Malta_Dog 0 #1 October 7, 2004 I've been thinking about the Aerodyne Icon as a 1st new rig. The only minus for me so far is that I can't have it with normal risers / normal rings. I realize that the rig is TSO certified but still I would like to know: How good is the relatively new Miniforce system? Has any of you experienced or heard of troubles related with this design? Are the oval rings more or less prone to jamming than 1) mini-rings? 2) normal rings? Thanks for your input. All your dropzone are belong to us!!!!111! Quote Share this post Link to post Share on other sites
NickB 0 #2 October 7, 2004 Put shortly, the point of the mini-force three ring release system is to return some of the mechanical advantage to the three-ring release system that was lost when the original, and much larger rings were made smaller and into what is now know as the mini-three ring release system. Made even more simple, at a minimum, with our mini-force system, the amount of force needed to be applied to "cutaway" will be reduced by no less than 35%. Also, the system has been tested in every direction and is compatible with most all three ring release systems. There are only a select few in Europe that won't work. This is because the cable housing is tacked down so the grommet on the riser and the grommet at the end of the cable housing won't meet. I am not away of any American system that is like this. Please PM me or call the office if you have any other questions and I will be more than happy to answer them for you. Nick Bosco Sales Representative North & South America Aerodyne Research Corporation 12649 Race Track Road Tampa, FL 33626 Tel. +1 813 891-6300 Fax. +1 813 891-6315 Mobile +1 813 679-7190 [email protected] www.aerodyne-int.com Quote Share this post Link to post Share on other sites
AggieDave 6 #3 October 7, 2004 Was the system tested on a load-test system similar to what Bill Booth does his testing and demonstrations on? If so, what was the pull force at various loadings? How does it compare to standard "big" ring 3-ring systems and standard mini-3-ring systems? I understand the 35%, but I'd like to see more data then just a percentage. I guess you can say I'm a bit of a skeptic...for instance, it took me jumping a skyhook cutaway system to be totally sold on the system.--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites
NickB 0 #4 October 7, 2004 Give me a fax number and I'll send you all of the data. Better yet, go to our website, www.aerodyne-int.com and look under the articles section. You'll see everything there. Nick Quote Share this post Link to post Share on other sites
AggieDave 6 #5 October 7, 2004 Do you mind if I post the data here on DZ.com? I'm sure I'm not the only person wondering.--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites
NickB 0 #6 October 7, 2004 I don't see a problem with that. Afterall, it's on our website for all to see. Thanks for checking with me first. Nick Nick Bosco Sales Representative North & South America Aerodyne Research Corporation 12649 Race Track Road Tampa, FL 33626 Tel. +1 813 891-6300 Fax. +1 813 891-6315 Mobile +1 813 679-7190 [email protected] www.aerodyne-int.com Quote Share this post Link to post Share on other sites
AggieDave 6 #7 October 7, 2004 No prob, its your data, so I should ask.I really wish yall would have compared the data with a set of correctly made standard 3-rings as well for a base comparison, too. Attatched is the data that I had asked for, comparison between a set of standard mini-risers and the miniforce system.--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites
mark 102 #8 October 7, 2004 Having read the article from the Aerodyne web site, I can accept that the force on the loop is reduced by 35%. That doesn't tell the whole story, though. What matters to me is how much force it takes to extract the cables through the cable housings. Only part of the resistance is from the pressure of the loop on the cable. A much greater part is friction of the cables inside the housings, because of contaminants on the cables and inside the housings (which I can do something about), and from bends in the housings (a rig design issue). Can Aerodyne say how much better their miniforce rings are when they are considered as part of the entire riser release system, on a typical skydiving rig which may or may not have had recent owner maintenance on the release system? Mark Quote Share this post Link to post Share on other sites
RMURRAY 1 #9 October 7, 2004 what are the results with the red cable rm Quote Share this post Link to post Share on other sites
NickB 0 #10 October 7, 2004 Mark, Unfortunately, the miniforce three ring system was not designed to address the problem of cutaway cable maintenance. It is a system designed solely to reduce the amount of force needed to cutaway a main canopy based on the weight on the mini three ring system and to reduce the force on the loop. The miniforce three ring system is compatible with most other systems in the market so cutaway forces may very from rig to rig depending on cable housing routing, but the main fact is that each particular rig's cutaway force would be reduced by replacing mini risers with mini force risers. If dirty cables are what's creating a hard pull, then the weight on the three ring systems hasn't even been addressed yet in the cutaway process. Proper cutaway cable maintenance (removing and cleaning cables) is recommended to be done at least every 30 days. Nick Bosco Sales Representative North & South America Aerodyne Research Corporation 12649 Race Track Road Tampa, FL 33626 Tel. +1 813 891-6300 Fax. +1 813 891-6315 Mobile +1 813 679-7190 [email protected] www.aerodyne-int.com Quote Share this post Link to post Share on other sites
