Confused! MIxture or Pitch?

[MotherGoose]

I've been flying planks for some 10 years and only recently started heli's. Got a Century hawk Pro, with ASP36 swinging the rotor. Problem is: VERTICAL performance lasks (my opinion) Sounds like blade speed runs out after about 30 feet or so in the vertical. Engine runs very cool, not a great amount of smoke though. Any ideas to help a converted "planker" out?

[BLACKHAWK DOWN]

prolly the pitch
ive recently done a lil reading on nitros as im trying to go from eletric to nitro birds
mabey ur bogging or racing the engine? to make it sound differnt
it should be fulent like a spanish speaker.
i cud be wrong but thats what i think it is

[easydoesit]

I would guess that your mixture is too rich. If it climbs 30 ft, the pitch should be ok. I would try leaning it just alittle, and see what it does.

[hawkman]

Hi Mothergoose.....quite a name there;-)

I might be able to help out, I have a Hawk Sport....the Pro is the jazzed up version with all the goodies like thicker feathering shaft....ballraced joints all around....and rear mounted tail servo etc etc.

I am really impressed with the Hawk.....mine could do with ball raced/bearing supported joints to take out some of the 'play' but then my servos are nothing special...they need to be ballraced too.

Anyway...I will stop blithering and try to help.

My Hawk is powered by an OS 32...your ASP 36 should be able to kick ***...

How much pitch do you carry.....I mean collective pitch....too much can cause some problems......your Gyro might be compensating as well....it could well add loads of correction which will also be a 'loading' factor....its not a huge factor but it will contribute.

I personally use -9 degrees...collective right down, +2 degrees...mid collective and +9 degrees collective right up......I might well revise these figures and go for -7, 0 and +7 degrees.

You really dont need anything like +10 degrees......and anything above that will cause big problems.......your engine might need tuning too.....there should be smoke...not too much...as long as you get oil deposits on the skid etc then you should be ok.

You could try some 'headloaders' these bolt on and replace the main blades...you can then run the engine and rev it up and adjust the carb if need be....just dont get hit by the headloaders. These devices are not perfect and cant really replicate your blades varying degrees of resistance as they go through their pitch range,......but you will be able to run your engine and get it within the right range of performance.

So......revisit your collective pitch arrangment.....if you do readjust then go carefully...if you set it up like mine then you will have a transformed machine...mine flys better now.....the whole idea of this pitch set up is to have it the same as for inverted flight/aerobatics....the throttle curves are different of course...but as you switch modes then there is no difference in stick positions...as such.

When you check your pitch range make sure the flybar is 90 degrees to the main shaft.....you can easily make a jig to attach to the boom.....the other end is fastened to the flybar to hold it in position.....make sure the swash plate is as level as possible.....or 90 degrees to the main shaft too.....I set mine by eye and have had no problems...but do get that flybar set up...you can then read off the pitch range.


10 years on Planks?? I started on planks a couple of years back....I still fly them...only got 1 left now....a crash resistant/tough low wing stunter...lovely little plane it is too.

I really am stuck on Helis now though.....they were the ultimate RC machine to fly.....I did a year on simulators whilst saving up for the real thing....first got hovering almost a year ago....now doing mild aerobatics plus inverted....wobbly inverted:-).....flight. Thinking about getting a 50 size Century Falcon........this is the coolest hobby ever.

Do keep in touch and let me know how things are....


Rob

[MotherGoose]

Thanx for the reply,can use all the help I could get. Question now is: WHICH NEEDLE?? I've run in the motor for 4 full tanks, and adjusted like the manufacturer indicated. The needle valve is 1 1/2 turns open and the idle about 2 from the point of letting air through if blown through the fuel line with throttle closed. Quarter stick sounds a bit rough thoug. As I increase throttle just over quarter, there is a sudden increase in headspeed, and just before liftoff headspeed is nice and high (no means of telling the RPM - but sounds like other heli's I've heard flying before). After hovering for a while, landing and closing throttle completely, the revs hang for a while (5secs) before settling in low idle. The engine runs surprisingly cold, i can put mu finger in the rear crank-case cover and hold it there without burning. What do you think? Leaner on idle or on main needle, and how do i destinguish between symptoms before deciding which one to adjust in the future (planks didin't really needed mush adjustment on the idle valve) Hope to hear from you soon 'cause i'm a bit scared it might cut on me in-flight - only have simulator auto practice, but radio set-up fpr Thr Hold.

