Posts: 1320
Joined: 4/22/2003 From: Elk Grove, CA, USA Status: offline
I got maiden flight. The plane is way. way underpowered. For the first flight I used 3s Apoge 1570mAh. It weights the same as the original NiMh 8-pack so it balances well in the plane.
With just a bit of wind (6 mph) I setup the plane so I could use about 100ft of paved runway at Mather Aerospace Modelers field. At full power the speed was still to low to fly after 100ft ROG. I lifted the plane to the ground effect and flew next 100ft just inches above the grass. Finally I started very shallow climb. First turn with about 10-20 degrees bank - more than that and the plane was falling down. Both engines did not run even - sometimes one run faster, sometimes both slowed down just to pick up speed again. Entire flight was at WOT but I did not climb higher than 20-30 ft. On the turns in order to keep it in sight I had to bank more and let the plane to loose altitude. After two exciting circles I set it back into the ground effect for landing. This plane is a floater. Flying 100ft inches above the runway did not want to land. The next approach I started much slower and this time after flare it landed. Not the perfect landing (a bouncing one) bot no harm to the plane. The battery was warm (not hot). recharging it at home I found in this 2 minutes flight (about 90 seconds at WOT) the plane used 385mAh. That is 15A total.
I believe this plane can not fly on stock NiMh 8-pack and for sure will not take off on 2s LiPo. I start working on BL motors for these EDF. My calculations shows 4000kv motor should be good for 2s LiPo and if I got everything right I should get two times more thrusts (500-600g) at less than 25A.
< Message edited by RysiuM -- 2/27/2008 6:16:06 PM >
_____________________________
Mather Aerospace Modelers, Inc. AMA Gold Leader Club, Charter #1243, Sacramento, CA
Posts: 1810
Joined: 12/23/2005 From: Frenchtown,
NJ, USA Status: offline
Sounds a little weak.
I went directly to Hyperion 12 mm 5800 kv motors on 4 Black & Decker PVX cells using GWS EDF 40's. 12 volts @ 12 amps. Thrust is 12 oz.
I just hand launched with a tiny bit of up elevator. Positive climb in 1 second. Pulled a banking, up, right turn. no speed change. back off of WOT & cruised up to 100'. Landing was different.
1' up, gust hits ME first. Then heads for the plane. WOT climbing turn. Approach again. 1# HOGS do not like gusts. 4 th try I flooped it into the 2' weeds. ok.
I am putting a simple 1 piece of bent wire, wheel to wheel in the spar setup. HS-55 servo will move both wheels at once. Then connect a retracting nose wheel off of the mains. No steering. At 2 oz. complete, OK in weight.
Posts: 1320
Joined: 4/22/2003 From: Elk Grove, CA, USA Status: offline
quote:
ORIGINAL: cyclops2 I went directly to Hyperion 12 mm 5800 kv motors on 4 Black & Decker PVX cells using GWS EDF 40's. 12 volts @ 12 amps. Thrust is 12 oz.
Are we talking about the same plane? A-10 (from Guanli) is equipped with GWS EDF-55 - the new version with rotor screwed from the front to the hub like on the picture few posts before. EDF-40 will be way to small for this plane. 10oz thrust is what I have now, but for 21oz plane it is just not enough.
Some pictures of the finished plane:
I made some cockpit interiors of the pink foam and painted with acrylic paint. The picture of A-10 instrument panel downloaded of the internet, resided, printed and glued into place. Pilot hand-carved of the pink foam - not a breath taking job, but from the distance is OK.
< Message edited by RysiuM -- 2/27/2008 8:13:28 PM >
_____________________________
Mather Aerospace Modelers, Inc. AMA Gold Leader Club, Charter #1243, Sacramento, CA
Posts: 86
Joined: 2/17/2008 From: San Juan Capistrano,
CA, USA Status: offline
quote:
ORIGINAL: RysiuM
With just a bit of wind (6 mph) I setup the plane so I could use about 100ft of paved runway at Mather Aerospace Modelers field. At full power the speed was still to low to fly after 100ft ROG. I lifted the plane to the ground effect and flew next 100ft just inches above the grass. Finally I started very shallow climb. First turn with about 10-20 degrees bank - more than that and the plane was falling down. Both engines did not run even - sometimes one run faster, sometimes both slowed down just to pick up speed again. Entire flight was at WOT but I did not climb higher than 20-30 ft. On the turns in order to keep it in sight I had to bank more and let the plane to loose altitude. After two exciting circles I set it back into the ground effect for landing. This plane is a floater. Flying 100ft inches above the runway did not want to land. The next approach I started much slower and this time after flare it landed. Not the perfect landing (a bouncing one) bot no harm to the plane. The battery was warm (not hot). recharging it at home I found in this 2 minutes flight (about 90 seconds at WOT) the plane used 385mAh. That is 15A total.
I believe this plane can not fly on stock NiMh 8-pack and for sure will not take off on 2s LiPo. I start working on BL motors for these EDF. My calculations shows 4000kv motor should be good for 2s LiPo and if I got everything right I should get two times more thrusts (500-600g) at less than 25A.
