KAPOW mixing - RC Groups
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Dec 15, 2016, 12:29 PM
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KAPOW mixing


Had a friend mention this to me a while back and I kind of let it go over my head. All I could think about was being line up and giving full stick and the plane speeding up and the plane hitting me. I can do that without special mixing.

Anyway after seeing LJ post on the new Avenger he mention it and was wondering who is using it. Does the wing go back to full clean ? Do you set it to say 90% to go clean? If I do things right I push the flap stick full up at touchdown. Where is the advantage to the KAPOW setup? Are a lot of you using this?

Its five degrees and the wind is blowing twenty MPH here today in Ohio, I have at least 2-3 months to overthink things.
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Dec 15, 2016, 01:54 PM
Red Merle ALES
Curtis Suter's Avatar
Can't comment as I have no clue what it is. Batman, Robin??
Dec 15, 2016, 02:11 PM
Registered User
If you put the flaps back up before touchdown as you are pushing full down, it is the same as the Kapow mix. This is not easy to get the timing right every time manually.

The mix helps the model rotate quicker when you need it to instead of just float past the spot. I haven't actually used it, but I can definitely see where it would be an advantage - especially if you are low and slow trying to get the last second and you really need the model to rotate quickly.

I'm sure there are a few more details to the mix (like I think the last bit of down stick travel gives significantly more down elevator as the flaps pop back up), so hopefully someone with experience with the mix (Bob M.) will chime in.

Tom
Dec 15, 2016, 03:09 PM
Daryl Perkins's Avatar
Actually, Kapow mix is a big help in the LZ. It was never about saving flaps or servos, but about instant rotation. Radio dependant, you can set it up as a separate flight mode, or as an addition to current flight modes. I have kapow mix active in cruise, all thermal modes, and landing mode. It's deactivated in all reflex modes and launch modes.

Bob McGowan gets the credit for the concept.

What's the concept? At full down elevator input, the wing goes into an extreme reflex position, and the elevator goes to max mechanical down position.

I have always been very good at closing the flaps at the instant of push over. But.... that only takes the wing to clean, and is restricted to whatever down elevator limits I have programmed for flight. This is the next evolution.

If you tend to land hot, you won't notice much difference unless you fly with minimal elevator throw. Where this really helps is when you get the model too slow and out of energy. You can still get it to shove over.

Good luck with it, and have fun!

D
Dec 15, 2016, 03:31 PM
Phil.T-tailer
Phil.Taylor's Avatar
ok - right - so its actually "dork" mode?
sounds pretty effective though!

Phil.
Dec 15, 2016, 06:21 PM
Registered User
Great explanations. Note: May be dangerous for those that can’t consistently put the plane over the spot at the right time, altitude, and speed. A buddy broke tail booms twice on fast landings with this setup before taking it out.

Bob
Dec 15, 2016, 07:03 PM
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THE EYE's Avatar
IT is ALL witchcraft! LOL
Dec 15, 2016, 07:11 PM
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Larry Jolly's Avatar
Curtis it is amazing with an Epower ship. Instant stop no slide through the spot floating on your Flap TEs. L
Dec 15, 2016, 08:52 PM
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Bob Could you explain exactly how it is suppose to work or if you have written it up somewhere else. Trying to wrap my brain around this.
Dec 16, 2016, 05:28 AM
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Thanks for the explanation Daryl. And I thought it was just because people didn't want to use their left hands I think I will give it a try.
Dec 16, 2016, 12:27 PM
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From the beginning


Quote:
Originally Posted by jerryshape
Bob Could you explain exactly how it is suppose to work or if you have written it up somewhere else. Trying to wrap my brain around this.
I developed this when I was practicing for the 2012 World Championships to be held in South Africa. I practiced landings hard and got very good. As I tried to take it to that next level of excellence, there was still one variable that seemed outside my control. This was the how much further then plane would go after I pushed full down to dork. This distance is speed dependent, but I had practiced enough that my touchdown speed was already very slow and consistent. Speed was not the issue, at least in my case after all that practice. I came to the conclusion that the variability I was still seeing really came from the airplanes attitude just before pushover. If I was slightly nose high when time to push over, it would arc slowly and land beyond the spot. If I was slightly nose down, it would dork more sharply and land in front of the spot.

Keep in mind that my goal at this point in my training was to turn my 98s (FAI tape) into 99s and 100s. Until I was hitting 98s and above almost every time, there were plenty of other things to work on and I had worked on them hard: These other things were much more damming to a landing score than a pushover which was a foot longer or shorter than I intended. There was no reason to focus on the inconstant pushover issue until I was hitting 98 and above consistently. In fact one probably does not even really notice the inconsistency in pushover until no longer making the bigger mistakes. I’m sorry, but Ka-pow won’t solve these bigger mistakes.

