rrTV-PHOTO   New HD TV
HOME   rrTV-PHOTO   GALLERIES   MY GALLERY   HELP-FAQ
myHOME PM pmRR MEMBERS 633 ONLINE 45 EVENTS SEARCH REGISTER  START HERE
 
7 pages [ <<    <     4      5     ( 6 )     7     NEXT    >> ]22171 viewsPOST REPLY
JR-Spektrum . E-flite . Futaba-RC

.
.
e-MS Composit Hornet > MS Composit Scale A-Star AS 350, Ecureuil AS350 with triple rotor head
 
 
mnb5
Heliman
Location: Zurich/Switzerland

Quote 
mnb5,

Is that a kit?

Raz

Yes, it's an inofficial kit by flying-hobby.com. Heli inclouding 4 sub-micro servos and fuselage for 179 USD: http://www.flying-hobby.com/product.asp?productSort=101

regards
mnb5
01-05-2007 Over year old.
 
 
DarkHorse1
Senior Heliman
Location: Gloucester UK

Noise?

Anyone know how to quieten down the plastic gear noise? As it becomes quite loud with the body on and would prefer not to drown out the nice whisper noises from the blades . Any tips, tricks or additives that don't damage gear life span?
02-01-2007 Over year old.
HOMEPAGE  
 
 
Heli PIC
Senior Heliman
Location: Petaluma, CA USA

I initially had bad gear noise when I did my first test fly. After checking the motor pinion and tail output shaft gear individually for proper mesh clearance and adding an extra bearing with a plastic retainer to the tail boom assembly (4 bearings instead of 3), the noise and vibration went away completely. I am very pleased with its FFF performance. I also used green loctite to secure the two inner bearings to the tail drive shaft.
02-02-2007 Over year old.
 
 
DarkHorse1
Senior Heliman
Location: Gloucester UK

Yes, I'm using a 5 bearing tail (3 spaced in the boom) and run quite a tight mesh with some slight lash, just sounds like a large drill when spooled up, made worse with the body on.

It was a bit of a struggle to get the CofG 10mm in front of the main shaft with an 85g 3xTP1320 prolite pack. I made a battery tray extension out of 2mm CF rods to get the pack right in to the nose with the ESC. Also required extending the battery and MS-116 ESC cables . AUW 432g

Not many flight hours on the heli yet so it may quieten down. Haven't really pushed Forward Flight, how fast are you going before 'pitch up' become serious. Looking at the numbers (with this calculator) at 2400 rpm the heli should be capable (in theory) of ~45mph but 'pitch up' may start to become apparent approaching 30mph (add more forward cyclic). What speeds do you observe? At what head speed? How much help are the tail planes at 5º angles?

Look forward to seeing your heli painted soon
02-02-2007 Over year old.
HOMEPAGE  
 
 
Heli PIC
Senior Heliman
Location: Petaluma, CA USA

For your vibration problem, did you check if the tail drive shaft and the boom are perfectly straight? Is there any fore-aft play on the tail drive shaft. You don't what the bevel gears too far in compressing the boom bearings; yet, you don't want any fore-aft play on the shaft. When I pressed the gears in, they were initially too tight. I had to use a pinion puller to reposition the tail bevel gear so that the tail shaft rotate freely within the boom without any fore/aft play. Also make sure that it's the metal insert on the front of the tail shaft that rides on the inner race of the front tail boom bearing. If the front bevel gear is pushed in too far, the back side of the front bevel gear may be touching both the inner race and the outer race of the bearing at the same time causing vibration at high rpm. I had to also straighten both the tailboom and the shaft prior to assembly. I setup my throttle and pitch curves to obtain 2300 rpm head speed when the throttle stick is above 50%.

My FFF is about 25mph. I have not yet explored its performance envelope. The only minuses I noticed are that it does pitch up fairly quickly when executing quick stop and the main rotor does not autorotate well even with -5 pitch.

