tfelber 0 #26 November 16, 2006 Probably what you saw is the point at which they popped their brakes. Most canopies with a well tuned DBS seem to hang motionless until the brakes are popped. This has nothing to do with vented vs. non-vented. The inflation time you saw is due to the venting. A vented canopy tends to pop into shape almost instantly. A non-vented canopy actually looks like you say where it is taking a breath. I would expect this to be more so when the DBS is well tuned, because it wouldn't have the forward movement to help keep the wing pressurized. The vented canopy has two inlets for air so the forward movement isn't as necessary to keep the wing inflated. Share this post Link to post Share on other sites
TomAiello 25 #27 November 16, 2006 QuoteCould my observations be because his brake settings are too deep? They could be, but I don't think you could say for certain. To check if brake settings are too deep, grab a riser and initiate a turn immediately after opening (with the brakes set). If the canopy turns, the brakes are either too shallow or just right. If the canopy stalls straight down without turning, the brakes are too deep.-- Tom Aiello [email protected] SnakeRiverBASE.com Share this post Link to post Share on other sites
TomAiello 25 #28 November 16, 2006 QuoteFound a typo: Where you say "Unvented Slider Up:" you go on to explain Vented slider down. Thanks. I went back and fixed it.-- Tom Aiello [email protected] SnakeRiverBASE.com Share this post Link to post Share on other sites
TomAiello 25 #29 November 16, 2006 Quote...wouldn't it make sense to buy a vented canopy now so I am consistent with my canopy? Sure. As long as you understand what you're doing, then whatever you want to do is what makes sense. In terms of getting used to the canopy, there's not a whole lot of difference (some in steep approaches, I think, but overall very little) between a vented and unvented canopy of the same model.-- Tom Aiello [email protected] SnakeRiverBASE.com Share this post Link to post Share on other sites
TomAiello 25 #30 November 16, 2006 Quote...picturing the canopy from the side with the nose facing left, and imagining the wind moving left, so the air that would be going into the nose is actually moving away from the nose. Do you think there's more to it than that? I'm not sure. I think you've captured the essence of it, but I also think that the "gust induced stall" phenomenon that Pete referenced is pretty relevant. Once the wing takes shape as an airfoil it could still be experiencing a gust induced stall.-- Tom Aiello [email protected] SnakeRiverBASE.com Share this post Link to post Share on other sites
base_rigger 0 #31 November 16, 2006 Let us not forget two very important things: -Different canopy designs benefit from vents more than others (Flik vs. Ace for instance). -Larger canopy size (260+) and underloaded canopies (.65 and lower) also benefit more. IMO, an Ace 220 loaded @ .75 will benefit much, much less than a Flik 322 @ .6. The only system on the market that I would consider putting holes in the bottom skin is the Troll MDV. I am also fortunate to jump smaller canopies (220 and 240) but depending on the landing area I would not mind a 200 or 180. I'd not jump anything bigger than 240 vented or not. Another 0.02...IMO vented canopies suffer from off-headings more than convetional ones. And I am not the only one thinking so...there is a saying...with a vented your chances of hitting a wall are greater, with a non-vented the chances of more severe injuries when you do hit the wall are greater. For the type and size of canopies I jump I do not see myself going down the vented route...If I was 200LBS plus I bet I would think much differently. Vent or no-vent PLEASE set your DBS!!! Ask tfelber about it...just to rub it in...You know you have a problem when maggot is the voice of reason at the exit points Share this post Link to post Share on other sites
Lonnie 0 #32 November 17, 2006 Quotevented canopies suffer from off-headings more than convetional ones. Where do you get that from? How many jumps have you done on vented vs un-vented?NEVER GIVE UP! Share this post Link to post Share on other sites
BASE864 0 #33 November 17, 2006 I bought my Flick 322 unvented (non V-TEC) and PCA'd it off a popular pre-bridge day object. I ened up cracking my tailbone because the canopy didn't have enough time to get flying and I landed hard on my ass. I got it vented and then did the same jump next year. There was a world of difference. Check out a video comparison on skydivingmovies.com I didn't put enough jumps on the non-vented version to notice a difference in forward speed. However, I think because the vented canopy starts flying faster, you would also start flying foward quicker. I wouldn't consider buying a non-vented canopy ever again - unless it was only going to be in a terminal rig. Because I fly a large canopy - I need it open and flying as fast as possible. The vents allow for this. Later, BASE864 Share this post Link to post Share on other sites
