Bob Pastorello

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***IF*** it's fifteen, it will be a GUARANTEED SLUG with a 2.4
I only mentioned that because I have a reputation as somewhat of a cynic and am an "Eeyore-ish" sort of guy. Tend to believe only what I see, and less than half of what I hear, even less of what I read....

After all, I just built a GP Ultimate.....

ben beyer

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I personally want to see the GP Yak first, but I may have to get one of these. Power would be a ZDZ 40. Tad bit heavier than the Brison, but more power!

Does it have CA hinges or hinge points?

Bob Pastorello

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Hinge Points, included. Holes pre-drilled. Manual shows pics of these.

bubbagates

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Ben and anyone else

The manual is right here. It does have some minor editing issues and is kind of barren on certain info like what servos are required but you'll get the point pretty quickly

http://www.hiddenhangarrc.com/k12043.pdf

All of CG's manuals are now free but this one was not posted yet so they sent it to me. I like getting the manual early so I can find out what I need that I do not alreay have

Bob Pastorello

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Thanks for posting that, Bill.

I have all the equipment stripped out of the Giles [&o], and now ready for the GB Yak... I'm thinking the Hitec 5945's at 2 per aileron likely ***DOES*** qualify for overkill, but they are here already, and saves me buying.

BTW - Brison 2.4, with Bisson Inverted mount - 51.8 oz, include plug, prop washer, nuts. CH Ignition w/Synchro module - 4.6 oz.... so all up - less standoffs and mounting bolts - this configuration - 56.4 oz, then add in ign. batt and switch, so roughly 61 oz..... Based on this design being around a OS 1.20 4C, or YS 140 4C, we're gonna have to offset almost 26 oz nose weight....

Sounds like rear-mounted rudder servos (x2) for sure !!!

bubbagates

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I was thinking along those lines also. SO I do not end up like I did with the Ultimate. I'm gonna assmble everything I can and weigh it. Then weigh everything I could not install and decide on what engine taking into account the need for 2 rudder servos.

Based on previous CG experience I'm thinking we gonna see 14 - 15lbs again with this plane. My other curiosity is with the dual aileron servos. I'm all for overkill but that just seems a bit much. The CG Sukhoi is a 72 inch wing span and almost full span ailerons, albeit probably smaller than th4e YAK. I tried my best to blow up certain pics of the manual to see what servos they were using and it looks like Futaba 3003's for everything but the rudder.

What I need to find out is where the servos are acutally installed into to wings. The outboard one looks fairly centered in the manual but if you did not notice, these ailerons appear to be counter balanced out at the tips. If the outboard servo is in the center of the wing I might just go with one 5945 in each wing instead of two. You'll get a weight savings of 4 ounces in just servo weight alone but will gain 2 ounces back with the twin rudder servos.

Just thinking out loud

BR289

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Bubbagates,
Thanks for the manual info. Its about time they stop charging for looking at the manuals! I was thinking of trying one of the new Evolution 26 gas engines in this plane ( Sport Flying )instead of the OS 1.20. I am getting the feeling its not enough........

Bob Pastorello

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Yah - that manual actually SHOWS an OS 1.20 being installed. I'd probably pay good money to get a first hand report of how THAT worked. I'm thinking "slug".... but maybe I'm biased against puny OS 1.20's....

Bill - you're right on the money - weighing the parts, then deciding. I was also thinking about the single aileron servo....but.... those are honkin' BIG ailerons if the pic in the manual has good perspective. Then again, a 5945 is a hoss of a servo on 6 volts...

Saving 6 oz plus (two 2 oz servos and the links/clevises/hdwe) in the wings by going single aileron would probably be worthwhile.

STG

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Ya, you can bet that it is not overpowered. It would be vertically challenged.

Bob, I like your new avatar picture.

bubbagates

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It might even be takeoff challenged. Especially if you are like me and love insane powered aircraft. which translates to firewall the throttle and power out vertically in 10 - 20 feet [X(]

He did what I was gonna do to my avatar so I did the Ultimate, I'm telling my mommy Bob WAAAH WAAAH WAAAH (Just kidding)

As far as the ailerons go. I'll decide when I see it sometime next week. You can bet I'll be using titanium links and the lighter aluminum arms instead of the honkin' Dubro plastic ones

ben beyer

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I'd probably just use two good carbonite servo's like a Hitec 5475 on each aileron.

