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General control line discussion => Open Forum => Topic started by: Brian Massey on October 23, 2009, 10:29:45 AM
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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 ;D from Sams (after October discount) that seems like a heck of a deal to me.
Brian Massey
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Brian, where is "Sams" ? do they have a website? Ta
Cheers Neville
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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 H^^
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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
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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!
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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!
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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....
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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
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I believe that Tom Dixon has a single page plan illustrating how to eliminate the cowl, and make better (stronger) gear, etc....
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$30.00 to England ain't bad, Some guys on Ebay want that just to ship within the CONUS LL~
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$30.00 to England ain't bad, Some guys on Ebay want that just to ship within the CONUS LL~
And did you notice that one went for $96 (+ shipping) last night ? ? ? ?
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What's CONUS? ???
Cheers Neville
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$30.00 to England ain't bad, Some guys on Ebay want that just to ship within the CONUS LL~
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
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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
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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)
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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. ;D
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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
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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
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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! :P 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!!!! n~ 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
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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? LL~
(photos enhanced just for the memories.
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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
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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
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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
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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! ;D
And I didn't have to pay import duty either? #^ (don't tell the tax man? :X) 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
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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 ;D, does yours? Mine arrives in early December; can't wait for this business trip to end HB~>.
Brian
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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 ;D Once again thank you SAMS
Cheers Neville
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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
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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
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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 ;D)
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
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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! LL~
David
51336
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Hi ED, heard You have a couple SIG maf\gnum kits around. I am Looking for one to build
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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
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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.
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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
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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
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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. LL~
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
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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! mw~
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? ;D) So I'll probably make a start over the Xmas period when the panto is finished and I have some time off! D>K 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
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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 LL~
Post us you project
Pics required!
David
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Excellent metal uniflow stunt tanks can be obtained from Brodak or RSM. 8)
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Will go look again...
I found the std vent tanks.
must pay atention mw~
Thanks
David
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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
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Brian,
Do you think it would be OK to post Dave's mods to the Chipmunk?
Thanks,
Jim
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Let me ask Walter, who gave them to me. I don't want to do anything that might not be ethical.
Brian
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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...
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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 ;D
Cheers Neville
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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. LL~
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Richard, your Chipmunk looks fantastic, but where is the pilot man??? you have to have a pilot ;D If you're going to have a glasshouse you need a pilot!
Cheers Neville
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Hey Rootbeard....just a little wax and some elbow grease should have that plane looking like new! H^^ ;D
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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
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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.
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Is that a SIG Chipmunk, Paul? The tail moment looks a lot longer than the Kit!
Cheers Neville
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Hey Neville,
I am not real sure. Some one gave me this plane, and he got it from an estate. I posted a few photos when I got it asking about it and several people ID it as a Chipmunk.
Maybe when I dig into it, there we be something stamped on a rib or some plane on the bones that will tell me what it is for sure. I got a Sig Akrobat as well, and the ribs are marked as Akrobat.
The Chipmunk did not have a plastic cowl, but the Akrobat did.
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I believe that is the first Sig Chipmunk kit, aka a "Van Loo" Chipmunk. The current kit is the "Super Chipmunk".
Mike Gretz gave a really nice history of the Sig Chipmunk genealogy.
I know there was a link on SSW, but maybe here too.
I found the link to a web page, but unfortunately the page seems to have vanished into the "ether". I'll post Mile G's. article- I note that this there seemed to be a link from Phil Brown's (aka Garf) CL Links site, but I don't find it anymore (it may have been to the now non-existent site also pointed at by SSW.
The top link (the pdf file) is Mike G's genealogy. The jpgs are the MAN article on the vanLoo Chipmunk.
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Dave Fitzgerald lengthed the tail moment of his Chips by 3 inches. So maybe . . .
Brian
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Chipmunk Mods :
1. Equal panel wings
2. Flap to elevator hingline , lengthen 3"
3.Stab/Elevator is I believe 1" longer .
4. Keep weight below 50 Oz.
5. Use La .46 or St .46
YES the mods make it a MUCH better flying airplane , I have build 4 Chipmunks the last being with the mods.
Dave Fitz used this is his younger days!
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Chipmunk Mods :
1. Equal panel wings
2. Flap to elevator hingline , lengthen 3"
3.Stab/Elevator is I believe 1" longer .
