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Bmwbob

Member Since 24 Jan 2013
Offline Last Active Jun 05 2013 04:56 AM
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#92189 Manuals needed for Power Blast 2-4 and 4-8

Posted by Bmwbob on 22 March 2013 - 03:39 AM

No harm, no foul. My skin is not thin in the area of my hearing issue. It's something I deal with, as you must have to deal with the leftovers from your excursion from perfect health. With all of the benefit that email is to those of us who live in a quieter world, it does have its drawbacks. Lacking the facial expressions, tone of voice and other body language cues that in-person communication offers, it's easy to misinterpret the motives and agendas of those with whom we are communicating. Further exacerbating the dilemma are the factors of no personal relationship knowledge of many we talk with, which triggers a too common tendency to suspect the motives of strangers, and, unfortunately, the existence of "trolls". Trolls delight in nothing so much as fomenting discord among once tightly knit special interest groups, posing as would-be participants, using Google to pick up just enough of the "shop talk" of the group to appear as one with some knowledge and active interest in the core discipline of the group. Truly dedicated trolls may even go so far as to show up at an organized event of the group (using some name different from their online persona) and buy a T-shirt emblazoned with a product manufacturers logo to affect a disguise. While in any group there will be actual participants that are,by their nature, persons who find interaction with others bothersome, TRUE trolls will not commit significant finances, time, or effort to the pursuit of excellence in the group's chosen area of interest. So, as one who, with crimson cheeks, has, too many times had to sweep up the crushed remains of treasured momentos knocked from the mantles of conversation by my unseen arm gestures, let me say that I take NO offense at your suggestion to use the telephone to contact Kent. In fact, it seems that there IS some technical issue that has prevented him from receiving at least three emails from me. END OF GROUP SESSION. Will all the attendees kindly deposit 5 cents in the coffee can on the table by the exit? Thank you for your kind attention! :-) Bob


#92146 Power Blast 2-4 hover mode

Posted by Bmwbob on 19 March 2013 - 10:25 AM

I've already dumped the short stock pigtails for some much longer ones with a bunch of knots in them. When I'm just static flying, I move around a lot. With the 2-4, some of it is even MY idea! :-) What I'm trying to simulate is being in the buggy where I won't be able to move forward or back. Of course, with the buggy moving, it will be a whole new ball game. I was just wondering if there was some dumb little thing I was overlooking that was making the 2-4 a lot harder to hover (in very light variable winds) than my 1.5 is. Bob


#91682 First time on the Power Blast 2-4

Posted by Bmwbob on 16 February 2013 - 01:00 PM

Get some and report back :-)


"There I was, alone at the flying site"........,,:-)
1. My soccer field site is history. Some nincompoop took that beautiful, huge, flat, grassy area and put 18 soccer goals and a bunch of sideline benches all over it! :-(
So, I had to relocate. Next best place is the unused land that used to host the football field for one of the two area high schools.
Not nearly as well kept now, but usable and only a couple miles further.
Can buggy there, but it will be bumpy.
2. We have a cold (for Florida) front approaching, so the (GUSTY) wind is up. Pulled out the trusty Dwyer pellet anemometer, held it up to the wind.
If anyone finds it, please send it back! :-)
Hmmm....would a SMART kiter get a 2-4 out in this stuff?
Nope.
So I did!
After getting the lines straightened out from the equalizing session, I went with the approximately 6.5" longer top lines.
Took a bit of effort to get it off the ground, but it went up. Much less sail rattle now.
"If some is good, then more is better!" (Alfred E. Newman)
Moved to the next knot out on the top, about 7.25" difference now.
Launch. Kite proceeding toward the top of the window. At about 3/4 of the way up, the gust that blew the Atchison and Topeka steam engine off the tracks hits.
" Nine one one. What is the nature of your emergency?"
HOLY AIRCRAFT CARRIER CATAPULT LAUNCH, BATMAN!
A quick glance down at where I USED to be standing prompts me to dump the power before this gets out of hand.
You heard it right. Gust hit and the next thing I know, I'm doing chin-ups on the handles a few feet over where I was standing!
Made me REALLY wish I had a Rev 4-8 out today!
NOT!!!!!
Bottom line: Looks like the trim ( at about 7+") is close. Kite accelerates like a AA fuel dragster with almost no sail rattle.
But you DARNED WELL better be READY when it happens!!!
Gotta get in some clean air before I kill myself!
Bob


#91680 First time on the Power Blast 2-4

Posted by Bmwbob on 16 February 2013 - 06:05 AM

 
No idea ... I alway found that more down / reverse / forward / pick-your-term to be entirely confusing and useless to me as a beginner. Now that I feel I am a more acomplished pilot I still just see it as something that is overly confusing to people and I just stick to simple english terms.
 
