PlaneKrazee

My Feedback: (14)

figueroa,

Nice glass. Did you use the replacement cowl as a plug for the new section?

figueroa

My Feedback: (22)

Skypilot, Kevin.
I just stretched and taped Seran Wrap across the hole and applied 1 layer of cloth to the inside of the cowl. When it started to set I applied slight pressure to round off the shape then I applied one more layer of cloth. To my surprise it came out very close to the original shape. This was just an experiment that turned out good. I do have another cowl on the way.
Thanks for the compliment.
Jose

PlaneKrazee

My Feedback: (14)

Jose,

The job you did looks real nice. You could bulge it more to get it closer to the scale shape and the front of the engine would be completely inside the cowl. GP made this area tighter than scale, if they followed the proper scale contour it would be easier to fit an engine inverted and completely concealed. I think they used a poor 3 view that Bob Banka has. He has better ones and I have seen photos of the original that show the chin to be more pronounced.

Shok

My Feedback: (28)

Here is my Fuji 43EI finally mounted to the airframe.
It really isn't very big at all and the cowling only took minor cuts.

The carb sticks out a bit but I plan on removing the velocity stack and that should make everything look good.

The performance should be spectacular.

cadconversions

My Feedback: (21)

Good job on the cowl hacking. Very clean.

figueroa

My Feedback: (22)

Great job Shok,
Do you have a photo with the cowl mounted ?
jef

Shok

My Feedback: (28)

no, silly me took the cowl off to finish out before I grabbed the camera.
Will get some next week.

The clearance for the prop ring is very tight but it's just big enough.

Ray44

My Feedback: (4)

Shok, Like to add my Congrats also, really super looking job.
Looking forward to seeing the pic's with the cowl on also.

Also, I've been thinking about getting the Roto 35, but maybe ought to take a closer
look at the Fuji 43EI think the price is about the same.

Ray

Shok

My Feedback: (28)

I chose this engine because of the weight needed to balance with other engines.
Plus it's size is small compared to it's power.
This engine will work in a very wide range of planes in the future.

PlaneKrazee

My Feedback: (14)

A engine that will put out the power of a 1.20 four stroke will do all the scale aerobatics this plane is capable of and it can be balanced by moving the ignition and ignition battery under or near the cowl.

Light flys better. This palne will land hotter and stall easier with a higher wing loading. It fly's great at 13 pounds, would fly well at 14#. I would not enjoy it as much at 15 to 17 pounds. It will become a brick.

Eric.Henderson

The weather in NJ was great today. The runway was damp but no puddles.

Time to fly....Yesireee!!!

The OS 1.60 started easily but nedded the idle srew adjusted several times to get a smooth transition.

The plane came up on the mains at 1/4 trottle and was flying at half throttle.

As a starter it was pleasing to see that the elevator-trim was still at neutral. Bringing the thrust-line down to zero had really helped in tha area. I think that 1 degree down-thrust would be better (as posted earlier in this thread - not by me)

After the first flight I made the following adjustments.
A couple clicks of right rudder sub-trim.
About 1/4 " of down elevator for half flap and 3/8" for full flap. I was using the JR AUX-2 channel three position s/w for flaps.
10% of anti-roll out rudder to aileron for knife-edge in both directions.
25% expo on ailerons and elevator
15% expo on rudder.
Some right aileon trim on one aileron that was initiallya little low at the tip.
A bit of throtte curve to get a swifter pick-up from idle.

On the second and third flights the 1.60 with a Mejzlik 18 x 8 pulled the plane straight up and allowed big round loops with effective down line braking. Up lines were good and down lines had a minor pull to the canopy. The Knife-edge could be held at 1/2 throttle for the whole duration of a pass. The forward positioning of the canopy seemd to help a lot. I did notice that the full speed tail-waggle exhibited by my first SuperChipmunk was not present any more.

The plane was flown four more times and was a blast every time. The snaps were good, as were the spins. The upright spin could be made to go fast with power, then faster with down elevator. Slowly feeding in opposite aileron got a pretty exciting flat spin.

Landings on half-flap were easy. There was little or no wind so I expected a long glide but that is not how it panned out. The plane can be flown with 1/2 flap engaged. A steep turn into final and a relatively steep dive lets you smooth out to level with not a great gain in speed. Skimming the grass lets the wheels settle to a smooth roll out. The modified tailwheel tiller worked just fine.

All in all a great outing and with a rain or snow forcast, a bunch of good memories to tide me over till the next good weather day.

GSNut

My Feedback: (8)

Yes, Lots of great and useful information.... and excellent photo's !!

A great flight report.

Thanks Eric !!

Cheers

Doug in Denver

figueroa

My Feedback: (22)

Congratulations Eric,
Sounds like you had a great maiden flight. It must be a rare occasion to maiden a plane in NJ in the middle of the winter. Great job on the review, cant't wait to get mine in the air. As you can see from my previous posts I am having engine fitting problems. Your Chipmunk looks great !
Hope you get to fly it again real soon.
jef

d_wheel

Is there enough clearance for a 20" prop?

Later;

D.W.

Eric.Henderson

I doubt it.

My 18" props "snick" the grass blades when the tail comes up and the plane is tracking level. The tips are always stained green.

BTW - I tried my YS 1.20 AC and YS 1.40 as an option before I cut holes and did stuff. The 1.40 is lighter by about 4 oz than the 1.20. The 1.60 is not too powerfull for this plane. You can do full bore low passes with the 1.60. The first one used a 17 x 10. The second one climbed much better with the 18 x 8.

The pitts style Brison or Slimline look better than the standard muffler but you may have to add nose weight.

