RE: 69" QQ Yak-54 (Full Version)

All Forums >> [RC Airplanes] >> Giant Scale Aircraft - 3D & Aerobatic >> Quique's Aircraft Support



Message

asmatt2 -> RE: 69" QQ Yak-54 (10/2/2007 3:00:25 PM)

Reza,
If I am running a 4.8V 2500mah battery, what servos would you recommend?



asmatt2 -> RE: 69" QQ Yak-54 (10/4/2007 5:46:36 PM)

I went ahead and got the 5645's on all surfaces and a 5245 on the throttle. What fuel is everyone running through their YS 110?



ben beyer -> RE: 69" QQ Yak-54 (10/8/2007 4:07:57 AM)

I'm using the Curtis Youngblood 30% Heli fuel.



UMD Pilot -> RE: 69" QQ Yak-54 (10/22/2007 6:31:42 AM)

Hello Everyone,

I am just joining this forum so I figure I will introduce myself. I just recently got back into R/C after a slight break due to time crunches with school. I was ALWAYS Quique Aircraft's BIGGEST advocate. I was in love with the planes and am a complete Yak-oholic. However, I never had the money to afford one of the larger Yak's. Now, I think I will have the resources to afford and properly equip this plane. It's the perfect size and is made by the perfect company.

There has been lots of debate about engines so far on the forum, so I wanted to see if i have a general idea of everyone's conclusions.

Saito 125 Four-stroke/O.S. 120 Four-stroke/YS 110 Four-stroke/O.S. 120 AX Two-stroke

Are these the main possibilities that everyone has liked?

Also, if these are the engines of choice, as far as the four-strokes are concerned which one is the most user-friendly? I only ask because I have heard negative things about YS engines and the constant tweaking they demand.

Thank you all for the help,
Matt



kochj -> RE: 69" QQ Yak-54 (10/27/2007 12:55:04 AM)

I just wanted to post my findings with my OS 1.20AX 2-stroke on a MACS tuned pipe/header comb..
It will spin the 17x6 with stock muffler around 9200 RPM's.
I was using Wildcat/YS Performace 20%nitro 2or 4 stroke fuel.

tuned pipe w/a 17x6 APC prop 10000-10500 RPMS
That is a 1000+ RPM increase folks!!!
I am sure no one here is going to go for Scale show apperance?????
put that pipe on it and haul bones!!...
That will save you that 30% heli fuel and you engine will last longer....


Justin



cje0114 -> RE: 69" QQ Yak-54 (10/27/2007 12:58:14 AM)

Hey Reza,

Is there any updates on the correct landing gear for this plane?

Thanks,

Chris



Brenner -> RE: 69" QQ Yak-54 (10/27/2007 2:16:03 AM)

Yeah!

I'm interesting in learning about landing gear updates too, and if there is no update, I'd be interested to know if there's a third party landing gear available that will fit the 69" Yak. Preferably something made out of carbon fibre to keep the weight down.



ben beyer -> RE: 69" QQ Yak-54 (10/27/2007 2:44:05 AM)

I got some CF gear from Graphtech. I haven't weighed them, but they do feel lighter than the stock gear.



Brenner -> RE: 69" QQ Yak-54 (10/27/2007 3:08:48 AM)

Which gear did you get?



ben beyer -> RE: 69" QQ Yak-54 (10/27/2007 3:22:34 AM)

I got the one for the 73". You just need to tell them to sand it down to 1".



Brenner -> RE: 69" QQ Yak-54 (10/27/2007 3:54:38 AM)

You mean this one?

#220 QuiQue 72" Yak 54 Version 4D
3-1/2" Base / 7-1/4" Total Height / 13-1/4" Spread / 1-1/4" to 7/8"
This gear is 1" Taller than stock and can be cut down if needed.

And did you mean ask them to cut off the extra 1"?



ben beyer -> RE: 69" QQ Yak-54 (10/27/2007 4:02:08 AM)

That's the one. The top is 1.25" and that won't fit in the slot. That's what you need to have sanded down. As far as the height, I'm just letting mine sit a little higher. You could cut it down if you wanted to. I drilled my axle hole in the middle of where it would go and it sits about 1/4-1/2" higher.



marlin847 -> RE: 69" QQ Yak-54 (10/27/2007 4:35:52 AM)

Hey Reza have you heard when they are sending out the correct landing gear for this plane? Marlin



Brenner -> RE: 69" QQ Yak-54 (10/27/2007 5:52:49 PM)

Good point!

I'd much rather have the stock gear, painted in the right color, without it being all cut up.



Rezagh -> RE: 69" QQ Yak-54 (10/27/2007 11:13:20 PM)

Hi Guys,

I will check on the landing gear status and let you know.

Thank you,
Reza



Brenner -> RE: 69" QQ Yak-54 (10/30/2007 2:11:32 AM)

Reza,

I trying to set up my elevator linkage with the replacement elevator horns that QQ aircraft Company sent me, and I'm having a lot of dificulty convincing myself that this setup is correct.

