PacificNWSkyPilot

My Feedback: (19)

I acquired a New-but-not-in-Box Extreme Flight Yak 54 in the 74" version.

This is a VERY nice bird, I cannot recall ever having seen structure so strong and so light. I've gone with the CRRC Pro 26CC gasser engine on it.

I was so impressed with the obvious quality and thought that must have gone into the building of this ARF that I trusted the instructions and went ahead and set my prop washer to 6 1/2" away from the firewall. Epoxied the H^ll out of everything and the next morning decided to fit my cowl. The washer ended up over an inch in front of the cowl. Fortunately my buddy helping me spotted that the gasser sat on offsets of just under an inch, so those got pulled off and we were back in business.

I just thought it might be important to tell everyboy to make sure that you don't trust the instructions, do your own measuring no matter how impressive the ARF is.

The instructions also say to use a 3" double arm on the servo for the rudder, but when my friend and I looked at the alignment we found that the tubes installed for the pull-pull wires (yes, pre-installed....NICE!) didn't set right for pull cables from a 3" arm. I had a 2.5" arm from Airwild hobbies and the 2.5" holes in the rudder control horns fit the cables almost straight through the holes in the pre-set tubings. Which is cool because I didn't have to go and find a 3" double-arm for it.

This comes STOCK with Carbon Fiber (CF) Tubes for the wings and the stabs, CF reinforced wing spars, CF landing gear and tail gear, Two-sided fiber control horns that fit beautifully in the precut slots in the surfaces. So far I have not found a single piece of hardware that I would not use. I'm famous for throwing ALL of the ARF hardware away and buying all new. I came up short one of the pull-pull attaching threaded rods, everything else seems to be there. The pin-hinges were nice, they might have been Robart but I didn't check to be sure. This plane is really nice and would be worth what Extreme Flight gets for it without any of the extras. It's a STEAL with the CF tubes and control horns and all the rest.

One thing seemed a little weird, I thought the Yak 54 had wheel fairings behind the wheel but this comes with full wheel pants. I haven't checked to see if I got my Yaks mixed up in my head, it doesn't make that big a difference to me at this point.

Mine is Red and White, from what I can tell Extreme Flight is now selling the Black and Yellow versions so I don't know if I'm a version behind or just a color-change behind. That's what you get when you don't build them right away.

This plane is SO light, it's amazing. I've got the gasser mounted and I had some servos and batteries in it and it weighed out then at 10.5 pounds. Shouldn't be above 11.5 when done by my figures. My electric postal scale is 4-ounces off, but I don't remember if it's 4 oz heavier or lighter. Assume the worst. What I'm getting at here is that ( without going and checking) I believe the wing area on this is 1160 Squares. This Yak is perhaps the single best out-of-the-box candidate for electric power I have ever seen. And believe me, I know nothing about electric and it STILL got me thinking that way.

For the rudder and elevators I didn't mess around, I went with JR 8611A's, I had them here. I'm trying to use some of the items I have around here rather than buying lots of other stuff.

So, here's my first question for tossing about. I'm now out of 8611A's, so I was looking at some JR ST126MG servos I have for the ailerons. They turn 142 oz/in at 6volts, but from what I can tell they aren't ball-bearing servos, although I've seen them advertised as that. And they are analog, not digital. I'm pretty sure they are not ball bearing, so please tell me if you know for sure. I fly aerobatics, but I'm not a 3Der by any means, so I don't think I'll lose much in the translation. They would seem to be powerful enough to control flutter.

I've looked for any reports on the ST126MG servos but couldn't find anything much good or bad,. One guy was complaining because his car didn't steer right with them after he rammed it against something, not exactly a real testimony.

I'm thinking I'll be just fine with these, but hey, RCU is here just for this sort of thing, right?

Thanks for any help you can provide, fellas.

Jim

JoeAirPort

My Feedback: (41)

Go with metal gear servos at least 100 ounces. Don't have to be digital but that's the only thing I buy these days. The biggest problem people make on the larger birds is to go with too small of servos, or don't use metal gear...and not setup the servo linkage properly. You can get away with this on the 40-60 size planes but on the 25% and up you need to watch your p's and q's. My 1st 25% CAP 232 had 80 ounce Karbonite servos on it. It fluttered after just a few seconds of flight and crash landed with rudder only. That was an expensive mistake. One new wing later, some epoxy, 5 new hitec 5645's (thank you Hitec) and epoxy, I was in the air and it lived on for a few seasons and was even re-sold. Make sure to use the outer holes on the servo horns. Go as close as you can on the inner-most hole on the servo arms to get the required surface deflection. That's the best advice I can give you. You have a nice plane there.

