RE: H9 ultimate questions
You are correct the Seiko can be considered a weapon - when driven at 12 volts the thing is so fast you can do some serious damage with the rudder! I worry about ripping the rudder horns loose.
We have a DA-150 with stock mufflers and a Mezjlik 32-10. We have had good luck with this prop and use it on all our DA-150s. So far we sense no lack of power despite the plane weighing 46 pounds. I will add baffling to the cowl this winter which should give us the opportunity to powerup the DA-150 a bit more.
We lost a prop during a pullout from a hover recently. We tightened the prop bolts immediately before the flight probably fracturing one and the rest was history. My Son was flying at the time and recovered nicely, we lost the right lower wing and the lower wing tube, twisted the cabanes a bit, and destroyed the engine hub. We did everything recommended in the Troy Built Models advisory to prevent this (washers, locktite, daily tightening). We have had problems breaking prop bolts in the past so we now use a torque wrench to make sure the bolts are between 60 and 75 ft lbs at the start of each day and instead of locktite we have a small amount of grease on the prop bolt threads to prevent galling. Flying Giants has 2 very helpful threads on the issue of lost props and prop bolt management. We also switched out 8611a's for 8411s on the ailerons to reduce weight and free up the 8611a's for other projects. We had a single, recurrent glitch that occurred at 2 flying fields which prompted us to change from the Emcotec DSPI twin with Longo batteries with matchboxes in each wing to the Powerbox 40/24 SC-12 with duralite LI-ions. When the same glitch developed in one of our jets we figured out that it was a transmitter (14MZ) problem (bad right stick). I'm not sure if the Li-ions can deliver enough power so we may switch to Li-Mn or Li-Po.
At this point we have invested a huge amount of time on this one but as of today its ready to fly again, all we need is less wind and higher air temps!
Phil