Question for the Tri-Blade Expert - martcerv

[PJA]

I bought a set of GWS Tri-Blade 9050 props, and tried to balance them with my DU BRO Prop Balancer...

I have watched some Youtube Videos to learn the best way to do this. One video says (and I seem to agree), that sanding isn't the way to go with the GWS Tri-Blade Props because of how thin they are. So tape is the better solution. However, I can't seem to balance all three blades. There are always two that seem too heavy to balance completely. I find myself putting tape all along the blade length and I run out of room, which seems so ridiculous... I admit, I'm doing something wrong...

I am reaching out to the Tri-Blade experts out there who have a lot of experience with these props and got me interested in using them, (martcerv, jumanoc, rilot). Any help or hints on how to balance these props would be much appreciated. I have learned a lot from you guys and am very grateful for all your input on this forum...

Thanks!

PS: I have already 'fit' the prop hole for the Phantom, and added the 8mm inserts on both sides of the hole for a nice tight fit on the motor shaft. My Phantom weighs in at 1198grams, so these Tri-Blades should provide better lift as you guys claim...

(Stock Phantom - with landing gear height inserts, Gimbal, GoPro Hero 3 - Black Edition, Garmin GTU 10 - w/CF platform, Turnigy Nano-Tech 2.2 25-50C Battery).

 

[martcerv]

Balancing wise for these I use tape also, I did use some clear nail polish earlier which also worked quite well just gave a rougher finish which I think possibly could hurt the performance a little more then tape.

As I dont have stock motors anymore and mine have a regular round 5mm prop diameter I dont need to ream or drill them out, if you do need to do this to fit to stock motors then you need to be extra careful and make sure you do a good job. If this is done badly and the hole is off center you wont be able to balance the props very easily if at all.

In terms of balancing them I put them on the DuBro and wait for it to settle and put a bit of tape on the lightest blade (these I think are too thin to sand though I use that method on other props) til this comes down a little and you will have another blade that is lightest now so also apply some tape here. Then once you have found the 2 lightest blades add or cut some tape off until you get it so it will balance in any position. If done properly it will hold position in any rotation and if you spin it each time it will come to rest in a different spot.

I just place the tape on the underside and at the start just put a larger then needed piece which I overhang then cut if need til it gets close. Then I will stick it to the underside once I have it set or if its very close you can just move it towards the tip or the hub depending if its too heavy or light. Its a little fiddly at first but you should be able to get it pretty well balanced and I had to do this a few times due to some crashes pushing too hard or close to trees. Since getting a gimbal I have been much more reserved in flight and so have not taken as many risks at speed or too close to trees so haven't done any blades in a while.

 

[jumanoc]

@Martcerv had said most of the same procedure I did with the Tri GWS 9050 and the Blue Tri-blades 9045.

I agree with no sanding. Be sure to lock in the correct way the DuBro cones to the right side of the prop (plain side of the cone must be on bigger hole side in prop)
I use long - thin tape stripes instead smaller -wide. Better a long stripe and you will cut small pieces until get balanced, then do a tight stick of tape to the prop. When 3 wings are balanced but stil rotate on DuBro balancer, I applied nail paint over the central nut opposite to the side that moves down and use a bit of hairdryer to dry faster, then turn prop until it get stable in any position.

I use mine with White Antigravity T-Motors, but tested before with stock motors also. My phantom is 1200 AUW, so the tri-blades lift easily on my 2600 mts ASL (very thin air here) so I get shorter flight times but compensation is the great power with the GWS Tri-blades.

The Blue tri-blades put 2 "horse power" on phantom when you throttle up :lol:
I use a GPS Data Logger (iGot-U) and with stock props meassured 3 mts x sec climb up full throttle. With those blues got 7.4 mts x sec

My 2700 mAh batteries went out of power (first alert level) after 7-8 minutes with blue Tri-blades 9045 and around 11 minutes with black GWS Tri-blades 9050 :mrgreen:

 

[PJA]

Thanks for the useful info, guys... I'll try to re-balance my Tri-Blades this weekend...

Let me ask you something, though...

Is it really necessary to balance any Props if you are using a Gimbal to isolate any vibration that would cause a jello effect while taking video? I did read in another Phantom Forum that balancing Props are also a good way to make your motors last while minimizing the stress on the motor shaft due to vibration, etc...

martcerv said:
Since getting a gimbal I have been much more reserved in flight and so have not taken as many risks at speed or too close to trees so haven't done any blades in a while.

So, if I read you right, your last line in your posts hints at the fact that since you now use a Gimbal you haven't balanced any blades recently...

I'm not one to put my Phantom through it's limits. My main concern is mostly for clean video without the acrobatics or high rate of speed... Since using my Gimbal the last few flights, I have recorded pristine video (even though I did have my CF Props balanced). I'm sure I will get the same results if I don't balance my props... Does this make sense?

 

[fizzviic]

Unbalanced blades can have a severe effect on the longevity of your motors. The last thing you want at any altitude or under any flight conditions is a motor coming apart or tearing itself loose.

 

[fizzviic]

I am loath to respond to our resident troll, but regarding my statement about imbalance causing motor destruction, I can speak from the experience of working for a designer/manufacturer of brushless DC motors. Unbalanced loads cause undo bearing wear, and bearing failure at even moderate rpm's can be catastrophic. It makes no difference if the imbalance is caused by a propeller, a out of tolerance shaft for a dozen or so other causes. I was merely stating a fact of life.

Perhaps our troll might wish to drill a hole in the crankshaft balance in his car engine and see what happens to the main bearings in a relatively short period of time.

I don't wish to argue. If you choose not to balance your props, that's OK with me. It's your machine, your investment.

 

[GoodnNuff]

So no facts that support the claimed "severe effect on the longevity" of Phantom motors, no incidences of Phantom motors coming apart or tearing themselves loose while flying.

What makes you think that DJI's Phantom motors are immune to vibration damage?

 

[dcoski]

If a motor was bound up at all, I believe the Phantom would act like a bird, shot by a 12ga, flapping and fluttering, but definately going down hard. This would not explain the flyaways where the unit shoots 300 ft. up and banks out of sight.

Exactly.

This is what happens when a motor cuts out only briefly:

https://vimeo.com/72165505

Just one