Fr Robert Ballecer, SJ ABOUT YOUR 250 octocopter nice with freezing the liquid but the single ...

[G+_T Nohands]

Fr. Robert Ballecer, SJ  ABOUT YOUR 250 octocopter nice with freezing the liquid but the single line is an issue I've encountered befor that has a simple change for better results, while lifting small aquariums 70 to 100 gallons that are only half broken down  (meaning still had sand live rock and a few inches of water) we discovered lifting the tank had  too much swing on our cantilevering portable A frame even when only lifting a few inches to swap or convert stands. It was just too dangerous so we put spacers built in shop that locked cables  narrow wide narrow and stopped the swing by over half and stopped the tank from spinning. What this correlates to quads lifting ice is instead of only one fabric line it might be worth looking at braided fishing line that's stronger and lighter than monofilament and fabric lines like twine. Assuming fishing line like spiderwire configured in four strands is lighter than the single line you were using, than four strands threaded through outer frame on bottom inner frame on top of your doubled 250 frames, afterwards use extra strands to make a cross construct to narrow the four strands to equal the distance of half the size of your frame and try to make you basket construct that holds and support your payload to a little wider than half the width of your 250 frame you might get much more stability which also gives you more energy available for lift since your octocopter doesn't have to expend as much energy compensating for swing AND twisting or spinning of your payload since energy can't be created or destroyed efficiency should offer more lift (In theory) ;) you will need that construct that keeps the four strands from flying around during takeoff because the strands are so light maybe put something on top of the strands to let go as you rise, unfortunately landing will be a problem maybe a box of styrofoam packing peanuts could catch it unless you directly attach the payload to the frame bottom. Anyways might be worth looking into playing with Padre. If you do I'd like to see what you come up with and watch on Know How or video posted here :) !

[G+_T Nohands]

Maybe add a central line since a whole spool of braided fishing line is way lighter than the line you used in your video

[G+_Jason Marsh]

I think a direct-mount approach would be better, as the lifted weight would be integrated with the chassis, making pendulum effects easier to control. Then again, helicopters are used to move massive quantities of timber, and those guys have that single-line lift down to a science. They handle the pendulum LIKE A BOSS, so maybe Fr. Robert Ballecer, SJ  just has some piloting skills to sharpen?

[G+_Fr. Robert Ballecer, SJ]

Jason Marsh I considered a direct-mount, but the problem with direct-mounting this much cargo is that the container would have to be so big that you interfere with the downwash from the props, cancelling some of your lift. --- I could probably do it with a large-class craft, but not with a 250.

 

You are absolutely right in saying that I need to sharpen my piloting skills... that will never be untrue... but the bigger problem is that it's difficult to counter the pendulum effect when you're at maximum thrust. -- You'll note that when I was lifting 3.85KG I was able to hold steady. At 5+KG, there just isn't any extra thrust for the motors to give, so a correction requires REDUCTION of thrust, exacerbating the imbalance. 

 

Still... it was fun! Lifting cargo takes some non-intuitive flying that was a challenge. :)

[G+_Jason Marsh]

Fr. Robert Ballecer, SJ you still have me beat. I can't fly five minutes without crashing. I was essentially just bowing to the timber pilots and ribbing you at the same time. When considering your build for next year's beer lift, what if the fixed, rigid container could be a single cylindrical/conical container, positioned centrally and with enough standoff to minimize interface with the prop wash. Imagine placing a lifting quad atop a magnum (or larger) bottle of wine.

 

And yes, your rig is going to need moar paar!!!!