sillie1111 0 #34 November 17, 2006 Hey Thanks! I have actually already seen this video, it does a good job showing the diff between vented vs non-vented. I actually got to see quite a few examples in person off that bridge this year, that was one of the reasons why I am looking into vented for my next canopy. We were standing at the bottom watching jumpers and you could tell every time which were vented and which were not. Most of the non-vented canopies were just scary to watch! It definitely got my mind going!~Shelly Share this post Link to post Share on other sites
Tyrion 0 #35 November 17, 2006 QuoteThe only system on the market that I would consider putting holes in the bottom skin is the Troll MDV. The Troll MDV already has vents. (forgive me if I'm wrong!) I'm not sure I understand the statement, would you mind clarifying/explaining it? Thanks! Share this post Link to post Share on other sites
TomAiello 25 #36 November 17, 2006 QuoteThe Troll MDV already has vents. (forgive me if I'm wrong!) MDV is an acronym for Mono Directional Valve, so no forgiveness is necessary.-- Tom Aiello [email protected] SnakeRiverBASE.com Share this post Link to post Share on other sites
Tyrion 0 #37 November 17, 2006 QuoteQuoteThe Troll MDV already has vents. (forgive me if I'm wrong!) MDV is an acronym for Mono Directional Valve, so no forgiveness is necessary. That's what I thought, which is why base_rigger's statement doesn't seem to make much sense to me. Share this post Link to post Share on other sites
base_rigger 0 #38 November 17, 2006 Quotewhich is why base_rigger's statement doesn't seem to make much sense to me Reading it back, yes is does not! What I meant is that if I had a gun pointed at my head given the choice of either fire or a valved canopy, well the only valved canopy I would get at the point in time would be the Troll MDV as its valved design is superior. And Lonnie please read my "IMO" and "0.02" used in the same sentence. Everyone is entitled to opinions and mine is give me a Mojo or an Ace anytime, no holes for me thanks.You know you have a problem when maggot is the voice of reason at the exit points Share this post Link to post Share on other sites
980 0 #39 November 17, 2006 Quote And Lonnie please read my "IMO" and "0.02" used in the same sentence. Everyone is entitled to opinions and mine is give me a Mojo or an Ace anytime, no holes for me thanks. Yes, everyone is entitled to their opinion. We are also entitled to ask what you are basing that opinion on. I know Lonnie has a few hundred jumps on both Aces and Blackjacks of the same size and therefore a very valid statistical sample to make conclusions on heading performance of the two types of canopies. I would like to know how what experience you based your statement on, as I am sure do many others who read this thread. thanks sam Share this post Link to post Share on other sites
Tyrion 0 #40 November 20, 2006 Thanks for clarifying Share this post Link to post Share on other sites MB38 0 #41 November 20, 2006 Quote...so why waste the money buying a (pricey) bit of technology that won't help you on the objects you are jumping? I think it's better to wait and get them on your next canopy, which you're more likely to be taking to such sites.Now Tom, do you see any reason not to "buy once" and stick with a particular canopy? Getting valves on one's first canopy may cost a little more initially, but it'll still be cheaper than a new canopy when the jumper moves to lower or underhung objects. Am I missing something essential? Some reason that something like a BlackJack may not be appropriate for most objects at all delays?I really don't know what I'm talking about. Share this post Link to post Share on other sites Fledgling 0 #42 November 20, 2006 I agree with you here. I would buy (and did) a vented canopy first time around so that I wouldn´t need to replace it later on. Share this post Link to post Share on other sites TomAiello 25 #43 November 20, 2006 QuoteNow Tom, do you see any reason not to "buy once" and stick with a particular canopy? Because it will wear out? From my perspective, it's "not worth it" because of the number of canopies I've gone through. My first canopy became vented (I sent it back to Basic Research when the original vtec [no valves] became available, at which time it had around 300 jumps) well into it's (and my) career. I've owned probably close to 20 canopies now, so I don't really see them as something you can reasonably "stick with". In my mind, they're more of a consumable product. Another thought about "sticking with" your canopy. Does that mean that when you buy your first canopy, you already know exactly what canopy will suit you best, and will never shop around again, look at newer designs, or swap manufacturers?-- Tom Aiello [email protected] SnakeRiverBASE.com Share this post Link to post Share on other sites bert_man 0 #44 November 20, 2006 I think it is likely that a new jumper buying their first canopy will probably hang onto it for a while, probably around a year at least. In that year, they will probably have advanced to the point where they are able to jump lower objects (which is what many jumpers in the US are limited to in their area) I think it's pretty reasonable for a new jumper to spend the extra money on a vented canopy when they know that they may soon progress to low slider-down strikeable objects. In addition, I think newer jumpers are less likely to be picky about which canopy they fly because they have less experience flying different designs. While a more experienced jumper may experiment heavily with trying new