Cougar429

My Feedback: (3)

Seems there is not a lot of movement on this thread lately. Perhaps everyone has parked theirs for the winter?

I'm waiting for my new OS 55AX to arrive. Wish I had waited to cut the cowl, but hopefully there will not be a large difference in contour. From what I can see I will save almost 4 oz at the tail with the swap for the EVO 46. If the math is correct then 9 should come out of the nose. That 3/4 pound is quite a dramatic cut in AOW.

If other projects don't get in the way, I may even build a lighter stabilizer assembly with C/F sticks for strength. Looking for a van so removing it for transport may not be such an issue.

Goldenduff

Mine is still on the drawing board (collecting build pieces).

I plan on using a J'EN .57 (excellent engine, a .40 bored out). It is pretty light (made a school boy error when swapping out a .40 OS- thought the .57 would be heavier but it's lighter, thus tail heavy first flight but luckily it was a trainer type model).

I will be using the .57 in my NS scratch build using the plans. Was thinking of using a perry pump to help CoG (Fuel tank at CoG). It was also reduce the strength required in the motor/fin thus saving balast weight and strengthening weight in the motor/fin as the tank will be in the fuselage.

I have been delaying for ages- its about 0 deg C lower in evening and my shed is an open barn!

Any thoughts on NS build (mini servo for throttle, standard servos mounted near rudder and elevator......what do you think of the perry pump idea, ive never used one......could always go electric but waiting for batteries to charge is rubbish!!!)

Cheers

siddus74

A fiend of mine has a Jen 57 in a Black Horse Super air, seems very powerfull, to early to comment on the reliability though . . . I have an OS50SHX in mine an OS55AX in my Arrow both with a small servo in the tail along withthe fuel tank . . . With regards the perry pump I think its a waste of time and money - build it to plan like the hundreds of others and enjoy it.

Scott.

Goldenduff

Fair enough Siddus 74,  the jury is still out- the other advantage of perry pump (aside from less likely to need balast) would be a BIG fuel tank for hours of fun between refueling.

My J'EN is reliable- practically had to dig it out after the tail heavy flight mentioned above, removed the head, carb and backplate, soaked it in fuel, reassembled and no worries!

Anyone got any comments re: perry pump? Are they reliable, easy to tune (one concern is the tapping the engine backplate) Not too worried regarding expense as it could be a good christmas present instead of something equally expensive that i wont use (jumper etc!)

Cheers

68mustang

My Feedback: (14)

Sometimes one of the backplate screw holes goes right into the crankcase so you just take it out and replace it with a pressure fitting.

Goldenduff

Gonna gO WITH PERRY PUMP UNLESS ANY RELIABILITY ISSUESS? KEEN NOT TO ADD BALLAST WEIGHT, FIT LAARGE TANK AND KEEEP ENGINE NACELLE WEIGHT DOWN FOR STRUCTURAL SOUNDNESS. AM NEVER USED A PERRY PUMP, ARE THEY RELIABLE? CHEERS

Cougar429

My Feedback: (3)

Mounted the OS 55AX this week and had to do a bit of carving and filling to the cowl, (love the Weldbond, as it softens up the shavings into a very good filler). That cowl is pretty tight, to the point it will only slip on if I remove the needle seat and head[:-]!

Had the chance to fire it up this afternoon. Only needed a slight LS needle adjustment. Not surprised since it came from Georgia and it was snowing lightly here[&o]. Initially tried a 10/8 3-blade prop and it spun it up decently, but thrust was not as expected. Dropped the original cut-down 11/7 2-blade and it pulls like a bear, at least another 30%. Did not get the chance to tach it, but has to be at least up in the 12,000 range. Looking for an 11/8 to cut down and try. Time to get out the fish scale and measure thrust.

Did some serious running around in the grass and had some fuel left when I shut it down at 10+ minutes, so surprised the economy not that much worse than the EVO 46.

Will try and take pics the next time I have it out.

Goldenduff, I've used both the pulse and shaker type Perry pumps. I find both very reliable, with the pulse type easier to tune. In fact, my new 72" Seawind has a worse CofG issue than the Northstar, due to the larger 12+ oz tank. Plan on oving it to the CofG and running the Perry Pulse on an OS FS90 4-stroke when I finally get it onto the build table, (yes, it can be done by adding a T close to the case vent fitting).

aa1a

My Feedback: (4)

I did the maiden flight of the new Northstar Saturday. It flew Great! It needed a good bit of up trim. This is a good thing because it means I can take some weight out of the nose. I kept the covering scheme simple so I wouldn't need to fix it after every time I flew it like the last one. It has a 46AX with a Macs pipe and a 10-7 three blade prop. I did a lot of the mods that I saw here in this forum. I put the elevator and throttle servos in a tray that slides in the back of the engine pod. I added the triangle fillets at the base of the pod. I enlarged the elevator. I moved the servos up front ahead of the bulkhead and added a second aileron servo. It came in a bit heavy, about 7.4 pounds. I hope to pull a bunch of lead out of the nose and get that weight down. The added elevator area helped a lot with the low speed handling. The elevator and throttle are very smooth and much less trouble than the long curved linkages on the last Northstar. This is the first time I ever used Ultracote. I was very impressed and I'll never go back to Monokote again. It's a great airplane and, sooner or later, I'll probably build another.
Jim

idigrc2

After starting this project two years ago, I finally got around to finishing it last night ans looking forward to the first flight.

Cougar429

My Feedback: (3)

Great news. What motor in yours?

