Original Posted By: "Barry Davis"
Folks,Anybody have any thoughts about the advisability of using Kevlar cable(Phillystran) for Drag/Anti Drag wires? On the surface, the physicalproperties look great.Thanks,Tom Bernie________________________________________________________________________________
Pietenpol-List: Kevlar Drag Wires
RE: Pietenpol-List: Kevlar Drag Wires
Original Posted By: "Phillips, Jack"
Re: Pietenpol-List: Kevlar Drag Wires
Original Posted By: "bike.mike"
Too elastic ?Hans "Tom Bernie" To Sent by: owner-pietenpol-l cc ist-server@matron ics.com Subject Pietenpol-List: Kevlar Drag Wires 06/02/2006 11:22 AM Please respond to pietenpol-list@ma tronics.com Folks,Anybody have any thoughts about the advisability of using Kevlar cable(Phillystran) for Drag/Anti Drag wires? On the surface, the physicalproperties look great.Thanks,Tom Bernie________________________________________________________________________________Date: Fri, 02 Jun 2006 12:17:10 -0700
Too elastic ?Hans "Tom Bernie" To Sent by: owner-pietenpol-l cc ist-server@matron ics.com Subject Pietenpol-List: Kevlar Drag Wires 06/02/2006 11:22 AM Please respond to pietenpol-list@ma tronics.com Folks,Anybody have any thoughts about the advisability of using Kevlar cable(Phillystran) for Drag/Anti Drag wires? On the surface, the physicalproperties look great.Thanks,Tom Bernie________________________________________________________________________________Date: Fri, 02 Jun 2006 12:17:10 -0700
Pietenpol-List: Stromberg Carb for sale
Original Posted By: KMHeide
Pietenpol-List: Stromberg Carb for sale
Original Posted By: Tom Bernie
RE: Pietenpol-List: Kevlar Drag Wires
Original Posted By: "Phillips, Jack"
RE: Pietenpol-List: Kevlar Drag Wires
Original Posted By: Tom Bernie
Pietenpol-List: Kevlar Drag Wires
Original Posted By: Tom Bernie
> Re: Pietenpol-List: Kevlar Drag Wires
Original Posted By: Tom Bernie
Tom,I googled the elasticity modulusKevlar 49 has a elasticity modulus of 120 GpaCarbon Steel has a elasticity modulus of 210 GpaThe higher the number the lower the elasticity.Kevlar has a higher fatigue life than steel, due to being more elastic.Probably Kevlar would be more suited as use in bracing wires, where thereis a lot of vibration, or control cables where there is a lot of bending.Inside the wing with no turbulence and no bending I would not use it, theadditional stretching might exceed the limits of the wood structure.Then again the certified aircraft builders Boeing and Airbus seem to useKevlar in secondary structures, why not in primary ?Hans Tom Bernie To Sent by: pietenpol-list(at)matronics.com owner-pietenpol-l cc ist-server@matron ics.com Subject Re: Pietenpol-List: Kevlar Drag Wires 06/02/2006 02:38 PM Please respond to pietenpol-list@ma tronics.com Hans,The tower instructions call for tensioning to 15% breaking strength thenunder that load it relaxes to 10% over a period of 30 days. Tower buildersseem to consider it equivalent to galvanized. I'm trying to get elasticityor dymanic stretching data. It weighs nothing and at .22" dia and 2100#breaking strength, it costs $.59 @ foot.Regards,Tom Bernie-----Original Message----->From: Hans Vander Voort >Sent: Jun 2, 2006 1:55 PM>To: pietenpol-list(at)matronics.com>Cc: owner-pietenpol-list-server(at)matronics.com,pietenpol-list(at)matronics.com>Subject: Re: Pietenpol-List: Kevlar Drag Wires>>>Too elastic ?>>Hans>>> "Tom Bernie"> nk.net> To> Sent by: > owner-pietenpol-l cc> ist-server@matron> ics.com Subject> Pietenpol-List: Kevlar Drag Wires>> 06/02/2006 11:22> AM>>> Please respond to> pietenpol-list@ma> tronics.com>>>>>Folks,>>>Anybody have any thoughts about the advisability of using Kevlar cable>(Phillystran) for Drag/Anti Drag wires? On the surface, the physical>properties look great.>>>Thanks,>>>Tom Bernie>>________________________________________________________________________________Date: Fri, 2 Jun 2006 16:36:09 -0400 (GMT-04:00)