The problem is that from neutral to full down, the servo only travels about 15 to 20 degrees or so, and the farther the elevator moves, the more non-linear the travel becomes. Towards the end of the elevator travel the servo's mechanical advantage reduces to zero, so any kind of wind load is going to stop the servo, or at least try to. My concern is that if I push full down elevator when flying at full throttle with this linkage, I'm going to rip the horn out of the elevator.

Another concern is the linkage goes over-center before the elevator reaches its full travel and it locks up, so I can't see why the hinge line is beveled on both the elevator and the stab, because the linkage doesn't allow enough travel to need the bevel. Seems very inconsistent to me.

Just for notation purposes, I am using the elevator horns, and the associated servo horn, that I was sent as a replacement.



Brenner -> RE: 69" QQ Yak-54 (11/1/2007 2:55:47 AM)

Reza,

I've spent a little time trying to figure out what's wrong with my elevator linkage, and I've come to the following conclusions:

Firstly, the elevator horn that you guys sent me is offset over the hinge line by 4 mm. This makes the down elevator travel more sensitive than the up elevator travel
Secondly, because the servo is offset from the center line of the stab, the linkage has non-linear behavior that also makes the down elevator travel more sensitive than the up elevator travel.

I'm attaching a CAD layout of the linkage using the parts you sent me, and a CAD layout showing an optimized version of the linkage that linearizes the travel and equalizes it in the up and down directions. I'm also attaching graphs of elevator travel vs servo rotation for both the stock and the optimized systems.

As you can see, in the stock configuration, I reach 61 mm of down elevator after only 28 degrees of servo rotation, whereas 28 degrees of rotation in the up elevator direction only gives me 42 mm of travel. In the optimized configuration I use 38 degrees of servo rotation to reach 61 mm of down elevator travel, and 38 degrees of rotation in the up elevator direction also gives me 61 mm of elevator travel.

I am going to drill a new hole in my elevator horn to remove the hinge line offset, and I am going to replace the rod linkage with a longer one so that I can get the optimized servo arm position when the elevator is at zero degrees. However, before I do this, do you agree with my assesment, or have I overlooked something stupid?



Rezagh -> RE: 69" QQ Yak-54 (11/1/2007 11:47:32 PM)

Nice work. I would have to check mine to see if I have that offset in my original plane that was approved for production.

Thank you,
Reza



Brenner -> RE: 69" QQ Yak-54 (11/2/2007 12:50:57 AM)

I've been working a bit more with the kinematics, and now I think I can get the linkage to work without drilling a new hole in the elevator horn.

What I would do is use the inner hole on the servo arm, and orient it at 83 degrees off the horizontal. The resulting linkage should look and work like it's shown in the attached pictures.



w4sm -> RE: 69" QQ Yak-54 (11/5/2007 3:40:32 PM)

I thought I'd report my experience with electrifying the 69" QQ Yak-54. After an e-mail exchange with QuiQue, he recommended the Eflite 110 outrunner with a 9s 4200 mAh battery, a Castle Creations 85HV ESC and an APC 18x10E prop. I followed these suggestions and the end result is outstanding. The plane weighs 9.5 lbs ready to fly and that includes a couple of extra ounces of wood and epoxy to beef up the landing gear mount. For batteries I used six 3s/1p 2100 mAh packs, two sets of three wired in series and the two sets in parallel to give 9s/2p 4200 mAh. On the ground the motor draws 65 amps with 2000-2200 watts at full throttle. Performance is spectacular. Most flying is at 1/3 throttle. Hovering is at half throttle. Full throttle is amazing vertical acceleration. I'm also going to try this model on an 8s setup, using two 4s/1p 3800 mAh packs in series. This should give very good performance as well, considering the overkill at 9s. Because most of the time is spent at less than half throttle 8.5 minute flights use only about half of the capacity of the 9s/2p 4200 mAh setup. 12-13 minute flights should give plenty of safety margin. If you're looking for a larger electric plane with spectacular performance that won't bankrupt you for batteries, this is an excellent choice.



Rezagh -> RE: 69" QQ Yak-54 (11/5/2007 3:51:27 PM)

Hi w4sm,

That is a wonderful set up. Could you please post some pictures of engine mounting. battery location. What stand off and size did you use. We would all greatly appreciate it if you could do that. or I can email me the pics at captainreza@gmail.com and I will post them.

Thank you,
Reza



w4sm -> RE: 69" QQ Yak-54 (11/5/2007 4:06:36 PM)


quote:

ORIGINAL: Rezagh

Hi w4sm,

That is a wonderful set up. Could you please post some pictures of engine mounting. battery location. What stand off and size did you use. We would all greatly appreciate it if you could do that. or I can email me the pics at captainreza@gmail.com and I will post them.

