Prop Balancing !

happydays · Jan 30, 2014

I ordered via paypal last week too. Thanks PullUp for the great videos on how to use the rod.

Just one thing, though, I don't use the Scottish liquid therein, however I am partial to a Hendriks with cucumber or a naked Bombay Sapphire - would that suffice? Will my balance be affected?

Pull_Up · Jan 30, 2014

Your balance will be...

Just use a well-made glass and check for level before you start. After a few drinks just double check you're not sanding the wrong end otherwise after trying to correct the error, then correct the corrections you might end up with blades thin enough to see through!

happydays · Jan 30, 2014

Aha! The 180 degree test could therefore apply!

Sledge · Jan 30, 2014

Glen, thanks for looking into this! It will probably show in a day or so....I'll report back. Dave

Shrimpfarmer · Feb 3, 2014

Hi Glen

Received my rod this morning and very pleased with the quality of it. Going to give it a try using Pull_Ups glass technique. Thanks very much for getting these made.

Shrimpy

AllanVB · Feb 3, 2014

Bigvern said:
Hello
I have received the rods today from the supplier.
I have packaged one and been to the post office.
The cost will be:

Europe
Cost of rod                    £13
Postage & packing        £3.40
Total                            £16.40
Plus 4% Paypal fee       £0.88
Total                             £17:28

USA
Cost of rod                    £13
Postage & packing        £3.90
Total                            £16.90
Plus 4% Paypal fee       £0.89
Total                             £17:79

UK
Cost of rod                    £13
Postage & packing        £1.40
Total                            £14.40
Plus 4% Paypal fee       £0.58
Total                             £14.98

Please note this is £ not $ thank you.

Sorry about the paypal fee but they charge me on money paid into my account, I have looked at paying direct into my bank account but people outside the uk would be charged too much by the banks to make it viable for them!

Apologies again about the paypal fee but I have tried to keep the costs down, small runs of having these made is very expensive.

Please pay via paypal, as orders are received I will post out, please send your full name and address when ordering.
My paypal is     [email protected]

Postage times are
UK               1-2 days
Europe         3-5 days
USA             5-7 days

I hope everyone is happy with that.

Thanks Glen, Happy Flying !!!!

Looks like a great product with great reviews. I just ordered. How long does it take to US?

Pull_Up · Feb 3, 2014

Psst! You just quoted the answer. Near the bottom. Bit that says "USA 5-7 days".

Don't worry, no one noticed.

AllanVB · Feb 3, 2014

Pull_Up said:
Psst! You just quoted the answer. Near the bottom. Bit that says "USA 5-7 days".

Don't worry, no one noticed.

!! Working on my 1st cup of coffee !!

Sledge · Feb 3, 2014

Still haven't received mine......

Count · Feb 4, 2014

Me neither. Going on 2 weeks now...

Drone-Outlaw · Feb 4, 2014

Shrimpfarmer said:
Hi Glen

Received my rod this morning and very pleased with the quality of it

Shrimpy

I'm sorry I couldn't resist.... :mrgreen:

M

mediaguru · Feb 4, 2014

I just got my DU-BRO balancer a few days ago along with some P2 props. Been trying to balance them by putting the rubber washer in the cap but it is VERY inexact and the results are different nearly every time. The solution here is great.

My cuz here owns a machine shop here (Utah) and we've discussed making a P2 prop balance bar like this, and we will see if he can make the bar thinner. The tolerances will be within several thousands of an inch. Great idea.

Bigvern · Feb 4, 2014

mediaguru said:
we will see if he can make the bar thinner. The tolerances will be within several thousands of an inch. Great idea.

There is no problem making the bar thinner ! easy job, the problem here was the cost.
The cost for each bar would be double what they cost me now!
cheers Glen.

mediaguru · Feb 4, 2014

Bigvern said:
mediaguru said:

we will see if he can make the bar thinner. The tolerances will be within several thousands of an inch. Great idea.

Click to expand...

There is no problem making the bar thinner ! easy job, the problem here was the cost.
The cost for each bar would be double what they cost me now!
cheers Glen.

Since this is my cousin, making one for me will likely not cost anything. I do understand the extra money for extra machining though.

helping · Feb 5, 2014

The second aspect in prop. balancing is the amount of lift each blade produces. Asymmetrical lift could easily cause more vibration than the weight difference of each blade.

Rigging helicopter blades in the days before the synchronised strobe, a taut piece of canvass was stretched between the ends of a large letter C that was placed at the end of a pole. The helicopter was anchored to the ground and the engine run up and the blades' pitch were angled to generate lift. The canvass was held against the blade tips. Each tip was marked with different coloured chalk. The blade that produced the most lift left a mark above the others and so forth. The angle of incidence was adjusted and the process repeated until all the blades produced the same amount of lift. The blades weight was not an issue as they were detachable and could be weighed separately.

As an ex-aircraft engineer and commercial pilot, and never having flown a quadcopter, I would try the above with a piece of paper. Mind you, there's probably only a microscopic blade flex under load over such a short distance.

I've looked at a couple of moulded quadcopter blades and could see the mould join marks. If a plastic mould cannot get the weights of the blades the same then the aerofoil sections wont be the same either, ditto the lift generated.

Even the smallest imperfection on any leading edge would cause a large variation in lift.

I've seen the same with a ceiling fan when someone tried to drill holes in the blades to eliminate imbalance. It was altering the angle of the blades that illuminated the vibration.

I'm looking for a Phantom owner in Melbourne, Australia for advice as I intend buying one.

pault · Feb 5, 2014

That is a very interesting post and would suggest that maybe if the balance was more or less OK it would be best not to to do anything. If however, the balance is way out what are people's opinions on the best way to correct it without disturbing the profile, taking material off or putting tape etc on ?

mediaguru · Feb 5, 2014

Speaking of the discussion about making the balance bar thinner...

For those who may want to use the bar by itself to do a quick balance on the edge of a table, the thinner bar would not work. Perhaps making a bar which weighs enough or is long enough to counterbalance the weight of the prop is an idea for those without prop balancers like the DU-BRO?