4dogspete

I always found that a 7 x 7 prop made an OS 15FP seem to lug a bit. a 7 x 4 seemed to work a bit better (or maybe it was an 8 x 4) it's been a while.
No - I think the 8 x 4 was on an OS 25FP. The #4 pitch seems to let the R's go a bit higher and it'll seem to go vertical a bit better.
Pete

badger5964

My Feedback: (6)

Installed HS-82MG servos in each wing for me Shrike 40. I finally flew for the first time without flutter. Next week it should be ready for 15% ntiro and pipe tuning.

SpeedBoy

Nice to know that flutter is no more on your shrike [sm=cool.gif]

Did you tune the pipe ???

badger5964

My Feedback: (6)

I have not been able to tune the pipe. The globee tachometer I have was never a good performer and I have thrown it out. Ordered a TNC tach tonight, everyone thinks they are great.

I did use 15% nitro and pick up some speed. In a dive I did get some more flutter but was unable to repeat it. It stopped when plane leveled out. It sounds different so I guessing it is the elevator this time.

I won't make it back to the field for a couple weeks, by then I should have my tach. I'll post some tach numbers, etc.

It was windy today and this plane is a excellent wind plane. I'm getting comfortable with it. Does great rolls and incredible speed. However I desire a standard aerobatic plane. ALthough I am excited by the high speed, the Shrike will never be first choice to bring to feild. It will however remain part of my hanger, something a pull out every couple months for a different experience.

skyflyer47

My Feedback: (2)

Hey Guys has anyone built a giant shrike. I have been tinkering around in the basement with 200 % 40 size plans. Planning to use a 26 cc gas. Any Ideas would be welcome. Will post pics when the build starts.

skyflyer47

My Feedback: (2)

Whos the guy with the shrike plans? Do you have rib templates and how much you need for them? thanks skyflyer.

AlphaWhisky

Hi Skyflyer,

That will be an interesting exercise for sure. However, I hope you have considered the logistics of getting the thing to and from your flying site and storing it too. To date I have built only the small 35" version - a great performer too - but it`s one-piece construction certainly seemed to be more of an issue when transporting and storing than more regular designs with removable wings.

Good luck with your project for all that....

Alan W

skyflyer47

My Feedback: (2)

Thanks for encouragement travel should not be a problem. Allready have a double wing tube and removable wings the fuse is only about 60".

AlphaWhisky

Plug-in wings sound like a practical solution - will make for easier fuselage covering too...! How about posting some pictures of your progress in due course?

Cheers,

Alan w

skyflyer47

My Feedback: (2)

I will post pics when i start building, so far I'm in the drawing and planning mode.

dalkhaw

Gents - I am based in Phnom Penh, Cambodia. I am still a beginner rc flyer (3 flights with a 46 sized trainer and plane is still in one piece). I am almost done with a Sig Wonder kit and am just checking the CG. To my surprise, with a OS15LA and using a pack of Futaba 250mAh battery as per instructions, the nose tipped up. I have tried moving the battery pack & servos forward but without success. I am still about 90 gm (3.2 oz) short. I am using a normal Futaba s3003 servo for the ailerons and 2 micro servos (20 gm each) for the throttle and elevator. How did you get your cg balanced? Kindly assist me with any information that may be helpful.

My other option is to use a normal 1,000 mAh battery with a Enya 15 or 19 engine.

Thanks
Regards

4dogspete

Hmmmm - seems like if the nose tipped up, you need to move the battery forward (ie add weight to the front) to get the nose down - right?

dalkhaw

Thanks Prundel. I have already moved the batteries forward max.

4dogspete

Well, there's always the 'heavy hub'. Generally a brass hub that fits on the engine crankshaft instead of the regular prop nut and spinner. If you go this route, be certain that the hub has the correct threads for the prop nut.
Just another thought.
Good luck.
Pete

dalkhaw

Hello Pete
Thanks for the good idea. I do not have a brass spinner but have an aluminium piece which is too light. After spending the day looking at the different options including fitting an Enya 19 but had to eject the idea. I have installed the engine mount sized for the OS15 LA and the Enya 19 or 15 are much larger.

I have finally found out that my stabiliser weighs a lot at 100 gm, probably caused by the Sig Aerokote covering. I am now taking the route to remove the two vertical tail fins and fitting only one at the centre just like a conventional plane design. This will reduce weight to near achieving the cg, with the added advantage of the tail fins not coming off in the event of a bad landing. (heyI'm still a beginner).