4. Keep weight below 50 Oz.
5. Use La .46 or St .46
YES the mods make it a MUCH better flying airplane , I have build 4 Chipmunks the last being with the mods.
Dave Fitz used this is his younger days!
I wonder if Dave F. read Ted Fancher's Twister modifications----3 inches added to fuse length sounds familiar! Also helps balance a heavier engine.
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Dave Fitzpatrick lengthed the tail moment of his Chips by 3 inches. So maybe . . .
Brian
Brian, ya' might want to fix that typo. ;D
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Richard, your Chipmunk looks fantastic, but where is the pilot man??? you have to have a pilot ;D If you're going to have a glasshouse you need a pilot!
Cheers Neville
Neville,when he found out that I was the one who was actually going to be in control, he jumped off my bench and hid himself in the "grey area" of the shop. Haven't seen him since...can't say that I don't blame him! ;D
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Richard, I find pilots all over my workshop! ;D probably doing what yours did? LL~ I normally sit them down, and give them a good talking to, and tell them its not that bad a job. By this time my wife is reaching for the phone, to call for the men in white coats LL~ They normally live to fly the next model, I have some from the '60's, though when my Sheeks Spitfire bit the dust after the elevator horn broke, I never did find the pilot, that flying site is now a housing estate, so I hope he got a decent burial! Got to go, the men in white coats are knocking on the door! ;D
Cheers Neville
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Brian, ya' might want to fix that typo. ;D
Lengthened/lengthed; potato/potahto. I was once married to a "Professor of English" . . . she couldn't teach me much either. n~
When I remember to use it, I find spell check very helpful. y1
Brian
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Clint may have been referring to the spelling of Dave Fitzgerald's last name...oops! b1
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Clint may have been referring to the spelling of Dave Fitzgerald's last name...oops! b1
Drat! I did it again! HB~> HB~> Back in '05 I chaired the Pontiac/Oakland Western Regional Convention. One of our guest speakers was Art Fitz (drum roll please) patrick! We became pretty good friends and now every time a name starts with "Fitz", guess what I say . . . To further befuddle my brain, he also goes by "Fitz".
If you like automotive art, you should check him out. He did all the great Pontiac ads from the 60's when they were all hand drawn. He also designed the sports car stamps from 2005 (which out sold the Disney stamps) and more recently consulted on the Disney movie Cars. www.fitz-art.com
My apologies to the "other" Fitz. H^^
Brian
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Clint may have been referring to the spelling of Dave Fitzgerald's last name...oops! b1
Now you got it. ;)
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Now you got it. ;)
I may not be fast, but sometimes I'm not as slow. y1
Brian
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The Flyin' "Fitz" says to bring in a Chip at 50 ounces! Gads, what am I doing wrong! All the "parts" collectively weigh 47.2 ounces now, with no finishing work applied! HB~> That's the wing, fuse, stab/elevator/rudder, B40 with prop and muffler. I still have to add landing gear, covering, dope etc, etc. Am I building a pig? ~^
I know I've added extra bracing around the tip weight box and bellcrank platform, but certainly not measured in the pounds. I'm using all the stock kit wood, could that vs. contest grade make that much difference???
Brian
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Brian, let me start off by saying that your woodwork it excellent. However, the weight is a major concern. Depending on the rest of the finish work and hardware, you could be looking at a near 60 oz Chipmunk. That's a problem. Start looking at ways to trim this thing down. You might need to rebuild the stab/elev assembly with lighter wood. Trim the center of the ribs out. Same with fuse assembly. Maybe re-sheet the fuse top. Anything you can do to cut weight.
Come on guys, let's help him out with more ideas!
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AARRRRGGGGG! HB~> HB~> When I totaled the individual weights I included both the wing with flaps, and wing without flaps weighs!! HB~>
The correct skeletal weight is 35.3 oz. #^ I feel much better, but a bit more stupid. I may be on target for that 50 or so ounce Chip. #^
Brian
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You need to weight ALL the parts - LG, fuel tank, wheels etc. as well as the skeleton to get a realistic figure. In other words, everything but the paint. Plan for 8-10 ounces for the finish. I'd use monokote or Ultra-kote on the wing. Many Chips are finished that way and it is a lighter finish than a full-on dope paint job. 8)
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You need to weight ALL the parts - LG, fuel tank, wheels etc. as well as the skeleton to get a realistic figure. In other words, everything but the paint. Plan for 8-10 ounces for the finish. I'd use monokote or Ultra-kote on the wing. Many Chips are finished that way. 8)
I think John Paris's Super Chipmunk has a Monocote/Ultracote covering with paint for the sunburst pattern, and he regularly cleans people's clocks with it at the Sig Contest.
