Author Topic: Sig Super Chipmunk (Read 46232 times)

Brian Massey · « **on:** October 23, 2009, 10:29:45 AM »

I'm still pondering a "Winter" project, and have been looking at one of my old favorites; the Sig Super Chipmunk. I've always thought that it is a beautiful plane to look at, and given it's record, it must fly pretty dang good too. Anyone have experience with the kit? How good is the die cutting and what quality balsa? At 74 bucks

from Sams (after October discount) that seems like a heck of a deal to me.

Brian Massey

Neville Legg · « **Reply #1 on:** October 23, 2009, 10:46:32 AM »

Brian, where is "Sams" ? do they have a website? Ta

Cheers Neville

Matt Colan · « **Reply #2 on:** October 23, 2009, 10:56:52 AM »

Correct me if I'm wrong, but I think the kit is laser cut now. Grandpa built one for the 2005 season and he said it really flew great, but the Brodak 40 in it ran out of fuel on the way up on the 4 leaf and the plane went in. He fixed it and only about 5 flights later the motor got sick during the horizontal 8s and it went in, all but the tail was salvagable. From what I remember, it flew well. He does have a partial kit of another chipmunk he may build in the future, but he does have a lot of planes he needs to finish.

I would say build it, it should fly well, just make sure you are able to shim the tank. The way the nose is designed, you can't shim the tank, so you may need to move the motor mounts up and put aluminum pads on the mounts. That is all I can really remember and give advice to

Good luck

Brian Massey · « **Reply #3 on:** October 23, 2009, 11:02:15 AM »

Hi Neville; Yes, Sam's Stuff and Hobbies: http://sshobbies.com/

It's also listed on the Sig site at only 79 bucks: http://www.sigmfg.com/cgi-bin/dpsmart.exe/MainMenuFV4.html?E+Sig

Brian

Bill Hummel · « **Reply #4 on:** October 23, 2009, 02:18:20 PM »

Hi, Brian, the Sig Chipmunk is one of my favorites, I've built 5 with another underway. I like the old ST 46 for power. The kit is adequate for wood, most is ok to use. I'd suggest losing the heavy plastic cowl, and build a "normal" front end. Also like to build the wings with equal spans, but that's a preference. Years ago, Rick Campbell flew very competitively in the northeast with a slightly modified 'Chip...flew exceptionally well. The usual caveat: don't get it too heavy with paint/dope finish. 46-50 ounces seems to be a nice range. Good luck, great stunter!

wwwarbird · « **Reply #5 on:** October 23, 2009, 05:23:12 PM »

The Chipmunk is not laser-cut but it is still a decent kit and a good flyer.

If you decide to build one, a good tip/mod is to go ahead use the extra outboard wing rib that is supplied in the kit but not used per the plans. This is because the design is "old school" with a longer inboard wing. The extra outboard rib is in the kit though because it just works out for them on the die-cut sheets. You'll understand better when you get the kit in your hands and look it all over. Some have done this and then even made up and added another inboard rib to maintain the overall wing offset. Either way is a good update that will give you more wing area. Just keep in mind you'll have to make up new spars etc.

Happy building!

Walter Hicks · « **Reply #6 on:** October 23, 2009, 06:13:59 PM »

Extend the tail moment 3" and add a couple of inches t the stab and elevator and go for it. Dave Fitzgerald did this many years ago. I built one this way 46oz with ST .46 flew very well. Stock wood is heavy for stab, elevator, rudder.

LA46 would be perfect....

Neville Legg · « **Reply #7 on:** October 26, 2009, 03:31:52 PM »

Thanks for the info. Brian, I've just ordered a Chipmunk from Sam's, 'gonna cost $30 to get it to England though!
3" seems like an awfully long extention to the tail moment? mind you the nose looks a little on the long side! But it obviously flew well?

Cheers Neville

peabody · « **Reply #8 on:** October 26, 2009, 04:11:08 PM »

I believe that Tom Dixon has a single page plan illustrating how to eliminate the cowl, and make better (stronger) gear, etc....

