Ronaldo

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Posts posted by Ronaldo


  1. This is how I close mine, it helps checking kill line setting. You may also try to center the bag a little better on the tray before closing the flaps as the rig looks kind of distorted. Kneeling on the bag to squeeze air before closing the flaps helps too.
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  2. Just a few ideas:
    -Low porosity fabric is about 30% cheaper;
    -Reserves have straight panels and identical ribs which simplifies cutting and sewing processes;
    -Reserves are usually not customized which reduces production costs;
    -Low porosity fabric is easier to sew which probably makes production faster;
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  3. Dude, you can't go wrong with either one. I have bought many times from R&T and recommended this dealer to many friends who were also very pleased. I have nothing but good things to say about Roy and his team.
    I have ordered a couple of items through RS recently and was really pleased with the customer service. Augusto is also Brazilian which makes things really easier for me.
    You can blindly choose from any of them, believe me.
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  4. I tried to get the specs for a Crossfire a while ago. I tried every source I could and as far as I understood Icarus won’t give the specs so you cannot build your lineset (you have to buy one from them). As their canopies are all Vectran lined you don’t have to worry about trim issues, just line wear.
    I used to have a chart for the Crossfire 1 (it was given to me by Simon Mundel) but I lost it when I had to format my PC.
    Let me know if you can find another source.
    Good luck
    Ronaldo
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  5. Quote

    :)What I do for years is: pass the tapes under the loops & close the snaps, hand tack the tape after the snap to the cap inner surface with "Super Tack"
    & the cap will stay in place.

    Quote


    That’s a really good idea; I'll do it on mine. Just curious though…why would you want the cap to be so easily removed? Why not use knots like the ones you find on Racer pop tops? The only big advantage I see is when you want to wash the rig (you can quickly remove the cap and wash it without the PC)

    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  6. A few weeks ago a friend of mine had a terminal reserve deployment. He was jumping a Wings EXT. At first he thought he had recovered everything (main, reserve handle and reserve PC/ freebag). It was only when his rigger started packing that he noticed that the pilot chute cap was missing. Apparently, the snaps that hold the cap in place got open during deployment and the cap released from the pilot chute. He heard that this happened to at least one jumper in another state (but I can’t confirm that).
    Has anyone experienced this before? I have assembled the cap a few times and found the snaps to be extremely strong.

    Blue skies,

    Ronaldo
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  7. I was having trouble trying to contact them by e-mail a while ago. Daniel Preston told me they had received a huge order from the military (precision parachutes) and thus they were extremely busy at that time. Maybe it is still the case.
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  8. It won’t take long to reach terminal and although it feels completely different than what you’re used to, it is an amazing experience. My first balloon jump got me more scared than my first jump (ASL) but I liked it much more. Scarier than both jumps was only my first BASE.
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  9. Wow:o! Was this demo rig equipped with 3 canopies? Do you have a picture of it? Is it necessary to do a full reserve repack after each jump? Do you have to pay for these repacks?
    Sorry if these are dumb questions but I got really curious about the set up. We rarely see demo gear here in Brazil.
    Safe skies!
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  10. I may be wrong but I think the Skyhook does not increase the chances of line twists on your reserve even if you cut away under a spinning main. As far as I understand the concept, the reserve reaches line stretch fast enough to avoid most of the twists to develop. Anyway, I think it is better to have a reserve above your head faster even with a few twists than wasting a couple hundred feet trying to get stable.
    The downsides I can think of right now are adding a little bit of complexity (and maybe potential mistakes) during reserve packing. Also, in some cases where you need to delay your reserve opening (such as in collisions and/ or entanglements).
    IMO it is a fantastic idea. If I was getting a new container I would seriously consider a Vector because of it.
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  11. As the majority here I jump a Wings but my first rig was a Racer. IMO the Racer beats the Wings (and many others) in terms of comfort and weight. Both rigs had a custom sized harness so I can make a really fair comparison.
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  12. I still get this feeling occasionally, especially when go jump after being on the ground for a couple of weeks.
    If you decide to join the sport one thing that would help you overcome this feeling is learning as much as you can about your equipment. Learn how to pack, inspect and assemble (with supervision or with a final inspection from your rigger). Learn the mechanical aspects and philosophies between different brands of gear, ask and read a lot. Once you learn how it works and start to jump your own pack jobs you’ll feel much more confident on the equipment and on yourself. Modern skydiving equipment is very safe and simple. Accidents are almost always caused by human error so do your best to reduce this.
    My second jump was the worst in terms of fear, simply because I had tasted all the adrenaline and fear of the first jump and was now asking myself if I wanted to go through all of this again. Believe me, it was worth.;)
    Safe skies!
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  13. Pendulum effect. When you have a streamer the pilot chute and canopy drag are exerting a force that is pulling you up. Your weight is pulling you down and this is pretty much a stable system. It is kind of similar to hanging under a parachute. This effect is increased by the big distance between these two forces which is due to the length of the lines. Even small forces at this distance will generate enough momentum to stabilize your fall in a vertical position.
    On a hybrid the distance between the points where the forces are applied is small. Also, since you need to start the hybrid from a belly position the difference in speed (and drag) is also very small which makes it difficult to reach stability immediately. Once you stand up, the drag force on your hands will work against your weight to help you stabilize.
    Hope it helps
    Blue skies!
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  14. Good question, I use trial and error until I can pull about ½” (12mm) out of the last grommet using a power tool and good strength. I tend to adjust it tight so it is usually difficult to close the container with a pull cord (but not tight enough to damage the grommets or stiffener). I also kneel on the bag for a while compressing the air and pull the flaps with my hands to help closing them.
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  15. Hi,
    If you’re planning to keep the canopy for a while and are willing to spend about $160 on it I’d suggest you think about doing an h-mod. My Cobalt 150 had some opening issues that seemed to be cured completely by this modification. The openings now are slow and very consistent, there was also a slight improvement in performance but nothing to be concerned about if you’re comfortable flying it.
    All my openings before the h-mod were exactly like yours: short snivel with the center cells inflated then a fast inflation of the outer cells and a rapid descent of the slider.
    If you like its flight characteristics and are planning to jump it for a while it may be worth the money.
    Here goes a video comparing both openings (before and after the mod). Please note that the first was one of my canopy’s best openings (without the mod), the average openings were faster than that.

