victapilot

Sorry, yes that's mph. It's the theoretical speed of the air pumped by the prop. The plane will go that fast only if 100% efficient, which none is. The good news is that the engine rpm will increase in flight, so speed will increase (you knew that!). Here's a useful link. (And your pipe will make it sing!)

http://www.rcpro.org/rccalc/PitchSpeed.aspx

Wild-flyer

Well I guess I will join this club. I built my Shrike as soon as the kits were available, but then life got in the way of flying, so it hasn't flown yet, I couldn't get my hands on a rear exhaust K&B 3.5, so I ended up with a MVVS .21 with a tuned pipe that will kick in at about 18,000 rpm, so it should be fun. Been flying electric to keep my fingers working.

Quikturn

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Hey, what a cool link. I just saved it on my tool bar.

Now if I just has access to a radar gun to clock its speed I could calculate the rpm gain when it's unloaded.

victapilot

You can get a fair estimate of speed using Doppler. There are a couple of RC versions that you can use. Need flypast at top speed, as low as possible, 2sec inbound 2 sec outbound minimum. Record sound or video. See positngs by THEDONon rcgroups for more info.

skyflyer47

My Feedback: (2)

I just joined the shrike club don't currently have one but had one loved it crashed it need a new one. Mine will be electric. Also have the 40 size plans blown up 200% for an 86 inch wingspan 50 cc gas shrike. That one will take a while to come to life. I mentioned it a few months ago on this thread its still in the works. I e-mail mustang for some templates. skyfkyer

FX4L2CX

My Feedback: (10)

Now that would be cool...86 inch wingspan.

skyflyer47

My Feedback: (2)

Hey guy whos the one with the shrike 10 plans and templates I'm thinking i would rather build the smaller version for electric flight. skyflyer

FX4L2CX

My Feedback: (10)

I finished up the rest of my engine testing today...I got a solid 20,400 rpm with an APC 8.75x8 and 30% nitro...that's a full 1,100 more rpm than last tests....I hope the airframe holds up after she unloads in the air...

Kevin

helifryer

My Feedback: (1)

hey yall. due to breakage, and wear and tear, (from the previous owner of my shrike ; i only have 3 flight on it - all perfect) i have been forced to strip, repair, and recover my beloved shrike! im doing a build log on my blog (here - http://www.rcgroups.com/forums/showthread.php?t=1202057 )

i have some big time repairs to do....and then i have to decide on a covering scheme. bright visible colors! lol

wish me luck...

Quikturn

My Feedback: (12)

Hey helifryer,

Saw you post on rcgroups. It's amazing that it didn't come apart in flight. The problem I see with it is that the builder did not use the fiberglass tape from the root of the leading edge back about 4-5 inches. The leading edge does not carry through the fuselage like on most airplanes because the fuel tank is located there. 2 1/2 fiberglass tape will add the support you need to keep the wings rigid when you whipping that bad boy around. I blended mine in with spakling then sanded smooth and brushed Balsarite over it before covering. Now it's rock solid!

Another thing I noticed is the lattice work is missing from the tail support area aft of the wing. You can add it or just sheet over it for added tail support.

helifryer

My Feedback: (1)

ok. thanks for the tips man (your shrike looks awesome! )

i will go ahead and add that bracing in the tail. cant hurt anyhow....(might throw off my balance a bit though....)
i have some fiberglass cloth. ill  go ahead and use it on the root of the wing like you did. (thats a good idea! ) and i think i might also use some fiberglass cloth at the spot where the tail section connects to the main body.

i also just noticed that my shrike doesnt have the sheeting on the wing like urs does....i might add that too.

so tomorrow after school i might head to the hobbystore. looks like i need:
-balsa for repairs, adding bracing, and sheeting (not expensive right? balsa is pretty cheap)
-balsa filler for smoothing things out
-covering (duh) to cover the plane with. i need to decide on a covering scheme! aaaah!

thanks man!