Leester · « **Reply #9 on:** October 26, 2009, 04:19:21 PM »

$30.00 to England ain't bad, Some guys on Ebay want that just to ship within the CONUS

Ralph Wenzel (d) · « **Reply #10 on:** October 26, 2009, 05:09:43 PM »

Quote from: Leester on October 26, 2009, 04:19:21 PM

$30.00 to England ain't bad, Some guys on Ebay want that just to ship within the CONUS

And did you notice that one went for $96 (+ shipping) last night ? ? ? ?

Neville Legg · « **Reply #11 on:** October 26, 2009, 06:19:39 PM »

What's CONUS?

Cheers Neville

RandySmith · « **Reply #12 on:** October 26, 2009, 06:25:51 PM »

Quote from: Leester on October 26, 2009, 04:19:21 PM

$30.00 to England ain't bad, Some guys on Ebay want that just to ship within the CONUS

My Exact cost by Airmail from the US post Office was 39.00 to ship the Chipmunk kit to the UK

By the way you do not need to change any diminsion on the plane, it will fly very well as designed, loose the plastic heavy wheel pants though

Randy

John Paris · « **Reply #13 on:** October 26, 2009, 06:31:09 PM »

Quote from: Neville Legg on October 26, 2009, 06:19:39 PM

What's CONUS?

Cheers Neville

Neville,
CONUS=CONtinental United States. I first heard it while I was in the military. Good choice for an airplane. I have one now and should be making time for another this building season.
John

Shultzie · « **Reply #14 on:** October 26, 2009, 06:56:08 PM »

Quote from: Walter Hicks on October 23, 2009, 06:13:59 PM

Extend the tail moment 3" and add a couple of inches t the stab and elevator and go for it. Dave Fitzgerald did this many years ago. I built one this way 46oz with ST .46 flew very well. Stock wood is heavy for stab, elevator, rudder.

LA46 would be perfect....

Just a few minutes ago...I went out and measured my old busted Super Chip that started out the with OS 40 and then later switched to the ST-46 up front.

This is that old vintage model that I had been flying since waaaaay back in 1976 that was good enough in those old daze-days to steal a few trophies as well as best finish silver plates at the OLD IMPLODED SEATTLE KINGDOME Model Fair 78 after over a year of constant flying.

Since those early daze...I have gone through 2 motor mounts...3 cowlings...and 4 or more sets of slim line rubber O ring tires.
Over the years...I have given away many of my old stunt models...but somehow always enjoyed flying this modified SuperChip...that always seem to avoid contact with the tarmac (that is until last year)
Best of all...the price was right on this kit as I had won this Super Chipmunk as a prize drawing and after looking over the kit....thought it would be a good winter project.

I kept the canopy for a fiberglass mold.....and all of the wing ribs. I dumped the rest of the kit into my excess balsa wood storage bin and replaced the balsa with my bundles of choice graded balsa that I had been hording since the early 60's.
I did get a bit carried away with some design modifications.....

I kept the nose length bout' the same...
but flap hinge line to the elevator hinge line was stretched out to 15.5
The wing has an added rib to each side...and the tips on both the wing and elevator outline also changed
(I didn't didn't care for the original more rounded tips with those tip ribs)

I then fattened up the elevator thickness and lengthed the stab and elevator to 25 inches.
Its been sooooooooooo many years......

I don't have the plans or the chances that I made from the plans..but after reading the changes that Fitzee did on his model,
It would appear at first thought...that perhaps our Super-Chip models must have been pretty close in measurements, exception for the longer aspect wing...(due to the extra rib on each wing panel?
With the OS 40...that model weighed in at tad over 47 ounces and LUCKED OUT WITHOUT ADDING ANY TAIL WEIGHT...(until I switched to The ST-46)

Balsa Butcher · « **Reply #15 on:** October 26, 2009, 07:16:02 PM »

Since I won a Super Chipmunk (thanks Randy) at last month's Stunt Hangar drawing - you bet I'm taking careful notes of this thread.

Ed Prohaska · « **Reply #16 on:** October 26, 2009, 11:34:49 PM »

I'm a Sig dealer. Since about 2 years ago, the kits I've been getting have a few laser cut parts. Box weight varies from just under 4 pounds (rare) to around 4.5 pounds. One "challenge" is the large cowl which swallows the Fox .35 shown on the plans. The LA .46 is a good engine choice for this kit (and many others). You can get an OS extension for the muffler, to help it clear the cowl and an extra tall custom venturi (Lee Machine Shop) that sticks out far enough to choke the engine. Getting a needle valve to exit the cowl is sometimes an "issue". The RSM "ST style" NVA with an extra long needle (when available) is an option (or use a remote NVA, if they work 4U). Lately, the supply of Sig control line kits has been sporadic. I'm told a scarcity of suitable balsa is the problem.