PS: Just get more 8411's for ailerons, that's where the flutter happens.

exeter_acres

My Feedback: (2)

couple quick things...

the prop is supposed to be about an inch or so in front of the cowl...

this is normal for a Yak due to the large cowl.....


rudder cables, were you crossing or running straight? It should work just fine with the 3" arm..

There are two schemes for that size Yak... the Red/WHite....and the Black Yellow...

Not two versions, we just don't have any Red/white in stock... the red white came with pants, the black/yellow came with Spats.
If you would like black spats (we do not have white spats in this size) they can be order here:
http://www.extremeflightrc.com/store...products_id=39


Hope this helps a bit.... and enjoy

maineflyer

My Feedback: (44)

If they are crossed the 3" arm is perfect. You want to try to get 1-1 ratio on your arm to horn length. This gives you the best mechanical advantage for the servo. You will live the plane. I agree you should use metal geared servos for this size plane. It would be very easy to get flutter. I also recomend sealing your hinge gaps using either tape or clear ultracote. One big thing is check your horizontal stab incidence, the big thread on here discusses this and is very necessary and will make an "ok" flying plane into a great performer.
Good Luck
Jeff

Waynesworld

The 3" offset arms that i ordered from extreme flight when i ordered the plane worked great, i believe they were swb arms. No slack what so ever and wires are straight back not crossed

exeter_acres

My Feedback: (2)

We run our wires straight.....

styk

Hi Jim
My only concern would be the use of a 26cc CRRC Having owned the EF Yak for a year now I fly it with a Saito FG36 and it's a perfect combo IMHO i would have went with a 35 or even a 40cc 2stroke gasser I just think you will get bored after a while not having the power the Yak needs Seen one fly with a ZDZ 40 and it is awesome,so much power Remember you can always throttle back and the power is there for when you need it
Best Regards
Styk

exeter_acres

My Feedback: (2)

Sadly, I would tend to agree......

It will fly the airplane just fine...but you will not have stellar upline or 3D performance with the 26cc engine.....

BarracudaHockey

My Feedback: (11)

Exeter, you coming down to FX3D with Chris?

exeter_acres

My Feedback: (2)

Yep....we sure are!

BarracudaHockey

My Feedback: (11)

Excellent, see you there! I should be easy to find.

Oh......and if y'all think this plane is nice with a 26 or 28 you should fly it with a 46

JoeAirPort

My Feedback: (41)

Didn't I see a recent video of a guy from Europe using a 26cc with a pipe? Oh that's right, he made his own pipe tunnel. Man that thing had tons of power. Wish I had the video to show you. He said the pipe tunnel was easy to make and I agree, it wasn't that hard at all.

PacificNWSkyPilot

My Feedback: (19)

I actually didn't ask about the engine. I like the engine I have for it, that's the engine I wanted for it. I traded off a 50CC model for this one, so I'm not about to put a 50CC into it now just to make other people happy.

I stated up front that I don't DO 3-D, so a reduced capacity for 3-D is no issue at all. In fact, I find people who do 3-D to be much like people who fly helis, they stand right in the middle of the field and not off to one side,and all landings and takeoffs have to wait while they do their 3-D. I've never liked ANYBODY who thought that what they like should be liked by everybody, even if it inconveniences them. With that reason at hand, I wouldn't even need the other dozen reasons I don't like them both. Safe to say adding a bigger gasser is scratched right off the list.

In fact, I placed a 3-inch arm on there today and it did not line up well with the tubing. The 2.5" arm did, and using the inner holes is right at 2.5", and I think it will fly just fine. Again, I'm not a 3-D guy and won't ever be, it should be just fine for my purposes, and that 8611A servo will power it through anything it needs to be powered through. It's a non-issue. And for the record, I cannot think of a reason in the WORLD why a prop backplate should be over an inch away from the cowl. A quarter-inch is fine. But I'd be interested in hearing why it SHOULD be that far out. Some reason other than "the cowl is big".....that doesn't make any sense at all.

Sorry if I seem a little bugged about things, my friend recommended that I post my findings and my servo questions here, and I TOLD him that all I'd get is a bunch of power-crazy people telling me to strap a bigger gasser on the front of it, and that not ONE post would address my questions about the ST126MG JR servo.. Unfortunately I was right again, and that kinda ticked me off.... thought there was a little more going on in here technically than that. Pretty disappointing.