Greetings Frikkie

[MotherGoose]

Thanx for the quick reply, astnished by you guys' enthusiasm!! Makes me wonder why I only joined now.... would have made my decision of buying he hawk much easier. Its quite new in South Africa, and only one dealer stocks the kits and parts. It has been around for just over a year (Sport) and i bought the first Pro in SA!! Lotta pressure on me now to perform....

Now, in normal mode I'm running -3, mis stick +4 and +9 on tops. No real experience in how much should be where, as the Instruction manual doesn't specify reccomended pitch angles like the TT Raptor for instance. I dont want to fiddle too much with idle-up 1&2 right now, first want to get the feel of the chopper. Throttle hold is set-up though with -7, +4 and +9.

Initially in the climb (first 10-20 feet) she climbs real strong and motor seems to cope quite fine, but then you can hear the motor labouring and headspeed dropping quickly - that's when I call quit and bring her right down. This afternoon the engine had no power whatsoever when i came down after the vertical climb, and the headspeed was so low, I hovered wit about 7/8 stick to get her over the landing pad. Thats why i think somewhere i got the mixture wrong as well. Got some advice from Easydoesit as well, will try to take a pic this afternoon with engine running on the ground, see for your self the amount of smoke, it seems too little to me, but hey I'm the rookie here! It just seems like when looking at foto's and videos of other Helis that they produce more smoke. Let me stop here, confusing myself more. Pls keep in touch

Frikkie

[hawkman]

Yeah....most people here are very keen on Helis....they are quite complex little beasts which usually fascinate general onlookers etc.....there are a few myths about Helis....like how impossible they are to control etc.

I would take a good look at your engine settings.....lean the 'Low end' this is usually found on the throttle body.....its a small screw....if you have been involved with planks then you will know what I am saying..it can be found within the throttle arm, deep inside..try adjusting this in a bit....same with the main needle.

I know what you mean about smoke and how much there seems to be on other Helis.....but some of them are using different fuels with different oil percentages....plus the helis could well be set up for aerobatics....higher revs etc.

If your engine adjustments dont improve anything then take a look at your throttle curve....this may need adjusting......I have found my mid stick setting needs about 40 percent....instead of 50 percent......but I wonder about the throttle barrel and its 'curve' ....say the barrel looks to be 50 percent open.....what is its true power percentage?

Not aiming to confuse you here....but do try adjusting those curves.....it sounds like you have a proper heli radio.

You are correct with your Idle up comment.....its better to leave things 'off' untill you master basic flying....your set up for throttle hold is interesting with the -7 degrees. Have you tried doing autos yet? they are tricky to do but will save your machine....or at least a majority of it. I tried autos and actually touched down....but then had a boom strike:-( 30 size blades just dont have the oomph when it comes to autos...they arent heavy enough which is why -7 is needed.....headspeed is what its all about....keep it up and you have energy to play with....and you can land nice and carefully.

Slap that heli down, with not enough headspeed = boom strike which means bent feathering shaft, broken blade(s) and a bent boom. Keep practising on the simulator:-)


First to own a Hawk Pro in SA? I like centurys helis....they are good value and tough...and cheap to fix....you can get away with straightening the main shaft and feathering shaft....a boom can usually be sorted out....I drove a socket down through mine after it got boom struck...bad auto....dont ask;-)


Rob

[MotherGoose]

Hey Rob, thanx for the reply.

The low-end on the ASP is situated inside the barrel, and if i get you right, this is the one to lean it a bit just now. It's now 17:30 and i'm off to the field,will let u know later how it went. Won't pay too much attention on the smoke, as long as the motor doesn't run too hot. So by the way, I had the scary experience of an actual auto on my second circuit!!! Took some time to get the motor running initially, turned out thet the low end was FAR too open, and flooded the whole time and refused to start. With all the engaging of the starter motor, the motor fan nut (on the crank) came loose end on turning downwind I heard a squeeking noise end the motor stopped instantly. (Later to be found that the fan screwed out on the crank thred and stopped against the cooling shroud!) At that time I had -10 set up on Thr Hold..... MISTAKE She came down like a rocket, but luckely i caught her quick, a bit high though, but managed to put her safely on the deck- no damage at all. No need to mention, that was all for that day. Thank goodness for hours on the sim practicing those autos! I must be off to the field, will let you know how it went. Wish me luck!

Frikkie