The Super Chipmunk kit has been in production since the early 1970s. I think this is longer than any other full fuselage, flapped stunter, even the famous 1957 Nobler. Since so many were made over the years, there are lots of kits "out there" that never got built and often show up on Ebay. I've sold dozens but never built one. I've seen many fly and have flown models built by others. It's a nice flying design and looks good in the air. There is room in the long nose for up to a 6 oz. tank. A rear exhaust .40 or .46 (PA, RO-Jett, Stalker) would fit right in. I wish it were available as an ARF or (preferably) a fully take-apart, bolt together, totally ready to fly model.

Regards, EWP

Brian Massey · « **Reply #17 on:** October 27, 2009, 10:56:22 AM »

Good Luck with the Chipmonk Neville; Keep us posted on the construction. I have to spend most of November gone on a business/pleasure trip to Montana and Colorado, so I'll wait until I get back to order mine. Dont' want it sitting on the front porch for a month.

Brian

Neville Legg · « **Reply #18 on:** October 27, 2009, 12:35:41 PM »

I shall try to build and finished it over the coming winter, the full size Chipmunk was the first aeroplane I ever flew in, and I did aerobatics too!

I was strapped in the back while the student RAF pilot did all the work. As we were flying over the sea, we had to wear a Mae West! (life jacket) and the one I put on was damp with disinfectant after the previous air cadet had thrown up all over it! Lovely!!!!

And I'd just had a fantastic RAF Sunday lunch, which I kept down, despite the loops, stall turns, and barrel rolls! That was the mid '60's, don't know if I would handle it the same now?
Mr Shultzie, your so called beaten up Chipmunk looks fantastic in the photos! Think I might sheet the wing? I always end up messing up a silked wing.

Cheers Neville

Shultzie · « **Reply #19 on:** October 27, 2009, 01:46:44 PM »

Quote from: Neville Legg on October 27, 2009, 12:35:41 PM

I
Mr Shultzie, your so called beaten up Chipmunk looks fantastic in the photos! Think I might sheet the wing? I always end up messing up a silked wing.
Cheers Neville

Sheeting that wing would have prevented my favorite judge from leaning over my brand new model just before his pen fell out of his shirt pocket and impailed itself through the silk span.

Last photo our PG...if memory hasn't totally failed....Phil is pointing out either the little handy SMILEY FACE decals that I kept in my tool box...just to make those QUICK PATCH REPAIRS
or more likely.....the little rapid-o-graph pen flaws?

(photos enhanced just for the memories.

Brian Massey · « **Reply #20 on:** October 27, 2009, 07:48:45 PM »

Hey Neville;

Keep me posted your progress with the Chipmunk. I ordered mine today, but requested a December delivery due to business trip conflicts. Sam's is very accommodating, seems to be a good place to do business.

Brian

Neville Legg · « **Reply #21 on:** October 29, 2009, 01:56:30 PM »

I don't know when my kit will arrive, as we now have a Post office strike here in England, its not good for the little company I run either!!!

Cheers Neville

Brian Massey · « **Reply #22 on:** October 29, 2009, 03:52:32 PM »

Sorry about that stike; hope it doesn't last too long. The shipping was $7.50 on my order, but our Post Office isn't great, just hope it arrives in the proper number of pieces.

Brian

Neville Legg · « **Reply #23 on:** November 03, 2009, 10:48:30 AM »

My Chipmunk arrived today, despite the Post office strike! Nice kit, a few bits of timber on the heavy side, but very good for the money!

And I didn't have to pay import duty either?

(don't tell the tax man?

) Once I tidy up my workshop, I'll get started! Fantastic! looking forward to it. Thank you SAMS hobbies, Mr Sam and all the others there, very good service!

Cheers Neville

Brian Massey · « **Reply #24 on:** November 03, 2009, 08:25:27 PM »

Hi again Neville;

Glad your kit arrived in "one" piece

. Home mine does too. Keep me posted on your progress. One of the posts suggested that the kit may now contain some laser cut parts

, does yours? Mine arrives in early December; can't wait for this business trip to end

.

