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Old Nov 19, 2010, 12:57 PM
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New to B400

Hi all,

I just got a used B400 and went through the setup 90* arms and level swash 0* pitch and +/-10* pitch. I also set all the swash settings -90, -90, 90 to get the pitch to +/-10* and the cyclic pitch to +/-5*. So far so good. It has stock cyclic servos and DSP75 on the tail. I put in new O-rings in the head with 3 shims on each side plus the step washer. It has a eflight 440 motor with 10T pinion and headspeed seems good by ear.

I'm used to flying my T-Rex 250se and it has about the same setup. It has crisp cyclic and is really stable. The B400 seems to have strange to me mushy cyclic and seems to not want to move on command but then it's a little too much. Not an issue at altitude but down low on landing approach it is a little difficult to control due to lag in the cyclic response. It has wood align blades and on my 250 I use carbon fiber, is the wood causing some of this?

How much cyclic pitch (degrees) are you guys using for 3D? My 250 has +/-6* and is quite responsive compared to the B400.

Thanks, Don
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Old Nov 19, 2010, 02:18 PM
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Don, mushy cyclic is usually play in the links, low head speed, bad dampers, flexible blades, or bad servos. The Blade 400 should be as crisp as the 250, but you'll notice a difference between a new heli and one that's a little worn in - the 250 actually wears out pretty fast, and you should notice it getting mushy as well, but you replace the links and it tightens up again.
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Old Nov 19, 2010, 04:54 PM
With great pwer comes great 3D
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Wooo Hoooo. Did my first flips today and after 5 or 6 they were easy and clean. I'd say I'm at 20 flights with the Blade 400 and doing well minus that whole melting gear issue that caused me some problems earlier this summer.
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Old Nov 19, 2010, 05:15 PM
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tulsa jokelahoma
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wooohooo just managed a 5 ft high full batt hover and no crash took a while of 3 inch hovering and sim time but it feels great
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Old Nov 19, 2010, 06:18 PM
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I am still on the Phoenix sim! It is always windy here!
VP
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Old Nov 20, 2010, 03:18 PM
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swash leveling

Hi all,

I never got an answer on how much cyclic pitch is needed for the B400 to do proper 3D. I've set my SWAATS to -90 -90 +90 and get +/-10* pitch and +/-5* cyclic with the pitch ST pitch curve 0-100 linear.

I noticed the swash wasn't level at all positions so I centered all the arms at 0* pitch and the throttle in the middle in ST mode. It has now improved but still isn't perfect. I'm using the DX6i and I can't see how to level the swash throughout the swash travel. On my 250se I use a Walkera WK-2801pro and it lets me do two mixes pitch > elev and pitch > aile and has 5 postions to make corrections. I can only see that the DX6i gives me D% and U% with these mixes, so how does one get the swash setup well?

Thanks, Don
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Old Nov 20, 2010, 05:09 PM
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Hey Don,

I'm not sure what you mean "+/-5* cyclic" ... can you explain?

Usually on the B400 you level the swash at mid-stick first, like you mentioned. Then, in addition, you level it at maximum stick, and then again at minimum stick, using the Travel Adjusts to tweak the servos at those extremes. In between it's pretty much assumed to be close and I don't know of anyone (who's posted about it anyway) who uses the mixes to make sure it's level throughout it's entire vertical travel.

-John
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Old Nov 20, 2010, 05:49 PM
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Originally Posted by FR4-Pilot View Post
Hey Don,

I'm not sure what you mean "+/-5* cyclic" ... can you explain?

Usually on the B400 you level the swash and mid-stick first, like you mentioned. Then, in addition, you level it at maximum stick, and then again at minimum stick, using the Travel Adjusts to tweak the servos at those extremes. In between it's pretty much assumed to be close and I don't know of anyone (who's posted about it anyway) who uses the mixes to make sure it's level throughout it's entire vertical travel.

-John
He's talking about the maximum deflection of the blades by cyclic stick. To measure the aileron part of cyclic pitch, blades at 0 pitch, flybar level: position blades over nose and tail, then move the cyclic stick from one side to the other. Measure the deflection with a pitch gauge in the same way as you do with the collective, and adjust with the aileron value in the swash mix, in the same way that you use the pitch value to adjust collective pitch. Then to measure the elevator part, turn the blades 90 degrees and repeat the process, using the elevator value in the swashmix to adjust.

Then to check for binding, rotate the blades 90 degrees from whatever position the are in, move the cyclic stick again and check that the flybar cage doesn't touch the blade grips. Around +/-5.5 to 6 degrees is as much as the stock head design allows.