I would strongly advise that you all consider fixing the 2 degrees up-thrust that is on the supplied fire-wall.. If you use their mount it would take about a 1/8" insert on the top two bolts, You can see that the cowl lines up better with the drive washer when you do this.


In the two attached photos. The one without a prop is the 1st plane that still had the upthrust. If you look carfully you can see that the drive washer is further forward at the bottom. The one with the Tru-Turn hub is at zero degrees and lines up much better. I know it is hard to see but comparing them might give you the correct image.

I am definitely looking forward to some IMAA in the summer with this plane.

Regards,

Eric.

cadconversions

My Feedback: (21)

So it sounds like the 1% up thrust needs to be fixed period. Glad I haven't hard mounted my cowl yet.

figueroa

My Feedback: (22)

Kevin,
I ordered my ROTO 35 yesterday, I should have it by Wednesday or Thursday . While I was at it I set up a store account with RC Showcase. They are a great company to do business with. They just serviced my ZDZ 80 and I was very pleased with their service . With any luck I should have my Chipmunk flying by the end of the month.

Eric ,
Thanks for the heads up on the engine thrust I will make a point to change it when I install my engine.
Good luck with your Chipmunk guys.
jef

Ray44

My Feedback: (4)

jef, what are you going to use for an exhaust with the
Roto 35??

Ray

cadconversions

My Feedback: (21)

jef,

I just ordered some some carb ball links for the roto from rcshowcase. They just came out with them a few months ago. It's an easy way to hook up the throttle to the carb and choke. They're really cheap. If they haven't shipped your order yet, I would call them back and add them. Nothing wrong with the carb as is just the ball links make setup that much easier. I ordered a set for my MVVS as well. They are $4.50 each and include the ball link hook up for 2-56 rod as well.

Glad you liked the roto 35vi. I'll also try to get the thrust washer spacer that I used for you as well. Did you go with the supersonic inverted pitts muffler as well?

Eric.Henderson

I measured it as 2 degrees relative to the stab and the wings which were close to 0 degrees. If you stand back you can see it.

Please don't be too alarmed. The plane will still fly with the upthrust that it comes with! What happens is that when you go full bore the plane climbs. If you trim for level flight at speed, then it will dive on lower throttle settings. It also buggers up the knife edge. My current Chippy has zero elevator trim. The first one, with the same CG, carried about 3/8" down elevator trim.

I must thank a pevious post that brought it to my attention.

It really is worth the effort to sort out this problem in an otherwise great ARF. Once done you get to fly a plane that is easy to hold on line.

It is hard to express the sheer joy of a 20' high, canopy in, knife edge that holds for the length of the field.

Now all I need is a ribbon to cut :-) and a better definition, or spelling, of a Lomcevak.................

Eric.Henderson

I found it. - Here is an excerpt from the orignal note that I was talking about. He got 1.5 degrees upthrust so it may vary a little per plane. I found that the canopy floor was close to zero for my super accurate, but heavy, digital level. Which means that you could easily check yours with a spirit level or one of those small laser levels.


Eric.

GSNut

My Feedback: (8)

Hi, Eric....

Am Sorry you had the same problem but glad your findings were essentially the same as mine. Always nice to find out someone else concurs.

In my case with the tail heavy condition it was almost a fatal first flight that luckily only needed some minor repairs.........heeee, to close to the ground to cause much but the spider web cracks in the fuse due to the whip lash effect.

Am glad to say it's been flowen severl times since. But once bitten am twice shy and need to build some confidence in the aircraft to be totally happy.

I can't blame it all on the aircraft, but am responsible for some of it. Like a bran new Trans. that I hadn't properly programmed do to ignorance of some of the technical aspects involved. Since then and with A Big Thank You to Larry Stoughton (The local club Guru) That has been corrected.

Cheers All

Doug in Denver

Eric.Henderson

There you are Doug. (Joining the Patriot fans in their superbowl celebrations - not???)

The CG is critical and once set right the plane is a baby to fly.

As regards programming I went a bit nuts on mine. I the have ailerons on two channels and the flaps on two channels. I programmed the flaps on a three position switch channel with auto-down-trim at each setting. Then I slowed the flap deployment to about 1/4 normal speed.

I can put in 5 degrees of up aileron on both ailerons for slow speed landing without flaps. ("Often called airbrake") Will put in some aileron differential when I get more familiar with the roll axiality, or lack thereof. I mixed, on a switch, both flap servos for elevator linked to flap action for tighter loops, inside and out.

I can make all four of the into an aileron but it does not do much so I did not use it this time. (The flaps will go up a little even if they are made for down only)

I mentioned the above so that you can see that I have to think quite a bit before I touch anything in the program at the field

Got any snow out there??

Eric.

P.S. I wonder how that upthrust got past their testing etc.?

GSNut

My Feedback: (8)

The C/G is as you say Absolutly Critical ....on this one. Anybody reading this be Safe and check and recheck.

Naugh...no parties going on hereabouts.. They the (Bronco's) are like the Colorado weather...it changes every 15 mins. too ! The snow here is so dry it doen't melt it evaporates the next day or so. Wyo. folks say their snow wears out from the wind blowing it back and forth.. heheh

I have been studing the 9C manual and haunting the Faq site here on the Universe but it is still slow going for a pre computer ole timer. Am about to try my first pre mix on the Chipmunk..that being to add some elevator to the flap when applied..wish me luck..??
Think I will follow your lead there and use your set up percentage wise..

Can't hurt too much.. maybe. Slow your Flaps down...eugh ?? I Think I can do that.

Will let you know bout the next test flight, weather permitting.

Cheers

Doug in Denver

figueroa

My Feedback: (22)

Ray,
I am going to use the wrap around pitts style muffler which RC Showcase sells. I think it's made by Supersonic.
jef