biplane bill

My Feedback: (5)

Flight report

SuperTiger 3250 1.98 cu
Inverted Slimline Pitts
18-10 prop
wildcat 10 percent

2 clicks down 2 clicks right ail 2 clicks right rud

3 flights and I love it. First big plane and I'm not going back to small stuff. Motor has ample power and for $179.00 you cant hardly beat it. I did the math and It would take 117 flights to break even on the cost of a gas engine ( thats old math and based on the cost of a DA-50, so maybe 80 flights on a Fuji) Anyway, Recommended throws were right on, the only thing I might change would be more low rate rudder, but only for better ground handling. Neutral ail knife edge, pulled ever so slightly to the belly, only made roll to the right, didn't try knife edge on left roll. Snaps were clean and predictable. Landings were a bit fast and elevator sensitive. Will add a bit of tail weight and a bit more expo for next flights. (even though knife edge would indicate less tail weight, I can fine tune that latter with ail diff) Vertical unlimited at 3/4 throttle

No complaints at all

Bill

Blueyonder

My Feedback: (3)

Bill, thanks for the report. I've always loved the Sporster. Any photos??

Would the OS 160fx be enough engine for this bird? I assume it would be....
I happen to have one needing a home.

Joe

biplane bill

My Feedback: (5)

os 160 would be enough. Ive always liked my stuff a little overpowered though. Think Ill hook up smoke on it. makes hugh loops!!. No pictures yet. Going on vacation tommorrow, try to hit you with some next week.

Bill

gary41

My Feedback: (5)

I received my Giant SS a few days ago, and the quality and fit of the contents is outstanding! It looks like GP has done a really thorough job of selecting and working with the Chinese factory. Let's hope the quality doesnot degrade. The only complaint I have is the Monokote..the workmanship in its application was very good, however those darn wrinkles just keep comming back within 16 to 20 hours after I follow the instructions in the manual on removing them. Has anyone got a good solution to this problem?
(Other than removing the Monokote and replacing it with Ultracote) The covering looked nearly wrinke free when I opened the box. The plane has not even been out of my workshop, yet. Temperture in shop is about 75 F.

Power for the SS will be my Fuji 32, so I am sue I'll be adding tail weight!

mnrcaerobat

My Feedback: (197)

I have had better luck removing wrinkles on my arf's with an iron. They seem to come back for me when using a heat gun? Which are you doing?

gary41

My Feedback: (5)

Used a heat gun the first time, 2nd time I used my Hangar 9 Iron set at 350...the last time, I set the iron at 380...seems to have worked-so far!

Thanks for the reply

frabru

I just received my Giant Supersporster and it look good. I was considering either a BCMA or Brillelli 40, however, from what I've been told by both of the above engine suppliers, I will have to cut the cowl for clearence for the muffler. It appears it will be a pretty big hole and I really don't want to do it. Is there any other engine that will fot withour cutting a big hole in the cowl. Although I want to try gas, the Magnum 1.80 4 stroke looks interesting.

any feedback will be appriciated.

biplane bill

My Feedback: (5)

Crash Report

8th flight started uneventful. Motor started 1st flip, a little warm up and off we go. Couple low passes, Cuban 8, inverted pass, immalman (sp) and POW horizonal stab self destucts on the down line. Wasn't even pulling elevator and off power. (I know you don't believe, but had witness) Both sides failed in the same place. Was able to make somewhat level knife edge but no directional control, so into the woods it went. Found it 20 feet in a tree. Made comment to helper that prop wasn't even broke. I climbed the tree, knocked the plane down, and broke the prop. Just added insult to injury. Oh well Hobby services says they are going to replace. Still love the plane, flys out of this world.

jrf

My Feedback: (551)

That is the result of elevator flutter. Super Sportsters are particularly prone to it. On the next one, make sure your control systems have the proper mechanical advantage and are slop free. Seal the hinge gaps and set your ATV at 100% or more at the recommended travels.