I'm very glad you like 3-D. I don't. I'm glad you like to set up ALL of your planes that way. Not everybody does. I'm glad hanging a plane on its prop is exciting to you. It looks kind of stupid to me, unless the next thing is a tailslide. Normally I wouldn't presume to be telling you how you should set up your own plane when you've already indicated how you have planned it out, especially when you didn't ask me about that. Funny how rare that seems to be in here. Normally I wouldn't tell you what you should go and do. But right now, I'm sorely tempted to.

Not everybody in the world is power-mad and has to run their birds balls-to-the-wall all the time. Some of us have some ideas that are a little more tame.

Oh, and in case you are asking why it is this area of the forums if I hate 3-D, ask the Mod who moved it here. I posted it in the giants area. Everybody thinks they know what I should be doing.

I was leaning toward buying a second one and setting it up with electric power after using this as a testbed with the 26. Now....not so much.

Have a great day. I'm off to find a JR servo forum. This is a first, though. The first time I've ever unsubscribed from my own thread.

Jim

styk

My God how touchy can a guy get Did it never occur to you just to thank the guys and tell them that you would prefer to stick with your 26 The guys on here are taking the time to try and give you some honest advice and you hit back with a reply like that .
I dont do 3D either and am not power hungry All i was saying is that i OWN one and have been flying it for the past year and have personal experiance of it and was only passing on my thoughts But hey keep asking the questions, you never know some other mug might try and give you advice
GOODBYE

Jake Ruddy

My Feedback: (40)

Gee Texas, if you knew it all why did you bother posting?

You posted in the Giant Scale 3D Forum This is not a Giant Scale plane. I moved it here because I thought most readers here are fimilar with this plane and you would get the most input.

First, you have a 26 that is weak on power to begin with. 2nd the plane's going to weigh 12-13 pounds, scale flying will be just with that 26. If you had purchased a quality 26 that had more power you would probably be more happy.

However since you know everything I will leave you to your thoughts.


ps. some of us 3Ders compete in IMAC as well and can fly a straight line better than most of the pilots in a club.

exeter_acres

My Feedback: (2)

the st126mg should be fine....
personally I prefer digitals as I fly IMAC and want the plane to be precise.... actually I find I use more throttle with IMAC style flying than 3d


as for the engine placement...

the reason IS...well...the cowl is big.. due to the inefficiencies of the air passing over and around the cowl, the prop sticks out a bit further.
Might want to check pics of full scale Yaks...
as you can see...there is a larger space than other planes....



enjoy

PacificNWSkyPilot

My Feedback: (19)

Gee Jake, what part of I DID NOT POST IT HERE, SOME MOD DECIDED TO MOVE MY POST HERE did YOU not understand? The engine came with the plane. And I like it. And I really don't give a flying jump if you don't.

I also "know it all" enough to know that a question that is not asked doesn't require answering. If you took your little Volvo wagon to the auto parts store and were checking out windshield wipers, how NUTS would you think a guy was if he walked up to you there and started telling you how you need to drop a 427 Cobra engine in that bad boy and throw some 50's on the back???? Of course, if MINE weighed 13 pounds like yours I'd probably want a bigger gasser in it too. My AUW is right at 11 to 11.5.......... are we even talking about the same model?

And I wouldn't KNOW if a 3-Der can fly in a straight line, I've never, EVER seen one who could leave his fingers off the sticks that long. I just figured that if they can't figure out how to move off to the side so the rest of us can fly, then they're just jealous that we know how to use a runway and are standing in the way just to be jerks. I just figured they're heli pilots who crashed all their helis and are just doing what they usually do and using whatever they have hanging around that flies.

Exeter Acres, thanks for the photo. It does stick out. Once I check my CG and see where things lie, I might put those standoffs back on it. At least it's an easy re-conversion. Thanks for the opinion on the ST126MG servo, that was the opinion I was out here asking for. I was trying to use what I have around for this, but I wouldn't do so at the risk of an unsafe application. I figured since they're in the wings I can always swap them out later easily enough. The 8611A's are running the rudder and elevators, but with the size of the ailerons I didn't want to put something in that might lock up outside of neutral. I'll think about those spats.

