Jump to content


Photo
- - - - -

First time on the Power Blast 2-4


  • Please log in to reply
24 replies to this topic

#1 Bmwbob

Bmwbob

    Occasional Poster

  • Forum Member
  • PipPip
  • 53 posts
  • Location:Mims, Florida

Posted 09 February 2013 - 07:46 PM

Thanks to all your suggestions, I have the 1.5 trimmed out pretty well.
So, I tried the same approximate settings on the 2-4 for the first flight.
Short answer: NOT!
Finally ended up with the bottom lines about halfway in , and the top lines nearly all the way in.
Now it flies. Seems pretty sensitive to trim. When it accelerates, it tends to pull on the back lines harder, and if I don't react quickly enough, it gives a "snap" and rattle until I restore more pressure on the back lines.
Might have to try a lower grip on the handles.
Does this sound pretty typical for this kite, or do I need to do something different?
Bob

#2 kwmf

kwmf

    Regular Poster

  • Forum Member
  • PipPipPipPip
  • 587 posts
  • Gender:Male
  • Location:Durban, South Africa

Posted 10 February 2013 - 11:18 PM

In my Blasts and Blast 2-4 I still have longer tops than bottoms ... but not as extreme as my 1.5 setup.

 

To generate power you need tension on the bottom lines and theres a fine line between locked in power and over-sheeting the wind (naturally too much tension and you either fly slow or in reverse).

 

Remember, the power series are big fat and heavy so you can throw the idea of precision out the window - hence the different tuning. It's still a case of longer tops, but not as much and the flying technique is different.



#3 Bmwbob

Bmwbob

    Occasional Poster

  • Forum Member
  • PipPip
  • 53 posts
  • Location:Mims, Florida

Posted 11 February 2013 - 07:01 AM

In my Blasts and Blast 2-4 I still have longer tops than bottoms ... but not as extreme as my 1.5 setup.
 
To generate power you need tension on the bottom lines and theres a fine line between locked in power and over-sheeting the wind (naturally too much tension and you either fly slow or in reverse).
 
Remember, the power series are big fat and heavy so you can throw the idea of precision out the window - hence the different tuning. It's still a case of longer tops, but not as much and the flying technique is different.


I just measured. I have the stock (carbon wrapped) handles with metal D-rings at each end where the leaders attach.
Measuring from the D-ring out on the leaders to the knot where the lines are attached, I have this setup:
Top lines :1.5" These are the lines going to the leading edge of the kite.
Bottom lines: 3".
This seems backwards to most suggestions, and IS the reverse of what I have on my 1.5, but I started out with the top lines all the way out and the bottom lines about 3/4" out and the 2-4 wouldn't even launch.
As it flies right now, it launches OK, though not as briskly as I would like, and maneuvers OK for a "sky truck". The only real beef I have is when it gets a gust and accelerates, I can't get on the bottom lines fast enough to prevent the sail from doing the "shaking a stiff sheet rattle" which bleeds off speed and power.
Logic suggests I pull the bottom lines in some more, and I may try that again next time.
I did try moving my grip lower on the handles, but that didn't fix the problem.
Ideas?

#4 awindofchange

awindofchange

    Frequent Poster

  • Forum Member
  • PipPipPipPipPipPip
  • 881 posts
  • Gender:Male
  • Location:Las Vegas, Nevada

Posted 11 February 2013 - 11:28 AM

The line settings will vary depending on how you normally hold your handles. What works for one person will probably not work for another. :)  As mentioned above, there is a very fine line between full power and over-sheeting (stall/reverse) or depower (rattling).  It takes a lot of time to really get one of these into control and learn the feel of the power, once you do it is awesome.



#5 kwmf

kwmf

    Regular Poster

  • Forum Member
  • PipPipPipPip
  • 587 posts
  • Gender:Male
  • Location:Durban, South Africa

Posted 11 February 2013 - 11:22 PM

Moving your hands down has a similar effect to making the top leaders longer and bottom leaders shorter ;)

 

As Kent so rightly pointed out everyone is a little different. Since we all follow the same anatomical template and move the same from a biomechanical point of view, we can draw up some basic constants. However, the variations in implementing that anatomical template mean that there will be varying levels of success for those basic constants and adaptation is required.