Quikturn

My Feedback: (12)

Thanks for the compliment helifryer. Not sure why my pictures came out so large but if you click on "enlarge" it will right size the picture.

The uncovered airframe is built per the plans. I opted for the dual aileron servo setup and added rudder control which works great.

Yes, sheeting between ribs 1 and 2 will also add strength to your wing. Highly recommended. Someone mentioned sheeting the tail support area with 1/16 balsa instead of 3/16 square bracing. This does the same thing by stiffening up the tail and it's easier to cover. On the bottom there should be balsa triangle stock between the vertical tail and the tail support area for added support.

Some people have argued that the fiberglass tape on the wing root was not necessary and omitted it but after seeing what happened to your airplane I'm convinced more than ever it's there for good reason.

Balsa is not very expensive. I used drywall filler because it sands easy but it also dents easy so watch out. Balsarite helps you covering stick to areas like epoxy and filler.

Good Luck!

helifryer

My Feedback: (1)

ok! my shrike is all put back together, and ready to fly again! here are the pics:  http://www.rcgroups.com/forums/showp...8&postcount=15

its rock solid now, and looks way better.

today i went to a swap meet, and picked up a OPS tuned pipe, a tachometer, and a prop for the shrike (8x6)

i haven't mounted the pipe yet, because i couldn't find a header the right size though.

so i ran the eingine a bunch today (on the ground) and got it all tuned out again. and my new tachometer shows that at full throttle, leaned all the way to perfection, with an apc 8x5 running 15% cool power, im getting about 1557 rpms! is that good? its really screaming at full throttle! lol i was told to expect a big jump in RMPs when i add the pipe! anyone know about how many more i can expect to get?

im gonna have to look around to find a header now. my engine is a Magnum Pro .25.  so if any of you know of saomething that would work, or has one that you wanna sell me, please let me know. im just gonna have to shop around a bit, and take some measurements and do some reasearch i guess. (i bet an OS, or a thunder tiger header would fit...bolt pattern...idk?)

cant wait to fly it again! (the weather is getting nice too!

helifryer

Quikturn

My Feedback: (12)

helifryer,

Your Shrike looks good! Bet you can't wait to fly it again.

You may want to check macspro.com or tower for a header.

juanjulian

My Feedback: (9)

I´m building a Shrike 10 intended for electric.

Have a post in KIT BUILDING, should have done it in this forum, that recently discovered.

Will apreciate any recomendation now that I´m in the building process.

The only problem I know for the moement is to reinforce the front spar which I already did.

Cheers

Juan

helifryer

My Feedback: (1)

yep. i ordered a header from tower today. got a $10 discount too! (the $10 discount code that i had expired in feb. tho...but since i had some free time, i sat there and "adjusted" the coupon code (guessing randomly) untill i did eventually end up getting a $10 discount! haha! )

the code that worked was was 010A5 - its good for $10 off a purchase of $29.90 or more. (i had to buy two props, and some fuel line as well in order to meet the $30 since the header was only $25...but once i got the discount, the total with shipping was $26!) so i hope that coupon code will help someone else out.

im trying to decide if i want to put the pipe on the bottom or the top of the plane...its looking like on the bottom might be easier, but idk...dont want to be messing it up ereytime i land....  i might have to re-drill my firewall to adjust the motor mount. right now, i have the engine on a 45% angle to the right, so the exhaust is just barely going under the wing.  (and awww crap... ill probably have to move some stuff around to re-balance the planes CG...i hope that the pipe doesnt add too much weight...

i cant wait till it all gets here! i think ill fly the shrike once without the pipe, just to make sure that i did actually put everything back together right, then maybe once the weather cooperates, and my schedule frees up, ill fool around with the pipe and see if i cant make this thing go ballistic! haha

victapilot

Hi!

For Electric, you should conside using elevons, one servo in each wing. That leaves lots of room in the fuselage for batteries. There's a picture of mine in a post a few pages back

Good luck!

