themanimal

My Feedback: (1)

Hey all, I just brought home a carl goldberg super chipmunk and started scouring threads for details on the build. I had a few questions...

1. To retract or not retract? I think retracts are cool but the straight back style with half the wheel exposed is kind of lame. has anyone installed regular 90degree retracts?

2. Independant aileron servos or just stay with one. I have a computer radio so I suppose two would be best so that I could use flaperons but I would also like to keep weight down. (I'm putting a TT 61 on it).

3. If I ditch the retract idea, how are people re-enforcing the landing gear mounts?

4. Last but not least..Flaps whatdayathink?

Thanks for any and all advice, I can't wait to finish this bird!!

Jerry Sigur

The stock landing gear blocks usually split at some point.
The wood is rather soft.
I replaced mine with some I found at a hobby shop.
However it would be easy to fabricate some using either
hardwood or aircraft grade plywood from the hobby shop.
I used two aileron servos on mine. Flaps would probably
work well.
All in all a very nice flying model.
Jerry

Crazy Legs

I built the Super Chipmunk kit in 1989 and still have the airplane. It flys the best out of all the models I've built; straight as an arrow and never, never stalled on a steep, slow turn on final. The wing loading is very light and with the O.S. 91 four stroke, it has plenty of power. Use a good APC propeller and you'll love it!
Someone also told me that the landing gear was a little on the weak side, so I beefed up all the supporting structure in the wing with triangle stock. I also put brass tube inserts in the holes where the gear legs plug in. It sure paid off because that landing they gave me originally sure bent up allot on our grass field. After many occurrences (about 100 in a year or so) of removing the landing gear legs to straighten them out on the pic-nick table, I decided to buy the Robo-Struts. I cut the original legs off, shoved them in the top of the Robo-Struts, and J.B. Welded them in there for good. If you don't' do this they struts will come off at the worst times. This alone cut my gear leg bending experiences in half. My landings looked allot less bouncy too. If you fly on pavement of any kind, you may not experience this problem; but with grass, you're going to be straightening out that landing gear allot! The Struts will make your day more enjoyable, and they work good too. The CG on this plane turned out to be such that it wants to nose over while it taxies if the landing gear struts are bent the slightest bit rearward from your last landing.
I also installed the flaps. They did make a difference in landings in that you can slow down much more before you have to touch down; this airplane is a real !QUOT!floater!QUOT! without them. I had to mix in some down elevator to compensate for the trim difference though.
If you don't mind a little extra work, go for the Fiberglass cowl and wheel pants right off the bat. No kidding, you'll be wasting your time and paint on the ones you get in the kit. Pitch the ABS ones in the trash or use it to water your wife's plants!
Another thing I did was pitch the lower wing faring they give you that's made out of ABS. Make your own in 30 minutes or so out of some 1/8 inch balsa. The one you make will look 2000 percent better and will be stronger too. use Wax paper to protect your mating front piece on the wing from sticking to the rearward fuselage surface when you glue it on. Also, use masking tape if you blend it into the bottom of the wing. I started sanding mine with out protection and realized I was putting divots in the wings lower sheeting. BTW, just so happens that when you pick up that wing, your thumb wants to press dead nuts on the middle of that faring. If you build it out of balsa with a couple of ribs inside you'll be real glad you did; it'll last much longer.
That's about all I can remember from my build. Oh, check that the bottom of the fuselage panel is straight. Trace it on a piece of paper, fold the paper in half and note any dissimilarities (overhangs). If it's anything like mine you can actually glue the bottom back in the die-cut sheet it came out of and re-cut out the bad parts of the bottom so the plane will be straight.
Good luck with your building,
Mike D'Amico
Palm Bay, Florida

blvdbuzzard

The only thing I would do to it are build it with two alieron servos, flaps, no retracts, I never had a problem with the landing gear blocks, just the wire. I did epoxy a fillet around the block and ribbs. The flaps make this plane come in slower then a trainer. Flip the switch and watch how the nose comes up, hangs there for a little, then settles in to a nice slow nose up desent to a wlaking speed touch down. I have had 2 and loved every minute I had with them. They will do anything you want. It is a stable plane yet will do lighting fast spins and snaps.

Dru.

Sprink

Mines still going strong after 3 1/2 years. Did not beef up the landing gear blocks at all, still good as new. However have replaced the legs, as mentioned above they bend backwards, so you have to bend them forewards or the plane will nose over. After too much of this they break.

I went with flaps, and the do make a difference. Mixed in 20% down to retrim the plane though for them.

Power is a 91 FX, really pulls it around! . Surprisingly smooth flyer, taught me a lot.

themanimal

My Feedback: (1)

Thanks so much for all the build tips, especially mr. crazy legs. Sound like I need to do something about those pesky landing gear.

Thanks again!!

Brian

Catdog

I just finished mine a couple of months ago. Flies great. I DID beef up landing gear blocks with extra balsa and fiber glass cloth strips/CA. The flaps are great, and go with the duel aileron servos.
In addition I installed a pull-pull system for the rudder. It was very easy to install. I heard it was diffucult gettng pushrods down through the back of the fuse - although the elevator rod wasn't difficult.

I would recommend also upgrading the tailwheel to a sullivan or something similar. I fly off a grass field and I've had to bend the tailwheel back a few times (along with the main gear!)

Has anyone shortened the bottom of the rudder a bit to get a bit more up elevator?? I think you could push the aerobatics a bit more if you did.


Rob C.

