EPPYak55 ... build guide, videos, free plans - Page 844 - RC Groups
Thread Tools
Sep 12, 2017, 09:13 AM
Kit Manufacturer
coreman's Avatar
Originally Posted by bazsound
my heavy yak flew! well it did for 2 circuits when it suddenly tipped and sent to tje ground was in low rates so did t have enoufh up...

its flyinf slightly nose up. iv just rpaired it to test again but i thonk it has some up thrust...
or it could be tail heavy
Latest blog entry: BluFO-XL review by Tim...
Sign up now
to remove ads between posts
Sep 12, 2017, 09:35 AM
Registered User
Originally Posted by coreman
or it could be tail heavy
its definatly not tail heavy, im right on the CG mark have tripple and quadrouple checked it.

I fixed it and took it out again with the ailerons tweaked, i think i may have had a little up on the ailerons. its still flying with a slight nose up attidue but its fairly stable.

It actuallyf lew int he wind, probably due to the extra weight, although it did have a tendancy to want to roll over in turns , maybe the wind catching it.

One thing i did notice was that it had a tendancy to rock so , dunno if its the wind or if its because its heiver on one side than the other, the rocking was biased to the heavy side as in if i didnt correct it, it would end up more and more banked to the right with each rock.

ive got a video uploading so you will see how its flying, but i think its a big success. Managed a full batterie with only one OOPS with no damage. The 2nd battery i accidently launched it up side down, noticed my mistake and though i had corrected but was too close to the ground. This partialy tore off a control horn and the glue on the seam between the to rear side peices gave so the tail can now wag a little.

Simple fix with some hot glue and redo the control horns.

its got enough power to hover despite it being much hiever and flight times seem not half bad. My battery was at 12.2v got about 5 minutes flight which brought me down to 10.4v (BIG OOOOOPS) need to look at esc settings, its one of those bl heli ones.

if the weather is ok tomorrow ill get out tomorrow for more testing, but now ive flown it im more confident with it in the wind.
Sep 12, 2017, 10:02 AM
Registered User
My yak55 flying outside int he wind :-)

Yakk 55 32" foamboard rc plane (4 min 6 sec)
Sep 12, 2017, 10:14 AM
Registered User

Nice video, Baz

Flies pretty well, doesn't it. Congrats.
Sep 12, 2017, 11:50 AM
Hot glue held together by foam
balsa or carbon's Avatar
Originally Posted by bazsound
My yak55 flying outside int he wind :-)

Success .... indeed ! Good job !
Sep 13, 2017, 03:04 AM
Registered User
its hard to tell because of the wind. ive just carried out some repairs from an accidental inverted launch by the time i realised i had already initiated up elevator instead of down and it nosed into the ground.

Now ill get everything centred properly, theres just a slight breeze today so just waiting ont he batts charging and ill get out for some more involved testing. :-)
Sep 13, 2017, 05:01 AM
Registered User
Just had my ESC blow up. was flying around (its a bit windy but not too bad) and got too low to the ground couldnt pull up and landed (wasnt a crash merly slid along the grass). Checked everything made sure ESC didnt get wet (as the grass is wet.)

launched again and did a circuit, came back into wind slowed down and let it glide there in the wind just under half throttle when suddenly the motor quit, BEC was still worked so i glided it down with no damage. I thought oh maybe i hit LVC when suddenly smoke starts pouring out!!!! runs over thinking its the battery... nope its the ESC one of the fets vapourised itself.

Motor is toast aswell several coils are burnt..... I guess this motor cant cope with the extra weight? or maybe i damaged it in my 600g cardboard failure.....
Sep 13, 2017, 05:37 AM
Registered User
ok just did some numbers in ecalc (not quite sure how accurate it is as im using best match figures) and it looks like i seriously overpowered the motor. according to ecalc in puylling 15amps 150w. way over the motors rating.

So i think i have a few ptions. i could uprate the motor and lower KV.

with the 8x4 prop it says i should be gettingg 600g thrust i could lower the prop size to 6x4 and that would get me under 10amops and still have a 2:1 power ratio...