Excellent thanks, pricy motor for sure but food for thought

pricy motor for sure but food for thought

I agree with you it is over over priced but unfortunately no motor
is like it efficiency wise and Kontronik who has a patent on it makes sure that no one will copy it.
There was a copy some time ago (not that good, it was throwing magnets)
but Kontronik killed it (not for me to decide if it was right or wrong) .
The only possible alternative is a Neu motor i have found (with gearbox)
but the overall price tag is not small either so i am unable to order one to try it.
The pictured motor was purchased used, there is no way i can justify ~600 Euros for the motor, the gearbox
and the matching ESC.
BTW the gearbox is modified for pusher application otherwise the shaft will move forward and jam the motor.
The Gearbox is offset not a planetary type because of the added cost for a (very good) Kontronik
planetary gearbox.
I have done some testing with the kontronik motor alone (direct drive) with a 11x6 or a 11x7 propeller
on a 6 cell lipo and it is a promising setup i think.

Someone who has a made a launcher, what angle do you set it at and tension of bungee do you use? I would like to build one shortly and have an idea.

Crazy1

Originally Posted by crazy1pilot

Someone who has a made a launcher, what angle do you set it at and tension of bungee do you use? I would like to build one shortly and have an idea.

Crazy1

I read that 5x the AUW of your wing is the rule for sailplanes. You can start around that!

Felipe

I tested my launcher today for the first time. 12kg of load on the bungee for a 3.25Kg X8

I will try less but it was windy, snapped a prop so retired for another day

bungee (2 min 10 sec)

The parachute I think needs to be inline so only deploys when slack, but it was an action man toy chute so I doubt it would take 12kg.

I will reduce the tow hooks angle too to help with an earlier release

Very windy conditions so one maiden launch with power out, the others were just glide tests

I recently learned that i had to use a MUCH smaller parachute or it would occasionally get struck by the prop, and i recently went to just a small streamer. It works much better without the chute.

10kgs of pull - 12 degrees on the ramp. Ramp angle not critical - 5 - 15 degrees works. Neither is bungee tension - anyhwere between 8 and 12 kgs is good - my X8 weighs 3.3 kgs.

Seems to me that's just asking for trouble. Here's a launch for a heavy glassed Stryker and it's easily off the hook without any pilot chute to complicate things and (by the looks of things) potentially screw things up.

12S Stryker with Mega 22/60 motor. WORLD RECORD 204mph! (3 min 34 sec)

Here is a Catapult I have been working on,, hopefully sometime soon I can start building it.. should be under $100 to construct (about$80) and very simple design, all aluminium and shouldn't have much fabricating required.

Crazy1

AERIAL MEETING IN ZAGREB (7 min 44 sec)

7:11 my X8 launching, hands off,
no need for catapult
(2 cameras, FPV, 2x 5000 4S batt)

I've hand launched 15+times.. my X8 is set up for 2X 3s 5000 but i only fly off one when i hand launch,, after that it becomes to heavy,, the catapult will allow be to have a full payload and reliable takeoff.

Crazy1

Ps. I enjoyed the video! nice job!

Crazy1

thnx,

I think the problem with your setup is in 3S power source.

obviously this bird is best flown @ 4S setup, 2x 5000 batteries and low KV motor,
because that way it flies for long >70 min (can swing a larger prop = more efficient)
it handlaunches without problem with plenty of power for steep climb (bigger prop = more static thrust)
(can do roll immediately upon launch, 3:27 in vid 3 posts up)

There's nothing special about 4S, or being able to cruise for 70 minutes on nearly 150Wh
of capacity. 2x 4S 5000 has 4/3 the energy of 2x 3S 5000 but also weighs 4/3 more.
Should be getting closer to 100 minutes at minimum cruise amps on 4S 10Ah setup.

What he's talking about above is that the plane is simply heavier and less pleasant
to hand launch with the weight of two big batteries.

ian

Oh no it launches just fine by hand,, quarter throttle and she's gone.. Almost 1-1 climb 13x8 carbon folding prop. But after you start loading the extra gear on, I'd rather not have to deal with holding it,, not to mention accidental flipping of switches when trying to pick it up. I'd be nice to have it on the catapult and be able to sit down and launch it with my mask on. Might even hook a servo to the release and use an old three channel 43mhz TX,, then I can have it set up away somewhere and I can be sitting in my cair ready to go. The catapult is 8' long and folds in half for transportation. I also don't like that shinny 13" carbon blade by my hand who knows,, I might stick with hand launching,, but it's worth a shot.

Crazy1

Originally Posted by Dr.Tom

thnx,

I think the problem with your setup is in 3S power source.

obviously this bird is best flown @ 4S setup, 2x 5000 batteries and low KV motor,
because that way it flies for long >70 min (can swing a larger prop = more efficient)
it handlaunches without problem with plenty of power for steep climb (bigger prop = more static thrust)
(can do roll immediately upon launch, 3:27 in vid 3 posts up)