JasonInAugusta

I also picked up the CG Yak the moment it came in the door at the LHS. (I work there )

Here's a shot I took after mocking it up...


I've since installed the landing gear and control surfaces.

The only problem I've ran into so far is that the slots in the fuse don't allow the landing gear bolt holes to line up. I needed to remove about 1/8" of material on the rear of the slots in both the fuse and the interior ply to get all three bolts in each leg to seat correctly.

I weighed the assembled airframe at 8lbs, 9oz.

Bob Pastorello

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Well, Jason - THAT looks pretty cool..... would you measure the diameter of the cowl, please?
Is the outboard aileron servo hole about in the middle of the span?

The weight you gave means a 14.5 lb bird with my Brison.... or more....

How's the covering??

We are ALL jealous......

bubbagates

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OH OH OH...nice looking. The stock pics do not do it any justice.

I'm also curious about the questions Bob asked

bubbagates

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Everyone. I have been digging around and looking at the other YAK's in this size range and all are using a single aileron servo. So unless the outboard mount is not on center (or reasonably close) and the ailerons are not flimsy, I do not see a reason for dual servos if a single is used of sufficent power.

So lets take a look at this using a single aileron servo and my Fuji 43 at 4lbs 2ounces (66 ounces) with everything including the battery

We have an airframe at 8lbs 9 ounce (137 ounces) minus the wheelpants if you go buy the picture

Figure 6 servos (one per aileron, one each for the elevators and 2 for the rudder) at 1.9 ounces each (hitech 5945's) we have 12 ounces rounded out
Now figure 6 ounce for extensions, 8 more ounces for control linkages using the stock stuff,

A 3 ounce 20X8 Bambula prop and a 8 ounce spinner and 6 more ounces for switches

Total = 246 ounces or 15.3 pounds

The Brison will be lighter, probably close to 14.5 pounds

I think both the Brison 2.4 and the Fuji 43 will be good choices but the Fuji will be somewhat lacking for 3D, for insane power then any 50CC.

ben beyer

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I think one 5945 on rudder would be enough for this plane. The only reason I would do 2 is if I needed tail weight. Does it seem to balance with a pull-pull and something like a Brison 2.4 or ZDZ 40, or would you need to mount the servos in the tail?

bubbagates

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Ben,

At this point we are just assuming things but we could be close considering the recommended engine is something like 1.5 to 2 lbs lighter. I would love to be able to use a single tail servo to save the weight along with a single servo per aileron.

I was just throwing some numbers out to get an idea of some possibilities

ben beyer

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That's cool, I don't know if anyone has one of these in the air yet or not.

Bob Pastorello

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At least on RCU, it looks like a race between me, bubbagates, and JasonInAugusta..... mine is due here Weds. But I have this "job" thing that keeps me from my toys. Wonder who will be the first flight report????

Balsa Steel

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You forgot to include a throttle servo when you added that up.

e28m5

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Thought I might be the first with this plane, but nooooooo.... Went to the LHS today to order a different plane, owner mentions that he just got something big in, hadn't unpacked it yet. So we crack open the box, out pops the Yak, and so does my checkbook almost simultaneously! I have an OS 1.60 for it, I know it won't be ballistic, but that's what I have for now.

bubbagates

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Yep, I have the work thing also plus my flying season has all but disappeared for now. We just got a fresh layer of snow, about 6 inches of it and more coming mid week or so they say.

I have everything I need but I have the feeling my Fuji is goning to end up not being enough so another 3.2 Brison might be going into it and yep, I forgot the servo for the throttle so another 1.5 ounces.

76.ta

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I have a new saito 180 and with the muffler it is 34 oz.
This would save alot of weight over the 60oz or so gas engines.
This is the largest glow 4 stroke they suggest.
What weight plane will a saito 180 pull vertical?
Thanks,
Roy

Bob Pastorello

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Bill - If we *need* to bolt a 50 cc on this one, I will puke. The wing loading at that weight will be ugly. My calcs came up to 14.1 with the Brison. Iffy.

Maybe the problem is that I ** refuse ** to put a large glow engine on ANYTHING anymore, thereby creating my own problem. Gassers are heavy; end of story. We need airplanes to lift 'em, but WE want them to be light as a feather.

Where's those helium bladders, anyway....

bubbagates

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I agree. I'd rather not have to go to another 50cc since I have a perfect good 43cc sitting right here.

I wonder if I chop off a few cooling fins would I be able to get it down to the Brisons 2.4 weight

Did you look up at the ceiling???