 

Personally, I have developed my own point of view on handles, tuning, etc (and one day I will put it on paper ... honest) that no longer rely on specific measurements or other such things. I can pretty much pick up anyones rig and (assuming lines are even and leaders/handles give me enough adjustment range) tune it for me in just a couple of minutes.

 

My hand goes to a consistant reference point on the handles and then my tuning is based on how the kite responds to given hand positions I use in various moves. Basically I use a don't worry about the specific measurements, but rather focus on tuning given my own biomechanical range of movement, neutral hand position, etc.

 

That said, specific measurements are surely useful to anyone who doesn't know where to start or what to do....

 

For my tastes when it comes to the blasts .... I would say that if you measure from the handle rings I would guesstimate that I would want the top leader set to about 4-5 inches longer than my bottom leader as a baseline and then I would adjust from there. For reference, I fly with about a 7-8 inch differential (tops being longer) on my 1.5 setups.

 

It's a very fine line between locking in the power and over/under cooking it. If that sail is rattling, you need more tension on the bottom lines - either by hands responding to the moment or by tuning it as such to set a more constant default.



#6 Bmwbob

Bmwbob

    Occasional Poster

  • Forum Member
  • PipPip
  • 53 posts
  • Location:Mims, Florida

Posted 12 February 2013 - 03:55 AM

Coming from a background of using power foils where you only feel the strong pull of the kite on the top lines, having to deal with the sudden ( and considerable) pull on the bottom lines that I am now experiencing represents an impractical increase in the workload. I can't imagine being able to buggy for very long having to wrench my wrists back to the degree necessary to prevent sail rattling with my current trim settings. It seems to this novice Rev guy that I should be able to achieve a trim setting so that when the kite powers up, the ratio of pull from top lines to bottom is pretty nearly equal so that the only reason to apply more effort to either end of the handles is to initiate some control input. If anyone's experience suggests that this is simply not going to happen, please tell me NOW before I make the next (LARGE) investment in a nice buggy and a Power Blast 4-8 to complete my kit. I can simply keep my 1.5 and 2-4 to play with and maybe add a vented 1.5 for the beach if I can't get the big Revs to trim out to my liking. So....whatcha think? Bob

#7 Bmwbob

Bmwbob

    Occasional Poster

  • Forum Member
  • PipPip
  • 53 posts
  • Location:Mims, Florida

Posted 12 February 2013 - 04:02 AM

Moving your hands down has a similar effect to making the top leaders longer and bottom leaders shorter ;)
 
As Kent so rightly pointed out everyone is a little different. Since we all follow the same anatomical template and move the same from a biomechanical point of view, we can draw up some basic constants. However, the variations in implementing that anatomical template mean that there will be varying levels of success for those basic constants and adaptation is required.
 
Personally, I have developed my own point of view on handles, tuning, etc (and one day I will put it on paper ... honest) that no longer rely on specific measurements or other such things. I can pretty much pick up anyones rig and (assuming lines are even and leaders/handles give me enough adjustment range) tune it for me in just a couple of minutes.
 
My hand goes to a consistant reference point on the handles and then my tuning is based on how the kite responds to given hand positions I use in various moves. Basically I use a don't worry about the specific measurements, but rather focus on tuning given my own biomechanical range of movement, neutral hand position, etc.
 
That said, specific measurements are surely useful to anyone who doesn't know where to start or what to do....
 
For my tastes when it comes to the blasts .... I would say that if you measure from the handle rings I would guesstimate that I would want the top leader set to about 4-5 inches longer than my bottom leader as a baseline and then I would adjust from there. For reference, I fly with about a 7-8 inch differential (tops being longer) on my 1.5 setups.
 
It's a very fine line between locking in the power and over/under cooking it. If that sail is rattling, you need more tension on the bottom lines - either by hands responding to the moment or by tuning it as such to set a more constant default.