MinnFlyer

My Feedback: (4)

You don't need to aileron servos, but if you want to go through the trouble, have at it.

I WOULD however, add the flaps. (Not Flapperons) The flaps work really well on this plane.

John Serjeant

CG Chipmunk, sauper kit and a nice build, do all the things the other guys mentioned; quite possibly the best kit I,ve ever built.
Hey guys in the U s of A, we here in the U>K> can;t get Goldberg any more.
Has or is the kits back in production?
If so, WHO could I approach to get a G,berg Chippie sent here?
thanks
JOhn Serjeant
Harwich
Essex
UK

themanimal

My Feedback: (1)

Ok sound retracts are definately out, Flaps are definately in but I am still debating about dual aileron servos or not. Seems to be a mixed bag. I want to keep the plane as light as possible ass I am putting a TT .61 in it and it sure is nice to have power left over to play with.

Would I really be able to tell the difference between one and two servos?

Live Wire

Regular retracts will weeken wings, reinforce the landing gear, learned the hard way. This is a good plane it has been rekitted more times than than I want to remember. Birth date 1976 and still flying Looks like it did in 76.

MinnFlyer

My Feedback: (4)

Personally, I don't think you'll see any difference between one or two servos. I used one in mine and it had a great roll rate (and I like a fast roll rate).

One thing I would suggest, get rid of the belcranks and use flexible pushrod to control the ailerons. That's how I usually do it, but I decided to try their method. After a while, I ripped out the belcranks and switched to Nyrod. The belcranks just had too much slop for my liking.

Sprink

I beleive that Lanier bought out Goldberg. No idea if anyone is importing them into the UK again, I haven't seen anything. Tower Hobbies will ship to the UK, but very expensive. I have thought of trying to find a European shop and getting one from there, no luck on that either so far. Only thing I have found which may work is a Malaysian internet hobby store http://www.myrcstore.com/. I've been looking as I quite fancy the Extra.

ukrconsul

My Feedback: (1)

It is Singaporean store.

Sprink

Have you bought from them, are they any good?

Cheers
Sprink

justrfb

My Feedback: (2)

What a great plane... I built mine in the late 80's and it was beautiful right up to the point where I drilled it in with dumb thumbs compounded by a panic maneuver. I pulled up when I should have pushed... I over rolled a steep banking turn, panicked, and pulled up. Up is down when the plane is inverted. I had flaps and a single aileron servo. Worked fine. Good luck.

wings

I was always under the impression that flaps were short for flapperons. Can you explain the difference?

Thanks,

Wings

blvdbuzzard

Flaps are just that. There is a section of trailing adge that you make into the flaps and the rest of the trailing edge is the alierons. The alierons do not go down when you flip the flap switch. The alirons and flaps are two seperate pieces so they work independtly of each other.

Dru.

wings

So flaperons is when you use the ailerons as flaps and flaps are when they are seperate from the ailerons?

Sprink

Yep

TOY4WD

I agree with Minnflyer, I have a single servo for ailerons & flaps. It has plenty fast roll response & you save some weight & complexity.

Bruiser

My Feedback: (1)

Here's the thing... Sure, it was designed for a single aileron servo. But my kit also says to use a .45 to a .60 for power. Therefore, it makes sense to me that if you are upgrading the engine size, it only makes sense to upgrade the control surfaces too. It's not like it is real hard to do, and that extra servo doesn't cost much anymore these days either.

Just browse through some catalogs and see how many .46 to .60 size airplanes still use a single servo... That should tell you something.

JMHO,
-Bob George

runover1

My Feedback: (10)

I have one I am getting ready to build. Does anyone have a good site to go to for scale photos. I would like to do it as close to scale as possible. Thanks, I can't wait to get started. I am thinking of powering mine with a RCV 90.

themanimal

My Feedback: (1)

here is the link..it also looked like somebody crashed that there chipmunk ;0

http://www.artscholl.com/Photos.htm

I just finished my chipmunk and here are the mods I completed.. (I think there cool and they didn't take too much more time.

Ditch the stupid plastic wingtips, cut some balso blocks, glue them to the wing tips and have at it with the dremel tool and sanding block. (NOW they won't crack and I can cover them).

Ditch the plastic underbelly parts.. Made mine out of scrap balsa and some new sheeting. (see above comment) Plastic look soo dumb and never lasts.

servo for each aileron, I mounted them sideways so that only the servo arm shows through. I basically built a removable plywood hatch with a small hardwood frame epoxied to it hat the servo mounts on. super clean looking and removable so I can get to it. the hatch screws into hardwood rails mounted to the ribs.

made custom landing gear blocks ..although I wouldn't do this again.. just reinforce the ones that came with the kit (i.e. epoxy the living s*$t out of them).
I also sanded a slightly steeper angle on the landing gear blocks so that the wheels would be a little bit more forward and the landing gear will resist bending. (more forward cant = better landing force vector).

i'm putting a satio .91 with smoke in mine. I'll probably never fly it b/c the last kit I put my heart and soul into I crashed in a day. soo..never fly inverted at dusk.


90 man hours of work.. 20 man minutes of fun.

You should be stoked though, when covered right this is one good looking bird!!

Russmall

I just finished my Chipmunk too. I made about the same mods as themanimal and I also added the flaps. I also added fiberglass cowl and wheel pants and trashed the plastic stuff. The engine is an OS90 FX and the weight is 8 lbs. even. I was hoping it would come out lighter than that but it should be OK with the flaps and all. Can't wait to test fly it.......RS