HK Skyfun has arrived

[DOG]

Bit of delay, not horrible though. Don't know how low you're talking, Derek.

Dan, what was the critter?

It look like a ferret. It moves like ours.

[danhampson]

Bit of delay, not horrible though. Don't know how low you're talking, Derek.

Dan, what was the critter?

its not my video paul i think it is the guys logo.

[Derek]

Yeah, is say the critter was a ferret.

As for the video...thanks for sharing that, Dan! There is a bit of obvious delay. Probably not a lot to cause issues but, based on that video, I think I'm gonna pass on the docking station. I'd much prefer no lag. I'm hoping to be able to get comfortable enough to fly below 10 feet for long passes across my flying field. I think the video, that low, will just be super exciting.

[Lee]

I really didn't notice any delay Derek.
But that was on my glider.
I want to put it on my Radjet, so we'll see if that works or not.

[Derek]

On a glider, I imagine the Mobius Docking Station would probably be ok. Most of the time, the glider will be slower and more predictable. I'm just afraid that the lag will cause grief in a full throttle, 5 foot alititude, pass across the field.

[Stambo]

I agree Derek, that is why we don't use the Mobius for FPV on miniquads.
I use it on my AXN and it's great, better image than my dedicated FPV cameras but at the cost of a very slight lag.
Some maths for ya.
60mph=100kmh(approx) I believe these things are capable of way more.
100÷60=1.6666km per minute.
1.6666÷60=0.0278km per second or 27.8 meters per second.
27.8÷5=5.56.
At that speed, 200 milliseconds or 1/5 second lag will mean you will be more than 5 meters further than what you are seeing.
You will hit that tree before you know it is there.

[Derek]

That's interesting, Stambo. Yeah I think the docking station isn't gonna work for me.

Vie got some more progress done on the build. Ill get more pics posted soon. I imagine ill have the plane "fpv flight ready" today.

[Derek]

I got the stock esc and motor installed. I upgraded from the stock, plastic gear servos, to some nice metal gear servos. I don't remember what servos these are but I've used them before. They are smooth and strong. I also mounted the servos on top of the wing, instead of the belly, to avoid linkages getting ripped off on landings.

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I added some t-nuts (blind nuts) to the underside and drilled some holes through the canopy for some nylon bolts to secure the canopy. I've read many reviews and comments about the Skyfun and quite a few people are having the canopies fly off on take offs and during flights. I'm not gonna allow that.

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Here is a pic of the canopy actually secured with the nylon bolts, one in front, one in the rear.

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Now I'm installing the FPV gear. I'm not real sure where to mount the Mobius, but I'll work on it.

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[Derek]

The HK Skyfun is now complete. It sure does look great!

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It's all wired up with 5.8ghz FPV and everything is working. I've really grown fond of the yellow and red combination. I've got two other planes with yellow and red but that's for another thread, lol. I do have one issue with this plane. With the FPV cam on the front, the video tx in front of the cg, and a 3S 2200mah pack, the Skyfun is very nose heavy. It's actually so heavy that I had to put my full allen wrench set on the tail for it to balance out.

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I still have to add the Mobius cam to the Skyfun, somehow. I might be able to get the battery to move rearwards to help with the cg. I may also have to just order a bigger, and heavier motor, to put on the tail.

I'm working the next two nights but I should be off Friday-Sunday. If the weather cooperates, maybe we'll get the maiden flight in. I'm really looking forward to tearing up the skies with the new FPV Skyfun!!!

[Derek]

I probably should have bought the KIT version of the HK Skyfun because I've replaced the nylon gear servos with some nice metal gear servos. I've replaced the stock esc and motor, too, lol. I replaces the servos because they just felt super cheap. Even the casing felt cheap, so the servos had to go. I replaced the motor and esc because I needed more tail weight to counter the weight of the FPV camera on the nose. So, the stock 2500kv motor and stock 25amp esc have been replaced by a Turnigy 2826-6 2200kv motor (I love these motors) and Turnigy Plush 40 amp esc. I don't know, for sure, what size prop comes with the Skyfun but it really felt cheesy, too, so I'm now using a 6x4 APC prop. That motor/esc/prop combination on the tail definitely helped to locate the CG. With that extra weight on the back, I was able to move the 3S 200mah pack forward enough to get the plane to balance out at the front edges of the finger grips on the belly of the plane. I have been told by a few friends that have Skyfun's that they enjoy the CG at the point. I followed their advice and marked my battery placement so that it did balance (slightly nose heavy) on the front edge of the finger grips.

