CrookedWing

I have a Extreme Flight Chin Yak coming in the mail in a couple of days. My questions are should Iuse the Super Tiger .51 and the stock Spectrum DS821 digital servos that I already have or should Ithrow down the cash for some high speed servos and a better engine, maybe a 4 stroke or a more reliable OS engine? I havbe never done 3d with a glow engine.

Thanks!

ThumbSkull

My Feedback: (57)

The 821 servos will work well.

Dead sticks are not very kind to the Chinn Yak.
If that 51 is a tried and true great runner and is very reliable in the mid-range (unlikely) then use it.
The OS55AX with a 13x4 or Webra50 with a 12x4 are much preferred for 3D.

rcflip

Thumbskull the Supertigre is known for its power when coupled to a descent pipe, the OS 55 will not respond as well to a pipe, the OS is also no powerhouse and requires a ridiculous plug to be reliable, your recommendation not mine.

closetguy

My Feedback: (13)

servos will do just fine,ST 51 if you use the stock muffler it may be a little nose heavy?
i am a firm believer in using what you have.i have a old Italian made ST51 and it runs great,at lease the last time i ran it,it's on a trainer and still have both.
the EF Chinn Yak is one wicked 3d monster,you love it,but it is fragile.

CrookedWing

Thanks Guys!  I will probably use the setup I have to get it going.  I will be using the stock pipr of the Supertigre but will look for a replacement on line somewhere in the meantime.  If ya'll have any recomendations on pipes that would be great!

ThumbSkull

My Feedback: (57)

Don't use a tuned pipe for 3D. Max power is irrelevant. Midrange reliability and response is paramount.
You don't want the peak that a tuned pipe will give. You can save weight with a macs one piece muffler but stay away from a tuned pipe.

Sam-E

You can pipe for any part of the powerband Thumby!!

ThumbSkull

My Feedback: (57)

Yes you can and put an annoying power peak wherever you want.
I like a smooth linear throttle with an even power band.

rcflip

Get a four stroke then!!!

flygilmore

FWIW, the kit built Chinn Yak is the shizz where as the flimsy EF version leaves lots to be desired( I've had both). As mentioned, make sure your engine is dead reliable-one flame out and the fuse will snap right behind the wing and other places as well. I love the OS .55AX and either a Xoar 13x4 or an APC 13x4 sport (thin blade). If you use the OS .55, first thing you need to do is put an OS "F" plug in there as they are prone to unexplained flameouts-lots of Bros on the other site have allready discovered this. Good luck!

For a 4strk, a Saito .72 or .82 will be ideal as well though wont handle quite the smacks on the groudn that the simpler 2strk, would.

CrookedWing

Just wanted to give an update. I did purchase a OS. 55AX and I did get an "F" glow plug. I just got the yak in today and am going to start building it tonight. It shouldn't take long. I was more than a little concerned about the Supre Tiger that I have since I have had flame outs with it already.

I think everything should go well as long as I can keep it in the air. I appreciate everyones help.

ThumbSkull

My Feedback: (57)

A great choice. I have 2 40 size with 55AX's and 2 with YS63's.
Check your H-Stab for rigidity, I've had one fail mid-air.

Give us a flight report after you have a few tanks through it.

wyo69cowboy

My Feedback: (2)

Ditto on what Thumbskull said. I had issues with my Saito .82 (air leaks) that I finally sorted, but had two deadsticks that broke the fuse of my ARF ChinnYak. Repaired it the first time, reinforcing with 3/8" flat carbon strips on top and bottom of fuse, but the second one broke it for good. It flew awesome, but was not built for my ham-handed skills! On the horizontal stab, somewhere I saw some pics and info on reinforcing stab on the ChinnYak with 1/8" carbon rod. Basically, just drill holes in h-stab and bottom of fuse, and CA or epoxy it in to triangulate and reinforce the stab. I personally saw another club member rip half his h-stab off due to flutter/speed on his ChinnYak; he was using a 13x6 on a Saito .82, and that was too much speed for this plane. Meant to fly low & slow lol

BR289

My Feedback: (106)

One of the things we discovered some time back was to use the 1/8 carbon rod under the stabs for extra strength seeing that the stab is really big and during some manuevers can get really stressed.