Brian

Neville Legg · « **Reply #25 on:** November 04, 2009, 01:00:29 AM »

Brian, the kit does contain some laser cut formers, but the die-cutting is very crisp! Not like the old Keil Kraft kits of the '60's, when we used to call it die-crushing!

I will keep you posted on the progress, I might make a few mods, not sure yet! By the way, you also get a nice little engraved pen from SAMS hobbies

Once again thank you SAMS

Cheers Neville

Bill Turner · « **Reply #26 on:** November 04, 2009, 01:13:24 PM »

Built one of these in 1979 and covered it in white mono with blue transparent for the wings. Stars and sunburst lines, looked great. But flew like a brick on a string. Fox 35 for power and it needed more. Gave it to a friend. I think he's still got it in his shed.. Need to ask him about it.

Thanks for great memories and they are a great plane. Just make sure you gots lotsa power...

Bill

Brian Massey · « **Reply #27 on:** November 06, 2009, 10:19:47 AM »

I haven't made up my mind as yet, but either a B40 or LA46 for power. I'll make the decision when I get a handle on the finished weight.

I'll be shooting for 48 oz or so.

Brian

Neville Legg · « **Reply #28 on:** November 06, 2009, 11:00:17 AM »

Made a spare copy of the plan, and have drawn around the parts, ribs and formers etc, in case I need spares or want to build another in the future!
I have a modified West 36 (Webra) that I need to try in this model, its a very powerful engine modified for C/L. (Detuned a bit

)
I'll shift the wing forward to the second former, about an inch and a bit, to give more lee-way for different size engines! I hate putting lead in the tail !!

Cheers Neville

W.D. Roland · « **Reply #29 on:** November 08, 2009, 06:53:22 PM »

Neville
Notice the cowl can be slid forward or back for different engines.
I had a ST .35 stunt with prop extension that was totally unsuitable as a stunt engine and changed to a O.S. .35S with out extension and slid the cowl back by simply drilling new mounting holes.

Got to fly it today Fantastic compared to recent success.
Airplane is soft on corners and slight hing in the overheads but should trim out easy enough.
The O.S. is fantastic on the 4-2-4 !

I finally have a decent stunter now need a decent stunt pilot!(working on that part)

I did not make copy of ribs and other stuff.
Hope I dont need a copy from you anytime soon!

David
51336

Peter Nevai · « **Reply #30 on:** November 15, 2009, 12:48:05 AM »

Hi ED, heard You have a couple SIG maf\gnum kits around. I am Looking for one to build

Neville Legg · « **Reply #31 on:** November 15, 2009, 02:35:02 AM »

David, could the soft cornering be due to the long nose moment? I have a number of engines I'd like to try in the Chipmunk, including a PAW35 diesel!!!
which is quite heavy, hence the reason for shifting the wing forward a bit. I have two OS 35's and as you say they run beautifully! I also have a brand new in its box OS 30 from the '70's, don't know if this one would have enough urge? I'm cutting a spare set of ribs for a mate of mine who wants to build one for a PAW 29 diesel as well ! We shall see how they perform, his will probably be lighter as they choice of would will be a little better.

Cheers Neville

W.D. Roland · « **Reply #32 on:** November 15, 2009, 09:50:22 AM »

Hey Neville
Was going to star a thread on that but you asked and saved me the trouble!
This O.S. 35s has the best 4-2-4 of any engine I have ever had!
Will check timing and compression on this one next time its out!.

Went out and flew the Chip yesterday.
Removing the tip weight has helped on the hinging and has smoothed out the corners as it does not wobble on return to neutral.
The corners are still soft though.

Flew the old Smoothie until the filter stopped up 1/2 way through the tank......
Very sharp corners!

This made me check balance points......

The Chip is dead on plans and even checked a set of plans from 70s...same.
The Smoothie balances much further back than the Chipmunk.

Just eye balling the M.A.C. and I would say the Chipmunk C.G. shown on plans is to far forward, at least .75-1 inch?
Will move it back some today and see what happens, that is if the weather holds.

Any comments on the Chip balance would be helpful!!!!!

Here are a few Chip pics. 46oz.