I think the B40 is a great choice for a liteweight but powerful engine for the Super Chippy.
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I started a Sig Super Chip about 1987 and hope to finish it some day soon. Seems like everyone recommends lots of power and I do not own any 40's or 46's. I do have a new Fox .35 with balanced crank, stuffer backplate, Marvin Denny's hemi-head and a Super Tigre needle valve assembly. I also have several O.S. Max .35S stunt engines in very good condition, two Veco .35's series 100, in very good condition and some McCoy 35 Redheads. This Chip will be built completely stock, using all kit parts. The kit itself, was purchased from a local hobby shop about 1984. Any suggestions would be appreciated. Thanks....TDurrill ???
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I'm guessing that if you can keep it light, (in other words, watch out for the plastic parts), and I would think about plastic covering, to keep the weight ALARA (As Low As Reasonably Achievable). Of what you have, I'd go with the OS35S. I believe it's bit more power than the Fox 35 but not a lot more weight.
The kit moments are set up (I believe) for the Fox 35--probably without a muffler, so the 35S (which isn't that much heavier) isn't a bad choice. However see if you can find a light muffler to strap on. Every bit helps!
I have a Super Chipmunk, and several 35's and two B 40's (plus a fair # of Fox 35's). I think I'll go for my B40, or maybe electric!. But it is important to watch the overall weight.
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I think John Paris's Super Chipmunk has a Monocote/Ultracote covering with paint for the sunburst pattern, and he regularly cleans people's clocks with it at the Sig Contest.
I think the B40 is a great choice for a liteweight but powerful engine for the Super Chippy.
Alan,
Mine is silkspan and dope. I think in the early days it was around 44-46 ozs but is closer to the 50 mark now. There is another on the board now with the same paint scheme in mind. I will use my DS 40 in it just like the old one. Hopefully it won't have to work as hard with the new one.
John
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I think the DS40 and B40 are about the same weight (almost identical engine with regard to weight).
Sorry to think your's was plastic. But with silkspan, I try to keep at least 10 feet away just in case I might drop something!
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Here is a letter written by Dave Fitzgerald to Walter Hicks (one of our club members) regarding the mods Dave made to his Chips. These changes took a great flyer and elevated it to championship level (Not that Dave's expertise had anything to do with it ;D. So with great thanks to Dave and Walter . . .
I've had to resample the scans down to get them to load here. If you want the full res scans (about 3.6 megs) let me know and I will be happy to email them to you.
Brian
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Brian,
Thanks for posting the notes (and thanks to Dave F. for making them!).
He mentions sanding the cowl down to fit the narrower fuse, but my guess is that this isn't the plastic cowl in the Super CHipmunk.
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Looking at the pictures, he has a couple of ounces that can still be removed from the ribs. When I get done with a set of kit ribs they resemble an I-Beam rib. Also sand all sheet wood before using or punching out parts. Looks good so far.
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Good idea Doc; I've never sanded the sheets prior to removing parts.
Thanks,
Brian
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Brian,
Thanks for posting the notes (and thanks to Dave F. for making them!).
He mentions sanding the cowl down to fit the narrower fuse, but my guess is that this isn't the plastic cowl in the Super CHipmunk.
Alan,
He is probably talking about sanding the two pieces a bit before joining. That would make the overall assembly thinner to fit the new fuse design.
John
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Hi Brian,
Very nice kit. Must replace the abs cowl/wheel pants for fiberglass parts. I finished one last year with monokote. Total weight is 42.5 oz with the Randy Smith Fox .35. Luiz- Mococa/Sp - Brasil
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Hi Luis; Very Pretty Chip you built! I hope mine comes out half that nice. I'm planning on a Brodak .40 for power, silk and dope finish and a flying weight around 50 oz. I'm considering balsa wheel pants and cowl, not sure yet.
Your paint scheme reminds me of Tom Warden's Continental . . . was that on purpose?
Brian
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Thanks Ty, that's another good tip. I may go in with the dremel and shave a gram or two.