It's been a while since I set up my cyclic pitch and I think I got that right, but if it doesn't happen as I described, just turn the head by 90 degrees and you should be sorted

I'm pretty sure the Walkera TX doesn't work in the way we are used to, and the end point adjustments don't do the same thing (although I'm not quite sure what they do actually do) and this is why they have these mixes instead.

Dusty
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Old Nov 20, 2010, 06:10 PM
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Originally Posted by flyinfreak View Post
wooohooo just managed a 5 ft high full batt hover and no crash took a while of 3 inch hovering and sim time but it feels great
Hey Congrats. and keep it up ,go slowly on the learning curve,You will start noticing the importance of head speed. Good luck and Best Regards.
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Old Nov 20, 2010, 08:23 PM
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United States, MD, Ellicott City
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Just bought a B 400 off RCuniverse. I fly all kinds of planes including 3d and a co ax heli so we will see how well this goes lol
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Old Nov 21, 2010, 11:49 AM
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Dusty,

Thanks, that is what I was looking for and your explaination is correct.

Also I think found the root cause of the wierd sluggish flight behavior I was having. It turns out that the flybar was draggy and not free moving like it should be. One of the blade grips was holding the thrust bearing race from rotating. Turns out I had a drill bit that fit perfectly and removed a few thousandths of material to give the clearance needed. So now the flybar is very free and should work well.

It is rainy and really windy so I haven't had a chance to fly it yet. At my LHS they have a B400 on display and it's flybar has very free movement and mine was draggy so I'm pretty sure that is the cause because I've had similiar problems on another heli.

Thanks everyone for your inputs, Don

Quote:
Originally Posted by Dusty1000 View Post
He's talking about the maximum deflection of the blades by cyclic stick. To measure the aileron part of cyclic pitch, blades at 0 pitch, flybar level: position blades over nose and tail, then move the cyclic stick from one side to the other. Measure the deflection with a pitch gauge in the same way as you do with the collective, and adjust with the aileron value in the swash mix, in the same way that you use the pitch value to adjust collective pitch. Then to measure the elevator part, turn the blades 90 degrees and repeat the process, using the elevator value in the swashmix to adjust.

Then to check for binding, rotate the blades 90 degrees from whatever position the are in, move the cyclic stick again and check that the flybar cage doesn't touch the blade grips. Around +/-5.5 to 6 degrees is as much as the stock head design allows.

It's been a while since I set up my cyclic pitch and I think I got that right, but if it doesn't happen as I described, just turn the head by 90 degrees and you should be sorted

I'm pretty sure the Walkera TX doesn't work in the way we are used to, and the end point adjustments don't do the same thing (although I'm not quite sure what they do actually do) and this is why they have these mixes instead.

Dusty
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Old Nov 21, 2010, 02:08 PM
Scotland the Brave
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Originally Posted by dbennettya View Post
Dusty,

Thanks, that is what I was looking for and your explaination is correct.
Hi Don

I'm glad I got that the right way round, it was getting late here when I typed it

Quote:
Also I think found the root cause of the wierd sluggish flight behavior I was having. It turns out that the flybar was draggy and not free moving like it should be. One of the blade grips was holding the thrust bearing race from rotating. Turns out I had a drill bit that fit perfectly and removed a few thousandths of material to give the clearance needed. So now the flybar is very free and should work well.
Are you using a Sonix head by any chance? I might as well mention this here as I know a lot of folk use Sonix heads on their b400s:

I have the same head on my Sonix 450, and I bought some Align SE450V2 feathering shafts just assuming they would be the same. They even looked the same when I got them, but it turns out that the 3mm sections at the ends are marginally shorter than on the stock shaft, which causes the thrust bearings to bind when you tighten up the bolts - easy enough to check, just fit a thrust bearing to a bare shaft, tighten up the bolt and see if the thrust bearing is free to rotate or not (this of course means that the Sonix thrust bearings must also be slightly different from Align ones)

Dusty
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Old Nov 21, 2010, 02:57 PM
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Originally Posted by beginner4life View Post
Just bought a B 400 off RCuniverse. I fly all kinds of planes including 3d and a co ax heli so we will see how well this goes lol
Shall we take bets on how long the first flight will be? I'm in for 12 seconds...
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Old Nov 21, 2010, 02:59 PM
Slowly but Shirley
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Originally Posted by beginner4life View Post
Just bought a B 400 off RCuniverse. I fly all kinds of planes including 3d and a co ax heli so we will see how well this goes lol
Hey , Welcome to our family. Good luck and have fun. For lots of quick info. check out the Blade 400 bible (Slyster). Best Regards.
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Old Nov 21, 2010, 03:19 PM
With great pwer comes great 3D
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Globe, USA, Clemson, SC
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I'm having more fun with this helicopter than I thought I would. More flips today turned out great. Onto rolls once I feel comfortable eventually.
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