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Old Jun 08, 2009, 09:20 AM
MB-Commander
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Hughes 500MD Tow Defender, 450 class, 16 minutes flight time.

Well, its finally here, after a lot of changes in configuration and the belt setback during the Orlando Funfly the latest MB-6B is now complete. With an average flight time of 16 minutes @1550 RPM headspeed, the heli is a joy to fly.

There are substantial differences between the MB-6A and the MB-6B. Some of those differences are a quad tail rotor and upgraded electronics, amongst others of course. Tail rotor reliability factor is been improved to be 100% reliable and no failures occurred during the exhaustive tail testings in crosswinds (what ruined the tail of the MB-6A) and several complete packs doing hard piros left and right.

Video is uploaded now, and its 15:43 flight time between spool up and landing. The video has no camera cuts, heli never goes out of the camera view... (beware dial-up, video is 134 Mb in size. Youtube won't let me host it b/c its well beyond their 10 minute limit)

MB-6B_endurance.avi - 134.6 Mb

Here is the picture of the MB-6B

MB.
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Old Jun 08, 2009, 09:37 AM
My hobby is why Im broke
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nothing about whats under the hood ? Batteries, ESC, Motor ?
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Old Jun 08, 2009, 10:26 AM
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Congrats, you have proved it could be done.

When I ran my 3 and 4-bladed head at around 1600 rpm with pod/boom they did okay. Easy on just 30a ESC and 3S2200. I did not time the flight but easily reached over 7 minutes. However, I have to use much higher cyclic pitch which got to become hard to control. I guess SK360 comes in as my thumb and brain ain't fast enough than micro-processor and sensors.

My apology for questioning you; to question is to learn.
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Old Jun 08, 2009, 11:22 AM
MB-Commander
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Quote:
Originally Posted by sidneyw
Congrats, you have proved it could be done.

When I ran my 3 and 4-bladed head at around 1600 rpm with pod/boom they did okay. Easy on just 30a ESC and 3S2200. I did not time the flight but easily reached over 7 minutes. However, I have to use much higher cyclic pitch which got to become hard to control. I guess SK360 comes in as my thumb and brain ain't fast enough than micro-processor and sensors.

My apology for questioning you; to question is to learn.
Apology accepted man.

But now be on the look out, somebody might chime up with 30 minute flight times.

The SK-360 is what really makes it enjoyable to fly, but the agility really comes from the airframe on its own. The SK-360 just brings order to Kaos.

Some recap: After the funfly's tail setback I was so upset that I almost gave up on it, but I am persistent like a bad habit... Since that video on the funfly, the MB-6 has been in various states of disrepair sitting on the shelf, waiting for parts to arrive from Hong Kong (I used the free shipping option.. BIG MISTAKE)

Cheers.

G.
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Old Jun 08, 2009, 11:42 AM
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I'm using Outrage G5 tail blades on my MD500 quad head while align tail blades are on A109 quad. G5 tail blades provide better tail authority in heavy and slow HS setup.
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Old Jun 08, 2009, 11:59 AM
MB-Commander
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Quote:
Originally Posted by sidneyw
I'm using Outrage G5 tail blades on my MD500 quad head while align tail blades are on A109 quad. G5 tail blades provide better tail authority in heavy and slow HS setup.
I've never tried the G5 tail blades as nobody local carries Outrage parts. What thickness, chord and length do these have?

All MB-6 versions use ThunderTiger E325 Mini Titan tail blades. Cheap and readily available locally (which believe me, after the 1 month wait for parts its is a blessing) All Align tail blades I've tried lacked the performance I needed and I've tried a bunch: the original Align plastics, the Align CF ones, the Align K&B ones and even the newest 450 Pro longer ones, no go on any of them.

MB.
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Old Jun 08, 2009, 12:10 PM
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I got them in less than 3 days from helidirect.com
http://www.helidirect.com/outrage-ou...ort=2a&op=list
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Old Jun 08, 2009, 12:23 PM
MB-Commander
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Quote:
Originally Posted by sidneyw
I got them in less than 3 days from helidirect.com
http://www.helidirect.com/outrage-ou...ort=2a&op=list
These? Link didn't work

http://www.helidirect.com/plastic-ta...and-p-7512.hdx
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Old Jun 08, 2009, 12:39 PM
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Link works over here. G5 tail blades are longer with wider cord. I've tried Esky Belt CP both plastic and carbon, Align both normal and large for 450, Blade 400 carbon and plastic. To my surprise - Esky plastic & carbon < Blade plastic < Align normal < Blade 400 carbon < Align large < G5.