One thing I know for sure about this particular 2-4 is that with a large (4+") top line length advantage over the bottom lines, you can back pedal and pull the kite all over the county and it will NOT leave the ground. The very first trim setting I tried was top lines fully out and bottom lines only out about 3/4" and that was the result.
I think I am close with the current setting, but the workload is still too high, so more experimenting is in order.
Bob

#8 kwmf

kwmf

    Regular Poster

  • Forum Member
  • PipPipPipPip
  • 587 posts
  • Gender:Male
  • Location:Durban, South Africa

Posted 12 February 2013 - 07:19 AM

Assuming that the bridle is fine and lines are even ... I assure you it works with that differential (and more). I've even had my 2-4 in the hands of an experienced kite surfer and land foil guy with no rev experience other than 20 minutes on my 1.5 the day before and he did just fine ... in some pretty low wind.

 

If you can get together with another Rev pilot that could could spend hands on time with you that would be first prize.

 

If you're using your wrists to hold the tension on the bottom lines that would, in my opinion, be a good indicator that you need to let the top leader out and/or bring the bottom ones in. I'll measure my 2.4 setting for you if you like, but I'm pretty confident you need to let your tops out.

 

Remember, these things do not fly like foils ... foils are made to fly forward and powerd by default, where a Rev has the hover as a neutral position. Kent is the best person to provide input on the buggy side of things as I mostly fly my stuff rec/static .... including my Flexifoils. The foils are easier to learn I feel and the Revs are a more technical fly, but they offer other possibilities once you have got it down.



#9 Bmwbob

Bmwbob

    Occasional Poster

  • Forum Member
  • PipPip
  • 53 posts
  • Location:Mims, Florida

Posted 12 February 2013 - 07:59 AM

Assuming that the bridle is fine and lines are even ... I assure you it works with that differential (and more). I've even had my 2-4 in the hands of an experienced kite surfer and land foil guy with no rev experience other than 20 minutes on my 1.5 the day before and he did just fine ... in some pretty low wind.
 
If you can get together with another Rev pilot that could could spend hands on time with you that would be first prize.
 
If you're using your wrists to hold the tension on the bottom lines that would, in my opinion, be a good indicator that you need to let the top leader out and/or bring the bottom ones in. I'll measure my 2.4 setting for you if you like, but I'm pretty confident you need to let your tops out.
 
Remember, these things do not fly like foils ... foils are made to fly forward and powerd by default, where a Rev has the hover as a neutral position. Kent is the best person to provide input on the buggy side of things as I mostly fly my stuff rec/static .... including my Flexifoils. The foils are easier to learn I feel and the Revs are a more technical fly, but they offer other possibilities once you have got it down.


Hmmm... Made me think...always a potential problem! :-)
The kite was a (single flight, so I'm told) very clean used one. I suppose someone could have fiddled with the bridle.
The line set (200lb X100') was new, and I'd like to think the lines were equal length, at least prior to the first flight.
Guess I will have to stake them out next time to the soccer (it's NOT football!!!) field and measure.
Thinking further, these kites must be bridled to fly at a fairly high angle of attack to keep the trailing edge inflated.
It's only when the 2-4 gets a gust and accelerates that it appears to dip its nose (evidenced by the sudden increase in pull on the bottom lines) so air begins flowing over both the top AND the bottom of the sail, thus the "shaking out the bed sheet" rattle.
I should be able to confirm (and possibly overcome?) that by moving my grip WAY down the handles.
Maybe I can find a posting somewhere that shows the Rev bridle setup and gives measurements for the various models.
"Fair dinkum"? :-)
Bob

#10 stroke survivor

stroke survivor

    Hard Core Kite Flier

  • Forum Member
  • PipPipPipPipPipPipPipPip
  • 1,728 posts
  • Gender:Male
  • Location:clackamas, oregon

Posted 12 February 2013 - 09:21 AM

A. - The only problem I can see with the bridle is that it is not setup correctly! Might of missed putting it on in the right places or just not correct! There isn't a lot of places to "change" the bridle or adjust it! It should be "right" from the factory!

B. - Find a constant hand position that is comfortable for you and adjust the lines from there! I coach bowling and tell all my students - change only one thing at a time! If you're constantly moving your hands and line settings trying to find something that works, it's too many moving parts! Narrow it down to changing only one thing and see how that works!

