Kris' GP Yak-54 buld thread

[YNOT]

Kris, my only question is what you had for breakfast this morning? That seems to be the only thing missing in your report.

[KrisW]

3D flyer, check out the first few posts to this thread. . the weights are listed there.

Ynot, I had coffee and 4 pieces of buttered toast for breakfast.

[3-d flyer]

Sorry Kris, Thanks.... i missed it there...

[GremlinX]

Video? Arrg. LOL

[KrisW]

Okay. .the Yak is 15 lbs 7 ounces dry.

Can we say HEAVY???

Here's an easy way to shed a few unwanted, and probably unnecessary,ounces.

In the pic, on the right, is the old ignition and receiver packs and aluminum spinner. Total weight of this setup was 19 ounces.

On the left, weighing in at a mere 11 ounces total weight is the replacement parts.

Going from a 4800 ma Fromeco battery pack to a 2400ma pack nets a savings of 3.5 ounces.

Going form a 1650ma NiMH 4-cell ignition pack to an 1100ma NiMh 4-cell pack nets a savings of about 2 ounces.

Going from a Tru-turn 3.5" aluminum spinner to a Pete's Models 4" CF spinner nets an additional 2.5 ounces of weight savings.

VOILA ! ! ! ! 8 ounces of unwanted weight. .GONE!!!

The 4800 pack and larger ignition pack would have been good for at least 1.5 hours of flying, the limiting factor being the ignition packs capacity. Most ignitions pull aobut 500-800ma/hour, on average.

The smaller 2400ma receiver pack and 1100ma ignition pack will be good for about 1.25 hours of flying, again due to the small size of the ignition pack. Being on a single instead of a twin, the ignition will pull less amperage, probably no more than 500ma at full throttle.

With the 5-digital servo control setup, you can expect 5-8 flights of 15 minutes furation from a Fromeco Li-Ion 2400ma pack before needing a recharge. Best bet is to use Fromeco's "8-ball" pack load checker before each flight to make sure you have the recommended voltage before flying. About the worst you can expect from the ignition pack getting low is a lack of rpm, but the engine usually will stay running at idle and maybe a little more, giving you enough power for at least one powered approach and landing, and the possibility of a well-flown waveoff if necessary.

So. . there we go. 8 ounces saved just by chaning a few components. On a 40% plane this would be equivalent to a 24 ounce savings, which is noticeable on the larger planes.

[3-d flyer]

Hey Kris.... you said Jeeum, got some video of this thing???? Your killing me here! LOL!!!

[3-d flyer]

Hello all, well i had a chance to weigh eveything today with a digital postal scale... I am pretty happy after seeing Kris's weight, I am sure if i try i can eliminate a little more as well.

The reason i am pleased is this weight includes an extra plate i added on top of the gear w/tri-stock to help re-enforce this area... I switched the fuel tank to a 16oz dubro (located under the wing tube) I am running 4- 5645mg hitec servos and a single 5955tg for the rudder. I have not yet cut the cowl or drilled out the stock spinner back plate either. My AUW came out to 14# 7.3oz Dry. With the D/A-50 and stock muffler.... The muffler i have coming has a shorter down tube so that will shed a little bit as well.... If i run a CF spinner i can loose another 2.5oz. The weight also includes cowl mounting blocks i am using insted of the ring (just a personal preference) Soooo, i am trying to shoot for getting this thing down to 14# Dry and i'll be pleased, i was expecting a 15.5# plane and was getting disapointed! This made me feel alot better.... So far so good!

[KrisW]

Good deal, 3-d.

I weighed mine today, after switching out the battery packs and adding a CF spinner. 14 lbs 14 ounces dry. . a much nicer number. Just shows how picking the proper components can make a big difference

[3-d flyer]

That's for sure.... WHERE"S THE VIDEO! LOL

[KrisW]

I dunno. Jeeum took some footage, but has not posted it yet. it was a bit disappointing too, given the prop I had on the plane, later flights were much better.

[KrisW]

Allllriiigghhhtttyyy ! ! ! ! !

Time for some more flight reports.

First off swapping in the smaller batteries and CF spinner dropped the weight to 15 lbs 4 ounces with a FULL tank of gas, or about 14 lbs 12 ounces dry, an acceptable weight for the plane, though I'd like to see it lighter (which you are going to be very hard pressed to do)

Todays winds were in the 10-15 knot range, quartering across the field, so everything required rudder corrections. Nose into the wind, the plane handled it pretty well, but with the wind from behind the plane it was easy to get excessive yaw by over-correcting with the rudder. This is on IMAC rates, about 15 degrees throw each direction, and still too strong IMO.

I did some more testing of this years sequences with the plane. Basic is dead-nuts easy to do with it. Set the line and it follows it except for rudder corrections. It's very easy to do smooth loops and if you don't go yanking on the stick the plane flies very smoothly. 4-points require just a breath of rudder in KE, otherwise they are very nice. Sportsman maneuvers are also incredibly easy to perform, even in the wind. I'm almost tempted to video the plane in sequence flying action, just to show how good it flies.

Now, for 3D. With the CG set at recommended position, you will never do a waterfall. . ever. The CG definitely needs to be move aft about 3/4-1" in order to get really twisted into some 3D antics. But, the plane will Elevator as it is now, with just a hint of flaperon dropped (about 10 degrees) and finding the sweet spot with the elevator, an Elevator into the wind is a straight down affair, with only minor wing rock. Adding spoilers instead would probably kill the wing rock.

Blenders are best done on low rate aileron, otherwise the plane is rolling so fast it can't flatten out. I'm talking 3.5-4 rolls a second here, so fast that you become disoriented. Add a little rudder to it and it's just wicked looking.

I tried some hovering, but with the wind and heavy nose it was very difficult. The engine had more than enough power to get out of trouble, though, which came in handy more than once.

I'll get some more flight info next week, move the CG aft and see how things work out. For now, though, the plane is very "safe".

[Ialwayscrash]

I just started mine today and noticed some of the same mentioned in earlier posts. I was able to remove the fuel tank plate with almost no effort and the glue used looks like white glue and not a lot of it. I am in the process of going over the plane with CA now. I am also intereested in reinforcing the landing gear area. What are your ideas on the best way to do this?? Any photos of the reinforcements??
Thanks
Alan