bicyclemonkey

My Feedback: (7)

I picked up the CMP Spitfire 120 a couple months ago and I'm thinking about building it next.

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My buddy has a brand new Aerovate 20cc he'll sell me on the cheap. Is this too much motor for this plane? I was thinking of a 1.20 four stroke since that's whats suggested but I like the idea of getting a good deal on the gas motor and getting to use cheap fuel. Plus I hear too many people at our club complaining about glow fuel and the mess.

What do you guys suggest? This will be my first fuel plane, everything else I have is electric so I know NOTHING!

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Experten109/40

My Feedback: (-1)

well I can only speak for myself, but I hate the fact that there are some beautiful WarBirds
flying around sound like weedwackers. thats like nails across a chaulkboard to me. so I
bit the bullit and bought THIS.

anyways, a 20cc motor isn't to big in my opinion.

bicyclemonkey

My Feedback: (7)

I know, weedeaters or chainsaws is how every plane at my club sounds. I'm really thinking about the four stroke even though the fuel is expensive and messy but the 20cc was offered to me for only $150. I just don't want the plane to be way over powered or the motor be too big that I have to hack up the cowl to get it to fit.

Experten109/40

My Feedback: (-1)

the one I bought is a 4-stroke GAS, not NITRO/glow. only 30 ounces.

bicyclemonkey

My Feedback: (7)

Ahh, I see that now. So, 20cc should be OK?

Experten109/40

My Feedback: (-1)

well I know alot of people are using the DLE 20cc in that size aircraft w/o problems.
so I assume so. but I'm sure somebody will confirm that.

big max 1935

My Feedback: (9)

A .60 engine is 10cc & that would make a 1.20 a 20cc engine. As long as it will not mess up the cowl too much I don't see any great difference. Max H.

bicyclemonkey

My Feedback: (7)

We're talking two stroke to two stroke right?

big max 1935

My Feedback: (9)

Now days I can see very little difference in power in any of them, two ,four or gas. If any at all I think the gas comes up at less power than the others . I sometimes use gas just for the extra nose weight for balance. A lot depends on prop size & nitro content with the glow engines. To me I like the gas for the cheaper fuel. Max H.

alanc

its a toss up, an engine that sounds like a hi-powered bee, or an engine that sounds like a continous farting noise, the 4 banger has been lauded as the scale engine sound, well, for me, its an abomination of a noise,but to theear, the most accepted,ideal, as P40K has stated, is 4 stroke gas, but can you justify thecost to the worth of the VERY semi scale looks of the spitfire that you have? you state electric is your passion, spend your money ona lekky set up, and go the bendini sound system, at the Brit nats, we had one of our hurricanes out front, with this system, totally merlin, with machine gun fire, never thought i would say it, but lekky is the way forward, stick withwhat you know,

LDM

My Feedback: (15)

The original CMPS were all suggested at 120 4 strokes . The performance written up by modelers was marginal if any details were added such as retracts ect and the needed to weight to balance .
The new CMPs while mainting much of the same specs are declared as 140 thru 180 size warbirds by the CMP .
I am not a fan of rocket powered warbirds but I am also not a fan of under powered ones .
The Spitfire will need nose weight , now if you build them like me I move all my servos as far forward as possible even at the expence of designing my own boxes in the wing , turning the servos on there side and running 4-40 rods with zero flex . This method moves the 4 wing servos ahead of the typical CG .