RysiuM ,
Maybe you got an A-10 with a bad stock battery or bad fan motors, but we have not had any problems flying our two STOCK Guanli A-10's (my son's and mine). On both the EDF-55 run smoothly and evenly. Maybe it's that pilot in your canopy? Take him out and fly it yourself. ;^)
We conditioned the stock 8 cell NiMH batteries when we first got the two planes, with a "peak" MiMH charger we use for our electric RC Helicopters (all Heli flyers know to do this). While the Guanli is no hotrod, we find the stock EDF-55 run reliably and deliver enough thrust to get off the runway quickly and get us up to 50 - 75 feet without a strain using the stock peaked batteries. We've ventured barrel rolls a few times too on our 5 - 6 minute flights. There have been others on this forum site (not this string) with these same Guanli A-10's, posting similar results to our experience too! So there is some agreement on the capabilities of this plane. This plane flies just fine .... not great on the power side though, which is why both my son and I wold like to upgrade the motors to brushless and higher rated Li-Po batteries. You are right, it does kinda "float" on the landing, so we leave it throttled up to force it down and then cut the power just as the wheel tough - just like landing a real 727
Question for you - WHY did you run the antenna wire external on top of the fuselage? We ran our inside the fuselage, poked a 10 penny nail sized hole out the rear of the fuselage where the Stabilizer attaches and ran the antenna out to the rear of the plane. Looks a he11 of a lot better. Hate to think us Heli flyers are more improvising and better flyers than fixed-wing RC'ers? (just joking)
Pardon the lousy pictures, junky video/digital camera, but here is my Guanli A-10 on the ground and in the air (about 60 feet).
< Message edited by websterphreaky -- 2/28/2008 12:22:07 AM >
Posts: 1320
Joined: 4/22/2003 From: Elk Grove, CA, USA Status: offline
quote:
ORIGINAL: websterphreaky Maybe you got an A-10 with a bad stock battery or bad fan motors,
I don't know, but from all calculations motors run like any brushed motor should. The battery provided was 8-pack of AAA size 650mAh NiMh. If you fly 6 minutes, of the same battery it means both motors take 6.5A = 25W per fan unit. I would think that it's kind of hard to fly 20oz plane with that power. If I run on the stock batteries both motors would take around 10-12A i imagine. That is half of the power I have now not mentioning 3minutes or less of flying time.
On the other hand motors I have may need to get some running time. They are not smooth in the air. I mean at WOT they change the speed by themselves what lets me think they may grind something while running. Maybe a little oil on the bushing will help (I think they are not BB)
The pilot in the cockpit weights less than the plywood battery holder I removed from the nose. It doesn't change anything in the flying characteristic of that model.
quote:
ORIGINAL: websterphreaky Question for you - WHY did you run the antenna wire external on top of the fuselage?
Inside the fuselage just behind the Rx I have ESC with all these 6 heavy gauge wires. I did not want to route RX antenna through that mass. I would rather have ugly antenna wire showing up than some sign of the radio interference.
There might be one thing, what makes this plane flying like heavy. Where is the CG in your A-10? There was no any information about it in the instruction, so I just kept it on the spar, but I'm afraid it may be to much forward.
_____________________________
Mather Aerospace Modelers, Inc. AMA Gold Leader Club, Charter #1243, Sacramento, CA
Posts: 86
Joined: 2/17/2008 From: San Juan Capistrano,
CA, USA Status: offline
quote:
ORIGINAL: RysiuM
There might be one thing, what makes this plane flying like heavy. Where is the CG in your A-10? There was no any information about it in the instruction, so I just kept it on the spar, but I'm afraid it may be to much forward.
I will try to measure the CG on our two Guanli A-10 soon and post it for you. I believe it is pretty close to the CL of the wing wheels because it barely keeps the nose gear on the ground with the battery in the original "pocket" location forward of the nose wheel shaft and servo.
We've never noticed any RF interference running the antenna wire past all the internal wiring.
Breaking in the motors may indeed be a solution to the irritate operation. The few early Heli's we flew that had big brushed motors, had to have the motors run for 15 - 20 minutes straight before they worked well. A shot of silicon spray lube too. We always blew a lot of cold air (high speed muffin fan across a chunk of ice) at the motors while we broke them in. Now all of our electric heli's are brushless.
Still interested in what brushless motors and LiPOs you choose (and where/how you put the battery) to upgrade your GL A-10.
Posts: 1320
Joined: 4/22/2003 From: Elk Grove, CA, USA Status: offline
quote:
ORIGINAL: AGUSTIN HERNANDEZ
RYSIUM ARE YOU USING THE STOCK ESC MAYBE THAT THE PROBLEM .