Quikturn

My Feedback: (12)

I want to put a pipe on mine too. I think above to wing is best. Like you said, you won't mess up the pipe on landing if you don't mount it on the belly. Of course, a rear exhaust engine would be awesome for this airplane.

Thunderpilot

OK guys. All this talk of breaking spars is making me real nervous!! I just spent a lot of time building a Shrike 10 with and OS 25fx. It is modified with landing gear (no nice grass in Colorado so gear is pretty much a must!); I also modified it to have rudders. It weighs exactly 3 lbs. empty. Whats the consensus?, Am I going to fold the wing on the first turn or what?

Also, the control throws seem pretty anemic. Any more precise recommendations out there?

Not like I am going flying tomorrow anyway as we are going to have 2 feet of snow on the ground on March 23!!!!!

Thanks!!!!!

helifryer

My Feedback: (1)

quick turn, thats like the exact same pipe i got for mine! thats a good sign i guess. is the speed/rpms worth the weight penalty? (its an OPS 3,5 speed pipe right?)

FX4L2CX

My Feedback: (10)

I would think your wing should be ok unless you are one of those guys who fly straight up and out of sight and then dive straight down at full throttle and then pulls up hard 10 feet before they plow into the dirt. I had 2 Shrike 10's both with .32sx and they were fine, but the wings were fully sheeted and maybe that was enough added strength to hold it together...or maybe I was easy on it too. I have a Shrike 10 and 40 now and they both have cf strips on the spars and tristock at the wing root as something more for the sheeting to bite onto when glueing.

Kevin

Quikturn

My Feedback: (12)

Thunderpilot, If you built your Shrike 10 per the plans, you should be OK. I'm not sure about the Shrike 10 but the Shrike 40 has 2 1/2 inch epoxied fiberglass tape to strengthen the forward wing root area. This is because the leading edge stock does not carry through the fuselage due to the fuel tank location. I feel this adds a lot of strength to the wing.

I modified mine with rudders too. It makes for cool snap rolls, hammer heads and spins.

I'm not sure what you did for landing gear but I would think spring type mains that mount to the bottom of the fuselage would be the easiest and lightest way instead of wire mains that mount in the wings. FYI, my Shrike 40 weighs about 3lbs.

Helifryer, That's an older style Macs tuned pipe setup for an OS 40/45 FSR engine. I don't know what the weight difference is but I expect about 600-1000 rpm increase so I think it'll be worth it. My main motivation for a tuned pipe is so I won't have to clean up the airplane all the time.

Now I'm trying to figure the best way to mount the pipe. I think I'll have to cut a hatch on the bottom of the wing in order to make a mount on top of the wing. I hate the thought of that. [:@]

helifryer

My Feedback: (1)

ok yall. my header and ect. engine stuff came in the mail today! (wow- really fast shipping! thanks tower!)

so heres the question: where on the header do i drill the hole to put the nipple for the fuel tank's vent/pressure line? does it matter?

also... looks as though i may have to re-drill the firewall after all in order to get the pipe up on top of the wing. thats gonna suck.

but before i start messing around with this pipe, im gonna try and get a few flights on my shrike just to make sure its all working (still havent flown it since i finished the re-build.

thanks yall! i cant wait to get my shrike over 100 mph!

Helifryer

FX4L2CX

My Feedback: (10)

As far as I can remember, most tuned pipes have the tank pressure nipple at the fattest part of the pipe itself...not the header. I asked the same question to my lhs owner and he explained it all to me, but I have forgotten all of the formulas and such that back up his teachings...I think it has to do with getting the highest pressure point in the exhaust stoke or something. All of my tuned pipes in my planes and boats are that way and they work great.

Kevin

Quikturn

My Feedback: (12)

That is correct. You want to drill a hole where the pipe first reaches the widest part. That's the best place. Not in the header, not in the middle of the widest part.

Here's a link to the Macs website on tuning.

http://macspro.com/tuning.asp