edmoor

My Feedback: (1)

ok.....i moved the cg 3/4 of an inch forward of the book.....balanced it upside down on my marks....i had originally added (5)....1/4 oz weights to the tail because it very very nose heavy.....and it wasnt quite enough to level it....but i let it go at that point. after moving the cg forward.....its still just a tad nose heavy....NO FUEL to the tank. so....i assume im being safe at this condition at the least....correct? and why do they balance these upside down?.......is it to get the weight of the fuse to hang on the wing?????

Larry S

My Feedback: (6)

emoore,
A tad nose heavy?? Perfect, just where you want to be. And to answer your question, yes. Upside down the plane will hang. Now the one thing you want to keep an eye on when landing is don't stall it, keep the speed up. IF you can get yours to fly as nice as mine, you'll be able to make nice slow flare outs, but first you need to play with the CG to get it correct. I've found the best way to do that is move your battery pack. Good luck with your plane.
Larry
PS: I'm really surprised your plane is that nose heavy but then again, I only have experience with the CMP 50 Corsair. I know with that plane it is very tail heavy to start out.

Sturtz

My Feedback: (20)

After I repaired mine I took it out a week or two ago. After moving CG forward it flew pretty darn good. Had to walk it to the asfault runway because it noses over easily. I put larger wheels on it when building but it could use even larger ones. With the small wheels (no wing area left to inlarge gear bays) it's pretty much a paved tarmac plane. Landed fine,,,but again had to keep it on hard turf.
No doubt I was flying it last summer slightly tail heavy but not enough to cause major concern. Turned out to be a faulty aileron servo extension. Moved the battery forward and strapped to fuel tank. Much better !!!
Like Larry, I used the GP CG Machine. Before placing it on the balancer I found the main spar,,, came forward of it slightly.(maybe 1/4 ") and balanced there. Flys nicely now and will make a fairly sharp turn now without snapping. Hammerhead stalls are uneventful now too thank goodness. Again,,, they are CMP. They are heavy and they are small. Most of the larger birds CMP makes fly just fine after dialing them in and putting the right engine up front. They will either make you a better warbird pilot or cause you to switch to Cubs and trainers.[:'(]

miklos

My Feedback: (38)

I had one and only one CMP plane. A 50 size P-40. What a disaster. [:-]Beautiful looking plane, but on it's maiden, she went straight up like a rocket about 20 feet and then tip stalled and crashed. [:@]Yup.... tail heavy. What a disapointment. Strange thing is a few months ago that plane was reviewed in one of the magazines and they gave it good marks and no mention of the CG being off. Go figure. [:'(]I won't buy another CMP after that fiasco.

KentuckyColonel

I loved the CMP P-40.....while sitting in the pit area. Flight number three......Loop, bank to turn right out of the loop, tip stall at 95-100 feet altitude, spin into the ground. Still can't find the Aces of Iron pilot......

edmoor

My Feedback: (1)

thanks all for you info.......i still have doubts about the cg on this cmp p-51....and also on my cmp 182.the skylane will sit on the mains....but push down on the tail.....and it sits there. havent flown either of them yet.....i think im gonna add weight to the nose of both....make em nose heavy....then take it from there. its a safe way to try em out. and yes....i did use the cg point according the cmp plans on this skylane....i questioned them....no reply. they make a very nice plane....a very heavy plane....but the cg cant be right. my tank is even half full on the 182 with a 4 stroke as far forward as possible.

Larry S

My Feedback: (6)

Instead of adding more weight, try to move whatever you can as far forward as possible. I have a Jemco P47 I maidened yesterday and I have the battery pack in the cowl under the engine mount. I made a small tray to set the battery pack on and secured the battery pack to it with velcro. I know we're talking two completely planes but they both have one common fact, they're both tail heavy planes. At least on the Jemco kit they give you the right location for the CG as on the CMP 50 Corsair, that CG location is way off but hey, look at where they have the machine guns located and you can see they didn't go far into depth on where things should be but I'll still stand by what I said before, once you get the bugs worked out of a CMP plane, especially the 50 Corsair, you'll have a real fun plane to fly. By the way, my P 47 is glassed, full cockpit with pilot, retracts and a vortact bomb drop, running on a Saito 100 and on it's maiden flight, flew perfect with only two clicks of down elevator needed. I still had to add two ounces of lead under the motor to balance it.
Larry

edmoor

My Feedback: (1)

your right on throwing out them directions.....if i were a newbie builder.....i could never even get the plane together with what they furnished. as i have experience....i realize that there is a cg location problem.....i dont own a balancing machine....i always done mine on my fingers. in 30 years....it hasnt failed me yet.....i choose to stay forward of the cg if in doubt.....and work my way back. cmp planes are heavy models....compared to balsa....but the scale is superb. i guess you have sacrifice something. myself....i wont ever buy another cmp airplane....if they cant get the cg right.....and clarify some of the building problems when you contact them....then im not interested. i was told by another hobby dealer that they dont communicate well.....they owned by china men. i will buld my own from now on. a lesson learned for me. end of my story on these cmp models.