In the case of my Power Blast 2-4 I use roughly a 6.5 inch difference in setting between top and bottom leaders - longer tops naturally. That is to say, if the knot I use at the bottom is at 3 inches from the attachment point (or any other constant point of measure you wish to use) then the top knot I use would be 9.5 inches from the equivelent top point. My leaders allow for a range of adjustment for both more differential or less differential.
 
My 1.5 setup flies with more of a difference than that, about 7-8 inches when I last looked. However the number is not important to me anymore since it varies from person to person and will be influenced by line stretch. I now tune based on a constant hand position and the flight dynamics of the kite so that all variables are accounted for by focusing on the constants.
 
Back on topic ... I'm not sure how my setup fits into your terminology I'm afraid ... I just use longer tops on everything and the difference between the top and bottom measurement in this case is about 6.5 inches.
 
What can I say ... I'm a simple man :)


KW,
One thing I thought might be helpful in determining the proper trim settings was to equalize my lines.
I figured that the 2-4 had dragged me around enough in the first 3 times out to stretch them.
I was right. On the top lines, the right one was 1" longer than the left.
The bottom lines were still equal length, but they were both 1" shorter than the (now equalized) top lines.
So, I swapped the top and bottom lines on the handles to get the line set equal overall.
I'll measure them again after another 3-4 energetic flights.
This morning I made myself a new set of leaders and pre-stretched them.
I'm now in the process of tying in the trim knots, starting (as was suggested) at the end nearest the handles and working out.
I'm using a 3/4" interval between knots.
When I go out to fly later today, I'm going to start with your suggested 6.5" top longer than bottom setting and see if I can get the kite to launch.
Film at 11! :-)
Bob


#91601 First time on the Power Blast 2-4

Posted by Bmwbob on 12 February 2013 - 11:41 AM

Once you get in the buggy, things change a lot. :)  Locking in the power when you are moving is much easier to do because you are going in a linear direction instead of forming an arc back and forth, plus you never hit the edge of the window when you are moving.  Locking in the power does require a lot more effort on your wrists/arms than with a traditional foil where you can use the majority of your shoulders and back to hold the power.  The biggest advantage with the Rev is that when you do start becoming fatigued while buggying/flying, just let the bottom lines go and the kite dumps nearly 90% of all power while still staying in the air.  This is something you can't do on a foil.  So even though you are using more pressure with your wrists and forearms, you can dump the power when it gets too much very easily.  Dumping the power just a little will ease the pressure a lot while still giving a bit of power to buggy with.  Lock the power in and the kite screams to life.
 
Another huge advantage with the Rev's is their ability to go upwind.  On the right surfaces, the Rev can point a buggy nearly 75-80 degrees into the wind.  With the best of foils you can usually only get around 50-60 degrees.  The acceleration and speed of the Rev's is another advantage.  They'll fly backwards nearly as fast as the highest performance foils (with the right experience of course).
 
Foils do have a couple advantages over the Rev.  1) they are super easy to fly, just tug and hang on....no real flying skills needed other than not crashing. 2) they pack down super small and can be stuffed into a small pack. 3) They don't have spars that could potentially be broken on a hard crash.
There are no real performance advantages with the foils over the Rev's.   Even the sizes of the foils have a disadvantage.  The Rev Power Blast 2-4 designates the size and power of the kite.  It is a 2m sail area, but it produces the power comparable to most 4m foils.  The 4-8 designates the same.
 
The 4-8 really excels in the buggy.  When flying static you really don't have the room to fully appreciate the performance of this beast.  By the time it gets powered up, you are usually at the edge of the window and need to man-handle it around to fly back the other way.  On the buggy this kite is a dream to fly.  The 2-4 is a lot better for static flying but it too really comes to its own on a buggy.
 
The technique to fly the power blasts is much different than that of a traditional power foil.  It does require some skill and proper technique to get the most out of them but once you master them, they are awesome power engines.
 