Brian
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Neva'nuff Chipmunk photos
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If I remember right, that is a father-son photo of the McClellen's. Hope he is doing better.
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If I remember right, that is a father-son photo of the McClellen's. Hope he is doing better.
Yes...That is the McC Clan!
(hope he is doing better?) Uhhh? Tell us more?
They were great modelers and great modeling friends...and made our CLPA world a betta' place.
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I heard he had to give up the Chairmanship of the aerobatic contest rules board because of ill health. If I remember right someone said something about heart troubles. Maybe Keith Trostle will chime in on this.
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Regarding Dave Fitzgerald's mods to the Chipmunk.
He tells me now that if he were building one today,(2010) he would build it box stock but power it with a PA .40UL
I think he's figured out that 75% of a planes flying ability is due to it's engine. Guess that's why he's using
a PA .75 in a 630 Sq In Plane.
Jim Pollock n~
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Still neva-nuff Chippy's....
Except for Bob Welch's beautiful winning Chipmunk here in the NW in the mid 70's and early 80's...this beautfull Super Chip by Bob Suoboda who place 13th at the 72 Nats rates WAAAY up there on the best of the best Chipmunkity list.
(This great shot was by Les McDonald's slide collection)
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Here's a status update on my Chip: The basic airframe is together; fillets are almost done; tail wheel mount is on; drilled and fitted for tank and engine and the controls hooked up and covered . . . I hope this last step was not premature. HB~>
So far the weights are:
Airframe: 26.8 oz (Bottom of fuse and cockpit are sheeted and fillets on in, along with some filling.)
Engine/muffler/prop: 10.5
Accessories: 7.2 (Included in this are the tank with tubes, vents and mounts; cowling; wheel pants; engine mounting bolts/washers etc and tail wheel.)
Total weight is now at 44.5 oz. with a silk and dope finish yet to be added. I think the dream of a 50oz Chip are doomed, HB~> perhaps 55oz is still in reach.
Neville, is yours started yet? If you have any problems/questions, just ask, I've probably made most of the mistakes possible. n~
Brian
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Brian,
This is what happens when you use the kit wood. The 50 oz or less can only be accomplished by using contest wood. The only wood I would use are the wing ribs! Or by carefully weighing each part and if it is light keep it.
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Brian,
As a last resort, you can lose the wheel pants. If you must have pants, try to make some vacuform ones out of lite plastic. Use Dave Brown or du-bro lite wheels(foam).Cut some lightening holes where you can, not to affect any structural points, of course! Should be a great flyer anyhow. It may be happier a little overweight, kinda' like GMA's Noblers that I've read about here!I shamefully cover mine with Ultrakote and used LusterKote for the colors.While not a World Beater, I love mine. ;)
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Brian, your Chipmunk is looking good! I haven't started mine yet, I've spent the last month trying to get over pneumonia, either in bed or sat in front of the fire trying to feel better, reading old Aero Modeler mags, and trying to get my enthusiasm back :( My mind is full of enthusiasm, but the body is so weak :P ;D It'll get better soon I hope?
Have you gone over your model with the sandpaper again? Like sanding the flaps, elevators, tail, fin and rudder to proper aerofoil sections. It can reduce the weight of these components by almost half ? Have you read Don Bambricks article on finishing his Fury in Flying Models, I think he got the finish down to a few ounces! Its all in the sanding, and preparation, apparently! H^^ Look forward to seeing it finished.
Cheers Neville
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Still neva-nuff Chippy's....
Except for Bob Welch's beautiful winning Chipmunk here in the NW in the mid 70's and early 80's...this beautfull Super Chip by Bob Suoboda who place 13th at the 72 Nats rates WAAAY up there on the best of the best Chipmunkity list.
(This great shot was by Les McDonald's slide collection)
One of the best looking Chipmunks I've ever seen. One can see the results of what is called "shaping" done with wood tools from Xacto tools and sandpaper around the fuselage and cowling! The little 1 1/2 inch spinner is simply elegant.
Thanks for the picture Don, and Les.
Chris...
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Brian,
This is what happens when you use the kit wood. The 50 oz or less can only be accomplished by using contest wood. The only wood I would use are the wing ribs! Or by carefully weighing each part and if it is light keep it.
You're right Walter; this is 100% kit wood. I decided to go all kit wood and make no real modifications. My plan is to make another from scratch using hand selected wood (This is one of the reasons I'm weighing this one so often.), and making some modifications. I want to see what differences I can tell between the two. I love the looks of the plane so won't mind having two.