I am using a Hitec PCM receiver. It's quite heavy when compared with a micro receiver; thus allowing proper CG (1cm forward of the mast) without moving the TP1320 battery forward.
02-03-2007 Over year old.
 
 
DarkHorse1
Senior Heliman
Location: Gloucester UK

> For your vibration problem,
The tail is smooth with the extra bearings and original build drive shaft straightening (learnt from the a few X-3D rebuilds). The only vibe I have is a slight main rotor (low frequency) vibe that shakes my frame and gyro a little to induce slight wag in HH mode (so I run standard rate for super smooth scale tail sweeps). The new head has got delayed and still waiting...

> main rotor does not autorotate well even with -5 pitch.
Your brave to even try it

> PCM receiver.
I would be happier if I were not using the old FM.
02-03-2007 Over year old.
HOMEPAGE  
 
 
Heli PIC
Senior Heliman
Location: Petaluma, CA USA

Finally done

I am not a good artist, so I chose a simple paint scheme for my A-Star. Looks like a bumble bee now.

For those who have finished the build, please let me know if you find it difficult to fly in windy condition.

FFF is about 25 mph at best. Any faster than that will make things interesting.

Here is my setup:
Align hh gyro in rate mode
HS55 servos
Hitec PCM rx
Jeti Spin 11 ESC
3S TP1350
Stock BL motor
Extra tailboom bearing with retainer to prevent vibration.
Use screws instead of crazy glue to secure the tail section to the fuse for easier disassembly during maintenance.
Flying weight 425g

02-20-2007 Over year old.
 
 
DarkHorse1
Senior Heliman
Location: Gloucester UK

 Paint looks pretty good. I know what you mean, simple is best if your artistically challenged like myself also

I noticed a bit of a handful in gusty conditions, constantly in and out of FF is not that nice. Haven't gone above ~25mph either yet. I'm expecting some 'pitch up' effect to creep in with lower tips speeds (~140mph compared to a Hornet at 160 to 190mph) as the difference between advancing and retreating blades air speeds becomes relatively significant.

One thing that may help flying a bit more predictable. Check your cyclic angle response in hover is square to stick inputs. I have slightly advanced the top half of the swash relative to the rotor. ...AR clap advanced for a slight forward skew on the swash to blade links, about a link width or swash ball width and the cyclic is spot on following the Tx sticks. Remember to reset the 0º pitch point back to mid stick. I just add about +10 in the subtrim menu for ch1, ch2 and ch6.
Or if your radio supports, try virtual swash plate mixing but with ~5º-15º it seems hardly worth using it.
02-20-2007 Over year old.
HOMEPAGE  
 
 
Heli PIC
Senior Heliman
Location: Petaluma, CA USA

Dealing with retreating blade stall during FFF

Ways to minimize retreating blade stall issue from my heli flying experience:

1. Slight left cyclic during FFF will better compensate for disymmetry of lift. We automatically do it without thinking in the cockpit because we have the first person perspective.
2. Higher rotor RPM will reduce the size of the reverse flow region of the retreating side of the rotor disc. At higher RPM's, less collective pitch is reqired to maintain altitude; thus reducing the chance of retreating blade stall.
3. RPM management is more effective than pitch due to the fact that the rpm/lift relationship is exponential where as pitch/lift relationship is linear. Remember K=0.5mv^2

FFF is fair if you give it slight left cyclic. But the transition from FFF to hover is still tricky with -5 pitch. I think the heli just doesn't have enough momentum (weight) to allow it to settle gracefully to a hover. I have to plan ahead and decelerate the heli slowly to avoid pitching up. Quick stops are ugly. The rotor doesn't autorotate well and the sudden increase in torque during leveling off usually results in unwanted yawing of the nose.

At this time 25mph seems to be the max manageble FFF speed. Let me know if there is any other thing we can do to better its FFF performance.
02-22-2007 Over year old.
 
