CMP Kits – Problems and Solutions
06-11-2006 | 12:34 AM
#151
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RE: CMP Kits – Problems and Solutions
I have two CMP arfs flying currently. A 50 size P-47 and 50 size P-51. Both have YS 91's and balance just ahead of the spar. They fly well with the 91's in them. My issue that I have had while building the P-47 was with the paint on the wing and rear stab. The paint jumps off the wing if you even look at it the wrong way. I ended up sanding down the wing and repainting the entire plane. For the P-51 I took a heat gun to the covered pieces prior to assembly. Once the covering was tightened up I went ahead and sprayed all of the covered and painted pieces with top flight flat clear. I've put 15-20 flights on the Mustang and the finish seems to be holding up pretty well. Both planes fly very well with my set up. I have looked at the websites for the suppliers and only have one question.............. spare parts? Cowls, Canopies, etc. it would be nice if you carried some of these replacement parts on the websites. Thanks.
06-11-2006 | 03:32 PM
#152
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From: Iowa CityIA
RE: CMP Kits – Problems and Solutions
Alex,
Sorry it has taken me so long to get back to you... I've been overwhelmed with work this past week.
I finally set my plane on a Great Planes CG machine today. It balances at 95mm from the leading edge at the wing root. I would recommend that people try between 90 and 100mm.
You may recall, before I moved the CG forward, my plane required huge amounts of down-trim on the elevator for straight and level flight. It would also porpoise badly when I slowed for landing, and occasionally would snap. It also dragged its tail when I was banked steeply in turns.... all signs of a VERY tail-heavy plane.
Anyway, I added an additional 5/8" plywood block behind the motor mount (to shim the motor further forward) as well as added lead weight to the firewall. I am using a YS 1.20 (a reasonably heavy motor) and about 8 oz of lead to get it to balance at 95mm.
I don't think that adding weight to the nose is a problem, as this eliptical wing design seems resistant to stall. I would guess that the wing loading could be increased substantially before it becomes unstable.
Most important is the CG. Move it forward! 120-130 is WAY too far back!
I hope this helps some of your customers.
Regards,
Noah
Sorry it has taken me so long to get back to you... I've been overwhelmed with work this past week.
I finally set my plane on a Great Planes CG machine today. It balances at 95mm from the leading edge at the wing root. I would recommend that people try between 90 and 100mm.
You may recall, before I moved the CG forward, my plane required huge amounts of down-trim on the elevator for straight and level flight. It would also porpoise badly when I slowed for landing, and occasionally would snap. It also dragged its tail when I was banked steeply in turns.... all signs of a VERY tail-heavy plane.
Anyway, I added an additional 5/8" plywood block behind the motor mount (to shim the motor further forward) as well as added lead weight to the firewall. I am using a YS 1.20 (a reasonably heavy motor) and about 8 oz of lead to get it to balance at 95mm.
I don't think that adding weight to the nose is a problem, as this eliptical wing design seems resistant to stall. I would guess that the wing loading could be increased substantially before it becomes unstable.
Most important is the CG. Move it forward! 120-130 is WAY too far back!
I hope this helps some of your customers.
Regards,
Noah
06-11-2006 | 03:40 PM
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From: Minnetonka,
MN
RE: CMP Kits – Problems and Solutions
ORIGINAL: AK Models
Same as above, also will offer pre-sale.
Now, let's get back to thread's intended use: Problems and solutions ONLY.
Thank you all for your feedback.
Same as above, also will offer pre-sale.
Now, let's get back to thread's intended use: Problems and solutions ONLY.
Thank you all for your feedback.
06-11-2006 | 08:29 PM
#154
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RE: CMP Kits – Problems and Solutions
My .60 size zero (World Models)(see my review of this ARF here on RCU) is a rocket with my YS .91 in it. This is my favorite plane to fly. I initially put a Saito 125 in the zero but, decided to try the YS .91 and the YS had lots more power. The flaps on this zero really work great and slow the plane right down without stalling it or causing other irritating problems.
If you want a Zero, get the World Models .60 size and whip a YS .91 or 110 in it and it will quickly become your favorite warbird to fly.
Forget the CMP crap. World Models will stand behind their products. CMP will just give you a bs story or even worse, just ignore you.
Your .50 size planes must really scream with the YS .91's in them.
About the only redeeming quality about CMP's .50 size Zero is that it looks cool after it's been shot down by a paintball gun.
If you want a Zero, get the World Models .60 size and whip a YS .91 or 110 in it and it will quickly become your favorite warbird to fly.