mark 102 #11 October 7, 2004 Quote[E]ach particular rig's cutaway force would be reduced by replacing mini risers with mini force risers. Nick, My question remains: by how much when measured at the pillow end of the cables? Mark Quote Share this post Link to post Share on other sites
NickB 0 #12 October 7, 2004 To find that out, you would probably have to pull test each rigs cutaway cable while there is suspened weight using regular mini risers, then try the exact same experiment using miniforce risers. Again, if there are other factors involved (ie dirty cutaway cables) then i'm sure that will adversally affect your experiment. Just like in science projects in school, part of scientific method is to reduce every possible error. The link Aggie Dave put on this post didn't show the entire explanation. It just showed the results we received. If you go to our website, it shows mathematical equations that may help you understand this better. Other than that, I don't know what else to tell you. If you have more intricate questions about this, please contact me directly and I will give you the e-mail address of our head engineer. Nick Bosco Sales Representative North & South America Aerodyne Research Corporation 12649 Race Track Road Tampa, FL 33626 Tel. +1 813 891-6300 Fax. +1 813 891-6315 Mobile +1 813 679-7190 [email protected] www.aerodyne-int.com Quote Share this post Link to post Share on other sites
mark 102 #13 October 7, 2004 Nick, I've been to the web site, I read the mathematical description, and I'm convinced that miniforce rings decrease the pressure of the loop on the cable. I'm just not convinced it makes any difference in actual conditions. If you are asking me to do real-world tests, it leads me to believe that Aerodyne has not done any such tests, and Aerodyne cannot say what the reduction in pull force at the pillow end of the cables would be. Advertising "35% reduction in pull force" for most skydivers implies "at the pillow end," and while there would be some reduction in pull force at the pillow end, it is certainly less than 35%. Mark Quote Share this post Link to post Share on other sites
FrogNog 1 #14 October 7, 2004 I would add something different than the reduction "at the pillow end ... is certainly less than 35%". I would say from a theoretical basis we don't know whether the 35% reduction number would be more or less than a jumper would see with dirty cables. The reason is that the 3-ring pulley system manages the tension on the "white loop" that goes around the cutaway cables. We know that when white loop tension is higher, cutaway forces will be higher, and when white loop tension is lower, cutaway forces will be lower, all other things (including cable dirtiness) being equal. The miniforce system has been proven, to my satisfaction, to reduce the white loop tension - as determined by reduced cutaway cable extraction force. When the cables are dirtier, pull forces are going to be higher because of extra resistance of the cable in the housing and possibly because of increased friction between the white loop and the cable. What we don't have any test data on is what the friction looks like between the white loop and a cable of increasing dirtiness at the white loop end. With a clean cable, we assume that the cable extraction force increases as a fraction of any increase of white loop tension. With a sufficiently dirty cable end, we might assume the cable extraction force increases as a larger fraction of any increase of white loop tension. If the relationship between cable end extraction force and white loop tension is linear and passes through the origin for both a clean and dirty cable end - even if the slope of the relationship between clean and dirty cable ends differed - then Miniforce's 35% reduction of cable extraction force (vs. a specific round 3-ring) in tests using a clean cable would apply equally to a dirty cable. But, again, we don't know the relationships between cable extraction force and white loop tension for clean vs. dirty cables. Is it linear? Almost linear? Does it pass through the origin, or close enough? Is there a discontinuity or nonlinear region at high loop tensions, as the cable deforms somewhat into the connector end? All of this looks at cable end extraction forces; the Aerodyne representative pointed out that extracting the dirty cable from the housing is a separate issue, and one I warrant the 3-ring system (miniforce or round) has either no effect, or only a partial effect on. (Tension on the end of the long cable could cause a dirty cable to drag more heavily on the u-bends in the housing, creating more friction. So a 35% reduction in tension on that cable presents the same friction problem in the u-bends that I wrote a lot about above for the white loop.) I think a much better exercise than asking Aerodyne about the miniforce effect on dirty cables is just to baseline pull forces on dirty cables. That's because I was surprised to see in the Aerodyne pull force results such low forces in the first place. They're showing a 35% reduction of a pull so light nobody should ever have a pull failure in the first place. Obviously they feel their invention has merit, or they wouldn't have invented it*, so additional pull forces of some sort need to be accounted for. (* I do not subscribe to the cynic's view that they invented something that has no merit, and are now trying to market it to success. Please feel free to adopt your own views.) I do agree that based on the documentation so far, it appears Aerodyne has not done the "real-world" testing some people mention. But that