Roo Man

My Feedback: (1)

I have an F27B Stryker that will not fly. It was put in a tree on it's last flight with what seemed minor damage to the fuse but on of the servos stripped a gear. Repaired the minor damage with packing tape and replaced the gears in the servo.

Tried to fly last weekend, battery was fully charged, new batteries in the transmitter, all control surfaces worked properly. Launched at about 45 degrees. It would stay in the air for about 30 to 50 feet but would not climb. I think the motor thrust line may have been changed in the crash. What angle relative to the wing bottom should the propeller be?

Any other thoughts.

Thanks
I

Hagar69

The thrust line should be pointing directly from the motor through the tip of the nose. This is also parallell to the bottom of the wing.

FERNDALE AIR FORCE

Sir, you want to launch your plane like throwing a dart with a touch of up.  This is assuming you have an anemic brushed motor and a NiCad power supply.

Glacier Girl

My Feedback: (4)

Yep as stated, it sounds like it wallowed along in a stall condition till it dropped. 

And as Hagar said if you draw an imaginary line along the motor shaft to the front of the bird, it should end right at the tip of the nose.

On the B's especially the brushed versions, you should throw it like baseball, like you're trying to cut down a runner from center field.

Not a sharp angle, but just enough to get the ball there in the air, and not hitting the ground at the pitchers mound.

Something else from the old days, check the prop. The B's were famous for a couple of things, either stripping out the inside of the prop, letting the shaft slip, or the prop would walk forward on the shaft, and bind on the mount bolts.  Either of these will cause a loss of power and make launching so much harder.

God that seems so long ago running the B model and with a brushed motor and nicads.  They sure have come a long way since then.

Roo Man

My Feedback: (1)

Glacier Girl,

The batteries are 1000MA Nickle Metal Hydride.

The prop is OK can't hardly pull off and it is clear of the motor mount.

The motor is at the right angle when the motor is not running but the section that the motor mount is attached to is very flexable, I will try to reinforce so it will be stifffer, maybe that will work.

Thanks,

Gary

Glacier Girl

My Feedback: (4)

Gary, yep the mount area was always a weak point on the A and B versions. We'd lay thin sheets of plastic or lite plyon the bottom across this area, and/or run a cf rod across it. Or you could look at the C version motor mount, it covers a lot more area and is much stronger.

If that area is weak it lets the motor twist, driving the front down and the back of the motor up, which makes the bird nose up even more.

If you can pull the prop off it more then likely is slipping. Take a pice of sandpaper and rough up the shaft. Put a drop of CA (super glue) on the shaft or in the prop hole and reinstall the prop. Will pretty much lock it on.

Brad

p.s take a look at my gallery for some of my Strykers.

Roo Man

My Feedback: (1)

Glacier Girl,

Impressive Gallery. Are they all current in your hanger?

Will re-enforce the mount area and try again.

The prop is on so tight that I can't pull it off without using a scewdriver as a wedge, could it still be slipping?

Thanks alot,

Gary

-pkh-

My Feedback: (2)

I had an original F27 (before the B version). Flew like crap. It would barely stay in the air with the brushed motor and NiCd/NiMh pack that came with it. I promptly converted it over to the F27C power system. I just bought the F27C motor, prop, and prop adapter, and modified the existing motor mount to fit the slightly larger BL motor. She flies nicely now. I liked it so much, I bought a PNP F27C to have for a backup.

BTW, with the F27C power system, a full throttle, 30 degree up hand launch works quite well.

Roo Man

My Feedback: (1)

When new she flew beautifully, plenty of power.

I think the tree is the problem.

I am planning to re-enforce the motor mount section of the fuse with 1/8" thick plywood. It would be about 3" from the trailing edge foward and run almost full width between the vertical stabilizers and mounted on the bottom of the fuse. Should I flatten the raised area in the center [on the bottom] that the motor mount rides on?

Gary

Gryphon

-pkh-

My Feedback: (2)

Well, since that close-up photo was taken, I had a "hard landing" with it, and the whole engine mount section chunked out. I glued it all back in place with some polyurethane glue mixed with some water (makes it thick and foamy). It's probaby got a little more down pitch that before, because it doesn't pitch up much more at high speeds than my PNP F27C. They both fly about the same. I was going to get the F27C motor mount when I did the original conversion, but it was out of stock. At this point I'm keeping it as is until I break something!

Hagar69

Roo Man,
Is it possible that your battery pack is getting weak? Have you been using the 1000 mAh pack all along? I believe the pack you have is heavier than stock..
Can you report the pack voltage after charge and after a short flight. Watt-meter readings would be even better.

Roo Man

My Feedback: (1)

The batteries have been used very little, too many crashes. I am almost positive the problem is with the motor angle.

Gary

Gryphon

-pkh-,

With the basic tape job that section of the motor mount wouldn’t have ripped off. (I learned that the hard way a few years ago after I ripped that section off more than once)

Without that mod it will rip off again.

Another alternative to the basic tape job would be to run a single C.F. (tube or strip) across the bottom of the motor mount (from left to right).

That C.F. alone will not help with other types of mishap.

The basic tape job can help in many ways in many key areas. If you add that C.F. in addition to the basic tape job then you will have a fairly resilient Stryker and it should fly better too.

__________________________________________________ ________

Hi All,

******Part 8 of the Dark side Stryker thread series will start in about 10 days.

You'll see lots of great information in it. Several how to builds, lots of pics, motor tables, data logger graphs......I'm sure many of you will already know a lot of the information in it, but there willbe something in it for everyone.

From Stock Strykers to 140+ MPHStrykers (speeds in level flight, with no tail wind and no diving using stock profile fuse).

Some motors make 9 times the power of stock F-27C at high speed.


Hopefully you'll join the new thread early on.


Later,


Gryphon

-pkh-

My Feedback: (2)

Thanks for the tips! I did reinforce the area with tape after the repair. I have seen the other reinforcement mods in some of the Stryker threads as well. Right now I'm happy with the stock F27C brushless setup, and I've got enough Stryker flights in now that I can grease the landings pretty well.

My crashes were during my first few flights with the upgraded F27. It didn't have a very contrasting color scheme from top to bottom, and when flying in the early morning it was hard to tell the orientation when it go very far out. I've since put some black & white checkerboard on the bottom, and that helps quite a bit. The F27C PNP already has a good contrasting color scheme.

I've got about 25 flights on each of my strykers now, and no more crashes or "hard landings" since those initial flights. I still have the stock servos in the PNP F27C working well, although I do have a pair of HS-82MG servos waiting to get swapped in though!