RunRyder - xrb FF transition trouble?

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e-Hirobo SRB Quark - Lepton - XRB Coaxial > xrb FF transition trouble?

kbeefy
Heliman
Location: anchorage Alaska

Got this little fellow into a larger area today and tried going a bit faster than a hover with no success. When I got home I changed over to advanced settings w/ the paddles instead of weights etc... Still can't go faster than a walk.

It seems to me like when it passes from a fast hover to foreward flight the af blade stalls or something, causing it to settle back to a hover... kinda 'swings' back, sometimes actually going backwards. If I apply more power I can somewhat overcome this, but quickly run out of headroom even in our hangar with 18' ceilings.

Next I'm going to try laminating some blades (been meaning to anyways), any other suggestions? Is this normal behavior?

Thanks!

rc= XRB-SR, tmaxx, JuggII, VMG 1:1= 83 cj7 on 36's, 99 f350 on 38's, summit 800 etc

01-11-2005 Over year old.

woppini
Senior Heliman
Location: bay area CA, flyin @ bayside r/c

unfortuneatly its normal flying characteristics

my wifes cooking is so bad, the flies are sewing the holes in the screen door

01-12-2005 Over year old.

Aerospacer
Heliman
Location: Central Minnesota

FF Pitch-up tendency

The more flexible the blades the more coning you get which opposes anything but hovering. Start out re-enforcing the foam blades per the posts of rickyblaze. This will probably improve the ff flight and give you more cyclic pitch and roll authority. If this still isn't to your liking, blades made of stiffer material are what you're looking for. I posted how I make wooden blades in the thread discussing the veering left problem in ff flight. This will be a vast improvement but not nearly as easy to do as taping the foam blades.

01-12-2005 Over year old.

kbeefy
Heliman
Location: anchorage Alaska

yeah, I reinforced the blades per rick's instructions with aluminuim tape, significant improvement and quick response to hovering inputs, but still can't maintain more than a moderatly quick hover in any direction before it pitches back. I did notice that if I hold cyclic input in the direction of intended travel, it doesn't seem to swing much, if any. If I return the cyclic to neutral when I loose pitch authority it tends to induce a large oscilation about the dampner inputs, typicaly taking the form of a circular 'swirl' looking like it's swinging on a string. After a few moments it will return to a hover though, so if nothings nearby no harm done.

I remember reading your post about the wood blades, I'll probably either attempt that or try some of the carbon fiber blades off ebay. How much improvement did the wood blades give you?

I thought that just hovering around would be suffecient for flying in my house, but I've allready became comfortable that I would like to try FF in my den, I often exceed the hovering capabilities just there except in a corner, seems to speed up then.

rc= XRB-SR, tmaxx, JuggII, VMG 1:1= 83 cj7 on 36's, 99 f350 on 38's, summit 800 etc

01-12-2005 Over year old.

Aerospacer
Heliman
Location: Central Minnesota

Pitch-up tendencies.

I felt that the wooden blades markedly reduce the pitch-up tendency. But I fly a fixed pitch Corona outdoors, so I am use to the fact that the faster you fly the more cyclic you have to hold in the direction you're going.

My Lama XRB tethered model doesn't have as tall a mast for the top rotor as the SR so that could be a factor in degrading FF on the SR as well. I flew an SR yesterday that a fellow club member just got and it had the stock foam blades with no tape re-enforcing. There wasn't room to test the FF characteristic compared to mine, but the general feeling I got was that it was not going to do well.

One interesting thing with the SR is they have a set of plastic paddles to replace the "giant" weights on the flybar. This is in addition to the linkage change between the flybar and top head that all the models have. I suspect if you are willing to give up the rock steady hovering stability, reducing the flybar authority in stages on the top rotor could be a big help. The stiff wooden blades did not detract from hovering stability in the least for mine. I have not tried a flybar linkage change because I got all the cyclic authority I can use for now at my skill level and available flying space.

01-12-2005 Over year old.

Saint728
Elite Veteran
Location: Sydney Australia Sponsored by: Quick UK

I can get mine flying pretty fast. I guess you have to get the carbon blades for it? Their really stiff compared to the foam blades.

Take Care,
Cheers, Patrick

MA Fury Extreme,YS 91,MPII,V-Blades,601
Raptor 50 SE,OS50 Hyper,MPII,QUK Head,TT600 Blades,601

01-12-2005 Over year old.

HOMEPAGE

kbeefy
Heliman
Location: anchorage Alaska

I allready changed the flybar weights to the paddles and moved the input lever to the advanced setting... it made a slight difference but not as much as the reinforced blades. I also tried setting up the dual rates on my controller, I upped it to 125%. That quickened the response slightly but didn't seem to effect FF.

rc= XRB-SR, tmaxx, JuggII, VMG 1:1= 83 cj7 on 36's, 99 f350 on 38's, summit 800 etc

01-12-2005 Over year old.

nc_skyrobo
Heliman
Location: Raleigh, NC

I also got the same oscillation to the left in FF. It travels at a 45 in FF and when I return the cyclic to neutral position it will oscillate around to the left and finally come around center. The tail doesn't rotate the whole body does while the canopy still faces forward. Once it comes around it hovers fine, hands off, blade tracking perfect. I tried everything and finally called MRC and spoke with Mike. He thought it had something to do with the flybar not being balanced. I tried everything he suggested and I still had no luck. During our conversation he said that's just the way they fly. I didn't accept that and he finally asked me to send it in.

I thought to my self I know this helicopter can fly better because I did have it at one time. I had perfect FF until I knocked it against the wall and broke the blades. After changing the blades it hasn't flown right since. Only today after closer inspection I see that the tip of the shaft where the flybar seats has a fine crack. This causes the flybar to wobble slightly, maybe this is my balance issue?