C. - Indeed, check those lines for equal length!! Never trust that any lines are correctly set up! Spend that few minutes confirming that the lines are good or need work! 

D. - If indeed you can get with other Rev flyers, you'll get things sorted out a lot faster! Something about having multiple minds working on the same problem!!

 

I don't fly the power stuff myself, but these are general ideas that seem to work in all Rev applications!! Good luck!


wayne from portland
You have 2 choices - live on or die!! I ain't the dying type!!!  Also known as "portland flyer" on some forums!

7346824786_f12fcda7bd_s.jpg7770032034_ebc85fc33e_s.jpg7776002900_89d33b664b_s.jpgLogoupdate.png

 

 

AKA member


#11 awindofchange

awindofchange

    Frequent Poster

  • Forum Member
  • PipPipPipPipPipPip
  • 881 posts
  • Gender:Male
  • Location:Las Vegas, Nevada

Posted 12 February 2013 - 10:36 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.



#12 Bmwbob

Bmwbob

    Occasional Poster

  • Forum Member
  • PipPip
  • 53 posts
  • Location:Mims, Florida

Posted 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

#13 kwmf

kwmf

    Regular Poster

  • Forum Member
  • PipPipPipPip
  • 587 posts
  • Gender:Male
  • Location:Durban, South Africa

Posted 12 February 2013 - 01:45 PM

I'm on my phone so haven't read all the new posts, but I did measure my setup for you... Top leader setting is 6.5 inches longer than bottom and my thumb rests on the back of the vinyl end cap at the top of the handle.

#14 Felix Mottram

Felix Mottram

    Forum Veteran

  • Forum Member
  • PipPipPipPipPipPipPipPip
  • 2,860 posts
  • Gender:Male
  • Location:London UK

Posted 12 February 2013 - 02:04 PM

I'm on my phone so haven't read all the new posts, but I did measure my setup for you... Top leader setting is 6.5 inches longer than bottom and my thumb rests on the back of the vinyl end cap at the top of the handle.

 

Could that be understood as maximum forwards?

 

Felix



#15 kwmf

kwmf

    Regular Poster

  • Forum Member
  • PipPipPipPip
  • 587 posts
  • Gender:Male
  • Location:Durban, South Africa

Posted 12 February 2013 - 11:11 PM

 Could that be understood as maximum forwards?

 

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 smile.png



#16 awindofchange

awindofchange

    Frequent Poster

  • Forum Member
  • PipPipPipPipPipPip
  • 881 posts
  • Gender:Male
  • Location:Las Vegas, Nevada

Posted 13 February 2013 - 10:56 AM

BMWbob - everything sounds spot on.



#17 Felix Mottram

Felix Mottram

    Forum Veteran

  • Forum Member
  • PipPipPipPipPipPipPipPip
  • 2,860 posts
  • Gender:Male
  • Location:London UK

Posted 13 February 2013 - 01:54 PM

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.

 

<snip>
OK I'll not attempt to make any further interpretation. Felix


#18 kwmf

kwmf

    Regular Poster

  • Forum Member
  • PipPipPipPip
  • 587 posts
  • Gender:Male
  • Location:Durban, South Africa

Posted 13 February 2013 - 11:23 PM

@Felix

Don't let me stop you mate ... just saying I find it confusing, but you're welcome to ask me whatever question you want (here or PM) and I'll answer as best I can. If someone finds use from that then all the better ... whatever works for them.



#19 stevepigeon

stevepigeon

    Regular Poster

  • Forum Member
  • PipPipPipPip
  • 547 posts
  • Gender:Not Telling
  • Location:Clearwater, Florida

Posted 14 February 2013 - 02:00 PM

i have all three power series and they are great buggy kites like Kent said it took some time to really get the most out of the power for buggying but once you do speed is incredible i actually like them better than my foils but it did take a while to get really tuned in to the kite i use a little more brake to stop fluttering its a small sweet spot but its a great spot to be in 


Steve & Sherri

#20 Bmwbob

Bmwbob

    Occasional Poster

  • Forum Member
  • PipPip
  • 53 posts
  • Location:Mims, Florida

Posted 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




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users