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Just a note here:
The paint scheme you have called a copy of Tom Warden's Continental is actually the paint scheme that Art Scholl used on his Chipmunk. I still don't think anyone has figured out the reason for the stabalizer separation from his plane that resulted in his all too untimely death. Every plane I see with that scheme, I consider it to be a tribute to one of the very best acrobatic pilots ever to step into a cockpit.
Jim Pollock :o H^^
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A long time ago Tom Dixon wrote an article about re-visiting the Chipmunk kit. He built it with the kit wood, mono-koted the wings and painted the rest with a dope based sport finished. I don't remember what the finished weight with but he was very happy with the way the finished airplane flew. I'd still consider carving the wheel pants out of light balsa or ommiting them altogether to save an ounce or two. Otherwise fly and enjoy, fortunately the Chipmunk wing is capable of flying a less than super-light airframe well. 8)
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Just a note here:
The paint scheme you have called a copy of Tom Warden's Continental is actually the paint scheme that Art Scholl used on his Chipmunk. I still don't think anyone has figured out the reason for the stabalizer separation from his plane that resulted in his all too untimely death. Every plane I see with that scheme, I consider it to be a tribute to one of the very best acrobatic pilots ever to step into a cockpit.
Jim Pollock :o H^^
Thanks for jogging my memory; I have gotten so use to seeing the paint scheme on the Sig box I forgot. I wonder if Tom Warden liked the paint scheme and took his ideas from there? If you haven't seen Art's flying in awhile, here's an old video of him in his Chipmonk performing the lomcevak. http://www.youtube.com/watch?v=UShzXAS50yQ
The pic is Tom Warden with his Trophy Trainer. Same paint scheme that he used on his Continental.
Brian
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I hope "better late than never" works on model diets.
Brian
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Ok, so here is one of those questions about the Super Chipmunk Kit that might seem utterly, inexplicably, simple to most. But sometimes things look one way and end up being another.
Started this kit. Built one in 1983, but I don’t recall how I answered this question. If you look at the picture of the fuselage side, you see the wing cut out. There is a solid line, and at front a dotted line. The instructions offer nothing whatever in the way of explaining which to cut on.
On a profile ship, where maximum wing chord on a tapered LE is in the center of a 1/2” piece of wood, obviously you cut to maximum size. On a full fuselage, am I correctly assuming that you cut on the solid line, and the dotted line indicates maximum chord hidden in the middle?
I know this sounds silly, but I don’t want to cut this until this question is resolved. A simple notation in the plans would have gone a long way here.
Gary
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Gary,
From the Sig "Super Chipmunk Building and Flying Instructions" booklet, basic fuselage construction "Cut the fuselage sides out of the 1/8" printed balsa sheets. Note that there is a right and a left side. On one side cut to the dotted line at the front of the wing cutout. This will later allow the wing to be inserted into the fuselage." Then in Final Assembly, "The leading edge of the opening on one fuselage side must be opened up to the dotted line to allow room for the center of the wing to slide by." And also "(Note alternate wing installation method described on the plan which is preferred by many modelers.)" I don't have the plans, but believe the alternate method is to cut the fuselage out beneath the wing to allow it to be installed, in which case the cutout wouldn't need to be enlarged on one side.
I hope that helps.
Gary
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Gary, thank you. That answers everything. Given that this kit is probably 35+ years old, the more recent instruction book isn’t there. Thanks again.
Gary
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Well, the copyright date on the instruction book is 1977...
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Well, the copyright date on the instruction book is 1977...
Interesting. I bought the kit used, that may be the problem. Plans show copyright date of 1973, but that may simply have never been updated. Perhaps the one I built in 83 had the booklet and that’s why I don’t recall being puzzled by this
Gary
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One of the planes in my stable is the Sig Akrobat which is very similar to the Chipmunk in size and proportions. My plane is covered with Monocote and weighs 46oz ready to fly. It is powered with an OS LA46 11x5 prop, 61' .015 lines eyelet to eyelet. I did have to add about 1.25 oz of tail weight to the rudder to get her to turn with authority. My plane likes to turn outside better than inside.Getting the full pattern out of it is no sweat I did use a plastic tank with muffler pressure. Enjoy your Chipmunk. PhillySkip