Dad and I took my Skyfun out for it's maiden flight today (with FPV gear installed but not powered). I wanted to get a few trimming flights under my belt before we get going with the FPV Skyfun, lol. Dad did get a bit of video. I'll share that as soon as he sends me the video file. So, how did the maiden flight go? Well, I still get worked up, very nervous and shaky, on maiden flights. We had a very nice and sunny day today. Winds were very light, gusting at 10-12mph roughly. I set the elevon expo to 20% with 100% D/R. Dad was my launcher. Once I calmed my nerves a bit, I told Dad that I was ready. I throttled up about 3/4 throttle and told Dad "GO". Dad gives me a very nice hand launch...35-40ish degrees and then I mashed the throttle to 100% and the Skyfun just takes off. Cool! I had to give a bit of left aileron trim because the plane was wanting to roll to the right in flat straight passes. Also gave a slight bit of down elevator because it seemed to want to nose up. Both trim adjustments kinda surprised me.

The maiden flight was now underway and I was doing real well while getting to know my new plane. Then we have a bit of a "brown spot" moment....I'm just about ready to circle around for a landing and the motor just cuts out, the plane goes into a nose-first spiral..straight for the ground. My first thought was "Great...my brand new FPV camera is gonna be toast!" Thankfully I did ease back on the elevator and the plane pitches up and recovers from the death spiral. I try the throttle and it's not responding, so I just point the plane into the wind and glide it safely down to the cushiony grass soccer field. It sure does glide well!!!

I walk over to the plane and I'm trying to make sense of what just happened. I get to the plane and check things over. The plane is fine..no damage at all. I check my receiver...solid orange light. I check the motor, esc, and battery....all are only slightly warm. Very very odd! It's like I had a brown out but I had a solid orange light on my rx. Weird!

So, Dad takes his Delta Ray up for the second time..flies around...and lands safely. I decide to put another battery in my Skyfun and Dad gives it another really good launch. This flight was just a lot of fun. My initial trimming was pretty well spot on. The CG really seems to be spot on. Full throttle passes are lots of fun. The Skyfun goes up....performs very well....even dodges an attack from a curious (maybe angry) hawk, lol, and then I shut the throttle down and just glide the Skyfun down for another landing. The Skyfun did roll over at the last minute. Pilot error on the flare but no damage done. What a cool plane!!!

Like I said above, once I get the video file from my Dad, I'll share the video that he got.

[Graham Lawrie]

Nice one Derek:) sounds like fun:)

[Derek]

Yeah man...the Skyfun was great fun today! I'll be zipping around with the goggles on real soon. I'm super stoked!

[Graham Lawrie]

Cool:) I have still to try my HK V1,s but they have been great indoors and very cheap:)

[Lee]

Looks great Derek. Can't wait to see it fly.

[Derek]

After inspecting the Turnigy 2822-06 2200kv motor a bit more, I found that one of the screw holes has, some how, stripped so badly that the original screw slides in and out of the hole with little difficulty. So, I'd have to order a new motor. However, I did find a 2215 1700kv motor that I bought from Hobbypartz.com. I had to mod the motor mount slightly but I installed that motor on the Skyfun and added an 8x4 APC prop. I hooked up my watt meter and gave it full throttle....it showed 308 watts at 27 amps. The plane (with FPV gear, Mobius, and 3S 2200 lipo) weighs 2 pounds even. I don't remember the exact numbers when testing the 2826-06 motor but I think I'm getting more wattage with this 2215 motor and 8x4 prop. I'll test this setup next week.