canopies; buying, trading, selling them; I think most new jumpers are out to purchase a conservative canopy that they can become comfortable with and grow into (edit: for a while). Just my 0.02 -Ghetto "The reason death cannot frighten me, is because life has cured me of fear." Web Design Cleveland Skydiving Share this post Link to post Share on other sites MB38 0 #45 November 20, 2006 QuoteAnother thought about "sticking with" your canopy. Does that mean that when you buy your first canopy, you already know exactly what canopy will suit you best, and will never shop around again, look at newer designs, or swap manufacturers?Of course not! It's why I asked. Thanks for clarifying.I really don't know what I'm talking about. Share this post Link to post Share on other sites MagicGuy 0 #46 November 20, 2006 QuoteMost of the non-vented canopies were just scary to watch! It definitely got my mind going! Oh great, so you want me to buy a 'scary' canopy. I see how it is.. Come out to the Perrine in March so you can jump with me!! Share this post Link to post Share on other sites Skydawg 0 #47 November 21, 2006 QuoteIn general, I'd say that the vents aren't [I]necessary[/I] for a beginner, because the vents are most noticeable on lowish slider down, and especially underhung (where you want the wing flying to avoid the object coming out below you), solid objects. Beginners shouldn't really be jumping those types of objects, so why waste the money buying a (pricey) bit of technology that won't help you on the objects you are jumping? I think it's better to wait and get them on your next canopy, which you're more likely to be taking to such sites. One good reason to get a vented canopy is the canopy is more likely to stay inflated during a cliff strike Share this post Link to post Share on other sites hookitt 0 #48 November 28, 2006 Quote Because it will wear out? A quote from This thread Quote I'd say an average canopy will last somewhere between 350 and 500 jumps. That would suggest it will last plenty long to have legitimate use for the vents. My suggestion would be to get the vents. My preference would be a Black Jack of proper size. Good luck.My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto Share this post Link to post Share on other sites andyhughes 0 #49 November 29, 2006 QuoteTailwind: As the canopy starts to transition, the tailwind essentially blows wind up the canopy from tail to nose. The canopy "perceives" this wind (in combination with the inflation forces) as "slowing" the rate at which the wind blows into the nose (or if you prefer, the rate at which the canopy moves forward). This means that the back surge air (the air that is flowing in through the vents and striking the topskin) is "stronger" by comparison, and hence more likely to cause a backsurge. The tailwind effectively deepens the brake setting during this step, and also results in a slightly slower inflation (i.e. a greater time from PC pitch to flying wing overhead). It sounds like some of the problems related to back-surge on vented/valved canopies could perhaps be counteracted by some Airlock-esque design features on the nose. In effect dampening the effects of relative wind on DBS settings? Share this post Link to post Share on other sites bert_man 0 #50 November 29, 2006 I'd be curious to see what that would do to heading performance, as cell inflation and pressurization would be almost entirely accomplished via the vents (since the nose airlocks might tend to be closed during opening). I would also think it would pressurize much more slowly, cancelling out the effect of the vents.-Ghetto "The reason death cannot frighten me, is because life has cured me of fear." Web Design Cleveland Skydiving Share this post Link to post Share on other sites Prev 1 2 3 Next Page 2 of 3 0
MB38 0 #41 November 20, 2006 Quote...so why waste the money buying a (pricey) bit of technology that won't help you on the objects you are jumping? I think it's better to wait and get them on your next canopy, which you're more likely to be taking to such sites.Now Tom, do you see any reason not to "buy once" and stick with a particular canopy? Getting valves on one's first canopy may cost a little more initially, but it'll still be cheaper than a new canopy when the jumper moves to lower or underhung objects. Am I missing something essential? Some reason that something like a BlackJack may not be appropriate for most objects at all delays?I really don't know what I'm talking about. Share this post Link to post Share on other sites
Fledgling 0 #42 November 20, 2006 I agree with you here. I would buy (and did) a vented canopy first time around so that I wouldn´t need to replace it later on. Share this post Link to post Share on other sites
TomAiello 25 #43 November 20, 2006 QuoteNow Tom, do you see any reason not to "buy once" and stick with a particular canopy? Because it will wear out? From my perspective, it's "not worth it" because of the number of canopies I've gone through. My first canopy became vented (I sent it back to Basic Research when the original vtec [no valves] became available, at which time it had around 300 jumps) well into it's (and my) career. I've owned probably close to 20 canopies now, so I don't really see them as something you can reasonably "stick with". In my mind, they're more of a consumable product. Another thought about "sticking with" your canopy. Does that mean that when you buy your first canopy, you already know exactly what canopy will suit you best, and will never shop around again, look at newer designs, or swap manufacturers?-- Tom Aiello [email protected] SnakeRiverBASE.com Share this post Link to post Share on other sites