The first prototype Super Sportster 90/120 lost it's tail twice from the same problem. (That was in the days of plastic pushrods.) They initially recommended that you use lead weights to balance the elevators, but the final solution was to move the hinge line back 1/2" to make the elevators smaller and use solid steel pushrods.

Jim

biplane bill

My Feedback: (5)

Yes, I'd buy off on that explanation. This is my first "BIG" plane. The only place I didn't go along with the instructions to a T was that I put higher torque rated servos on everything. Everything was aligned properly, all controls were 90 degrees, used the included push rods. Control horns were right on the hinge line. All travels were set per the book and was flying on low rates. I didn't seal hinge gaps. Not sure what you mean by !QUOT!ATV!QUOT! There was no slop in the setup.


Thanks for advise
Bill

jrf

My Feedback: (551)

ATV = EPA Transmitter adjustment of servo travel. Setting up the linkages for higher travel and then turning it down by using ATV/EPA instead of reducing the travel mechanically (by moving the pushrod in on the servo arm) reduces servo torque available to the control surface, reduces servo resolution at the control surface, and increases free-play around center. ATV/EPA should be set at 100% or higher wherever possible.

Dual rates have the same effect, so the worst case is having ATV/EPA set at something like 50% and then using a 50% low rate. Your 100 oz. servo would be delivering less force to the control surface than a 25 oz. mini servo that was set up for proper mechanical advantage. Not to mention, much worse resolution and four or five times the centering slop.

Jim

biplane bill

My Feedback: (5)

Just so I understand what you are saying: You want max movement from servo from given input accomplished by moving linkange IN on the servo arm and using the farthest hole out on the control horn. This radio runs up to 140%. So if I read what you are saying corectly: 1. mechanical adjust to achive close to 140% or stick with 100% ? on high rates with proper throw, and then 2. Dial down on the radio to achive low rates?


Thanks for the advise

Bill

jrf

My Feedback: (551)

Essentially, yes. But because the servo moves in a rotary pattern, 140% doesn't give a lot more linear movement to the pushrod than 100% and you wind up with reverse exponential travel toward the higher %. You can balance that out by offsetting it with the expo feature of the transmitter, but for most purposes, 100% is a good number. Once you have set the high rate mechanically, you will need to set the low rate on the transmitter (I don't know of any other way to do it), but if you find that you never use the high rates, it will be beneficial to go back and reset the travel mechanically to the low rates (or whatever rate you like best).

Servo torque is given in inch/ounces. If your pushrod is 1" out on the servo arm, the servo should deliver it's rated torque to the pushrod. If you move the pushrod in to 1/2" on the servo arm, the servo should deliver twice its rated torque to the pushrod. The closer you can get that pushrod to the center of the servo arm, and still get the control surface travel you need, the more power the servo will deliver to the pushrod.

And yes, always use the farthest out hole of the control horn. Leverage.

Jim

biplane bill

My Feedback: (5)

Jim,

Thanks for the input, I will definatly put that in practice when the new one comes in. Im also checking all the other planes in the hanger. Never put much thought in in. I checked and was not far off the curve, but some yes.

Bill

ckangaroo70

My Feedback: (51)

Bill

Elevator flutter is a known problem for the sportster, and having owned the Super Sportster 90/120, and also currently building another SS 90/120 I use the Manuals suggested method of static balancing the elevator which would also work for the Giant Scale SS. Here is the link to the Manual, and you will find the static balance method on page 44.
http://www.greatplanes.com/manuals/s...120-manual.pdf

biplane bill

My Feedback: (5)

The Giant ARF manual has a section that talks about flutter. Everything was followed in that section. I like the idea in the 120 manual and it would have been a great mention in the ARF manual. I will also build in this balance act into the new one.
Thanks for looking that up.

Bill

hamman

My Feedback: (61)

Bill,
No fun losing a new plane, but at least they are sending you a new one, makes one wonder if its no surprise to them what happened!

What servos were you using on the elevators? mine arrived this week, it was a scratch and dent item, only had box damage.

