The flying monkeys got me...

Helis and fixed wing

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AMA Intro Pilot Instructor

Sunday, June 19, 2016

Holy shit... that scares the bejeezus out of me!

I made some major steps forward today on the VQ Models P-51B.

I installed the Corona DS329HV mini-servo's I got from Hobby King. I'd like to pretend I did it on purpose, but they were in the standard servo section and I didn't look at the measurements... But I was going on specs for torque at 6V and these met my requirements at the price I was looking to invest. It just meant I would have to modify the servo trays.


It took me a while to fish the line through the wing to pull the servo lead through. This is the original size of the opening.



I cut some plywood and fitted it to the opening and the mini-servo.



And cut a piece to fit at the top to balance the edges. It was easier to do this in two pieces.



Servo fit tested. Snug.



And installed completed. They are fast and will work well with the Orange Rx3 stabilization receiver.

Now the terrifying part...




This is the 17" 4 blade of unknown pitch from the FMS 1700mm P-51 Ferocious Frankie.
Its ginormous...



The spinner is a tad big for the cowl, but not distracting wrong.



She's gorgeous!

And when I put the Watt Meter on with a fresh new 6S, and went to just above idle to check the edges of the blades to make sure they were aligned, she made a powerful roar...

Then I slipped the throttle up to 50% and the roar became a banshee.

I got to about 65% when the Watt Meter read 1800 Watts, and she was pulling like a monster chained, and the sound was the most frightening power sound I have ever heard! This was magnificent! But if I use this prop I am going to have to put a throttle curve in and governor the max throttle down a lot! This was amazing. 

When I received the 17" prop I didn't know quite how big it was. I was trying to find a prop that fit a 60" or so plane and the 1700mm came close at 66", and the 1400mm a little short at 55".   I went with the bigger one. I think its too big, though I was planning on a 17" twin blade, with a 4-blade I need to come down a couple of inches.  I have already ordered the same prop but for the 1400mm P-51. I have no idea how big that one will be, but I expect a couple of inches shorter and better suited. I think that cone will fit well too. MotionRC is wicked fast at sending stuff, so it will be here soon. 

Damn that was scary.  I wonder if this prop, with each blade screwed to the spinner plate, could be flown on a 10cc gasser?

Tomorrow I will put the servos in for the rudder and elevator. and the plane will be essentially ready to program and fly. I am thinking of using the two Hitec HS-485HB Carbonite gear servos on those surfaces. They are analog, but I can mix analog and digital servos with the RX3 Receiver. I am still considering just using the mini-servos, but not if I am going to be drawing that kinda wattage at anytime during the flight. The ailerons can handle it, but the tail feathers will need some oomph. I also want to install the 6V 5A voltage regulator tomorrow.

I was cleaning the underside of the wing when I realized the painted on graphics were smearing. Damn. 

It would be great if the new prop arrived tomorrow, but I think another day before it does.

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