W.D. Roland · « **Reply #33 on:** November 15, 2009, 10:00:19 AM »

Neville

Far from an expert here but on the .30 if you have a really light one it would be ok i think.

When mine goes 2 stroke the power is more than enough.
Will do overhead or any thing asked to all day in what seems like 5ft dia.

The .35 piston/sleeve will fit the .30 case, the .30 head will not work on the .35 sleeve.

So you know... a 4oz tank gives around 8min run time!!!!!!!!!!!!!!!!!

David

Neville Legg · « **Reply #34 on:** November 15, 2009, 03:55:00 PM »

David, I haven't checked the weight of the OS30, but I imagine there's not a lot of difference between them? physical dimensions are the same, then add on the OS muffler!!! My PAW 35 is heavier but doesn't need a large muffler or so much fuel! And it swings a far bigger prop. Diesel fuel doesn't attack nitrate dope either ! Your Chipmunk looks great, what kind of finish have you used?

Cheers Neville

W.D. Roland · « **Reply #35 on:** November 15, 2009, 05:27:43 PM »

Neville
2 of the OS .35s I built in 30 cases. Every thing is the same except the bore and possible the thinner sleeve on the .35 make it a tad lighter. I did file the .30 off the boss so as not to confuse myself down the road.

My understanding is a muffler is not required for smaller engines (.35)at most places so I just run a homemade header of about 3/8 dia to get the exhaust out of the cowl. Seems to quieten it some and is very light.

Thanks for the compliments on the Chip. A simple scheme but about like I like, matches the pilot.
Finish is all white monokote with the blue being some old transparent solar film that was laying around.
The cowl is painted with something spray paint from the hardware store.

I did replace the L.E. sheeting and the top of the fuselage with lighter balsa.
Also provided access to fuel tank, bellcrank, flap horn and moved elevator horn out side, so far glad I did as it has all come in handy.
Also tapered motor mounts to zero thickness from the firewall back.

As far as the diesel I know noting about them other than they have a compression adjustment.
The torque they produce should be good for stunt.(?)

Went flying this afternoon but did not fly the Chipmunk, was trying to sort the tank better on a profile P-40.
So far the best tank goes rich 1/2 way through the tank---strange....Also had to mount tank 1/2inch above venturi to get even upside right and down side wrong running..stranger even.

Hows the building coming?

David

Neville Legg · « **Reply #36 on:** November 16, 2009, 12:40:11 PM »

David,

We have to use silencers on anything bigger than a 10 size diesel! Even though a Cox 049 doing 15k rpm is more annoying!

I haven't had a chance to start on the model yet, all my free time is spent painting scenery for a village pantomine (a very English thing, men dress as women and women as men, then stand on stage and act the fool! And there's a fairy involved, with wings and a magic wand!!!!!! even the US spellcheck didn't recognise it?

) Then I have to learn the songs, as I'm in the panto band!! (don't know why I get involve in these things?

) So I'll probably make a start over the Xmas period when the panto is finished and I have some time off!

You seem to have a lot of good flying weather where you are? We've had high winds and rain here for weeks now! What type of tanks are you using, metal or plastic R/C clunk type?

Cheers Neville

W.D. Roland · « **Reply #37 on:** November 16, 2009, 08:56:16 PM »

Neville

Currently my tanks are old Veco stock(metal) some new some old some ..... junk.
I convert them to uniflow so old or new at least the rear of them come off for plumbing and cleaning.

Have a very few tanks that were mfg as uniflow out of a lighter gauge than the Vecos.
Been keeping an eye out for current version. these tanks were plated and lighter than Veco but same size and shape.
Any Ideas for current production of these anyone? they came out in the early-mid 70s?

Put on a Dress at Church once.....
Ran down the isle and then took it off.
The Preacher then put it on and ran back to the place I started running from.
We won the race. the other teams got tangled up in the Bras.guess we had more practice.........................
True story....dont know why but it is

Post us you project
Pics required!

David

Balsa Butcher · « **Reply #38 on:** November 16, 2009, 09:39:32 PM »

Excellent metal uniflow stunt tanks can be obtained from Brodak or RSM.