My first idea was to try to learn to put the plane in the exact same attitude every time just prior to pushover. A very slight nose down attitude seemed ideal then I’d push full down at the right second. Perfect in theory but hard to master I found. I saw improvement in my average score when consciously trying to control final attitude just before push over, but I’d still accidentally end up nose high now and then and blow a landing, long and 98.

My second idea was to try and get the plane to rotate faster via plane setup and control throw. Reduce the pushover variability rather than increase my pilot skill. I had always been a “dork with the flaps down” kind of guy, but I had read how others pushed their flaps up at the same instant they applied down stick for faster rotation. Not sure I believed it, but gave it a try. Some improvement, but subtle. More experimenting. More down elevator travel is what I really felt like I needed. Over time I did experimenting with radio programing, trial and error, and pretty soon I came up with this setup where with full down elevator stick activating a “stick switch”, surfaces would go to wild extremes and the plane would dork fast and hard regardless of attitude. Down elevator would hit the absolute mechanical limit (I put on a longer than typical servo arm and dramatically lengthened the slot in the fin for the full flying stab rod). Flaps did not just go up to neutral, but way up like crowed ailerons.

It was good that this was automatically engaged with full down stick because I don’t know if I could have re-trained my flap thumb after being a flaps down lander for so long. Also note that with a high elevator dual rate being engaged only at the very end of elevator stick down travel, I could still make normal elevator movements on approach without it being overly sensitive.

I showed this to my Worlds team mates at our practice in Denver and it still makes me smile when I think of the wide eyed looks, laughs, and shaking heads I got as I slowly moved the elevator stick to full down and then bam, the control surfaces jumped suddenly to these extremes. They saw how the plane plunged into the spot almost as suddenly as the control surfaces jumped. I swore them to secrecy until after the worlds. For me at least, my style, I felt it was a game changer. Daryl is the one who named the setup “Ka-Pow” and the name stuck.

This was back in 2012 when we all used full flying elevators. When I got my first modern plane with an articulated elevator, I was again disappointed in the way the plane rotated slowly. I made the articulated elevator go max travel but it just did not have the authority my full flying stab did. Keep in mind I’m talking at the extreme down angle I had used for Ka-pow, not what normal people use. Back into the radio menu I went and I added another mix, camber, to the down elevator stick switch which would make my ailerons also deflect up in extreme crow just like my flaps were doing. This got me back pretty close to the rotation I could achieve with my old Ka-pow setup with a full flying elevator. This is the setup I fly today.

I’m sure there are dozens of different ways to set Ka-pow mixes up on various brands of transmitters, but here are some old notes I dug up on what I originally did for the Airtronics SD10G to get you thinking.

- Set up a “stick switch” near the very end of full down travel (let’s call it SW2).
- Use SW2 to activate an additional dual rate for elevator (3rd in my case) which has an extreme amount of down (all you can get mechanically with down compensation and full down stick). This allows the landing elevator rate to not be overly sensitive as you are approaching the spot, but gives you the ”ka-pow” when you push all the way.
- Use SW2 to activate a C-mix. Master = elevator. Slave = Right Flap. Rate = 150% (max)
- Use SW2 to activate another C-mix. Master = elevator. Slave = Left Flap. Rate = 150% (max)
- In your surface menu set your right and left flap limits such that the flap can never go up beyond its mechanical limits regardless of what the mix tries to tell it to do (so you don’t stall and fry a servo).
- Now when you come in and engage the “ka-pow” mix, the flaps jump up. The flaps will come back down when you release the down elevator stick.
- I do not make these two C-mixes and the dual rate common to all flight modes. I Select separate and set them up for landing and cruise mode only (the two modes I may be landing from).
Last edited by Bob McGowan; Dec 16, 2016 at 03:50 PM.
Dec 16, 2016, 02:57 PM
Registered User
Bob thanks for sharing. By the way I love this kind of stuff. I'm a model setup nerd.
Dec 16, 2016, 03:06 PM
Registered Taranis User
Miami Mike's Avatar
Mike Shellim includes this in his latest F3J/TD setup for OpenTX and gives the credit to Daryl Perkins. I correspond with him occasionally so I'll alert him to this thread.
Latest blog entry: Taranis: Aileron-To-Rudder Mix.
Dec 16, 2016, 03:23 PM
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Larry Jolly's Avatar
Thanks Bob for both coming up with this and for the explanation. By the way I cannot emphasis enough that this is not a magic bullet. If you cannot fly an energy managed approach and you throw this mix in you will damage your model. It literally reacts and rotates your glider so fast you will not be able to react.
If you are in the pocket at the proper low speed energy approach the nose will stick. If you are hot and fast the nose will stick and the rest of your glider will keep going. BEWARE and be ready to have your landing scores increase. L
Dec 16, 2016, 03:46 PM
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Thanks Bob for all the info.