 
DarkHorse1
Senior Heliman
Location: Gloucester UK

> if there is any other thing we can do to better its FFF performance.
Higher RPM is the sure way to reduce the onset of any retreating blade stall (pitch up) effect in FF. If you don't encounter vibes, the manual says the head assembly is OK to a max of 2600 rpm. With the fixed 14T/70T/14T conical gear ratio (only 14T conical available) you are limited to the max RPM achievable when running up to 100% throttle (with respect to pitch demands). Or you have to use a higher rpm/v rated motor or try 4s for 3K rpm with a 15K tail!!! Not unless you moderate a throttle curve to 80% max. The increase in voltage should run less Amps and cooler if the RPM and weight didn't rise too much.

I'm using the EM350/20 motor (Axi 2212/20 12A 1150 rpm/v 57g) which will hit ~2500 rpm in hover but I have a main rotor/body interaction oscillation above 2400 rpm, probably some offset head geometry somewhere. So I only operate around ~2300 rpm.


Having observed a stock CP2 experience pitch up effect at low rotor speeds (1800 rpm) I noticed that the fly bar helps reduce the effect. As the rotor changes plane lifting the front of the disk and the flybar resists this change (conservation on angular momentum), you get a situation as if effectively some forward elevator were being applied automatically. Of course we don't have this flybar damping on our 3 blade setups which is probably why we see these little differences in FF handling and FF to hover transitions.
02-22-2007 Over year old.
HOMEPAGE  
 
 
DarkHorse1
Senior Heliman
Location: Gloucester UK

> the sudden increase in torque during leveling off usually results in unwanted yawing of the nose.
Not sure how much torque we are talking about (don't try n say that too fast) but the tail has handled full pitch climbs so far. No ballistic climb as there is some physical delay built into the rotor response (thin chords, soft air bite) but the tail hasn't stepped out on me yet and that's with REVO and standard rate gyro mode (MS-044 at 15% send = ~70% rate gain). May be check the tail pitch slider limits are at full or add more bias pitch off centre to the normal hover torque direction. The tail could be blowing out at low RPM, what RPM do you estimate your running?
02-22-2007 Over year old.
HOMEPAGE  
 
 
Heli PIC
Senior Heliman
Location: Petaluma, CA USA

For those who have completed their A-Star project, please post your finished paint scheme of the model. I am redoing the paint job of my yellow bumbblebee due to hangar rash; my little boy picked it up then dropped it on the floor.
Many thanks
Hiko
03-14-2007 Over year old.
 
 
DarkHorse1
Senior Heliman
Location: Gloucester UK

I found these Ecureuil AS-350B image databases useful:
www.jetphotos.net
www.airliners.net
www.alecbuck.com
www.tsis.ch/heli/ecureuil
www.helispot.com/photos/
03-14-2007 Over year old.
HOMEPAGE  
 
 
DarkHorse1
Senior Heliman
Location: Gloucester UK

Ecureuil FF video


...MS-Ecureuil-AS350-FF.wmv 30Mb 3.5 mins 50fps WMV format
03-29-2007 Over year old.
HOMEPAGE  
 
 
DarkHorse1
Senior Heliman
Location: Gloucester UK

Any news out there?
Progress. problems, pictures?

I'll try to do some 25mph+ testing soon. Should have pushed a bit harder in the last video but haven't had many outdoor flights and wanted to take this model one step at a time, maintaining a zero crash rate.
04-04-2007 Over year old.
HOMEPAGE  
 
 
DRSHeli
Heliman
Location: Fort Wayne, IN

I have been reading this thread for some time now trying to determine if my flying and modeling skills are up to the task of this model. I have three HIIs and don't have a problem building and flying them other than constantly pursuing vibration elimination. I own Raptors 30 and 50 along with two TRexes and still enjoy precision, smallness and quality of my Hornets.

I am thinking about buying the Ecureuil but have a couple of questions:

How different is the three bladed head from the traditional two blades/flybar setup?

Is the stability of the three bladed head that different?