Forget the CMP crap. World Models will stand behind their products. CMP will just give you a bs story or even worse, just ignore you.
Your .50 size planes must really scream with the YS .91's in them.
About the only redeeming quality about CMP's .50 size Zero is that it looks cool after it's been shot down by a paintball gun.
06-11-2006 | 09:46 PM
#156
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RE: CMP Kits – Problems and Solutions
All of the pics of the foregoing planes are better products than CMP puts out. I have built and flown all of them and can speak from experience. Buy one of these instead of wasting your money on CMP's crap.
06-11-2006 | 09:57 PM
#159
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RE: CMP Kits – Problems and Solutions
More still. Jacquiline should have simply been more respectful if not helpful in resolving my issues with the crap they sold me rather than ignoring me. I guess they will just have to read about me whining infinitum about the garbage they sell and how they fleeced me on some of their garbage.
06-12-2006 | 12:12 AM
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From: Butte,
MT
RE: CMP Kits – Problems and Solutions
Jimmy Skids, sounds like the way my .90 Spit flies, more like 3D plane than a warbirb. I was flying it for the first time yesterday and when i was going vertical if I gave it more than a hair up on the elev. it would literally flip it over forward like a 3D and the tail would almost want to go straight down in the corners no matter how slow or what angel of approach i used. It's balanced at 125mm. I wonder if the CG of 90 - 100mm applies to this plane as well. Would be more practial and make more sense. MANUALS NEED TO BE REWRITTEN. They do absolutely nothing for the setup other than confuse you.
At just over 11 lbs with the RCV .91 and a 14x7 APC I am only getting 8000 rpm out of the motor and it seems very under powered, in comparison to the the vid from YT with the same plane/motor combo. Starting to wonder about that, even with a 20mph tail wind it was slow and sluggish at best.
Going to glass the wing and rear stab and paint it then get a gas motor and see how it does. Got some video of the maiden flights yesterday and will post them when I get done with them so you can see what i was talikng about.
SHane
At just over 11 lbs with the RCV .91 and a 14x7 APC I am only getting 8000 rpm out of the motor and it seems very under powered, in comparison to the the vid from YT with the same plane/motor combo. Starting to wonder about that, even with a 20mph tail wind it was slow and sluggish at best.
Going to glass the wing and rear stab and paint it then get a gas motor and see how it does. Got some video of the maiden flights yesterday and will post them when I get done with them so you can see what i was talikng about.
SHane
06-12-2006 | 02:42 PM
#161
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RE: CMP Kits – Problems and Solutions
Shane,
I had the same problem with my CMP Spitfire. I progressively added more nose weight (and shimmed out the enigine, too) until it flew well.
Finally result: Balances at 95 mm. I would recommend 90-100 mm for this plane. Alex from A-K Models is aware of this, and I think that he is informing his customers that this could be an issue.
Good luck,
Noah
I had the same problem with my CMP Spitfire. I progressively added more nose weight (and shimmed out the enigine, too) until it flew well.
Finally result: Balances at 95 mm. I would recommend 90-100 mm for this plane. Alex from A-K Models is aware of this, and I think that he is informing his customers that this could be an issue.
Good luck,
Noah
06-12-2006 | 03:13 PM
#162
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From: Butte,
MT
RE: CMP Kits – Problems and Solutions
Appreciate all the advise, now i just need to get the wing glassed and install the retracts and I'll give it another go. Thanks alot.
Shane
Shane
06-12-2006 | 03:25 PM
#163
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RE: CMP Kits – Problems and Solutions
Shane,
Alex was not exaggerating when he wrote about how much I enjoy taking this plane out to the field, now that it flys like it should. It's a fantastic flyer, but it just will not fly well (or at all, for very long) when set up so tail heavy. I have no idea where CMP got the range 120-130 mm. That far back is ridiculous. I hated this plane with a passion for a long time, and I was about to stomp it into the ground before I sucked it up and started experimenting with the CG. I think Alex posted my email to him over the weekend, but in case you missed it, I also added an additional degree of downthrust to the motor. So, in my estimation, the CG could probably be moved even further forward than 95 mm. I would start there, though.
Good luck with the re-work of the wing.
You'll not be disappointed.
Alex was not exaggerating when he wrote about how much I enjoy taking this plane out to the field, now that it flys like it should. It's a fantastic flyer, but it just will not fly well (or at all, for very long) when set up so tail heavy. I have no idea where CMP got the range 120-130 mm. That far back is ridiculous. I hated this plane with a passion for a long time, and I was about to stomp it into the ground before I sucked it up and started experimenting with the CG. I think Alex posted my email to him over the weekend, but in case you missed it, I also added an additional degree of downthrust to the motor. So, in my estimation, the CG could probably be moved even further forward than 95 mm. I would start there, though.