bert_man 0 #44 November 20, 2006 I think it is likely that a new jumper buying their first canopy will probably hang onto it for a while, probably around a year at least. In that year, they will probably have advanced to the point where they are able to jump lower objects (which is what many jumpers in the US are limited to in their area) I think it's pretty reasonable for a new jumper to spend the extra money on a vented canopy when they know that they may soon progress to low slider-down strikeable objects. In addition, I think newer jumpers are less likely to be picky about which canopy they fly because they have less experience flying different designs. While a more experienced jumper may experiment heavily with trying new canopies; buying, trading, selling them; I think most new jumpers are out to purchase a conservative canopy that they can become comfortable with and grow into (edit: for a while). Just my 0.02 -Ghetto "The reason death cannot frighten me, is because life has cured me of fear." Web Design Cleveland Skydiving Share this post Link to post Share on other sites
MB38 0 #45 November 20, 2006 QuoteAnother thought about "sticking with" your canopy. Does that mean that when you buy your first canopy, you already know exactly what canopy will suit you best, and will never shop around again, look at newer designs, or swap manufacturers?Of course not! It's why I asked. Thanks for clarifying.I really don't know what I'm talking about. Share this post Link to post Share on other sites
MagicGuy 0 #46 November 20, 2006 QuoteMost of the non-vented canopies were just scary to watch! It definitely got my mind going! Oh great, so you want me to buy a 'scary' canopy. I see how it is.. Come out to the Perrine in March so you can jump with me!! Share this post Link to post Share on other sites
Skydawg 0 #47 November 21, 2006 QuoteIn general, I'd say that the vents aren't [I]necessary[/I] for a beginner, because the vents are most noticeable on lowish slider down, and especially underhung (where you want the wing flying to avoid the object coming out below you), solid objects. Beginners shouldn't really be jumping those types of objects, so why waste the money buying a (pricey) bit of technology that won't help you on the objects you are jumping? I think it's better to wait and get them on your next canopy, which you're more likely to be taking to such sites. One good reason to get a vented canopy is the canopy is more likely to stay inflated during a cliff strike Share this post Link to post Share on other sites hookitt 0 #48 November 28, 2006 Quote Because it will wear out? A quote from This thread Quote I'd say an average canopy will last somewhere between 350 and 500 jumps. That would suggest it will last plenty long to have legitimate use for the vents. My suggestion would be to get the vents. My preference would be a Black Jack of proper size. Good luck.My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto Share this post Link to post Share on other sites
hookitt 0 #48 November 28, 2006 Quote Because it will wear out? A quote from This thread Quote I'd say an average canopy will last somewhere between 350 and 500 jumps. That would suggest it will last plenty long to have legitimate use for the vents. My suggestion would be to get the vents. My preference would be a Black Jack of proper size. Good luck.My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto Share this post Link to post Share on other sites
andyhughes 0 #49 November 29, 2006 QuoteTailwind: As the canopy starts to transition, the tailwind essentially blows wind up the canopy from tail to nose. The canopy "perceives" this wind (in combination with the inflation forces) as "slowing" the rate at which the wind blows into the nose (or if you prefer, the rate at which the canopy moves forward). This means that the back surge air (the air that is flowing in through the vents and striking the topskin) is "stronger" by comparison, and hence more likely to cause a backsurge. The tailwind effectively deepens the brake setting during this step, and also results in a slightly slower inflation (i.e. a greater time from PC pitch to flying wing overhead). It sounds like some of the problems related to back-surge on vented/valved canopies could perhaps be counteracted by some Airlock-esque design features on the nose. In effect dampening the effects of relative wind on DBS settings? Share this post Link to post Share on other sites
bert_man 0 #50 November 29, 2006 I'd be curious to see what that would do to heading performance, as cell inflation and pressurization would be almost entirely accomplished via the vents (since the nose airlocks might tend to be closed during opening). I would also think it would pressurize much more slowly, cancelling out the effect of the vents.-Ghetto "The reason death cannot frighten me, is because life has cured me of fear." Web Design Cleveland Skydiving Share this post Link to post Share on other sites
