Posted by fly time |
Oct 20, 2008 @ 11:58 AM | 1,930 Views
I flew the Sea Fury some more yesterday, this time with a new Mystery 3S 2200mAh 25c battery. Big difference over the 15c batteries I had been using before! The uplines were long and fast, though straight up unlimited vertical is not possible with this setup.
The big VarioProp 5-blader needs a fair amount of power, ideally 250-300 watts. The Himax 2025-4200 is rated for about 200, but it can put out a little more than that with proper cooling. With the 25c battery, I'm probably running at arounf 225 watts at WOT, but that is just a guess. I would put it on the meter to see for sure, but on about the 4th landing the prop struck the pavement and one of the blades snapped off. I will need to order some new blades because I don't have any spares.
After breaking the vario, I decided to fly it with the FSK/Manzano Laser Works prop (5 FSK 9x7 blades from Hobby Lobby installed in a plywood hub cut by Charlie Manzano). This is the 5 bladed prop that most guys are using on their Sea Furies. I had bought this prop before I stumbled across the VarioProp but had never flown with it. It works really nicely, and makes a little more noise than the VarioProp when you load it up. I would say the Vario is better though, as it has more thrust. The FSK blades are really soft, and they bend quite a bit under load. On the positive side, they are hard to break.
After flying with it for a few minutes, the prop shaft collet gave loose and the prop flew off with the plane about 40' over my head It was already a little tail heavy as the plane was balanced for the heavier VarioProp, and now with no prop at all it was definately not gliding well. I circled once and dropped the gear, then lined it up over the big asphalt parking lot and mushed it down to a hard 3 point landing. No damage I must say, I have been very impressed with the retractable gear that E-Flite includes with this model. Very sturdy!
Posted by fly time |
Sep 16, 2008 @ 01:46 PM | 2,043 Views
I finally flew the Sea Fury the other day. The wind was gusting up to about 12 mph, so not ideal for a maiden flight, but I had waited too long already. She flies well, though I would prefer a little more power to turn that big prop. Here's some video of the flight.
After the flight, I decided I would try to step down the gear ratio a little to squeeze out a few more RPM's. I have two heat sinks installed on the little 20 mm Himax, so hopefully I can push it a little more. Before swapping out the gears, I decided to run it up on the watt meter to see exactly what I'm pulling with 7.33:1 gear reduction. I got it up to WOT and 22 amps, then about 2 seconds later the RPM's dropped and the gears started making a terrible grinding noise I shut her down and took out the motor. The spur gear is shot! I have a feeling that the Himax gearbox is not quite up to the task. I was pushing 260 watts at the point that the gear failed, so my guess is that it's designed for about 200. I thought about ordering a Cobri gearbox, but it has a 4 mm shaft and my VarioProp is drilled for 3mm. Then I found the Hyperion gearboxes. It has a nice beefy spur gear, comes with either a 3mm or 4mm shaft, and is rated for 300 watts. Perfect! It's also half the price of a Cobri. Item ordered and on the way from allerc.com. I'll try it at 6.8:1 to start.
Posted by fly time |
Sep 10, 2008 @ 12:53 PM | 1,940 Views
I have slowly been putting together the new E-Flite Sea Fury. Supposedly this model can go together in an evening or two, but I always manage to figure out the hard way to do things Actually, I have been working on a number of mods so that mine will be unique in a sea of identical ARFs. Here's what I've done or am working on:
1) Himax inrunner and gearbox instead of the recommended outrunner. For a warbird, I like the noise that an inrunner and gearbox makes, plus I can spin a bigger prop while burning up fewer electrons.
2) 10.4" diameter 5-bladed variable pitch VarioProp. This prop is SO COOL! It is bigger and beefier than the commonly used Manzano/FSK 5-blader. I have a Manzano prop also, just in case the Vario proves to be too much.
3) A scratch-made scale spinner made from Z-foam, painted red of course.
4) Closer-to-scale wheels on the mains and tail
5) Gear doors
6) Pilot moved forward in the cockpit (he can reach the rudder pedals now!)
7) Polished aluminum pannels right behind the exhaust stacks
8) Heat sink and additional cooling ports for the inrunner, which will be running hot with the big VarioProp on the front.
Can't wait to fly this one! It should be ready soon.