Good luck with the re-work of the wing.
You'll not be disappointed.
06-12-2006 | 03:32 PM
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From: Butte,
MT
RE: CMP Kits – Problems and Solutions
I did put a degree of downforce in the motor prior to this outing and I must say it helped a ton. I could actually run it the length of our runway (700') and it would'nt try to rocket off the ground until I wanted it too. My feeling were the same as yours going out thiw weekend, it was fly or die. Fortunately it flew well. Really looking forward to getting this right. We had a bunch of Spits at the Warbirds Over the Rockies this weekend and they are very cool in the air. We even had a fullsize Spit along with a B-17 and a Mig-17 do fly by's while the show was going on, will post some pics here shortly. Thanks again.
Shane
Shane
06-13-2006 | 12:35 AM
#165
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RE: CMP Kits – Problems and Solutions
My World Models Zero really rips with a YS .91 in it. I put about 6 flights on it today. This plane is an outstanding ARF. Control surfaces come all hinged. There isn't much to do to complete her and the flaps work great.
Don't bother buying CMP's crap. This zero will not cause any headaches and the CG was right on and the plane needed no extra weight to balance.
Don't bother buying CMP's crap. This zero will not cause any headaches and the CG was right on and the plane needed no extra weight to balance.
06-13-2006 | 01:04 AM
#166
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RE: CMP Kits – Problems and Solutions
Unfortunately, before I figured out the problems with the CMP .50 size Zero's that I had bought, I bought a CMP Spit.. I have it completed but, have not yet flown it. I am in no hurry to fly it. I have a YS 120 in mine and the final weight of mine is 12lbs 10oz. It is on the heavy side because I detailed the cockpit a little bit and added a full size pilot.
I thought about hinging the canopy and putting a parachute on the pilot and when the plane rolls the pilot would drop out. Any of you guys try anything like that?
I balanced mine at 115mm but, still left it nose heavy. I needed 9oz. of lead in the nose to balance it.
I doubt that any motor that can only turn a 14x7 APC will be enough to pull an 11lb.+ plane. If it does pull it, it won't be much fun to fly with that motor in it. It would certainly make take offs and landings eventful. It's nice to have the extra power especially to take off of my clubs grass field that resembles the surface of the moon from all of the grubs and gopher holes. Short roll-outs are a must on crappy grass runways.
Funny thing is that my CMP Spit and my KMP ME109 look like they were made in the same factory. I also thought this about my Hangar 9 ARF's and my Sportsman Aviation Spit. Yet the reports about the KMP ME 109 are not at all like the negative stuff we've heard about CMP's planes. So, coming from the same factory, CMP IS capable of correcting the problems but, simply chooses not to.
I thought about hinging the canopy and putting a parachute on the pilot and when the plane rolls the pilot would drop out. Any of you guys try anything like that?
I balanced mine at 115mm but, still left it nose heavy. I needed 9oz. of lead in the nose to balance it.
I doubt that any motor that can only turn a 14x7 APC will be enough to pull an 11lb.+ plane. If it does pull it, it won't be much fun to fly with that motor in it. It would certainly make take offs and landings eventful. It's nice to have the extra power especially to take off of my clubs grass field that resembles the surface of the moon from all of the grubs and gopher holes. Short roll-outs are a must on crappy grass runways.
Funny thing is that my CMP Spit and my KMP ME109 look like they were made in the same factory. I also thought this about my Hangar 9 ARF's and my Sportsman Aviation Spit. Yet the reports about the KMP ME 109 are not at all like the negative stuff we've heard about CMP's planes. So, coming from the same factory, CMP IS capable of correcting the problems but, simply chooses not to.
06-13-2006 | 05:59 PM
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From: , URUGUAY
RE: CMP Kits – Problems and Solutions
hi i have a cmp edge 540t first flight tail heavy . got it down ok just !!!!!
does any body have one of these if so can you give me a cg or maybe i need down thust!!!
all help wil be good!
does any body have one of these if so can you give me a cg or maybe i need down thust!!!
all help wil be good!
06-13-2006 | 08:46 PM
#168
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RE: CMP Kits – Problems and Solutions
Different plane, same story. I don't get it. I can't believe that any company that manufactures a product does not test it prior to shipping it to the public. CMP needs to get their act together. CG is a very basic but critical component of a build and builders rely on the manufactureres stated CG. The sadest part is that they do not seem to care. It doesn't appear that they have taken any steps to notify people who have purchased their planes (or their distributor's) of the problems or better yet try to corret them. Sorry for the rant, but it sucks putting a new plane in, but it really sucks when it not your fault.
