Aeroworks 85 cc Yak

Ground Pounder

Well-Known Member
After a few test flights there was another slight leak/seepage just below the exhaust port. I called DA and got the torque values for the engine. 100 in/lbs for the backplate and 95 in/lbs for the cylinder. I found two bolts in the cylinder and two in the backplate that needed significant tightening. This was after 5 flights so the need to torque the bolts was not a surprise. A few more flights showed only a very minor seep. OK with me.
 

Ground Pounder

Well-Known Member
Dang do they have a warranty on that thing or what? Wasn't it $95 or something?
Yes it was expensive. Major bummer.


They seem like good people so yes I am going to contact them over the next couple of days. One of the Florida flyers gave it a hard test on a paved runway. It had no wear but mine was trashed after a coulple of flights. Conflicting outcomes.

I will dig into it to see if there is a valid cause for the extreme wear.
 

Ground Pounder

Well-Known Member
Yes it was expensive. Major bummer.


They seem like good people so yes I am going to contact them over the next couple of days. One of the Florida flyers gave it a hard test on a paved runway. It had no wear but mine was trashed after a coulple of flights. Conflicting outcomes.

I will dig into it to see if there is a valid cause for the extreme wear.
Traded e-mail with Vern at White Rose. The first batch of wheels used a compound that was OK for grass but did not hold up very well on pavement. The latest version is much harder and works fine. I am going to send the unit to him and he will fix the wheel and upgrade the axel for free.

Vern continues to demonstrate that he is a class act.
 

Ground Pounder

Well-Known Member
Performance evaluation

Ok, that pretty much wraps up the surrounding details. Now on to the flight testing. My background includes control line and free flight in the 50s and 60s. Heavy pattern and heli’s from the mid 70s to 1990 and then back at it early last year. I spend a lot of time setting up and dialing in a bird until it really flies better than I do. For this Yak I used the AeroPerfect, then two CRC throw gauges and finally a set of 15” CF 1/16 rods to really have it dead nuts on. By the time I finished up it was very apparent that the AW bird was straight and all of the surfaces were zero/zero. Significantly better than my QQ or EF Yak. CG was 1/8” behind the recommended location.

The AW 85 cc Yak flew better of the board than my dialed in QQ 102” Yak (+100 flights) and EF 88” Yak (+ 100 flights). Right out of the starting gate it was a blast and at the same time very relaxing and enjoyable. I am not as capable as some of you 3D gorillas but I know what I like and this is it. I told a buddy that if I had to make a choice today and only fly one bird the AW Yak would be it.
 

Ground Pounder

Well-Known Member
Why?

It is light but that does not fully explain the difference in their flight envelopes. It took me a few minutes to figure it out. All designs are a compromise. I have seen a clear trend toward the thinner airfoil sections that perform very well for general flying, 3D and IMAC. 3D is a niche of a niche. I don’t fully agree with using a thin section for 3D. The QQ is using (round number based on quick measurements) a 13% airfoil with a high point at 40%. The AW Yak has a 15% airfoil with the high point at 27%. This is s huge difference. The thicker airfoil and placement of the high point provides a VERY forgiving flight envelope. There is no tip stall tendency. Period. Blenders are very tight, knife edge snaps are clean, hovering is go-to-sleep easy, harriers….it just floats, and hovering waterfalls are a piece of cake. At under 21 lbs. acceleration is in the OMG category (or as the Brits might say – rousing). The DA is turning +6300 out of the box with a Xoar 26 x 10 on Pennzoil 32%. The temp was 98-101 degrees and the field elevation is basically at sea level

Build it light and you will have a great bird that is a blast to fly and very forgiving at the same time. Low speed performance is exceptional and something that I really enjoy and appreciate.
 

Ground Pounder

Well-Known Member
Finally got an accurate weight. The original build article came in at 22 lbs 11 oz. My final weight with wheelpants, Nova spinner and a J&J/dubro tailwheel set up is 21 lbs 4 oz.

Net reduction of roughly 1 1/2 pounds and worth the effort.
 
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