So dont be afraid to look into a 140 or larger 4 stroke with a 90 degree bend or turbo muffler to keep it all in the cowl

Edwin

My Feedback: (2)

I had two cmp 120 spitfires. Flew them both with saito 120s. Definately NOT over powered. It will give a little extra for emergencies. In my opinion, the perfect match would be a saito 150 or 26cc gasser. I have also flown the rcgf 20cc and saito 120 in the same plane to compare power. Pretty much equal in my opinion. The only difference was the little bit of extra weight with the gasser. You will find that the cmp airframes build a bit on the heavy side. They takeoff and fly ok. Stay on the throttle while landing, the stall is nasty. The stall is pretty standard warbird mostly break to the left. I lost my first one when I flew through the sun and lost sight of it. The second I flew for a couple of years then sold the air frame. Lost interest in flying it. I would highly suggest you throw all the hardware away. Its very soft metal, the screw heads twist off. Even though I used their control horns I would suggest replacing them. They are a hard plastic and brittle, but I didnt have any break on me. Just one of those warm fuzzy thoughts. I ripped out the servo tray and moved all the servos up to the cg to help keep the weight down. I was able to balance it without any led doing that. Pay very close attention to the retract mounts. They cut lightening holes in the ribs in the two I had, very bad. I would suggest beefing them up with some 1/8" ply. You will have to cut some of the mounting rails out anyway to fit any of the major brand retracts. The cg location is the only thing of use in the manual, they got it right on this one. CG location on many other cmp planes is wrong. When drilling the holes for the wing mounts in the fuse wing saddle be careful not to go too deep, only until you break through. Otherwise the bit will punch through the fuse wing fairing. I did that on my first one and had to do some glass work to fix it. If you look closely at one of the ad pictures on Nitro Planes web site you'll just barely notice where they did it too. You can see their patch, mine was in the same place. I found the flaps to be useless and on the second spit, I just glued them in place and saved the weight of the servo. I used spring-air 85deg retracts with 1/2" struts, looked pretty good. It wasnt no barn burner but it looked fairly good in the air for the money. Take all this with a grain of salt, some people thought it was a great plane. Personally, I think its ok for the price and the work you have to do to it. You raise the price, it wouldnt be worth it to me.
Edwin

Forgot to mention, the glass work is polyester, not epoxy. I didnt have good luck getting epoxy to stick to the fuse when mounting things. So I used goop from the hardware store. Worked great. I think I used JB weld on the wing fairing patch. That was a long time ago.
Edwin

bicyclemonkey

My Feedback: (7)

I seriously am the only one at my club that brings electric planes to the field (so far my largest is 63") so there's pressure to go fuel. Everyone at the club is on the gas powered band wagon and I hear nothing but complaints for glow fuel from them. I like electric but kind of want to try something new. It also gets pretty annoying because if my plane is the only one in the air all is fine but as soon as someone cranks up their fuel plane I can't hear my electric plane anymore. I'm thinking of keeping my electrics smaller in size for use at the park/soccer fields close to my house and flying fuel on the large stuff at the club field.

This Spit has a few scale issues (the canopy and the fuse length seems too short) but for $177 I figured I'd try it for my first large warbird.

alanc

Dont want to get into the scale wotnots of the CMP spit, suffice it to say its not the best, and goes further than the small amount you have noticed, BUT, its a good flying thing, and better than a lot out there, but that engine, why should you want to bend to the gas boys? forge a new path, go with your gut, when they hear the thing, with a bendini sound system blasting out, they will be the envious ones!!!

the hurri on our stand attracted many, many admiring comments, the realism, from merlin start up, to the merlin crackle, its not just a merlin, its got the startup, throttle up, and theengine goesright through, the rev range, even the shutting down is totally authentic, and, for an additional thing, you get the sound of 8x 303 machine guns too!!! now tell me, who will be the detractor, you, or your head in the sand gas buddys

tevans55

The decision is easy to make. You indicated you don't want to hack up the cowl so borrow the engine and set it up inside your cowl and see what the damage will be. I have the ESM Spit (about the same size) and I am using an OS 120 AX inverted with a JTEC wrap around pits muffler. The only openings are under the nose with nothing but the pipes out the bottom. Good luck on your build!

By the way, if you go to youtube and look under RCRCKY and go to KMP Spitfire I think mine is still listed there.