-- end of rant--
-- end of rant--
06-14-2006 | 07:24 AM
#169
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RE: CMP Kits – Problems and Solutions
I have the 70ws 1.20 big camo P-47 and i have the big 1.40 72.5ws P-51 both un flown. Has anyone flown these planes that can list there COG?.
After reading so much about the listed on the plan cog being wrong im kinda worried.
Thanks
After reading so much about the listed on the plan cog being wrong im kinda worried.
Thanks
06-14-2006 | 01:34 PM
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From: , URUGUAY
RE: CMP Kits – Problems and Solutions
i had a uk display pilot fly my edde movedthe cg forward 15 mm and cut down the throws fly's better
still does anybody fly one and if so what did they do to rectifie this problem
still does anybody fly one and if so what did they do to rectifie this problem
06-28-2006 | 03:37 PM
#173
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From: San Diego,
CA
RE: CMP Kits – Problems and Solutions
I have the CMP 120 Zero with a Saito 180 in the nose. I have over 50 flights on the plane.
Here are the issues I have but overall I love the plane:
Wing or tail incidence is off as I have to fly the plane with a lot of down elevator to maintain level flight. There is no way to adjust the wing in the fiberglass saddle.
I wish it came with flaps as it is so hard to get the langings really smooth... may be from the incidence.
The paint chips easy but is not a big deal as I have a match touch up for both colors.
The epoxy for the servo & Fuel tank trays is weak and needs to be redone.
You need ot add elevator and rudder controll rod supports mid way in the fuse to keep them from fluttering and breakage.
Overall it has no bad habbits and is just a great fun to fly bird. The saito 180 has unlimited vertical yet flights need to be kept at 5-7 minutes. GSP also keeps some of the parts in stock as I was able to get a new canopy.
Here are the issues I have but overall I love the plane:
Wing or tail incidence is off as I have to fly the plane with a lot of down elevator to maintain level flight. There is no way to adjust the wing in the fiberglass saddle.
I wish it came with flaps as it is so hard to get the langings really smooth... may be from the incidence.
The paint chips easy but is not a big deal as I have a match touch up for both colors.
The epoxy for the servo & Fuel tank trays is weak and needs to be redone.
You need ot add elevator and rudder controll rod supports mid way in the fuse to keep them from fluttering and breakage.
Overall it has no bad habbits and is just a great fun to fly bird. The saito 180 has unlimited vertical yet flights need to be kept at 5-7 minutes. GSP also keeps some of the parts in stock as I was able to get a new canopy.
06-28-2006 | 04:14 PM
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From: Warner Robins,
GA
RE: CMP Kits – Problems and Solutions
So far my dad and I have two of the CMP models. Pop has the .50 Giles 202, and I recently got the .50 Yak, and one of the local guys has the Swallow .90, and there are a couple of warbirds around too.
Im really impressed with them for the price. They are decent airplanes for the low cost.
The Swallow flys just like a pattern plane. Not much more to say. Smooth, and sharp.
The Giles flys well too. It slows down really well, and floats for miles. Really surprising for its low wing area. Rolls really well on axis, and looks GEORGEOUS with that wild paint job.
I havent finished my yak yet, but come on....120 bucks for a fiberglass yak. DIRT CHEAP
So far in building it, I havent run across any problems. You dont even really need an instruction manual if you've built arfs before. Its pretty self-explanitory. The manuals do leave alot to be desired considering they are in chinese...but they have pictures even an idiot could understand. The plane looks great. Nice paintscheme, glossy smooth fuselage. Ive seen worse kits.
Im doing a build thread on the yak right now...its located here
http://www.rcuniverse.com/forum/m_43...tm.htm#4397872
You would think no one on here knows how to calculate a planes correct CG based on the posts. You do know you can measure the wings, and calculate where the CG is supposed to be.
Both mine and my dad's plane came from Nitroplanes.com - havent had any problems ordering from them. Order it...its at your house in a week. No problem.
Im really impressed with them for the price. They are decent airplanes for the low cost.
The Swallow flys just like a pattern plane. Not much more to say. Smooth, and sharp.
The Giles flys well too. It slows down really well, and floats for miles. Really surprising for its low wing area. Rolls really well on axis, and looks GEORGEOUS with that wild paint job.
