tIANci

Here is what the both planes look like side by side ... have to start working on mine. The EP conversion for the 74" is a real temptation, especially when I have access to Flight Power. Any comments on using an AXI 5330 running on 9S?

AsM

Wow that big one is tempting. EF must stop making great stuff otherwise i'll be broke forever
Dyu reckon a saito 125 would be enough?

tIANci

Andy - its AUW with an OS160FX is just under 11 lbs. Hence I would say with the SA125 will just about fly her only with hardly much performance for good 3D. The SA125 will turn a 16x6 or even 17x6 giving you about say 13 lbs thrust thereabouts. The OS160 is turning an 18x6 or even up to an 18x10.

Maybe at least a SA150 at the for good 3D fun. I wanna get a YS160 for this baby. Seen one on my pal's CG SU26 and the performance is really nice even with only 5% nitro.

AsM

Hmm. YS setups in the Uk are v. expensive with fuel costs so i'll probly go for the saito 180. Only 1oz heavier and hardly more expensive. Also ive been eyeing up that engine for a while now looking for an excuse to get one

Maudib

My Feedback: (51)

I would think the Saito 1.25 would be the minimum engine choice for the 74" model. You might need to really work at balance with it being a full lb lighter than a 1.60 (including mufflers)

Still, with some effort and light building... perhaps you could beat the low weight in the suggested range... and maybe come in at 10 lbs? Until people get some (hopefully end of August) it's mostly conjecture as to weigh and balance.


I suspect that the 1.20 would be like the 1.00 was on the 68" Enough to hover with a little pull out... and a few mods to balance (like placing the battery on a "tounge" that sticks out over the engine. It would be an extremely light build... Run 30% to get maximum power from it... and a person might emjoy it quite well...


Still, if you haven't purchased a motor yet... the O.S. 1.60FX or Saito 1.80 are going to provide the 3D power most will require...

tIANci

I love the YS as it performs so well, of course you pay a lot for the engine and then the fuel cost is nuts. I hope to get my YAK up in about 2-3 weeks time, will let you all know more by then.

Dart373

My Feedback: (2)

A 1.50, heck I have a 1.80 on my 68 and it just flys so well.... Yeah, its a tick heavy, but the 1.80 is an animal. As for the YS VS Saito... that Saito 1.50 or 1.80 drinks some fuel now! Neither are good on fuel... This is interesting to see the different power plant ideas... I am still waiting for the gas guys to jump in here with their ideas on a gasser... WOuld an MVVS 26 have 3D power?

Maudib

My Feedback: (51)

Well, I consider myself a gas guy... very much so.

But when it comes to power to weight... everyone values different criteria... for instance I would never consider a Saito 1.80 on the 68" just too heavy for my wingloading tastes... It certainly would be mondi power:weight ratio though... and I really dig that too, but not at the expense of wingloading.

Now since you love the 68 with a 1.80 on it... then you're the type of person that needs to put a DA50 on the 74"... again I would never think of it... but you'd get a similar feeling aircraft... heavy wingloading but stupid power.

If you are looking for similar power:weight as your 68 was with a 1.80... you will not enjoy ANY of the 35cc or less engines on this plane... as NONE of them will spin a prop the same as a Satio 1.80 will... some will run an 18x6-8 at about 6500-7000 rpm... but your Saito 1.80 is putting out more than that. And the 35cc or under will weigh more.

At this point in time there really isn't anything in the 35cc or under class that is good for great 3D/light wingloading and are more suited for scale applications like a CUB, warbird, etc... UNLESS it's specifically designed ultralight and featuring a canister/tuned pipe... Like the 3W ExtraFun with the 3W28 on a can.

In my opinion the 40cc is right at the turning point for power:wieght ratio and wingloading on a plane this size... but still a little heavy...

Exactly why this bird doesn't have a "gas" recommendation for a powerplant.

When you are at this point... price is no longer a determining factor and it's about the same price to go with a sweet 50cc bird with a DA50... than something in this class with a smaller gas engine... Then you have a great gas powered aircraft with excellent power:weight AND wingloading.

