the pope

Well it looks like you have made your mind up . Get 4x of them and with your $5 servos it will be a fun ride for sure .Just as a FYI a flier at my club went down the hobbyking route with hobbyking servos gas engines etc etc bla bla bla and has crashed more planes then most of us has had hot dinners . Servos burned up causing crashes , engines having probs causing crashes etc etc .(hobby king has its place and I get stuff from them all the time ). Let us know how you get on , I for one am very interested and wish you all the luck in the world . It seems that your not interested in anyones advice so im a bit perplexed why you posted here in the first place . Cheers the pope

Mcubed

I think you need to read back through this thread a bit more, The most pressing problems are excessive vibration, Cam and ignition timing. I can assure you that my motor sheared one of its mounting bolts because of vibration not needle fiddling. As the motor wares in you do need to adjust the carby, once run in is complete you should not have to touch them again unless you change your fuel mix. From what I have seen and74 experienced with this motor some come out of the factory very good and some will shake any airframe to bits. If you are prepared to do some minor modifications to a shaker ( Like putting heavy slugs into the counterweight) then you should have no problems. As to servos, well that is not what this thread is about! Hopefully you get four smooth runners. I am buying some four mil tungsten carbide.

3136

OK so you don't own one of these engines, and you have never run one, yet you know that everyone who actually has bought and run them is an incompetent imbecile who don't know how to use a gas engine.

And perhaps none of the vibration issues is related to poor design and imbalance of the moving parts, it must be user incompetence hey????

OK I dare you to put 4 of these on that connie.

hsukaria

What kinda half-***** engine stand are you using? Looks like some old soap boxes with duct tape? Of course it will shake!!! Did you balance the prop, blades AND hub? The engine sounds nice though

gjhinshaw

My Feedback: (303)

I have NOT made my mind up! The 5$ servos are running GREAT for me as I buy direct and NOT HOBBYKING! The servo is 7.50 and sells for 85 bucks..... Torq. is 420ozin. and speed is .12 at 6V. To me its not a bad servo as I have using them for 5 years now. As one of you said..... If your NOT afraid of doing some extra work on it... I'm not at all.... Are ALL of them bad??? What is the percentage of bad and good???? Some say they are bad and some say they have no issues... Am I correct on this??
I am NOT calling ANYONE names 3136, But YOU are.... There is NO reason to call anyone names, Its just what some people like to do,3136. I have been looking at this engine as its the right size, I have also looked at the RCV engines, But these are hard to find. These would be better as they are STRAIGHT....... A lot of the video's show people moving the needles back and forth, and I see it at our field too... Mark, YES, I know as they break-in you have to lean them out a little..... (little for a gas engine is 1/8' NO 1/2 to 3/4) I am NOT trying to bash anyone, Nor will I.... Unless YOU come at me... Than hang on!!! There is always someone that knows more than you, and some of you don't like that concept... I hope that I am making myself clear on this, If not... REREAD...
I am NOT interested in loosing my plane to poor equipment, and that won't ever happen! If you knew what I fly you would know and understand this. Most know that this hobby is sometimes trial and error, correct? There are planes that have crashed and there are planes that WILL crash. The people that say they have NEVER crashed, They don't ever fly! People that say they have NEVER had a engine die, Have never started one. People that say hey have NEVER had a bad landing or take-off, have NEVER Taken off or landed! Get it????? So.... saying all this I hope you understand where I am coming from and understand that I am NOT bashing, name calling, etc....... understand, I hope.....

w8ye

My Feedback: (16)

Sounds as though you included everything that was on you mind?

SJN

All 4 strokes rock....not matter the brand

gjhinshaw

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No, not really.... People judge you for things being said, NOT for what you are trying to say.... They think of all bad, and not for trying to ask or learn from

gjhinshaw

My Feedback: (303)

I have a couple of those engine's!! LOVE them! I did send them to a guy in Florida who changed them over to GAS!! No more Nitro burners....

ALFIEV

Great to hear of another happy camper!! Congratulations on the maiden flight with the NGH 38. There's quite a bit of negative spin coming through on this thread, some of it justifiable, and I've been guilty of seeing this engine with the glass half empty perception. It's nice to hear some good news..... well done!!

Alf

Heli-NuBee

OK, does anyone else think that we have lost the purpose of this forum? Sorry guys, but I have had good and bad cheap engines and good and bad expensive engines. I don't think we can ever solve that kind of debate here. For example, I had a Saito 180 that ran great but had so much vibration that it shook airplanes apart. I ended up giving that engine away because I could not solve the vibration problem. From what I read on this forum, I may run into a similar problem with the GF-38 but I will not know for sure until I give it a try.

Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

Basil Yousif

My Feedback: (3)

We should be addressing advanced issues like how can we fix a vibration problem - what can be the causes of a problem like vibration. Fuel, Valve or cam adjustment, ignition module etc.

gjhinshaw

My Feedback: (303)

From what I have gathered from this thread is that this engine is like the big Quadra engines. Some of you may remember that we called them "THUMPERS" Great engines, BUT we had to beef the engine mounts up to withstand a Sherman tank blow.
Same thing here it looks like.... Also... Could the poor running be caused by insufficient motor boxes? Remember when they came out with the rubber engine mounts? I remember losing so many RPM's from those things.....and I still have lots of them laying around here..... The best thing we all figured out was to put 3/4 ply on the firewall and bolt the engine and go! Use PLENTY of Epoxy and pin the block EVERYWHERE we could...... Could this be the lost secret to this puzzle????

w8ye

My Feedback: (16)

The advanced solution to your engine vibration problem has been answered twice already.

The answer is: Your test stand is no good. It needs to be a sturdy one.

the pope

Would you be so kind and tell us the brand and model number of your servos ? They sound so good I want some myself . Cheers the pope

PARDAL

I guess if motor vibrates, the energy must be dissipated:
Insulated mounts => motor oscilation
Rigid mounts and or stands => plane vibration
Motor balanced => less vibration in motor & plane.
Think about.

ALFIEV

Makes sense. Don't know if the vibration is really that big a problem. It appears that a lengthy run-in programme results in decreased vibration, and the "dampening" effect of the airframe complete with wings also helps. My experience, and I think others in this thread have also reported, is that this is the case. Certainly, when mounted to my ESM Corsair the vibrations did not seem to be of a magnitude which would "rattle the plane apart". I did have my reservations when I first ran the engine on my test stand. My test stand was made up of a 1/2" ply mount plate fixed to a 2"x2" beam of wood clamped in a workmate (portable workbench) with two large weights slung off the end opposite the engine to ensure it didn't tip forward under engine thrust. To be sure, the workmate was a little "rattly" , but it all worked well and I am happy enough with the outcome.

Alf

PARDAL

I think vibes go from motor to the firewall,then to the fuzelage then to wing and tail.
The fwrd part of fuze is generaly stiff and light and most of the vibes reaches the Rx and servos area.
I've lost an F3A due to vibration of a ST-90 and the damaged Rx (72MHz FM) was packed into 10 mm rubber foam.
I would rather balance my engines.
I noted 4s with ignition presents more torsional vibrations with ignition too much advanced or retarded but after tuning this is not an issue.

I'm affaid "lengthy run-in programme results in decreased vibration" will not happen becouse, teoreticaly, imbalance/vibration are function of rotating and reciprocating masses. These masses dont change with run-in.

SrTelemaster150

Likewise for tuning. An imbalanced engine will not improve with tuning. It will not vibrate more due to not being in tune. It may shake more at idle when out of tube, but at mid to full RPM it is the balance that determines vibration or the lack thereof.

PARDAL

Please, Telemaster, reed again. ""more torsional vibrations with ignition too much advanced or retarded""
Whren you find the optimum ignition advance, it is solved.

Heli-NuBee

I ran my NGH-GF-38 engine for the first time today. The engine ran well but shook very hard. It shook so hard that it broke the motor mounts and the throttle linkage. This engine is not for me and will go into the club raffel this next month. I will replace it with something suitable to the airframe.



Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

Basil Yousif

My Feedback: (3)

Do you want to sell it to me. If so how much - I want a parts engine - [email protected]

You can put it on the stand and run it for 5-10 hours that should get the vibration out. Keep adjusting the valves and check the prop balance. Make sure your near TDC when you malke the valve adjustment. Also make sure the intake manifold bolts are have blue Locktite.

Mine was probably worse than yours here it is running after 5 hours on the bench:

http://www.youtube.com/watch?v=88JDgtFkuUo

mchandrayan

Heli-NuBee
That Bf 109, is that from CMP/KMP?
One of our fellow flyers had this model with an OS 200 four stroke, and the engine broke the mount.
I don't think the issue is with the engine in your case, more of with quality of the model

Heli-NuBee

Thanks guys for your input. It is a CMP BF-109 and the motor mounts are less than stellar. After some consideration, the engine ran well but with a lot of vibration. I think I will try it on another airframe with more sustantial motor mounts.

Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

Basil Yousif

My Feedback: (3)

Right now you can get the BF-109 on clearance at Nitro Planes for $207.97:

http://www.nitroplanes.com/cmpmebf10h12.html

Probably the only Nitro large scale plane in stock they have. I want the 1.20 size Zero but they will probably never get it.