I had planned on using Hitec 475s on the elevators but I think I will use 645s after hearing of your problem.

On sealing the control surface gaps I use clear Monocoat, just crease it real good and iron it in on the bottom side of hinge line gap.

I think the next one you build will be ok, I have to finish my Ultimate 160 before starting on mine. Best of luck, Larry

gary41

My Feedback: (5)

Sorry about the mishap, but many thanks for sharing it with us. My Giant SS is ready for it's maiden flight, however I have not sealed the hinge gap! I WILL, now! In an effort to strengthen the TE of the horizontal Stab, one method which is easy to do, is to use a carbon fiber rod on each stab side, entering the fuse just above the tail gear mount, as was done in the Hangar 9 Funtana .90 ARF. Holes were simply drilled in the stab and fuse and the two rods glued in place with epoxy. This was done instead of conventional flying wires and has so far proven to work well on my Funtana. I see no reason NOT to do it the my SS.

Gary

smokingwreckage

Control linkages can never have zero slop. A friction fit will risk over-powering the servo, especially when the pin or wire going through the servo arm or control horn is not perpendicular to the surface it goes through. Shorter pushrods "rock" more in the holes than longer pushrods. Even changing temperatures can affect the amount of play in a linkage. Since some play is inevitable, the further from the servo arm screw or hinge the pushrod link is hooked up, the less free movement of the control surface is available for flutter.

To minimize or prevent flutter, set the link as far out on the control horn as possible, then set the throw by attachment position on the servo arm. If the link at the servo arm is not in one of the two outermost holes, change to a longer control horn and start over with adjustments.

I never use anything but 100% EPA. Higher EPA provides very little increase in travel, and lower EPA wastes servo power. If EPA is necessary, you could have used a smaller, cheaper, and lighter servo, and saved money while having a lighter, better flying airplane.

This applies only too control surfaces. I always use the innermost servo arm hole and outermost nose gear arm hole to reduce turn radius as much as possible, and usually still have too much. I use the outermost hole on throttle arm, and whatever servo arm hole provides full servo travel with the best resolution--I want full throttle to be just barely full, and idle to be idle with just enough extra travel for the engine kill feature to work properly.

smokingwreckage

By the way, I'm thinking of a GP Giant Super Sportster with the Brillelli 26 for my next plane. However, I really HATE adding dead weight to balance. Can anyone shed some light on how close the plane will be to balancing with a 42 ounce engine?

gary41

My Feedback: (5)

Mine is powered by the heavy Fuju 32, which weighs 59 oz with muffler...I had to add 6.5 oz to the tail. You may not have to add any weight. If you are a little tail heavy, you can mount you receiver battery and / or fuel tank in the forward position (which was designed to be used with the glo engines.) Hope this helps.

biplane bill

My Feedback: (5)

Giant Super Sportster V2.0 has arrived. Thank you GP and Hobby Services for making it right. Hopefully we will have better luck this time.


Bill

NM2K

My Feedback: (14)

I had one of these backordered when Tower first made the announcement, but then cancelled it after spotting the landing gear position in the wings. I wanted to see how others made out with theirs before buying mine.

The BCMAE and Brillelli 40 & 46cc gas engines would be a prime choice for that model at $325 plus shipping, or thereabouts. Even a 26cc SPE conversion would probably fly it well at under $300 delivered.

I am glad to hear that you are enjoying your ST 3250. You can't beat that low price, that's for sure. I'm not much for cleaning up that much expelled glow fuel at this point in my life, but for those that don't mind...

More tail weight will make the elevator more sensitive, but I'm sure you know that already.

Kostas1

Some pics plz!

gary41

My Feedback: (5)

Bill;

Yes, good luck with #2! Have two flights on mine, and the Fuji 32 seems to provide plenty of power. Regarding the potential weak horizontal stab, I did install two lengths of carbon fiber rod angling up to about 2 inches from the end of the stab from a point about 3/8 inch above the tailwheel. I also sealed the hinge line--- 'cause I could