3.0M CARF YAK 55SP

[Andy Thomas]

I am wondering if anyone out there has any serious sequence time with this airframe? Also what percentage are your coupling and downline mixes? Also can anyone make a good precision comparison between this and the 3M 260? I understand either plane will fly very well I am just looking for any significant nuances with the Yak. Thanks!!

[Andy Thomas]

Bump!

[pepatrick]

I have one..but mostly fly for fun...0 mixing on knife edge...Ask Wayne Matthews...he flies it unlimited IMAC...He thinks there is no better flying plane on the planet...I agree..I love mine...I just dont fly as precise as Wayne.

[Andy Thomas]

Thanks for the info, I pm'd him so maybe he will chime in. I did see where he made some observations after about 50 flights or so.

[Stu_D]

I have clocked almost 22 hours of air time with my Yak 3.0 and almost all of it has
been Advanced IMAC . As for things to say about the air frame there's not
much to tell . I had to decrease the right thrust with some 1.6mm (16G)washers
and the engine is moved forward with 50mm (2 inch)stand off's . up/down thrust
is stock and so is every thing else .

I also fly with no mixes but if I was going to put it in I would be looking at about
1% of up ele to top rudder in both directions and 1% of down ele to low throttle .
I think that both these small problems could be easily be fixed with some up thrust
and a re trim of the plane .

I dont like using mixes as i have got myself into trimming problems in the past and have also found that all mixes create their own hassles so I prefer to know the
problems I have and deal with them as they come into play .

I did have a problem with the plane being nose heavy and not presenting the break
in a snap very well . I added 120 grams the the tail and the problem was fixed .

As for comparing the 3.0 Yak to the 260 its a bit of an ask but i will have a go .
The 260 is a lot faster and presents (breaks) the snaps a bit cleaner than the Yak .
The yak rolls A LOT better than the 260 and its speed controll is much more
constant than the 260 . The 260 is a missile with the 150 and I think the Yak is
more suited to a 170 class of engine .

Thats about all I know about the 3.0 260 as I have only flown it twice
I tell you when faced with a choice between the two air frames I went for the
Yak ,

Stu

[Andy Thomas]

Very good stuff, thanks for taking the time!!!

[wmat7039]

Hey Guys.... Having flown the 3m 260 at the latter part of the year & started practicing with the 3m Yak for the 2008 season, it is very apparent that these two aircraft require different techniques to accomplish the same feat.

I agree with Stu D that the 260 breaks & snaps cleanly. The Yak needs a more rearward CG to get that break & autorotation but if you go back too far, in heavy wind situations, it will be bounced about. So a compromise is what is needed there.

The DA 150 that I have on the 260 (with MTW 110K mufflers & 28x12 Mejzlik three blade prop) pulls it with authority & it will go high very quickly on the verticals if full power is used. Diligent throttle management helps here rather than banging it to full on the up-lines. On the Yak, the reverse is being experienced. I'm using a DA 150 with MTW 110 but had to switch to a Mejzlik 2 blade 30x12 as my verticals were no good with the three blade. I do agree with Stu D regarding the engine.... a 170 will be the right fit for this plane. I know that John Schroder is using a DA 150 with a Greve pipe installation & he does have the vertical penetration he wants with that set-up. Up to now, I have not flown the Yak with a Greve pipes combination, so until then I cannot honestly comment on it.

Mixing: The 260 requires more mixing than the Yak in pitch coupling. The 260 also required more mix in roll coupling. The Yak is very neutral and has no roll coupling in my sequence mode, although I have now added 1% on the rolling circle mode, since the plane is a little tail heavier than my original set-up. Unlike Stu D, I like to mix my airplane out as much as possible & do not see a detrimental effect (to me) once it's done properly.

On the vertical up-lines snaps, the Yak requires MORE aileron throws & these had to be added with a mix instead of flying with a lot of throw in my sequence mode. The spins are beautiful & predictable. For Hammerheads, I had to add more rudder & she goes over effortlessly. Dowlines are definitely slower than the 260.

I now have 90 flights on the Yak & will be going into the first IMAC contest with it at the end of March in Griffin GA. After that contest, I will give a honest competition flight report in my thread on the Yak.
3m CompArf YAK 55sp Build

Hope this helps you.
Wayne

[Andy Thomas]

Wayne I very much appreciate your insight into the yak. With my wood arfs requiring more routine maintenance and stomach than desired, I think a composite plane is in my future. Good luck at the contest, I will be standing by for a contest report.

[Extra260]

	Quote: Originally Posted by budgetdude
	Wayne I very much appreciate your insight into the yak. With my wood arfs requiring more routine maintenance and stomach than desired, I think a composite plane is in my future. Good luck at the contest, I will be standing by for a contest report.

You cant go wrong with a compy, I love mine!!!

[Andy Thomas]

Have you flown it yet?

[Extra260]

	Quote: Originally Posted by budgetdude
	Have you flown it yet?

No, still got a few more feet of snow to melt

[Artie Johnston]

	Quote: Originally Posted by wmat7039
	Hey Guys.... Having flown the 3m 260 at the latter part of the year & started practicing with the 3m Yak for the 2008 season, it is very apparent that these two aircraft require different techniques to accomplish the same feat. I agree with Stu D that the 260 breaks & snaps cleanly. The Yak needs a more rearward CG to get that break & autorotation but if you go back too far, in heavy wind situations, it will be bounced about. So a compromise is what is needed there. The DA 150 that I have on the 260 (with MTW 110K mufflers & 28x12 Mejzlik three blade prop) pulls it with authority & it will go high very quickly on the verticals if full power is used. Diligent throttle management helps here rather than banging it to full on the up-lines. On the Yak, the reverse is being experienced. I'm using a DA 150 with MTW 110 but had to switch to a Mejzlik 2 blade 30x12 as my verticals were no good with the three blade. I do agree with Stu D regarding the engine.... a 170 will be the right fit for this plane. I know that John Schroder is using a DA 150 with a Greve pipe installation & he does have the vertical penetration he wants with that set-up. Up to now, I have not flown the Yak with a Greve pipes combination, so until then I cannot honestly comment on it. Mixing: The 260 requires more mixing than the Yak in pitch coupling. The 260 also required more mix in roll coupling. The Yak is very neutral and has no roll coupling in my sequence mode, although I have now added 1% on the rolling circle mode, since the plane is a little tail heavier than my original set-up. Unlike Stu D, I like to mix my airplane out as much as possible & do not see a detrimental effect (to me) once it's done properly. On the vertical up-lines snaps, the Yak requires MORE aileron throws & these had to be added with a mix instead of flying with a lot of throw in my sequence mode. The spins are beautiful & predictable. For Hammerheads, I had to add more rudder & she goes over effortlessly. Dowlines are definitely slower than the 260. I now have 90 flights on the Yak & will be going into the first IMAC contest with it at the end of March in Griffin GA. After that contest, I will give a honest competition flight report in my thread on the Yak. 3m CompArf YAK 55sp Build Hope this helps you. Wayne

Hi Wayne, do you think it will be ok to mount two 8711s in the tail of this bird, push pull "will it not make it too tail heavy? Thanks Artie