LDM

My Feedback: (15)

Edwyn , great point agree 100%
Alac same on your end , good points about eflight , I thinking of moveing all my fuel birds to e-flight

bicyclemonkey

My Feedback: (7)

I really do like electric but probably wouldn't go to the expense of putting a sound system in this cheesy CMP spit, maybe the ESM 89" would be deserving of one. The fuel guys are always joking with me about electric not being able to fly as fast as the fuel planes, so it would be neat to build this thing electric and fast and prove some people wrong. The threads I've followed of this plane being converted to electric the builders have had to use 10s or 12s packs just to get enough weight up front to balance.

LDM

My Feedback: (15)

Again , the balance can be solved in the assembly if you also move the wing servos forward , that is key .
I was a fuel guy , 100% on the fence with fuel vs eflight . So for fun , I got 55" airfield P40 , the ease of pulling up to the field , getting out and plug in a bettery , wow !!!
I am really starting to hate taking a field box , fule , charging the starter battery ect .
Fuel engines at $300 plus , when I can get a powerful motor for $50 thru $100 bucks , same with batterys now that they have come down in price .
Eflight is definitly in my future , its easier and I can do some chores around the house while chargeing my batterys under my watchful eye , so I can duel task then head out to the field

alanc

the sound system, motor, batteries, are not welded to the plane, they can always be transplanted to something better when the time is right, and the plane, with no cowl cuts, still fresh, will sell for a good pricemaybe to the gas jockeys

our 50cc spit is in another ball park, to lekky that one would take$$$$$$$$$$$ it will be done by someone i expect

LDM

My Feedback: (15)

Not to change the thread , but is there a turnkey sound system that is sold complete for the CMP /ESM size planes ?

bicyclemonkey

My Feedback: (7)

I can pick up the 20cc gas from my buddy for $150, then pay $2.69/gallon for fuel and fly all day long.

The 5S 5000mah batteries even from Hobby King are $50/ea. I would need a pair of these and only get 15 minute flight times approx. So if I have two pairs of batteries, there's $200 in batteries for approx. 30 minutes flight time. Then I'd have to go home and charge the rest of the day.An appropriate motor is about $45 from Hobby King.

It would seem that as long as you can get a gas engine for cheap, the electric is best left to planes that can run on no more than 4s or a pair of 4s etc.

I have a 78" Tigermoth that is E-ready and it will run on 8s 5000mah and a motor that cost me like $35 from HK.

I think if I can build this one to run on a pair of my 4s batteries I'd do electric...So I may give it a shot yet.

Experten109/40

My Feedback: (-1)

nah man, go gas! won't regret it at all. trust me, at the field, your gas engine is going to be louder
then any electric.. even with the speakers. + that sound system weight 1lb-1 1/2lbs. now you
gotta figure out speaker placemant, cg, etc.

Edwin

My Feedback: (2)

Hey monkey,
I'm not an electric fan but theres a guy in our club thats all electric and flys a large 3D plane (along with his heli's) on two 5s 4000ma lipos. He has a charger that can full charge both of them in 15 minutes. He uses a 1000w high dollar charger, but it works great. These also arent your average lipo batteries either.
Edwin

SkyPilot101

I have the rcgf 20cc (realy 23cc) installed in a Seagull 120 Decathlon AND, all I can say is GO FOR THE DLE 20! It's not only stronger, pulling almost 15 lbs of thrust compaired to about 12 for the rcgf, but slightley smaller, making for a cleaner install. Keep in mind your total all up weight, for spirited performance you want at least 25% more thrust in lbs than the plane weighs. For a plane weighing 14 lbs, I would recommend the dle 30, with 18 lbs thrust.

For those complaining about weed wacker sound I say HOGWASH-Listen to this Spit with 50cc http://www.youtube.com/watch?v=H6q_STb5mQw

bicyclemonkey

My Feedback: (7)

The manual says model weight is 10lbs. So after retracts and stuff (I hope the ESM Spitfire retracts will fit) I'm guessing it may weigh up to 12lbs? I may be cutting it close with the Aerovate 20cc it seems.