appearance could be for at least two other reasons: * Perhaps their real-world testing showed a smaller percentage benefit. This doesn't mean no benefit, or even insignificant benefit, but just a less marketable appearance of benefit. * Or, it could be that they couldn't come up with a "real-world" dirty cable testing protocol that they could either show was valid, or that gave meaningful results. If dirty cables change their pull forces by 30% seemingly randomly based on whether the dirty side is "up" or "down", or dirty cables have slightly lower pull forces after each pull they undergo because they transfer dirt from the cable to the valleys in the housing, and cables cannot be "re-dirtied" to specification in a way that yields reliable dirtiness-based baseline results, it would be impossible [edit: not impossible, "far more difficult"] to show their product was good, bad, or neutral with any statistical significance. What I'd like to see is a study of pull forces between dirty and clean cables. The results of that might be "if you do nothing else, clean your cutaway cables. If you do one more thing, buy Aerodyne's MiniForce. " -=-=-=-=- Pull. Quote Share this post Link to post Share on other sites
jumpwally 0 #15 October 7, 2004 Instead of debating, send an e-mail to the inventor of the 3 ring to get a 2nd opinion. ;-) otherwise, this post seems like old ladies argueing about , is it cold or is it chilly...............wtsmile, be nice, enjoy life FB # - 1083 Quote Share this post Link to post Share on other sites
NickB 0 #16 October 7, 2004 Mark, At this point in the post, I have to feel that you are actively searching for a debate. All I can do is supply you with the facts that I have available to me which I have done. If you would like to discuss your theory more in depth, I have offered and will gladly provide you with the contact information of our lead engineer. I think we have lost sight of the original purpose of this post, which was to quell the fear a customer had about the miniforce three rings system and to provide this customer with a little general background information about the system. I have provided this person witht the same factual information I am able to provide everyone of my customers or potential customers. Please contact me via e-mail and I will supply you with our Engineers contact information so as to not put his e-mail address on the Web. Cheers, Nick Nick Bosco Sales Representative North & South America Aerodyne Research Corporation 12649 Race Track Road Tampa, FL 33626 Tel. +1 813 891-6300 Fax. +1 813 891-6315 Mobile +1 813 679-7190 [email protected] www.aerodyne-int.com Quote Share this post Link to post Share on other sites
mark 102 #17 October 7, 2004 Thanks, Frognog. You said it better than I. Mark Quote Share this post Link to post Share on other sites
Malta_Dog 0 #18 October 7, 2004 Nick, thanks for your answer. I hadn't checked the article section on your website ... d'oh! I understand that the ovalized middle ring, by lengthening the lever arm, reduces the load on the loop. What makes me a bit uneasy with the mini-force system is the possibilty that the middle ring, by pivoting 90%, would lock into the big ring. Agreed, I can see on the pictures that the oval ring has been designed to prevent this to happen, but I still wonder how hard a shock on the rings has to be to allow the locking. Has it been tested yet? If only an extremely hard opening/collision (i.e. causing serious injury or death) gives a remote possibilty of a ring lock, then I have no problem with that. But if another diver kicking you in the rings while RWing is enough to jam the system, that would make me really uncomfortable. OTOH, I think that the dirty housings are a non-issue regarding comparison of the pull force needed to liberate the mini-rings and the mini-force rings: 1) dirty housings will significantly increase pull force both on mini-rings and mini-force rings (and normal rings...) 2) dirty housings is a factor upon which we (the end-users) have full control. So if you used high quality mini-rings against your mini-force rings during the test, I really can't fault your comparison protocol at all. All your dropzone are belong to us!!!!111! Quote Share this post Link to post Share on other sites
NickB 0 #19 October 7, 2004 This miniforce system is part of the TSO that our entire rig meets the standards of. This TSO is C23d which is the most recent and as far as I know, most stringent of the TSO's. This TSO includes high weight and high speed testing. You won't generally find something in this sport that is different from the norm. which hasn't been fully tested. This system was tested to the same test used on all other three ring release systems and has never locked up. The other nice thing about our miniforce rings is they are thicker, making it much harder to bend or deform these rings in the event of a hard opening shock. I hope this helps you with your questions. Please let me know if you have anymore. Nick Nick Bosco Sales Representative North & South America Aerodyne Research Corporation 12649 Race Track Road Tampa, FL 33626 Tel. +1 813 891-6300 Fax. +1 813 891-6315 Mobile +1 813 679-7190 [email protected] www.aerodyne-int.com Quote Share this post Link to post Share on other sites
Malta_Dog 0 #20 October 7, 2004 Thanks again for another fast answer. It gives me good vibes about the customer service. I'll tell you that I'm almost sold on a complete Aerodyne rig...unless I can get a Vector 3M with skyhook for a good price. Even then, the canopies will be Aerodyne. Thanks again. All your dropzone are belong to us!!!!111! Quote Share this post Link to post Share on other sites