Nice you have weather to allow for it. We're under a foot and a half of snow and blistering winds here. Thinking of popping off the gear and trying it straight from snow, but have to wait for the weather to warm up a bit.

aa1a

My Feedback: (4)

Good looking Northstar!
I pulled a bunch of lead out of the nose of the purple Northstar. I moved the CG back 1 inch to 15" ahead of the trailing edge. We have a float fly tomorrow. Looking foreword to getting some more flights on it.
Jim

Cougar429

My Feedback: (3)

That sounds quite far back, considering the normal was near the step. Interested to hear how it flies.

Yak Dude

aa1a, Your balance sounds about the same as my NS with the fuel tank empty. Please let us know how it flies at the float fly this weekend. I would like to know where this float fly is as I live in So. CA.
I have been deployed again for a while and during my free time I've been working on a shrunken NS. 50%. So it will be 22 in WS and about 28 in long. Will put up a few pictures soon. Wes.

Cougar429

My Feedback: (3)

Yak Dude, that sounds close to the dims on my Polaris, (electric version of the Northstar). What do you plan for power?

Yak Dude

I'm using a Thunder Tiger .07. Swings a 6 x 4. I've installed a 2 oz tank and the 2 servos in the tail. The radio and all the push rods are the same as the big Coast Guard. I'm adding the wing lets and will cover when I get home in March. All stuff installed the weight is at 15 oz. So add the covering and a couple more oz in the nose to balance should be it. I'm surprised how light it came out. I've been trying to get a pic to upload but the internet is to slow and it won't load. Wes.

Yak Dude

Here is a pic of the 50%. Almost ready to cover.

Yak Dude

Side view.

idigrc2

Y.S 45 with stock muffler.

aa1a

My Feedback: (4)

The Purple Northstar flew great yesterday. No problems, no bad habits. The CG seems just right. At 15" ahead of the trailing edge, it's still 1" ahead of the step. The elevator trim is back to neutral. The elevator is very smooth and effective compared to the old Northstar that had the servo up front. The added surface area helps too. I believe both mods are well worth the weight penalty you pay (my opinion). On a related note, a friend lost his Northstar yesterday. He was having trouble with pitch control and stuck it into the lake while trying to get it down. It hit hard! He had the elevator servo up front for what it's worth.
What is the "Northstar wobble" that is mentioned earlier in this thread?
Jim

Cougar429

My Feedback: (3)

I misread your original CofG specs, so your spec of 1" ahead of the step sounds right.

As for the Northstar wobble, a couple of pointers. First is that a delta can generate lift at extreme Angles of Attack. However, it has a tendency to dump that lift in an oscillating fashion, causing first one wing to drop, then the other, Slow speeds and high alpha can really get this going.

Another factor on the Northstar that seems to create this was the blunt aft end of the tip floats. Due to this I angled mine forward at the top, giving a more severe cutoff angle at the bottom which should also help break suction on the water and relieve some of the aerodynamic drag this shape creates. The Polaris is this way. To make up for the reduced wet area I increased their width by 15%.

ronwc

My Feedback: (404)

Test flew my Northstar I got on trade yesterday. Someone around Sarasota built it and did a beautifly job - has OS 46 with pipe. I started by balancing about 16" from trailing edge. Engine was running very strong on 11x6 APC. Had quite a bit of throw on controls. Takeoff was long and i had to really pull it off with elevator. It didn't need much trim but elevator was not effective at all to the point of being risky. Landed fast but fine. Moved battery back about 4" and increaded elevator throw, flew a little better but brought home and am going to go with the 15" CG. Beautiful plane in the air, roll rate perfect. Sits very low in water but taxi's very well even in wind - here are a few pics -

Lil Hoss

My Feedback: (58)

Well I been reading the post on the Northstar for about 4 months. I finally bought a kit and built it. My first build and covering. ( I always buy ARF's)
I must say it was a easy build after refering to comments and pictures on this site.
I maidened it off the snow last Wendsday here in southern Wisconsin. What a flyier. VERY NICE, FAST and responsive. Coulpe clicks of left ailiron 2 clicks of down elevator and it flies as stright as a arrow. Slows down to a crawl on landing.
It is powered by a new OS 46 AX that gives it plenty of power. I built it according to plans execpt I put the throttle and elevator servos in the fuel tank compartment. It weighs 7#.
The bottom is glassed and painted. 1 oz cloth.
This one is a keeper........ I can hardly wait for winter to clear so I can try it off the water.

I highly recommend this build

Hoss

Yak Dude

Lil Hoss, Lets see some pictures. Glad you built one and that the tips and pictures everyone has done has helped. Welcome to the world of kit building. Sounds like you went with the balance aft some from the plans. You did great by fiberglassing the bottom for flying off the snow. I have not done that yet. I'm in the wrong state. I love the plane so much that I did all the wing area, engine size and total weight of the 50% to see how that would work. I have a week left in the sand and then I'll be home to finish this little thing up. I'll post when it's all covered. Congrats again on your first plane and first flight.

Lil Hoss

My Feedback: (58)

Thanks YAK DUDE
Yes I am very happy with the whole model in general. Too bad you don't have snow......
Here are a couple pictures of my build. I must admit I made my color scheme close to another person posting on this site. I don't remember his name off hand but his Northstar looked GREAT. Hope he doesn't get upset????
All our snow melted in the last few days so I will have to wait for another snowstorm.

Take care
Hoss

Yak Dude

Very nice. I bet it shows up very well in the sky. I really like the Balsa USA and North Star on the wings. It's the little things that make a plane jump out.
I need to have a bright color job on the small one so it shows up good to. If I can ever get out of CA and back to what my wife and I call home, UT or MN, should have the snow I need. Wait till you fly it off water and low altitude. The plane can really slow down when done rite. Keep it about a foot off the water and start feeding in lots of up along with power, but don't let it climb. The plane can almost stop and softly plop onto the water. I'm still trying to get a good video of mine doing it. Hopefully this spring and summer. Wes