I havent finished my yak yet, but come on....120 bucks for a fiberglass yak. DIRT CHEAP
So far in building it, I havent run across any problems. You dont even really need an instruction manual if you've built arfs before. Its pretty self-explanitory. The manuals do leave alot to be desired considering they are in chinese...but they have pictures even an idiot could understand. The plane looks great. Nice paintscheme, glossy smooth fuselage. Ive seen worse kits.
Im doing a build thread on the yak right now...its located here
http://www.rcuniverse.com/forum/m_43...tm.htm#4397872
You would think no one on here knows how to calculate a planes correct CG based on the posts. You do know you can measure the wings, and calculate where the CG is supposed to be.
Both mine and my dad's plane came from Nitroplanes.com - havent had any problems ordering from them. Order it...its at your house in a week. No problem.
06-28-2006 | 04:20 PM
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From: Warner Robins,
GA
RE: CMP Kits – Problems and Solutions
I'm on my 3rd one of these.
Plane: CMP 3D Giles 40 size
Engine: Tower .75 (I know, but it hovers at 1/2 throttle and pulls out like you shot it from a cannon)
Problems:
Firewall is weak. It's just 2 pieces of lite ply and it's very weak. I cut it out with a hobby knife--takes about 2 minutes. I replace it with 1/4" hard ply.
It needs a tailwheel. The wire skid that comes in the kit is useless. You can't control the plane on the ground unless your constantly blipping the throttle to get the rudder to work--then you end up taxiing around at unsafe speeds.
The Stock wire gear is weak. I replace it with aluminum gear. Specifically, I buy the gear from the Great Planes 25% Giles ARF. Cut about 1" off each side (2-piece gear) and then install a hardwood plate in the fuse to bolt it up.
The pushrods could be upgraded to a heavier size. I find them to be kind of undersized for this plane. It's similar to 2-56 size and it needs to be closer to 4-40 size.
This is a longshot:
I'd like to see the fuse design changed. It's VERY weak under the wing saddle. This is because the whole top of the fuse is the plastic canopy.
Change the design so that the wing attaches from the bottom and has a belly pan on it. Build up the top of the fuse like most other planes and get a standard size canopy instead of the huge plastic piece that the plane has now.
This would add a tremendous amount of strength. The plane isn't really all that light to begin with--so changing the fuse desin won't kill it.
I know that this would involve a complete redesign of the aircraft, and also a re-tool at the factory. It probably won't happen, but it would make the plane a lot nicer. Just wishing out loud more than anything.
If you could get the LG, firewall, and hardware beefed up--I'd be tickled.
Thanks for listening. I hope this was constructive.
Plane: CMP 3D Giles 40 size
Engine: Tower .75 (I know, but it hovers at 1/2 throttle and pulls out like you shot it from a cannon)
Problems:
Firewall is weak. It's just 2 pieces of lite ply and it's very weak. I cut it out with a hobby knife--takes about 2 minutes. I replace it with 1/4" hard ply.
It needs a tailwheel. The wire skid that comes in the kit is useless. You can't control the plane on the ground unless your constantly blipping the throttle to get the rudder to work--then you end up taxiing around at unsafe speeds.
The Stock wire gear is weak. I replace it with aluminum gear. Specifically, I buy the gear from the Great Planes 25% Giles ARF. Cut about 1" off each side (2-piece gear) and then install a hardwood plate in the fuse to bolt it up.
The pushrods could be upgraded to a heavier size. I find them to be kind of undersized for this plane. It's similar to 2-56 size and it needs to be closer to 4-40 size.
This is a longshot:
I'd like to see the fuse design changed. It's VERY weak under the wing saddle. This is because the whole top of the fuse is the plastic canopy.
Change the design so that the wing attaches from the bottom and has a belly pan on it. Build up the top of the fuse like most other planes and get a standard size canopy instead of the huge plastic piece that the plane has now.
This would add a tremendous amount of strength. The plane isn't really all that light to begin with--so changing the fuse desin won't kill it.
I know that this would involve a complete redesign of the aircraft, and also a re-tool at the factory. It probably won't happen, but it would make the plane a lot nicer. Just wishing out loud more than anything.
If you could get the LG, firewall, and hardware beefed up--I'd be tickled.
Thanks for listening. I hope this was constructive.
ALL OF THE ABOVE were done to the giles as we recieved it.
Firewall replaced with beefed up one
Tailwheel included
Carbon Fiber landing gear...nice!!!
Pushrods are 4-40
Wing saddle changed to have a bellypan, and the top of the fuselage is fully boxed in