Just checked my invoice, this is the one - http://www.helidirect.com/plastic-ta...and-p-8119.hdx
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Old Jun 08, 2009, 12:55 PM
MB-Commander
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Quote:
Originally Posted by sidneyw
Link works over here. G5 tail blades are longer with wider cord. I've tried Esky Belt CP both plastic and carbon, Align both normal and large for 450, Blade 400 carbon and plastic. To my surprise - Esky plastic & carbon < Blade plastic < Align normal < Blade 400 carbon < Align large < G5.

Just checked my invoice, this is the one - http://www.helidirect.com/plastic-ta...and-p-8119.hdx
Perfect,
I'll get two sets of those then and give them a try. The MiniTitan tail blades I am using have a really wide chord and are almost as long as the new TREX450 Pro tail blades and those were the 1st ones I've found that matched the specs I needed. BTW, the place you recommended for blades a while ago in another thread is great. It takes a little long for them to get here in FL, but its very reasonably price, almost like a steal!

MB.
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Old Aug 30, 2009, 12:03 PM
Redjestird Youser
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Hey, I'm wondering what tail gearing you were running back when you had the 2 blade tail setup? Was it the 'old' TRex gears, or something beyond that?

I got a CopterX 4-blade head on the way to convert my Smartmodel Littlebird into a more realistic model (gotta get some 3mm balsa for the tail too), and am thinking of staying 2 blade tail using the 'old' gears along with a G5 12T pulley (+9% speed). Do you think that would work out ok running extra-low headspeeds?
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Old Aug 30, 2009, 12:49 PM
kin
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Try ! it should be ok ! less 0ne teeth the pinion gear of motor and down a bit hovering pitch ,see motor hot or not !if still hot less 2 teeth motor gear ,if the rotor speed ok but tail become slow reaction ,add the length of the tail blade .let see how it fly !

Quote:
Originally Posted by SidewaysLS4
Hey, I'm wondering what tail gearing you were running back when you had the 2 blade tail setup? Was it the 'old' TRex gears, or something beyond that?

I got a CopterX 4-blade head on the way to convert my Smartmodel Littlebird into a more realistic model (gotta get some 3mm balsa for the tail too), and am thinking of staying 2 blade tail using the 'old' gears along with a G5 12T pulley (+9% speed). Do you think that would work out ok running extra-low headspeeds?
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Old Aug 30, 2009, 03:52 PM
Redjestird Youser
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I will for sure. Just did a bit of math...looks like the lowest I could go is 1900 rpm head rpm on my planned tail gearing (5.4 x head) to give enough tail hold for me for what I found hovering in a stiff left side wind then hitting full collective (2 blade head). 4 blade head w/more torque compensation needed....? Maybe I'll just copy the MB-6B, lol.

Gotta see just how much torque that might be considering it wont be 11 degrees pitch, but however there are more blades. Experimentation time for sure!
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Old Aug 31, 2009, 03:53 PM
MB-Commander
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Hey there,

I used roughly a 7.4 tail ratio to run 1600 on main without no authority problems.

For the MB-6A (two blade tail rotor) I started with the TREX 450 XL 4.95 tail ratio as baseline then I increased the speed by modifying the tail shaft with a 10T pulley and modifying the front pulley to use a Blade 400 tail accelerator pulley (15T)

While I think that lengthening the tail helps, during testing, the MB-6A had the boom extended to a 480 and I noticed very little difference.

This tail ratio should give you pretty good tail authority at almost any flyable headspeed but beware with main headspeed b/c at 1600 main you're spinning the tail at close to 12k RPM.

Hope this helps.

MB.
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Old Sep 02, 2009, 11:12 AM
Redjestird Youser
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Most certainly does! I was scratching my head on a faster front pulley, thanks for the Blade 400 tip...on the way.
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