    http://discovirtual.uol.com.br/disco_virtual/ronaldo.pqd/Skydive
    type password: “portalpqd” then click on “h-mod.wmv”

    Blue skies

    Ronaldo
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  16. Thanks, I may try that also:P
    I don’t think cotton X nylon would make a huge difference for pants, especially if you don’t make them too baggy.
    BTW, don’t forget to sweep the floor and clean the mess once you’ve done (this is the worst part):D
    Safe skies!

    Ronaldo
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  17. I’m making my third free fly pants right now. I started copying one of my favorite cargo pants which I think was a good way to start, but now I’m using patterns that I drew according to my measurements. I haven’t tried with nylon, only with cotton so I can’t give you any tips on it. The basic sewing is not complicated but you need to plan ahead the sequence to sew each panel (I learned the hard way). Pay attention to seam allowance and clean-finishing (i.e turning the edges under and stitching).
    If you use cotton, check if you have to pre-shrink the fabric (I have just washed my pants and can’t wear them anymore).
    Here are a couple of pictures from my previous ff pant (the ones that I can’t wear anymore). I have to admit, my home made helmet turned out much better.[:/]
    http://quattorcsi.dyndns.org/resende-20060826/68.html
    http://quattorcsi.dyndns.org/resende-20060907/31.html
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  18. I totally agree with you that the drag coefficient varies slightly from one canopy to another as it depends basically on the form. I think the drag coefficient varies also with the stage of inflation (from center cells to a fully inflated canopy). Obviously I don’t have any data to support but I would assume it has a higher Cd once it is fully opened due to the concave shape of the canopy. I also agree that the surface area plays the most important role in the opening shock. The key to a soft opening is not allowing this surface area to increase too fast (make the canopy snivel a little bit), that’s what the slider is there for. I think the snivel is the most important stage of the opening, that’s when you lose most of the airspeed. That’s where the canopy should stay longer (IMO).
    If you consider that a larger canopy has larger cells then it is very reasonable to expect higher drag forces from the beginning (when only the center cells are inflated). It is important to note that large canopies are usually low performance, high drag airfoils. They usually have large nose openings which contribute to fast inflation. Possible ways to slow the openings include, covering part of the nose (such as with the h-mod), controlling slider and crossport sizes.
    Regarding student canopies, I guess you don’t want to slow openings too much as you increase the chances of line twists due to poor body position. One positive aspect about students and BASE canopies is dacron lines which absorb part of the shock.
    BTW, I think engineers should be banned from these forums, they’re just too geeky:P

    Safe skies!

    Ronaldo
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  19. Hi Ross,
    IMO the opening process is a chaotic event thus you should expect an eventual slammer even if it’s a good opening correctly packed canopy. I also agree that slider placement is the key to good openings. One trick that I find very useful to control slider position during packing is to start wrapping the tail area close to the lines, then placing a finger on this first roll, roll the rest of the tail. Also, when narrowing the canopy, try to place your knee right bellow the slider (over the lines), not at the slider grommets. If you put pressure right over the slider you may end up spreading it and unrolling the tail.
    IMHO a good canopy should open soft with just a good flaking and the slider against the stops. If you have to do a lot of tricks to make it open properly then it's a canopy problem (design, construction or line trim). Just my opinion though.
    Blue skies!
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted

  20. I’m no rigger or instructor so please check this advice with someone you trust.
    If it is your own rig you can readjust the toggle position to maximize your flare. On your next jump check the brake line length. Once the canopy is open, check for traffic, unstow the brakes and do a quick check like this: while holding both toggles up, look at the brake lines and make sure they have a small bow at the tail (they should have a large bow now). Pull both toggles and perform a deep flare with maximum arm extension (look at the canopy). The canopy will flare but in your case will probably not stall. Try wrapping the lines around your hand (just one turn) and see if you can reach the stall point. Give this information to your rigger so he can evaluate the best toggle setting. The ideal setting is when you have a bow in full flight and also are able to reach the stall when flaring deep for a few seconds. If you have short arms and a large canopy it may be difficult to reach both points. It is a good idea to do this check once in a while as the brake lines get shorter which will affect the original settings.

    Be careful when stalling the canopy, start it and recover slowly. Don’t do it without talking to your instructor first.
    Hope it helps

    Safe skies!

    Ronaldo
    Engineering Law #5: The most vital dimension on any plan drawing stands the most chance of being omitted