4dogspete

I suppose the look of the SIGWonder will be a bit different with only a single centered vertical stab. But we all try to go with what works.
Ichecked with Tower Hobbies, and it seems they don't make a heavy hub for the 5mm thread on the crankshaft. I actually have an airplane with an older OS.15FP engine - probably uses the same thread, and found a thick heavy washer thing that I added to the front which is bolted on with the prop nut. Looks a little strange, but it works.
See pic below.
Not sure what it came from, and it doesn't look real smooth, but since Ineeded a little extra nose weight, it works.
Just another thought.
And since you may have a 1000mah battery, just wondering if using that battery in the most forward position will get you there?
Pete

dalkhaw

Pete, even replacing with the 1000 mAh battery does not help as I am still short of 30 gm which I could probably add some weight to the nose to compensate. The total weight of the plane with installed gearis close to900 gm and putting a larger battery will bring it closer to 1 kg.AsI am usingan OS15 LA, Iam tryingmy best to keep the plane as light as possible.Putting a larger washer in front as weight is a good idea I have not thought before. I guess italsobecomes some sort of flywheel thathelps add momentum to the engine.But inpractice, have youexperienced any loss in engine power/rev? Thanks for your ideas.
daniel

4dogspete

Daniel
An OS 15FP certainly isn't a barn burner, and neither is the LS15. The little airplane that Ihave the OS15FP on is a slow airplane that falls into the category of Fun-Fly - fat wing lots of ailerons etc. so it certianly doesn't need speed. That said, I haven't noticed anything in the way of lost power, but if you find that's a problem there's always 20% nitro fuel that'll get you a bit more ooomph!
Ihave had a SIGWonder previously with an OS 20 that moved out pretty swiftly. With a light airplane and 15 engine, I think you'll be happy with however the engine runs. It certainly can be a handful, but due to its fat wing, will fly slowly, so don't forget to throttle back if it gets to be too scary. It's small and will get really small really fast if you let it get too far away from you.

I guess my point is to get it balanced the best way you can and make adjustments after the fact. I certainly wouldn't worry too much about how the engine will handle a flywheel, just be certain that the washers fit tightly on the shaft so you don't have a balance problem.

If it seems a bit doggy with the 15 (which I'd be surprised if it does)think about making a complete change to an OS20 or 25 and it'll really smoke along. (notice Idin't mention Enya or anything else, as I've not found any engine as reliable and easy to tune as the OS's.

Good luck and send along pics when it's done.
Pete

4dogspete

OK Here it is - my first shot at a .10 size Shrike. Powered with an K&B 3.5 (.20ci). Using HS-81MG servos in the wings for the ailerons. You can seethe hatches I made for access to the aileron servoson the photo of the underside. 250 mAh battery all the way in the rear including another 3 oz weight back there. I apologize for pleasurizing the stripe scheme from one of you guys - - Idid like the chevrons or darts or whatever they are.
Final all-up dry weight is 2# 6 oz. - I tend to build heavy no matter how hard I try to build light. And it's all ready for this holiday weekend - except that my wife has plans to go away. So it'll have to wait a week or so.

Alessandro 78

I'm here again:

here the latest goodies to hack my shrike (thanks Randy )

the question is ... where start to tune the pipe?
any suggestion is welcome

Alessandro

Alessandro 78

forgot to mention: the apc prop is a 6.5 x 6.5

Alessandro

dalkhaw

Hi Pete
This is it: My finished Sig Wonder; Cambodia Version. I modified the vertical stabilizer to reduce weight (actually not much diff) and made it stronger by gluing reinforcements at the root. Hoping to fly this soon. Thanks for your help and encouragement.
Daniel

4dogspete

Incredible Daniel
Maybe if you can find a friend with a camera - I'd love a photo of it in flight!
I'll do the same when I et the Shrike flying - just don't have anyone that can handle a camera like I can tho.
Send me your email to [email protected] .
Glad you have it finished.
Now one more thing.
When you hand launch it - hopefully you'll have a friend launch it for you. give it a couple clicks of up elevator to start. Then it won't just stuff the nose into the ground. You'll need to take out the up elevator after you get it flying.
Let me know how it works for you.
Good Luck
Pete

dalkhaw

Pete
I will get some pics when its flying. Need to find a good photographer. Probably be a couple of weeks as I shall be traveling. Will remember the up elevator during launch, + trimming too. I wish you well in your Shriek. It looks like a magnificantly fast plane.
Rgds; Daniel

dalkhaw

Pete - should I start off with a 8x4 or 7x 6 prop?
Thanks
daniel