With all that said... guys will fly this thing with all kinds of engines... from 3W 28's to DA50's... Saito 1.20's to Moki 2.1's... And almost everyone will say it's awesome. Because they will be grading with different criteria than you... and that's why we have such a disparage of reports on all aircraft.

It's best to look at what you have liked in the past... compare wingloading, engine/prop/rpms... and extrapolate accordingly... in your case if the 1.80 was hppy on the 68... then you'll need more than 35cc gas on the 74"... and a 1.60 offers more power to weight than a 35cc gas... spins similar props, but weighs 1.5-2 lbs less...

Ian.W

On with some info!

Anyway, unlike many (read: 99% of them) companies, Chris has listened to peoples comments on the 68" yak, and changed things for the better on the 74. For example...... a pre-isntalled canopy latch!

Ian.W

a strong, light Carbon Fibre tail wheel (stearable, just in this picture its not had its arm attached). Red screws are my own fittings, as i had them and they look cool

Ian.W

Other things include the double truss phelonic controll horns, which will have heavy duty 4-40 dubro pushrods attached

Ian.W

and again, this is another CAD masterpeice, first time these pics have been shown on the net!

and check it, NO FOAM!

Ian.W

more

Ian.W

another

Ian.W

last of the evening!

AcroJo

My Feedback: (1)

The 74 is looking better by the minute.

Here's a little something that may pull it around. MAXX Products 'Double Max'. Two 1800 watt outrunners, inline, spinning two 19X12 MX props in counter rotation. Their boasting 22 lbs. of thrust. Requires 10s LiPo and two CC85HV ESCs.

$500.00 will get you the twin motor setup, motor mount, two props and a custom aluminum spinner. Good amount of cash to do this setup with some quality digi's and the rest of the goodies. Don't forget a spare LiPo pack or two, but you won't have to worry about the P factor with counter rotating props. Joe

Maudib

My Feedback: (51)

Just a note that Extreme Flight's new site is now up and running with a full product page on the 74" Yak...

http://www.extremeflightrc.com

diamondave

My Feedback: (29)

about gas, i was eyeing up the evo26, says a 18-6 at 8700 rpm, that would be great, and its about the same weight as the 160, on paper anyway, i have the 160 in my 68 and thought it was perfect, at my altitude anyway(5000'), but i wanted to get out of glow, so the evo26 looks like it would be almost perfect for the 74, i think anyway

Maudib

My Feedback: (51)

To get an idea of what the EVO 26 might do... check out http://www.qqaircraft.com

Quique just finished testing it in his 73" Yak... full report and video on his site...

I suspect it will be similar in the EF 74" Yak...

Dart373

My Feedback: (2)

Man... I am so glad Chris stuck it out... and hung in there... I hope it is payoff time... we get a rad plane, and he gets the $. Th latch is excellent idea... thats my ONLY gripe was the canopy take a few minutes when you get to the field.. AWESOME!

tIANci

Ian - eeeerrrr ... where is the thrust line?

Maudib

My Feedback: (51)

I think I'll take a little credit for that latch idea... (or maybe not)

When I built the 87" and added a lot to that thread... Chris emailed me on the hatch latch mod... he thought it was an excellnt idea... he said at that point he might have to include that in future designs...

On the 87" there were a couple people who reported failures of the latch... but MANY utilzed the mod effectively.

That truly was the ONLY sore point on the 68 and 87 designs... trying to align those 4 hatch screws... I hope he continues these on future designs... maybe doubling them on larger planes.

The latches used in the 74" are of a little different manufacture... I'll bet they are even more resilient than the plastic housing ones I sourced from Hobby-Lobby.


It is AMAZING how convenient the hatch latch is for accessing the airframe... and I pretty much convert all my aircraft to the latch now.

Ian.W

sorry? how'd you mean??


more pics comming later today

Dart373

My Feedback: (2)

I am guessing no lines on the cowl for motor/thrust alignment.

Maudib

My Feedback: (51)

Probaby means he sees no lines lasered into the firewall to start with...

I'm sure the manual will dictate where to measure for the centerlines... and since this one is a prototype, it's quite possible the final will have these already burned in them...


Either way is perfectly acceptable.