To start using a three bladed head would it be better to put one on one of my Hornets?

Thanks
Don S.

DRS; Bergen Gasser, Raptor 30, TRex XL, TRex SE, Hornet II, Piccolo (original)
04-05-2007 Over year old.
 
 
RevGadget
Veteran
Location: Decatur, Alabama

Quote 
How different is the three bladed head from the traditional two blades/flybar setup?

Is the stability of the three bladed head that different?

With me, the set-up was about the same as the traditional two blades/flybar.

There is little to no difference in stability of the three bladed head. You know due to experience what to expect, how to respond upon lift off and if something is not right (is it controlable). Plus you are fimilar with Hornets, I was not. But if you take Darkhorse1 advice and get the tail set, you'll find it looks and handles sweet for its size and weight.


3D2me= One eye on the Tx, one on the Heli and my thumbs in between.
04-05-2007 Over year old.
 
 
Heli PIC
Senior Heliman
Location: Petaluma, CA USA

The 3-blade head is fairly stable, but FFF is not too impressive. Due to its heavier weight, vertical performance is not as good as its pod-and-boom counterpart.
04-06-2007 Over year old.
 
 
DarkHorse1
Senior Heliman
Location: Gloucester UK

As you would expect with the extra weight and lower RPM the handling is quite a bit more docile than any Hornet. Once I began to understand the slight handling differences on a 3 blade configuration, I was quite happy with the flight characteristics of the current setup (as in video) but it took a bit of fiddling to get smooth enough to enjoy flying. Hence not for beginner builders.

I set the CofG +15mm in front of main shaft with a few clicks of forward trim. In the video you can hear my pitch curves need some attention as the RPMs rise nearer full pitch, on climbout and when falling into dirty air effect, encountering moderate 'ring vortex state' (same as all my micro's). Note that I am using the EM350/20 (Axi 2212/20 12A 1150 rpm/v 57g) with the 8A MS-116 for ~2350 rpm, so don't mind being a little soft on pitch demands to keep a safe ESC current draw.

Running a lower RPM (2100 rpm) causes the cyclic stability to become less comfortable and can begin to feel like flying a dinner plate in a breeze.

Not sure about the FFF handling yet and don't expect it to be as fast a an X-3D, completely different machine requirements for a 1:20 scale heli. Would the speed scale up the same as the physical size? On paper the Ecuruil at 2300 rpm should maximum FF around +40mph (if it had a flybar), the stock X-3D should have a maximum FFF speed of around 50mph and a T-Rex maybe 70mph (going by the 1/3 tips speed method). Probably get FF handling related issues starting to become noticeable at 60% max FF.

> To start using a three bladed head would it be better to put one on one of my Hornets?
I didn't want to take my favourite X-3D out of agile action (only one at the time). Best to just fly the Ecuruil without fuselage for a while, although the CofG is more tail heavy with the fuse, it does give you chance to get the setup dialled in, smoothed out and possibly take a crash or two without wrecking all the time and effort you put into the fuselage construction.
04-06-2007 Over year old.
HOMEPAGE  
 
 
DRSHeli
Heliman
Location: Fort Wayne, IN

Thanks for the feedback. It gives me something to think about before the big Toledo Show this Friady!

Don

DRS; Bergen Gasser, Raptor 30, TRex XL, TRex SE, Hornet II, Piccolo (original)
04-09-2007 Over year old.
 
 
7 pages [ <<    <     4      5     ( 6 )     7     NEXT    >> ]22171 viewsPOST REPLY
Next D . Fast Lad Performance . Esprit Model

.
.
e-MS Composit Hornet > MS Composit Scale A-Star AS 350, Ecureuil AS350 with triple rotor head
  UPDATE SCREEN   PRINT TOPIC Advertisers 

Subscribe to This Topic

Wednesday, July 9 - 4:19 pm - Copyright © 2000 - 2008 runryder.com | email | link to rr | runryder needs cookie