Sig Super Chipmunk

[John G. Park]

Looking over numbers, it seems to me that the old Sig Super Chipmunk is comparable to the Vector, Viking and Oriental.
Yet, these other three are mentioned often in Stunt circles but not the Sig Super Chipmunk.

 Vector   50.5 span,  536  Sq,  42 1/2 length
 Viking    51 span      572 Sq    37 1/2 length
Oriental   55 span   550 Sq       35 1/2 length
Sig Chipmunk   53 1/2 span  570 Sq  39 length

Is it a question of "out of fashion or popularuty only?"

Is weight or airfoil or something else a problem?

Thanks to all for sharing opinions

19461946jgp

[Dave_Trible]

That's a very fine airplane.  Ask David Fitzgerald.

Dave

[Larry Fernandez]

If the Sig Super Chipmunk were Classic legal, I would have one hanging on the wall right now, in all its red white and blue glory. Powered by an Aero Tiger .36.

Larry, Buttafucco Stunt Team

[Dan McEntee]

  The Chipmunk is a very fine airplane. There are a few minor things to touch up and modify but in general is a very capable model. The Chipmunk wing is available as a separate kit, and makes a good start for a kit bashed or self designed model. It's strong, pretty easy to build straight and decently light. Blunt the leading edge a little more than what the plans show  if you decide to build it, and put a block across the top of the engine mounts, or gusset them to the firewall, to help stiffen up that area. If you want a classic legal Chipmunk, the original SIG kit designed by Jim VanLoo is classic legal, as is the original as presented in Model Airplane News. Joe Dill designed a standard Chipmunk that RSM kits, I believe and is classic eligible. Search the forum here for a post by Mike Gretz, and there is a link to his website that he has for the history of the Chipmunk and the other long time SIG stunt model designs.
  Good luck and have fun,
   Dan McEntee

[Curare]

Funnily enough, I just ordered one, and it should be here either today or tomorrow.

Apart from the tips outlined in the previous thread, anyone have any good tips on how to shave some weight out of it?

I'm tempted to do a glass cowling, and pants, if I get enough time to produce the moulds.

Also, powerplant, glow or electric?

[Sean McEntee]

If memory serves, dad's came alive with a ST46.  For lightness, check for heavy wood and replace as needed.  Only other thing I can think of is to carve a cowling and the wheelpants out of block.  Would probably be lighter and last longer too.  The glass cowling cracks over time.

[Dave_Trible]

The one my friend had and 'we' built was perfectly as it came out of the box.  Never thought the cowl or pants a problem, just a new way.  We put a McCoy .40 in it and it was superb.  Kevin has the kit and is going to put an RO Jett .40 with header muffler in it.  Perfect I think.  I think any stronger- than- Fox .35 or smooth stunt .40 is fine.  Pick up a nice Enya .35 on the Bay....

Dave

[wwwarbird]

 The Chipmunk is a real good airplane as is. I would however "round-file" the cowl and wheel pants and redo them in balsa, just a personal preference there.

 While not necessary, another great upgrade/mod to the Sig Chipmunk design is to make up two more ribs and add an extra bay to each outer wing panel. A little more wing area can be helpful to some of these "period" designs.  

 I've always thought it would be fun to take the Sig kit and redo the nose and cowling to look like a stock Chipmunk, for the inline Gypsy (or "Dripsy") Major engine. Along with that it would be very easy to redo the tip outlines for the wing, stab/elevator, and fin/rudder to revert back to the stock Chipmunk look. At that point we're essentially describing the Van Loo design. The last step would be a stock Chipmunk style canopy, and then finish it in a Canadian or British military scheme, lots of options there.

[Jay]

One thing nice about the Chip is that it's about 30 to 40 bucks cheaper than those Brodak kits.
 I never cared for the way Sig cuts out the ribs.  Instead of cutting them with the grain of the wood running fore and aft they cut them diagonally making them prone to break on hard landings.

I have one here that I was hoping to build someday.  One of my "roundtuit" projects.

I would go with a classic legal plane if I was to choose again. Ask Derek Berry,  according to him,  the Oriental is the best.


How is that Magician that you shows us going?

[Curare]

So I take it fitting a lekky to a chippy would get me a slappy?

[wwwarbird]

So I take it fitting a lekky to a chippy would get me a slappy?

 A Saito .40 would be great in a Sig Chipmunk. Any other good running .36 to .40 would work well too. Lekky? No thanks. 

[Randy Cuberly]

I had several Sig Super Chipmunks in the early to middle 70's.  The first one had an Enya .35III, The second and third had OS40H's.  All flew very well especially the ones with the OS40H.
The plastic cowls and Wheel Pants worked just fine if the seams were put together carefully and reinforced on the inside.  The ABS Plastic they used was very tough.  It finished very nicely.
Sig offered Chipmunk Wing kits and a lot of these found their way into other original designs.  It was a very good wing.  All of mine did have some substituted wood as a lot of the kit wood was too heavy.  Two of mine had build up stabs that were sheeted and they were considerably stiffer than the solid ones offered in the kit.
In the 70's and even early 80's there always seemed to be several of these at contests every where I went.

Randy Cuberly

[Curare]

Hmm, I think I have a .40H hidden in the roof, the only problem is it's RC 

[Serge_Krauss]

Getting back to the original question, a couple observations...

Everyone seems to like the Chipmunk. One of our members, Dave Heinzman just refinished his this year and, I think, said that it flew really well with a different powerplant. The answers to your question though might be...

1) The Chipmunk really does still get mentioned a lot, and those wing kits are used too.

2) The figures you quote aren't really relevant to performance. That 42 1/2" length for the Vector may include a longer tail moment arm, which would be. Other significant items include wing section thickness, wing leading edge shape, and horizontal tail area. Some planes are better configured in these ways and gain favor in performance. The Chipmunk is way up there in its own time frame. The Vector is probably noticably better than the others. I like my vector, but had a long-tailed Tucker Spl. derivative that flew very well with the older classic wing.

FWIW.

SK

[Bill Hummel]

Count me in as another Chipmunk fan.  First, it is amazing how much lighter you can scratch build the Chip over the kit.  The original Sig Chipmunk kit is classic legal, and to many is a "nicer" representation of the Chipmunk design.  Better front end design, too, IMHO.  Rick Campbell terrorized the east coast meets a few years back with his Chipmunk/ST 46 combo.  David Fitzgerald had similar success on the west coast.  Great flying ship!

[steven yampolsky]

Getting back to the original question, a couple observations...

Everyone seems to like the Chipmunk. One of our members, Dave Heinzman just refinished his this year and, I think, said that it flew really well with a different powerplant. The answers to your question though might be...

Serge,

The pictures you've posted are of the original Chipmunk, not the Super Chipmunk that SIG kitted. These are two very different models.
Here's mine:

http://syampolsky.fotki.com/model-airplanes/ron-connors-memoria/20070901-134400-00003.html

http://syampolsky.fotki.com/model-airplanes/ron-connors-memoria/20070901-105531-00003.html

[Brett Buck]

Serge,

The pictures you've posted are of the original Chipmunk, not the Super Chipmunk that SIG kitted. These are two very different models.
Here's mine:

http://syampolsky.fotki.com/model-airplanes/ron-connors-memoria/20070901-134400-00003.html

http://syampolsky.fotki.com/model-airplanes/ron-connors-memoria/20070901-105531-00003.html

   The ones that Dave flew were from the kit, with minimal mods (aside from eventually putting in an ST46).

    Brett