Yes I do. It is also possible. What I noticed if I connect motor straight to the battery it runs at 12A, if goes through ESC at WOT it takes only 10A. I will try to do five things: 1. Run these motors a while at lower rpm for breaking in 2. Lubricate motors just in case they need it. 3. Set EPA on the throttle to 140% (if ESC doesn't see 100% right) 4. Move CG a little back 5. Fly that darn thing again
As for brushless setup I calculated that I will need motors with Kv = 4000rpm/V and capable of running at at least 80% efficiency at 12A load. This would spin EDF-55 at 27krpm powered from 2s LiPo. Probably something like Great Planes Ammo 20-40-4040. I run calculation through Drive Calculation program (free) and got the following results:
But probably instead of these little inrunners I will use GoBrushless (double) setup for similar Kv. This will gibe me more flexibility in finding the right motor.
_____________________________
Mather Aerospace Modelers, Inc. AMA Gold Leader Club, Charter #1243, Sacramento, CA
Posts: 18
Joined: 7/10/2004 From: Philadelphia,
PA, USA Status: offline
It is obviously your motor and or fan problem. Fans should run smooth at all power level. What you are describing sounds like the rotor is not balanced and/or not centered so it is scratching the fan shroud at high rpm. That is like running a car with parking brake on. You for sure are not going to fly well. Check your fan shroud for scratch marks. I wouldn't be surprised if you find lots of marks. You have to dismount the rotor and motor to check rotor balance and centering or just replace the whole unit. You may get two GWS EDF 55 fans with 300H brushed motors preinstalled. These preinstalled units usually come rather well balanced and centered but you have to check yourself. If a rotor has shaft hole not drilled on center you can ditch it. If a rotor is not balanced (you need a good balancer to find out) you can add/remove weight to balance it but it is not easy to multiblade rotor.
quote:
ORIGINAL: RysiuM
quote:
ORIGINAL: websterphreaky Maybe you got an A-10 with a bad stock battery or bad fan motors,
I don't know, but from all calculations motors run like any brushed motor should. The battery provided was 8-pack of AAA size 650mAh NiMh. If you fly 6 minutes, of the same battery it means both motors take 6.5A = 25W per fan unit. I would think that it's kind of hard to fly 20oz plane with that power. If I run on the stock batteries both motors would take around 10-12A i imagine. That is half of the power I have now not mentioning 3minutes or less of flying time.
On the other hand motors I have may need to get some running time. They are not smooth in the air. I mean at WOT they change the speed by themselves what lets me think they may grind something while running. Maybe a little oil on the bushing will help (I think they are not BB)
The pilot in the cockpit weights less than the plywood battery holder I removed from the nose. It doesn't change anything in the flying characteristic of that model.
quote:
ORIGINAL: websterphreaky Question for you - WHY did you run the antenna wire external on top of the fuselage?
Inside the fuselage just behind the Rx I have ESC with all these 6 heavy gauge wires. I did not want to route RX antenna through that mass. I would rather have ugly antenna wire showing up than some sign of the radio interference.
There might be one thing, what makes this plane flying like heavy. Where is the CG in your A-10? There was no any information about it in the instruction, so I just kept it on the spar, but I'm afraid it may be to much forward.
< Message edited by shschon -- 2/28/2008 6:45:52 PM >
Posts: 1320
Joined: 4/22/2003 From: Elk Grove, CA, USA Status: offline
Fans are working well. I tested them on even higher rpm and there is no even slight vibration. What is going on with rpm is like ether motors are changing their performance or battery is warming up or ESC is doing weired things. All shrouds are clean without scratch marks. I bet these are GWS factory assembled units.
I did three things today: - I changed EPA to 140%. That gave additional speed to fans. Like ESC is locking now without PWM. - I put some lead in the tail cone. That moved CD about 1/2 inch back. CD is still about 1/8 inch in front of the spar, and the plane now can stay on three wheels or on two wheels and the tail. - I flew that darn thing again .
It took again over 100ft of runway for ROG and I had to wrestle it up before it went into the grass. Than flying it in the ground effect picking up more speed. First turn was still low but finally the plane started to climb. After about 30 seconds A-10 gad enough speed and altitude that I could make tighter turns. Then I was able for the first time to trim it for hands-off flying. It required about 10 clicks of up elevator and 3 clicks on the aileron to fly level. This was much better flight than the last one.
For landing I set it up flying above the runway almost on idle and without the flare I just set it on three wheels. The plane did not bounce at all. I think it was nose heavy on the first flight.
Talking to guys at the field (including the one who had GWS A-10) we got into conclusion that the plane would use much more thrust for take-off but it is enough for just flying around. Once it is in the air A-10 picks up speed and flies well. But mark my words: THIS IS NOT A BEGINNER PLANE. I'm going for brushless setup or sure. If I put lighter motors than stock I can move battery AFT, if I put heavier motors I can remove lead from the tail cone. I'm not going to push the limit of EDG units. I need no more than 10oz of thrust from each. This is easy doable as GWS claims these units can run over 35k rpm, but I want only 27k rpm.
_____________________________
Mather Aerospace Modelers, Inc. AMA Gold Leader Club, Charter #1243, Sacramento, CA
Printable Version
All Forums >> Electric Aircraft Universe >> Electric RC Jets >> RE: Nitro Planes A-10 Warthog for 95 dollars 
RE: Nitro Planes A-10 Warthog for 95 dollars - 