W.D. Roland · « **Reply #39 on:** November 16, 2009, 09:55:46 PM »

Will go look again...
I found the std vent tanks.

must pay atention

Thanks
David

Brian Massey · « **Reply #40 on:** January 22, 2010, 06:51:00 PM »

Hey Neville! How's the Chip coming?? I'm making progress on mine finally. I'm sticking pretty much to stock, just a few minor variations, such as adjustable leadouts.

Walter Hicks, a fellow club member gave me a letter written to him by Dave Fitzgerald. Dave laid out the modifications he made to fly the plane to the Nats championships. They are interesting mods and I will probably make another Chip to see what difference the mods make.

Here's where I'm at currently.

The wing is just dry fit to the fuse at this point.

Brian

Jim Oliver · « **Reply #41 on:** January 22, 2010, 08:01:49 PM »

Brian,

Do you think it would be OK to post Dave's mods to the Chipmunk?

Thanks,
Jim

Brian Massey · « **Reply #42 on:** January 22, 2010, 10:54:32 PM »

Let me ask Walter, who gave them to me. I don't want to do anything that might not be ethical.

Brian

Richard Grogan · « **Reply #43 on:** January 22, 2010, 11:15:04 PM »

What the heck is that looking in your window, Brian?(last photo) Looks like a ghost of a dog or sheep...

really weird! LOL
Here's mine.Not perfect but good enough.I think you will enjoy this bird stock.The cowl is a bit heavy, and the wheel pants with the hardware to mount them is a bit excessive. I wonder,however, what these other secret ingredients are being discussed...

Neville Legg · « **Reply #44 on:** January 23, 2010, 01:41:33 AM »

Hello Brian, your model is coming on well, mine is still in the box in the office $:-\$ . I'm recovering from pneumonia, started to feel bad before Xmas with a dose of swine flu. Been backwards and forwards to Hospital over the Xmas holidays! fantastic!!! So I haven't felt like doing anything. I need some 4'x4" 1/16th sheet for the wing, which my model shop is having trouble getting! Will start on it soon, I'm desperate to start whittling balsa again

Cheers Neville

Paul Taylor · « **Reply #45 on:** January 23, 2010, 08:24:42 AM »

Brian,
I love them bones!!!!! Keep the pictures coming.

And I have been down loading pictures off this thread because I will be doing (or redoing) a Chipmunk.

Here is a "hand me down" Chimpmunk I hope to recover and spruce up as a trainer. But then all my planes are trainers.

Neville Legg · « **Reply #46 on:** January 23, 2010, 08:35:18 AM »

Richard, your Chipmunk looks fantastic, but where is the pilot man??? you have to have a pilot

If you're going to have a glasshouse you need a pilot!

Cheers Neville

Glenn (Gravitywell) Reach · « **Reply #47 on:** January 23, 2010, 09:17:46 AM »

Hey Rootbeard....just a little wax and some elbow grease should have that plane looking like new!

Brian Massey · « **Reply #48 on:** January 23, 2010, 09:38:28 AM »

Hey Neville; Sorry to hear you've been under the weather; I pictured you already flying the Chip, and me just in the early build stage. I hope you feel like building soon. So far I'm finding the plans somewhat lacking in explanation and clarity. Maybe because it's been so long since I've built a kit that I've forgotten much of what is supposed to be common knowledge. Oh well. Much of the wood is good, some ok. Not sure if I'll use the molded cowl and wheel pants . . . I may make my own. If you continue to have problems getting the correct balsa, I've used Balsa USA and been very pleased with the wood. Not sure what the shipping might set you back though. I've also heard good things about National Balsa.

Richard; sorry to disappoint, but out that window is a silver tarp that the wind had blown around exposing the lawnmower and other tools; nothing as exciting as a dog ghost. We had wind gusts here in the Central Valley that got up to 51 mph. Unusually high for this area.
Your Chip looks great! I'm not sure I'm ready to tackle a complex paint scheme at this time, but nothing is prettier that the stock scheme! I've ordered some white to have on hand just in case.

Rootbeard; Your Chip looks pretty good! Are you going to strip it completely down, or just a quick refinish as a trainer?

I'll post more pictures soon; wasn't sure anyone would be interested.

Brian

Paul Taylor · « **Reply #49 on:** January 23, 2010, 11:07:40 AM »

Hey Brian,
It will get stripped to the bare bones. I will add a weight tip box, and may replace the lead outs for safety.