For the record, I don't really have anything against 3-D or helis, but I don't like pushy people. I don't run around telling everybody what I think THEY should do when they never asked me in the first place. Also for the record, I posted against my will because I knew that all I'd get back was people telling me to use a big gasser engine and nobody would even bother with my questions about the servos. I've found the power-mad propensities in RCU posters to be a bit disconcerting, they seem incapable of telling the difference between sport flyers and 3-D flyers and often they are rabid about it. I've been flying for 30 years and I could make this bird fly straight lines for half the day and aerobatics for the other half. I know by weight and design what engine a plane can fly well with, and this plane set up lean with 1160 square inches will fly famously on ANY 26CC gasser. And yes, it will hover, and even pull out of the hover. Anything more is wasted for a sport flyer. It adds more weight and makes the plane harder to handle, it takes the plane from tame to troublesome and from relaxing to stressful. I already have a Wild Hare 53CC Edge. That describes how it is. Why would I set another plane up to be just the same when I'm looking for something smaller and more relaxing?

Joe AirPort, I did see that video, and it did fly really well on that 26CC. I didn't save it either and tried to find it again, but haven't been able to yet. I've found some really great electric-powered vidoes from Ian in the UK, it flew so well that I was thinking about buying the black and yellow version and making it my first large electric power project. Still more research to do there.

Jim

Jake Ruddy

My Feedback: (40)

Jim,

If you read my post you would see that I am the mod who moved your post because it was originally posted in the wrong forum. YOU posted it in the Giant Scale 3D forum, so I moved to the regular 3D forum because this is not a giant scale plane.

PacificNWSkyPilot

My Feedback: (19)

Excuse me. I picked a forum and went with it. Seems RCU has no "Fairly Big but a LEETLE smaller than giant-scale Aerobatic planes" forum or even a Giant-Scale Aerobatics forum without a 3-D moniker attached to it that I could find within 10 or 15 minutes of looking. There is also no "Matching servos with the right job" forum either. I'm using servos that are heavy duty - as in meant for giant scale..... and I thought that if I had the choice of forums to post in...and I thought that I DID.....that Giant scale folks would likely have more focus on proper servo application .....which to me would be WAY preferable to rabid, purist 3-D guys.

I was right about that. I was wrong in thinking that I could post where I chose to.

And now.....The OTHER thing that I can choose. Unsubscribing.

You purists think you're all that. Well, you ain't. The rest of us have as much right to do what we enjoy doing as you do. Otherwise there wouldn't BE all those other types of planes and smaller but very nice engines for sale out there. But then, as selfish and self-serving as you guys are, that would never even OCCUR to you. Pushing unsolicited advice on others is just a logical extension of that to you, I would imagine.

"I'm a 3-Der! Everybody should want to be like ME! You need a bigger engine in that! MORE POWER! MORE POWER! ARRGH!"

Hmmm. Maybe that's the reason you're a Mod......

In truth, the definition of the word "Moderation" and the practice of 3-D directly conflict with each other.. Just an observation....

J

exeter_acres

My Feedback: (2)

[]....

MR G

I have a quick question about the 74" yak.

It appears that my Yak did not come with a cover piece to attach over the landing gear. Is this correct??

I am unable to find a picture of the bottom of a 74" yak that is completely built.

Am I missing a piece or what??

Thanks,

MR G

exeter_acres

My Feedback: (2)

Yes the airplane should come with them...they should be in the same box as the spats/pants...

Did you buy it direct from us? If yes, drop me an email with your info and I can get some out to you.
[email protected]

If bought used, then they can be ordered direct from here:
http://www.extremeflightrc.com/store...products_id=39

BarracudaHockey

My Feedback: (11)

If any of that was directed at me I wasn't telling you what you had was insufficent, this is a hobby, enjoy what you have, I was just chit chatting.

As for the gear, mine doesn't have anything there, though I could have easily lost it in a crappy landing I don't remember it ever having been there.

How long ago would a 74" plane looked like a monster at the field?

Happy flying everyone.

styk

DITTO
[][][][][][][]

Jake Ruddy

My Feedback: (40)

Jim,

I am a mod in more forums than the 3D ones and honestly it appears you have a huge chip on your shoulder towards 3D people. At our club 3D people are in the minority as are IMAC people so we typically are lucky to have 50% of the airtime.

I am sorry you have issues at your club, but I didn't even comment on the topic at hand so I really fail to see why your anger is directed at me. I merely stated why the thread was moved and commented on your OVERReaction which is very seriously what has happened here.


For future reference here are 2 non 3D forums


Giant Scale General http://www.rcuniverse.com/forum/forumid_467/tt.htm


ARF or RTF http://www.rcuniverse.com/forum/forumid_75/tt.htm


Since you are unsubscribing from your thread and none of the info has been useful to you I will lock the thread.