oldfart Elite Veteran Location: Vancouver, Canada
My Posts This: Topic Forum | Hawk IV with OS46Evan,
If you are running such a light load on the 46 (any 550mm blades) it will become hard to set for a "fat and happy" engine. Specially with an overly restrictive muffler, a light loading (no fuseage), and 32 gearing. (this will eliminate the foaming). Without the proper loading, it will be impossible not to have "lean" spots in the curve that will make the engine run harsh and vibrate causing foaming. As you may know, once the top end needle (main) is set properly, the hover needle is used to set for a smooth hover (no foaming). If the engine is not being loaded properly or has too restrictive an exhaust system then this "happy" hover setting on the idle needle will be hard to find without ending up overly rich at idle (engine will load and not want to run or accelerate). Then you may have to do the "hole" in carb casing mode.
NOTE: see my post lower down on "OS46 in Hawk IV".
1 - Who at Century told you that there is no gearing change for the heli? There may have been some misunderstanding or the info may have been given by a new employee, because there is such a thing. It is the primary drive pinion from the Falcon SE V2 - the 14T unit (the Hawk comes with a 13T one), part #CN2226 I believe.
2 - The stock 550 woody blades are very light and fully symmetrical. For best auto performance at the scale weight (with the fuselage) I would recomend some 550 semi-symmetricals like the FunKey, Hurricane or LT units. If you can afford them the Hi-Product Junior M's.
If you can get some wide chord 560mm units they would help "load" the engine better.
The best way to explain the "lack of performance" is to use a planker example. If one would put a 60 on a 40 size plane, but use the prop from the 40 size plane, he would find he has gained ,more RPM but not much "performance". Like running your car in a lower gear all the time - lot of reves but no go.
Givng us your TX numbers is relatively meaningless without associating them to "pitch" of the blades. You will find that "X" amount of pitch at "Y" rpm may be enough to hover a 6.5 lb. heli, but it will not lift an 8 lb. on the sme blades. That would require an increase in either X or Y or a combination of both. The settings of the pod and boom configuration of the Hawk IV is a lot different then those of my 81/2 lb. Bell 222 or that of my 4 stroke Schweizer 300.
As for the tail control, does it use the Hawk IV system (2mm pushrod through guides), or the old Hawk I " 1mm wire in nylon tube" system? |