Cox Hyper Viper *** And Chipmunk, now

NEW222 wrote:Love the plane. I had scored this one at a swap meet a little while ago but had not flown it. It is definitely in ok condition and had been flown hard in my opinion as I now know why the belly does not stay put. I had assumed that it had just broken at mounting locations, but thanks to you, I now know that there were 4 mounts for rubber bands to hold the lower belly on. I just took these pictures and see that only 1 of my mounts are there, hence the 3 'holes'. But, surprisingly, it came with the metal elevator doohickey. Anyways, thanks for sharing.

I can see we have different versions of the Chipmunk - the canopies are different. I think mine might have been a late issue and the brochures are from the time Cox was owned by Leisure Dynamics. Your markings may be from an earlier time as I have seen different box graphics that showed this plane had several iterations.

One thing, I am glad the pics helped as that is a big reason I post these things when able - in case they help someone else down the line. I didn't think the benefit would come that fast - ha.
Looks too breezy, again, today to get flight in. This plane is pretty light - at least the wings. The thin, hollow wings might not stand up to buffeting the wind would offer today, as the wings have to lug the relatively heavy fuse around.

I have your version of the Chipmunk and the last version of the Chipmunk. The last version had solid wings and in my opinion flew better. I used whatever I had to tighten up the engine. Vibrations will rob needed power. The engine in my older one would shake all over causing poor engine runs. The claim is that the plane could fly the entire stunt pattern. It will do it but it requires a lot of arm movement as you really need to lead the plane. I could probably nurse it through most of the maneuvers but I wouldn't bet the farm on all of them. The hollow winger flexes just as you were concerned. I ended up using canopy glue to tighten and stiffen the foam. The clips on the fuse break and this is essentially what holds the engine firmly in place. I personally wouldn't even make an attempt to use that spring whatever the heck it is that limits the elevator. It needs all the up elevator you can give it. I found when coming out of a high maneuver it likes to sink a bit and that extra elevator certainly gets you out of trouble. It's a fun plane to fly.

Pete,
Nice score.  I hope you have a great time with it.  For all my Cox foam wing planes (‘course, there ain’t but three…), I used hot glue to hold the wings in place instead of the wing tape.  I figure it’s more secure, and if I ever have to remove the wings I’ll just cut them back the ¼” that’s glued to the fuselage wing root.  And when I put them back on, I doubt I’ll ever notice or miss the ½” that’s been cut away.

New, I like the  color scheme of your stickers.  But they remind me more of a crop duster, rather than an aerobatic show plane.  And with the belly pan hanging down, it looks like the plane is grinnin’.

The Hot Mark

OVERLORD wrote:Great Chipmunks guys. This was my first plane I had as a present. It unfortunately didn't survive. It came in the same box as Peter's plane. But I'm surprised to see that this plane has got the BF 109 canopy. The BF109 had a black fuse with a different rudder and pale blue wings. I remember that from the Graupner catalogs. It's good to see that those planes were saved and are in good hands!!

Yeah, that was the genius of the Chipmunk.  The design/marketing guys just took the ME-109 fuselage and wing, molded them in white, added a different canopy and fin/rudder, and called it a Chipmunk.

I guess I haven't flown mine enough to notice the flex in the wings.  But then, on mine I removed the tape holding the trailing edges together and wingtips on, opened the wings up and ran two lengths of filament strapping tape on the bottom inside and two on the top inside of the wing shell, re-joined the trailing edges with epoxy, and then hot glued the wingtips and wings in place.  I'm a big believer in using filament tape on foam wings.

The Inattentive Mark

edit: I wonder how much affect putting thin carbon rods under the strapping tape would have in wing stiffness? A thought for the next time I use the hollow foam wings.

I'll get a bunch of docile flights in before I try anything with the Chipmunk. Some of your comments have me thinking there will be a hotwire-cut wing in the future, and I was already thinking along the lines of a light carbon spar - great ideas. Suring up the engine after a few succesful flights is now on the list. All in all, I like the planform of both the HV and the Chipmunk and when time permits (ha!) and good flight results I will look at recreating the planes from other materials. That plastic fuse can't take too much abuse, I presume. Plus, I got a hold of a Killer Bee for future bashing.

The model with the one piece wing had a different canopy and didn't come with that elevator clip. Seems like I remember that clip was to help adjust the handle to neutral?
Does it say anything in the instructions about the clip? Anyway, what a great tribute to Art Scholl, an extraordinary airman. I saw him do a low alt. flyby at an airshow standing on his wing.
https://www.youtube.com/watch?v=A-kHTmYjBQk

crankbndr wrote:The model with the one piece wing had a different canopy and didn't come with that elevator clip. Seems like I remember that clip was to help adjust the handle to neutral?
Does it say anything in the instructions about the clip?

The instructions say that it is to limit travel of the elevator for beginners. I posted a picture of the manual talking about this a couple of months ago, but I don't remember what thread that was in.

The Forgetful Mark

I will scan the brochures and instruction manual, but I am off to a club meeting right now.
But the clip is described as an in-flight elevator restrictor. Manipulating the elevator by hand with the clip on seems like 0-travel solution. Don't know.

That is a gorgeous shot of the SC, crank - magazine quality, before gravity happens to it.

Scroll down a few posts to find Marks copy of the instructions

https://www.coxengineforum.com/t9871-need-help-identifying-part#125215