Thank you,
Reza


Yes, I'll try to post some pictures in the next few days. I have out-of-town guests for the rest of the week, so it may take a little while to get back to RC stuff! Briefly, the batteries sit where the fuel tank would sit, I added a 1/8" light ply tray with double Velcro straps to hold them in. The radio/servos are powered by a Duraflite 2400x2 lithium battery that sits just behind the tray for the rudder servo. This makes the CG come out perfectly. The Eflite 110 is mounted with four 10-24 threaded rods, about 2.5" off the firewall as I recall. I use locknuts and washers on both sides of the mount and both sides of the firewall. This seems rock solid, but I admit that I haven't tried high power snaps, which would put maximum stress on the mount. I plan to add another "X" E-flite motor mount halfway along the threaded rods, with locknuts on each side to help eliminate any twisting tendency at high power. This may be overkill.



Brenner -> RE: 69" QQ Yak-54 (11/5/2007 11:57:41 PM)

An f3a 2 meter class pattern plane uses about 2500 watts at full throttle, so with a ready to fly weight of 11 lbs the power to weight ratio calculates out to be 225 W/lb. Your Yak weighs 9.5 lbs, so with a power output of 2200 Watts, your power to weight ratio is 232 W/lb. It's no wonder that it's such a performer.

One other possibility to consider is to replace your Li-poly pack with an A123 pack. A123 cells are quite a bit safer, cheaper, and they last for a lot more recharge cycles. Also, you can fast charge them in fifteen minutes, and they are safe to charge in the plane so you'd probably only need one pack. A 10s2p A123 pack would produce the same voltage as your 9s2p Li-poly pack, but it would be 6.75 oz heavier. However, you could probably save this weight by using a switching mode BEC instead of your Duralite receiver pack. If you do this you'd probably have to shift the battery pack around to get your CG right, but fortunately there's enough room in the Yak to move the pack all the way back to the servo tray if needed.

One other thing, I ran your numbers through Motocalc, and it pretty much agrees with everything you say. However, it does warn that the motor is at risk of overheating. I also checked the E-Flite website, and it says that the E-Flite 110 motor is only good for up to 2000 Watts. Are you sure that your motor is handling the 2200 watts that it's putting out? Although, I suppose that if you are flying mostly at half throttle, it's not going to be too much of a problem.



Brenner -> RE: 69" QQ Yak-54 (11/6/2007 4:06:53 AM)

Now that I think about it, you could probably get by with an A123 10s1p pack and end up saving weight. This would give you 2300 mah as compared to your current 4200 mah pack, but if you're getting 8.5 minutes with only 2100 mah now, 2300 mah should get you 9 to 10 minutes easy. Combine this pack with a switching mode BEC, and MotoCalc tells me that the resulting plane is going to weight about 8.5 lbs, the same as the equivalent glow version.

Actually, MotoCalc is telling me that a 10s1p A123 pack is going to draw quite a bit more current than a 10s2p A123 pack which lowers the pack voltage, so the optimim configuration is going to be closer to a 12s1p pack. The resulting specs would be as follows:

Full Throttle Motor Current : 69 Amps - 30C
All-up Weight: 9.1 lbs
Power: 1817 Watts - 200 W/lb
Static Thrust : 16 lbs
Static rpm : 6616
Prop : 18X10
Wing Loading : 22 oz/sq.ft

This would be a sweet setup. You'd fly for ten minutes, and then charge for fifteen minutes, without having to remove the battery pack from the plane, and I've heard that A123's can be drained repeatably without damaging the cells, so you could fly until the ESC blips the motor, and then land. All in all a very efficient way to fly.

Right now on Ebay you can pick up a 10 cell A123 Dewalt power pack for about $10 a cell, and loose cells cost about $16, so a 10s1p A123 pack is going to cost you in the region of $132, give or take. This gives the following cost breakdown:

Castle Creations ESC $210
E-Flite 110 Motor $170
1 12s1p A123 Pack $132
2 FMA balancing 10 Amp chargers $220
Gel Cell Field Battery $250
50 Amp DC Power Supply $275
Switching Mode BEC $35
Total $1292

You'd need two FMA chargers because they can only handle 6 cells max. That way you'd split the 12s1p pack into two 6s1p packs, and charge them simultaneously.

By the way, did you cut any holes in the bottom of your Yak fuselage for cooling? At 30C the battery would be running at rated capacity at full throttle, so it would need lots of cooling. This would help the motor as well.



w4sm -> RE: 69" QQ Yak-54 (11/7/2007 2:07:04 PM)

Brenner, Thanks for the suggestions and calculations! I'll mull them over when I have a little more time. I'm tied up this week and won't have time to take and post pictures of the setup until early next week. I did make a generous hole on the bottom of the fuselage for airflow. I'm not really concerned about the motor overheating as a I seldom run full power for more than a few seconds of vertical. Most of the time the power is at most 1/3 to 1/2. On landing after the 8.5 minute flights the batteries and ESC were just barely above ambient temp. The motor was only very slightly warmer. Not uncomfortable to keep your hand on it indefinitely.



Page: <<   < prev  6 7 [8] 9 10 11 12 13 14 15   next >   >>  

Valid CSS!




SITE MAP!   : :   FORUM RULES

© 2001 - 2007 24-7 RC, LLC, all rights reserved.
1