As far as the fuses breaking, it hasn't been an issue from Hard 3D flying or even high speed flying.......
Blair

flygilmore

The kit built CY also has a thinner airfoil and in my opinion (also shared by many others) is much more capable than the ARF version which, for most, is the most capable profile that they have laid their hands on! If you like the CY ARF, try building a Primo-does everything the CY does but also adds a great degree of smootheness to the mix as well.

jasburrito

vid of buds with os 55,13x4,standard servos and skis. The os 55 is rock solid,well worth the money.The os 8 plug is good,never had a prob.
The 1 in vid RIP,,,,,,,,,,,,,,,,,,,,,,,,switch went bad===dead plane
Sweet plane
up close
http://youtu.be/QfnlmMv718c

vid of carbon fiber upgrades
http://youtu.be/uOKKpMJpMas
cheers

CrookedWing

Awesome guys!  I actually think my kit came with some CF rods to reinforce the elevator with.  I do it with a lot of my foamies so it makes perfect sense for stiffness too.

I did have some more questions.  I haven't maidened mine yet but I have got it together and got the engine broke in.  It fired up on the first try with  some old fuel! 

Questions. 

the wings have airfoils on both the top and bottom.  I am guessing on the resting/default angle of the ailerons.  I have them horizontal with the lines of the fusealage now.

I am using a 4 cell battery that came with my spectrum dx7 radio package for this plane.  I had trouble binding it with this battery since I think the voltage isn't high enough(said the LHS).  Should I use a 5 cell battery or wil the 4 cell work fine if charged good.  I installed a switch and a charge jack on the outside of the hatches so I can keep it charged up. 



I am ready to fly this mule!  The winds here in Houston aren't cooperating at the moment.  I work off shore so I have a limited window in wich to fly but if it ever does calm down I have two weeks to do nothing but fly!

zac137

I would go with the 5 cell spektrum tends to have problems with anything under 6 volt packs. Have fun with that thing!

Zach

exeter_acres

My Feedback: (2)

The carbon rods are for the ELE
here is the addendum
http://www.extremeflightrc.com/manua...k_addendum.doc

I always use 5 cell packs on my glow setups....

ThumbSkull

My Feedback: (57)

Ditch NiCd and NiMh. I'll never buy another NiCd or NiMh RX pack.

With a123 and LiFe packs making the right voltage without a regulator, they are a way better choice for RX.

Set your ailerons even with a line drawn right through the elevator.

Dave McDonald

My Feedback: (19)

Glad to hear you invested in the 55AX instead of using the ST 51 and flirting with disaster.

We have had several brand new OS 55AX engines that were loosely assembled from the factory. This can result in air leaks when the engine warms up, which can cause mysterious flameouts. Be sure to tighten the bolts on the head and backplate. Then make sure the needle valve assembley is tight with the carb body. Also be sure the fuel line nipple is tight in the carb body.

You're playing russian roulette with a 4 cell nicad and a Spektrum......even if it's the battery that came with your radio. If you already have a 6 volt NiMH/NiCd, use it. If not, then take Thumbskull's advice and get a LiFe or A123 1100 mah battery.

Set the ailerons so they are parallel with the horizontal stab. Step away about 5 to 10 feet from the plane and sight down the wingtip to get them close enough. If you want them adjusted dead-on, shim up the tail of the plane so the stab is fairly level, then use a lightweight plastic bubble level to match the ailerons to the stab.

Keep us posted on your progress!

Sam-E

Rather strange advice guys, not sure how a ST51 is flirting with danger and I would be careful recommending an unregulated LIFE without first knowing the servo's to be utilised, yes most can handle the 6.6v but I have seen servos fail because they could not.  Another thing is the Nicd or NiMh battery, not sure how a little chin yak could tax the power system enough to cause a brown out, that is if a brown out is the reason you are against the old tech battery.

Dave McDonald

My Feedback: (19)

I have four ST 51 engines. They all run great at full throttle, and at idle, but tend to load up rich and flameout in the mid-range. The rich mid-range and the flameout problems are the reasons for flirting with disaster with a ST 51 on a 3D plane, and especially with a Chinn Yak ARF.

His first post said he's most likely going to use Spektrum DS821 servos, which work just fine on unregulated LiFe batteries.

By definition a tuned pipe provides a power boost beginning at a certain RPM. When slowly throttling up, the sudden power boost creates a sudden increase in RPMs. When slowly throttling down, the sudden power loss creates a sudden decrease in RPMs. These surges in engine power at certain RPMs are what makes a tuned pipe undesireable for 3D flying. If the header is set short enough so the engine never experiences the RPM surge, then the tuned pipe is no better than a muffler.

Sam-E

Geez you guys are defensive, such an uptight crowd!!! My bad on the servo thing but be careful I have seen servos melt on 6.6. I guess we will have to agree to disagree.

ThumbSkull

My Feedback: (57)

Not defensive, just passing on the been-there, done-that experience.

A lot of guys think everything they learned on the trainer applies all the time.
3D is a different world.