Hope that helps.  If you have any other questions please let me know.



Sounds like I will be re-learning all over again once in the buggy (BTW, I have a couple of questions outstanding to D. On yours).
Now that I have started thinking about what is happening with the kite instead of just focusing on line length differential, I think the learning pace will accelerate. I will be checkinge for equal length lines, however.
Here's how I interpret what's going on with the (power series) kites at various flight stages.
NOTE: I am a (private power and nearly glider) pilot and fly R/C as well, but I am NOT an aeronautical engineer.
1. Pre-take off: kite sitting on ground in full stall attitude with excessive positive angle of attack allowing relative wind to spill over the leading edge.
2. Launch: angle of attack decreased and artificial airspeed induced by stepping back and pulling on handles.
3. Power cruise flight: forward motion at optimum angle of attack. Air striking lower surface of sail is "wedged" rearward by the kites positive angle which, in turn, propels the kite forward and away from the pilot creating pull on lines.
4. Sail rattle: increased tension on bottom lines not compensated by pilot allows angle of attack to decrease and air flows over top and bottom of sail creating "flapping" of the fabric.
5. Power dump: tension on bottom lines is quickly released resulting in decreased angle of attack. Kite is now mostly into "glider" mode generating very little pull on lines.
6. Panic stop: while flying at speed, sudden pull on the bottom lines flips the lower surface of the sail nearly side-on to the relative wind direction resulting in maximum resistance to forward motion.
Geesh. Wish I would have thought along these lines to begin with!
Bob


#91465 Bit disappointed in REV quality

Posted by Bmwbob on 28 January 2013 - 05:40 AM

I just got my first Rev out for its initial flight/abuse tests this last weekend. Winds on the soccer field near my house were 0-5, up and down like a yo-yo. The 1.5 SLE would only stay airborne for a max 30 seconds. Got a lot of launch and landing practice! Finally took the SLE frame out and put the UL one in. This made it possible not only to stay up, but also try a few things like the inverted roll and launch. I had to stay up so high to be in any usable wind that I didn't really get to practice maintaining a fixed altitude while flying across the window as yet. Also, with that little wind, I couldn't get much action with the "slam on the brakes" maneuver. And, with the too-light and variable wind, it was hard for me to differentiate between the dumb things I was doing and the kite's own responses to the wind. The soccer field is an otherwise great place to fly with a HUGE flat grassy surface and few, distant obstacles (bleachers and goals), so it will probably remain my go-to place for a while, being only about a mile from the house. Thinking of getting a Power Blast 2.4 and/or 4.8 for the existing conditions and also as a re-entry to buggying which I used to enjoy. Good idea for a Rev novice or not? Bob


#91462 Lighter rear lines for Revs?

Posted by Bmwbob on 27 January 2013 - 03:42 AM

Hi, beamerbob, and welcome to the dark side. It's not so much a matter of strength as diameter. You will on occasion put 10 or more twists in them by doing spins, unequal diameter lines will begin binding up sooner.
 
This also means staying with the same manufacturer for uppers and lowers, as diameter will vary among them.


OK.
Thanks to all for the input.
I am an incurable "fiddler" and will very likely mess around with things unless there is a clear reason not to.
That, and I also have a set of 80/200 lines still new.
I'm going to post my Prism Stylus and Sky Tiger foils on Craig's List as soon as I can get around to opening them up to confirm their size.
Bob


#91433 Lighter rear lines for Revs?

Posted by Bmwbob on 24 January 2013 - 09:17 AM

I just bought my first Rev (1.5 SLE package) last weekend at the Treasure Island festival. Haven't had a chance to fly it yet.
Went totally nuts, joined AKA and subscribed to Kitelife. (Hi, John!).
Thanks to Ben and the others who stayed with me until I worked through the difference in handling.
I come from a bit of power kiting using mainly larger foils.
On those, the load is on the front lines, so I used 200 lb and up on the front.
For the rear (steering) lines, I never used more than about 90 or so (IIRC) lines.
I see that the Rev uses the same lines,front and rear.
Is it that this design has a higher loading on the rear than a flexible foil does, or is there some other reason?
I ask for economy's sake. I tend to buy bulk lines, sleeve and pre-stretch them myself. Saves a bunch of bucks. I can save even more by using lighter rear lines unless there is a sound reason not to.
So, whatcha think?
Bob