the retracts in. Did you install retracts at all? And was there much for nose or tail heaviness because the saito 91 and the ST 91 are only 1oz different in engine only weight and i got a pitts so any nose heavy or tail?

Sorry to here about the crashes and hope gravity doesn't hate you to much anymore!

Thanks again!!
Darion

I'm glad I found this post. I'm planning a build of a CG Chippy soon. It's an older kit, probably from the '80's.
The info here will help me considerably.
I plan on getting a fiberglass cowl and junk the plastic wingtips and belly pan.
Fly it with a OS 90 4-Stroke, or a Saito 72 4-Stroke.
I'm tinkering with the idea of rounding the tail section from the TE of the wing back and using a fillet to blend in the wing joint.I'm
also going to make the belly pan from balsa and since i'm flying from a grass runway, scrap the wheel pants and nix the optional retracts.
I'll probably use pull-pull for the rudder and go with two servos for the ailerons. Install the optional flaps.
Although another covering scheme is tempting, I'll go with the classic Pennzoil R,W & B.
Thanks guys for all your input on this build.



Tom

I built my Carl Goldberg Chipmunk in the summer of 1992, it is without question, the finest radio control model i have ever owned. Flying out of our small dirt strip here in California, it has never let me down, yes all the previous posts on suggested mods to the landing gear blocks, and one servo per aileron suggestions are very true. My Chippy has had its fair share of subjection to dumb thumbs but fortunately as of this date, none serious enough to send it away for good. Its without a doubt my "Old Reliable" among the R.C. aircraft hangar that i have collected through the years. Everytime i go to the field i bring atleast two planes, my chippy is always one of them. Although i cant say much for the customer service ive experienced with Carl Goldberg Lately, i can say with good confidence that they sure did well with this kit and most likely can conclude they dont make them like they used to. My first motor was an O.S. 45, later to a Junky Super Tigre S75, and now it is at its sweetest these days with a Magnum .91 . I run Powermaster 15% and which allows me to rotate to vertical at the end of my strip every single time. I have long since converted myself to an ARF flyer these days, but dread the day, if she ever goes, I will be a kit builder again, and a Goldberg Chippy it will be.

I have a Carl Goldberg INC Super Chipmunk. It's the total kit. It was my Fathers but he passed back in 2013. The model is complete... Just as if it were Brand New, I haven't a clue what the model is orth. Does anyone have an idea that they would be kind enough to share? I would appreciate and and all feedback... Thank You...

I tried posting images but since I am new I am unable to do so...

I’ve seen them recently sell on the forums for as little as $125 and on ebay for in excess of $300. I would be interested at #175

Sell to someone that will build it, that will be put a smile on your father's face as he looks down.