Larry S

My Feedback: (6)

I don't blame ya. Would be so easy for them to correct their mistakes and have a nice warbird. I guess what got me started with CMP was I wanted a Corsair without retracts already installed so that left out Hanger 9 for me. And like you my first CMP was balanced where stated on the "directions". On the maiden flight I had my hands full but got it back with no damage and that is when I started playing with the CG and I finally got it to fly nice until I put it in a snap roll and it wouldn't recover. On the second CMP Corsair I already knew where the CG should be and that it needed nose weight so I reinforced everything in the cowl and forward of the CG and went with a larger engine and that one flew great. I had the plane on a charger over night and went out to the field and got one flight in but on the second flight, the plane lost control and went in. Upon checking on what had happened I discovered the battery pack was completely drained and only after one flight. One battery had shorted out. I'll take blame, I now check my battery packs before each flight. I am waiting until the larger CMP Corsair gets back in stock and will try that one.
Larry
PS. Get one of those balancing machines. So much easier to balance a plane with one of those and much more accurate on keeping the CG where it should be. Well worth the money.

twinbrother

My Feedback: (7)

I just finished my 46 size P-51 Mustang from CMP and the CG of that plane is the same CG location of the 50 size one posted in this forum. Doesn't sound right. People are right to throw out the CG recommendations of these CMP planes. I had another 25 size Zero from Nitroplanes.com and the CG was 1" too far back on that, making it tail heavy. It crashed on maiden flight. I finally built the second 25 size Zero, moved the CG forward, and it flew awesome. I just can't understand why these guys at CMP can't get the directions for the CG correct. It's funny that everyone who *****es to Nitroplanes.com about how terrible the CG is on their planes that they say it's always the first time they hear about it. I've called them about the CG on every single plane I've ever purchased from them, a total of 4, and they say the same thing, "I'm the first person to grumble about it." I stopped buying from Nitroplanes.com because I didn't want to take my chances on terrible CG instructions anymore. Their products are cheap, but so are the instructions. And Raidentech.com, Bananahobby.com, Toyneer.com, Nitroplanes.com, are all the same company. Good priced products, okay quality, terrible instructions. You want a good flying warbird? Try the Phoenix Spitfire. Flies like it's on rails. And with retracts included, it's a great deal.

wdrosa

The 3rd P-51 I got from them, I set the CG just in front of the spar (right about where the rivit line is). It flew great after that. Just dont let it slow down. I did and it tip stalled and I could not recover it in time. It was another total loss. I finally broke down and got the Topflite P-51 gold edition arf .60 size. This one flies fast and slow very reliably. Most important is that the CG is dead nutts on the money. I should have got this one first. Good luck with yours.

texaswarbird

What is exactly your CG? I have one in my garage about to be built. Thanks.

texaswarbird

what exactly is your cg? I have one in my garage about to be built .Thanks.

wdrosa

I set mine slightly in front of the sparr. It flew good. Just dont let it get too slow. this plane has too fly it will not float.

edmoor

My Feedback: (1)

cmp planes......are nice looking planes.....very heavy planes.....the location for the cg sucks....as do the assembly instructions. i myself will never ever buy another model from cmp. i asked them 4 or 5 times for help on the cg....no reply. so if you buy one.....your on your own to figure it out. you get one chance to get it right....then it may be a disaster. a good looking plane dont always fly. ugly ones do. i will find another source for my scale models....cmp sucks.

twinbrother

My Feedback: (7)

You're right about that. The last cmp Corsair I bought was in January of 2008. I still haven't flown it yet, because I'm still researching the CG for this plane, the 50 size version. And you're right about the weight and their planes being tail heavy. This 50 size plane is 9 lbs running on a 6 cell with a 50 size brushless motor. And it's not any heavier because I had to cut through the firewall so I could move the batteries as far forward as possible as not to add any extra weight to this flying brick. I'm looking to fly this thing within the next month, once I feel the CG is on the money. You only get one chance with the CG, especially with these Nitroplanes CMP planes. Don't buy these planes if you're a beginner. Even a somewhat experienced pilot and arf builder will have problems with these planes.

texaswarbird

Thanks for the tip. This CMP sits in my garage for over a year. I bought it together with the P40 size 50. Most pilot knows it's a lemon now. My P40 crashed so I am not interested in building this Mustang until there are more info available. Now it's time to clear it from my garage; either by up the air, or down the dump.