Posts: 1153
Joined: 11/30/2003 From: Cadillac,
MI, USA Status: offline
I'll be ordering my Arrow kit from Morris at the end of this month. (Sold some stock and freed up some $$
Went online to rcmmagazine.com to see if I could get the 07/04 back issue, and found out one can access all of the online issues and look at the articles for no charge. (They have a user id and password for one to type in on the sign in page.) I punched up the Arrow build article, complete with photos, and am printing it out now.
I should be able to complete and fly this beauty off the snow by January, at the latest.
Posts: 5
Joined: 12/16/2003 From: APO , AE, Status: offline
Well, after reading the thread I had to go pull out my plans for the Arrow and start hacking balsa. I decided to also go with a crutch fuse and permanently mounted wings. This means I will use carbon tube spars for the wings. As I have a bunch and don't really use it as much as I thought I would, I decided to break out light balsa (5-6 lb stock) for the build. The wing leading edge is 11 lb stock, all else is the light stuff (well, the 1/16" fuse sheeting is normal balsa, around 8 lb). I too changed the nose profile, raising the tip to be on the centerline (like the Northstar), but did not see a need to widen the fuse as a check against the plans showed enough space for my battery packs. I plan to go electric on this, will put in 2.5 degrees downthrust. Current choice for motor is a BP 3520-7, if that doesn't seem to work well, I will use an AXI 4120 I have.
I like the mounting approach for the motor (hardwood column). I like it so much better that I'm going to use it on the model after this one--my second Northstar I have a Northstar in the box, that I bought some time back to replace one I had and essentially flown to death--it was a great model. I bought the kit with the idea of adding retracts and doing some other kit bashing, but now I think I will build it without retracts, but use a crutch fuse, change the motor mounting scheme to match the one in the Arrow (and lighten it up in the tail I would think), extend the nose 3" to help with balance (my first one took 14 oz in the nose!!), and of course go electric. I will get to work on this one as soon as I finish the Arrow.
Anyway, back to Arrow, my plan to balance is to use forward CG mark for initial balance, add 8 oz to tail and mark the new balance point, then remove the weight and rebalance at the new point, and use that as my initial flying CG. Not having to worry about a shifting balance point due to fuel usage, this should work out well. I plan to do the same thing on my Northstar, I flew the first one at the recommended CG, and it flew very well, but I could not get it to do an outside loop very well as when the nose when straight down it didn't want to pull through at all. I also remember reading about others moving the CG back 2" and flying without problems. Regardless, I am sure as marked it can be moved back for an electric model.
For the spars, just drilled holes in the wing ribs at appropriate spots and then put 1/32" ply plates(real ply, not the light ply stuff) on each side of the rib. At the first rib and in the fuselage I used 1/16" ply, give the wing will be glued to the side that should work ok.
As anyone who has built one yet should be able to attest, this is an easy build, even more so if you don't use a crutch fuse--I would not hesitate to recommend this model as a first build for anyone, it goes together fast and as straight as your building surface, and the unique design makes it even easier to smile wide when you say "I built it from plans." Now if I only had someone to cover it for me (I absolutely hate to cover), I would be in great shape
Posts: 5
Joined: 12/16/2003 From: APO , AE, Status: offline
Bob, just my luck you're in Michigan, I would let you have it in a heartbeat too I do seriously need to find someone, though, that will let me build for them in exchange for covering for me...Pete M
Posts: 5
Joined: 12/16/2003 From: APO , AE, Status: offline
No problem with the original design, my thoughts are this will let me build a lighter structure, and if not, a stronger one for the weight. It also completely opens the fuse as the only formers Iwill have are the nose, the nose landing gear ply former, and the rear ply former in the back where the motor pylon mounts. The crutch fuse approach allows the use of 1/16" sheet for the sides (without worrying about strength), and I plan to use 1/16" sheet for the top and bottom (front will be then covered with 1/32" ply for extra strength). I think this will give me an overall lighter model, I will post component weights as I get them done...Pete M
Posts: 5
Joined: 12/16/2003 From: APO , AE, Status: offline
Well, some progress. I have the rear landing gear block mounted. After confirming the fuse rear plywood former is perpendicular to the wing center line, I went ahead and started the pylon/vertical stab. The pylon/vertical stab needs to be sheeted on the other side, I have to wait until I get the wire in for the speed control. The motor pod is pretty well shaped out, since I don't have to make room for a fuel tank no need to maintain that square shape. I plan to have the speed control in the pod right behind the motor. I will leave the rear of the structure open and add scoops for cooling air flow. I will need to cut a hatch, of course, to be able to mount the motor or change it out if need be. I also raised the motor pod 1/2" to allow a 13" prop if I need to use one. I will put the downthrust in using washers at the top of the motor mount.
Elevons are also done, built up to save weight. I will just use film hinges, they have never failed me and the gap is automatically sealed as a result. Just a lot going on this time of year so have to get things done as I can...Pete M
< Message edited by pmisuinas -- 11/26/2007 1:43:55 AM >
Posts: 255
Joined: 11/25/2002 From: Manitou Beach,
MI, USA Status: offline
Hello everybody What is the concensus on finishing method of the Arrow/Northstar.... Film? fabric & paint? Fiberglass the fuse/film the wings?? I'll be using mine 100% from the water. Should be fun with a Jett-50! Just drilling holes in the fuse formers now. thanks
My last one had the fuselage glassed, the wings covered with Solartex and then the whole plane was painted. I'll use epoxy paint on my next one which will be #4. My current project is a pulse jet powered 3/4 size North Star. I'll post some pictures of it when the assembly is nearer to completion. At present I still have to finish sheeting the top and bottom of the fuselage and finish sheeting the tip floats. I'm rather looking forward to this one. If it crashes there should be plenty of water to put out the fire. Peter
Posts: 138
Joined: 12/8/2003 From: new baltimore, MI, USA Status: offline
Star- I polyureathane the inside,and I balsarite the entire outside then cover the outside in solartex. I had great success.It's a matter of prefrence.=Jeffo I'm building the Arrow 90% complete.
I think the bottom line on finishing a Northstar (or any aircraft for that matter) Is to put on a durable finish; especially if you want it to last. To me this means fiberglass on the sheeted areas with solartex on the open structure and then a really durable paint finish like an epoxy paint. With any aircraft designed to operate off water the interior of the structure has to be sealed and as Jeffo states some kind of polyurethane spray is satisfactory. A fiberglass/ solartex/paint finish is going to be heavier than a film finish but it should far outlast the film. My first Northstar was coverite/epoxy and it lasted nearly 20 years. When it finally crashed there were some as yet un-named life forms growing in there. Peter
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All Forums >> RC Airplanes >> Seaplanes >> RE: northstar help 
RE: northstar help - 
I have a Northstar in the box, that I bought some time back to replace one I had and essentially flown to death--it was a great model. I bought the kit with the idea of adding retracts and doing some other kit bashing, but now I think I will build it without retracts, but use a crutch fuse, change the motor mounting scheme to match the one in the Arrow (and lighten it up in the tail I would think), extend the nose 3" to help with balance (my first one took 14 oz in the nose!!), and of course go electric. I will get to work on this one as soon as I finish the Arrow. 
I do seriously need to find someone, though, that will let me build for them in exchange for 