I'm on my way to get a new shaft, I hope this is the cure. I'm so frustrated and fed up now, I've spent most of my time trying to tweak the flight rather than having fun. Anyone experience the same thing and find this to be the cure?

01-12-2005 Over year old.

rickyblaze
Senior Heliman
Location: Bloomington Indiana

I've noticed the same problem. It will take off fast forward from a hover then the only way you can keep it from climbing away is reduce throttle ,then when you do this it slows down and pitches up to a walking speed. I've looked at the swashplate and you have to be careful how much more you give it because the swashplate will rub against the rotor shaft if pushed beyond it's limits. Maybe using the shorter tethered xrb rotor would help ,I've got one maybe I'll give it a shot when I get home tomorrow

Rick

01-13-2005 Over year old.

HOMEPAGE

DeanM
Senior Heliman
Location: Oklahoma City, OK

How about the CF blades on eBay?

Has anyone tried CF blades such as those listed on eBay? (Search XRB helicopter)

01-13-2005 Over year old.

kbeefy
Heliman
Location: anchorage Alaska

yeah, what you said....

I've pretty much decided it's a good tool for learning the sticks but not gonna help me for any FF.

I just discovered today that it will make great coordinated turns with only rudder (yaw) input. When I was trying to make cyclic and yaw inputs it would turn to quickly and become un-coordinated. I was doing figure eights fairly well today, if you don't count the 'pitch-up' that seemed to occur every time I went through flat lateral pitch. It's very bothersome and I'm thinking I may have outgrown this thing after 4 days of practice.

rc= XRB-SR, tmaxx, JuggII, VMG 1:1= 83 cj7 on 36's, 99 f350 on 38's, summit 800 etc

01-13-2005 Over year old.

Saint728
Elite Veteran
Location: Sydney Australia Sponsored by: Quick UK

Quote
Has anyone tried CF blades such as those listed on eBay? (Search XRB helicopter)

Already said that in my post above. I said they are very stiff and work well. I bought mine from a on-line shop in Canada. Here is the link. http://www.jutstar.com/sf/index.htm Here is a direct link to buy the XRB blades. http://www.jutstar.com/sf/xrbblades.htm You can also get some from Helihobby.com They sell a set of carbon blades as well.

Take Care,
Cheers, Patrick

MA Fury Extreme,YS 91,MPII,V-Blades,601
Raptor 50 SE,OS50 Hyper,MPII,QUK Head,TT600 Blades,601

01-13-2005 Over year old.

HOMEPAGE

DeanM
Senior Heliman
Location: Oklahoma City, OK

Saint728...Sorry I missed your post above...Thanks for the info

01-13-2005 Over year old.

nc_skyrobo
Heliman
Location: Raleigh, NC

tape your blades

Man, what a big difference. I tried using packing tape as others have posted, wow! What control and performance now! I first took a piece and streched it over the bottom and folded the excess over the top. Then I took another piece and taped the top folding the excess over to the bottom. Then I cut off the over hang and put them on. Simple as that, I won't fly plane foam blades again. I now have the most controled and stable flights, in all directions of flight, even FF. No more 45 degrees. Try it.

01-15-2005 Over year old.

nc_skyrobo
Heliman
Location: Raleigh, NC

Actually I have to update my last statment... it still does 45 FF but just not as badly. It goes pretty straight if move slowly now, if I pick it up any more it starts its 45 FF.

01-19-2005 Over year old.

CWOAV8R
Senior Heliman
Location: Naples, FL USA

The biggest problem to overcome for fast forward flight is the fact that there is no cyclic pitch to the upper rotor system. Since there is no true bell/hiller mixing on the upper blade (no control over the flybar) it will always gyro stabilize the upper rotor to counteract helicopter movement. I thought for a second about putting a more aerodynamic set of paddles on the flybar. However without control over the flybar the best bet is to get as much weight off the ends of the flybar as possible.

Anybody tried to fly it with no weights or paddles on the flybar at all??

Stiffening the blades and using hard blades is the best it is going to get by reducing the coning angle thereby reducing the authority the upper blade has on the whole system.

I gotta say, for a teaching tool for hovering it is great. So far my son has only flown RFG2 and he was hovering the xrb around the house in minutes. It will be interesting to see how he does with a Humming Bird...

Ed

I tried flying upside down once... but I couldn't take the blood rushing to my head.

01-21-2005 Over year old.

stealth916
Veteran
Location: Rocklin, CA

I have found that you can make good transitions but you have to hold in some stick when you complete your maneuver to make it look good. I can come out of fast sweeping turns and stop dead in my tracks with no tendency to occillate - but you have to know that it will try and occillate on you and just compensate when you complete your maneuver. I am having a ball!

I consider the extra stick movement to be crosswind practice - I do not mind holding in Right stick when doing FF nor compensating at the end of maneuvers - I am convinced it will make me a better pilot - because you always have to fly the heli - not the sticks.

01-28-2005 Over year old.

stealth916
Veteran
Location: Rocklin, CA

Regarding the 'spritely' nature of the XRB SR - I found that after adding the optional fake cockpit, which adds about 12 grams, the heli is much more stable in altitude during hover and FF. It knocks a minute or two off your flight time. At first I wasn't sure I would keep it installed, but after flying about 6 times with it in, I must say I like the added stability in altitude. It also settles in nicer on landing and doesn't bounce near as much in ground effect.

Amazing what 12 grams can do ! Try turning your battery tray around and then add about 12 grams in the nose and see if you like it - cheaper than buying a cockpit to find out you don't :-)

01-29-2005 Over year old.

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e-Hirobo SRB Quark - Lepton - XRB Coaxial > xrb FF transition trouble?

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