Tom,I googled the elasticity modulusKevlar 49 has a elasticity modulus of 120 GpaCarbon Steel has a elasticity modulus of 210 GpaThe higher the number the lower the elasticity.Kevlar has a higher fatigue life than steel, due to being more elastic.Probably Kevlar would be more suited as use in bracing wires, where thereis a lot of vibration, or control cables where there is a lot of bending.Inside the wing with no turbulence and no bending I would not use it, theadditional stretching might exceed the limits of the wood structure.Then again the certified aircraft builders Boeing and Airbus seem to useKevlar in secondary structures, why not in primary ?Hans Tom Bernie To Sent by: pietenpol-list(at)matronics.com owner-pietenpol-l cc ist-server@matron ics.com Subject Re: Pietenpol-List: Kevlar Drag Wires 06/02/2006 02:38 PM Please respond to pietenpol-list@ma tronics.com Hans,The tower instructions call for tensioning to 15% breaking strength thenunder that load it relaxes to 10% over a period of 30 days. Tower buildersseem to consider it equivalent to galvanized. I'm trying to get elasticityor dymanic stretching data. It weighs nothing and at .22" dia and 2100#breaking strength, it costs $.59 @ foot.Regards,Tom Bernie-----Original Message----->From: Hans Vander Voort >Sent: Jun 2, 2006 1:55 PM>To: pietenpol-list(at)matronics.com>Cc: owner-pietenpol-list-server(at)matronics.com,pietenpol-list(at)matronics.com>Subject: Re: Pietenpol-List: Kevlar Drag Wires>>>Too elastic ?>>Hans>>> "Tom Bernie"> nk.net> To> Sent by: > owner-pietenpol-l cc> ist-server@matron> ics.com Subject> Pietenpol-List: Kevlar Drag Wires>> 06/02/2006 11:22> AM>>> Please respond to> pietenpol-list@ma> tronics.com>>>>>Folks,>>>Anybody have any thoughts about the advisability of using Kevlar cable>(Phillystran) for Drag/Anti Drag wires? On the surface, the physical>properties look great.>>>Thanks,>>>Tom Bernie>>________________________________________________________________________________Date: Fri, 2 Jun 2006 16:36:09 -0400 (GMT-04:00)
RE: Pietenpol-List: Kevlar Drag Wires
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Hans,I got the following reply from Phillystran -- "There are 2 versions of the 2100 product:The original version is the HPTG 2100 made from parallel Kevlar 49 yarnwith en extruded PE jacket. The modulus for that item would be17.5x10E6 psi (conditioned rope value).In 1990 a second generation product was introduced known as HPTG2100I.Also made from the Kevlar 49 but a stranded resin impregnated rope withextruded PU jacket. Modulus is 15.0x10E6 psi.The HPTG-I version is an inventoried item whereas the HPTG is made toorder with a 5K min.Kenneth KnightPHILLYSTRAN, INC.Manager, Industrial Sales215-368-6611 *107fax: 215-362-7956cell: 267-614-5623kknight(at)phillystran.com"Is 15.0x10E6 psi a useful value in determining the cable usefulness?Regards,Tom Bernie-----Original Message-----
Hans,I got the following reply from Phillystran -- "There are 2 versions of the 2100 product:The original version is the HPTG 2100 made from parallel Kevlar 49 yarnwith en extruded PE jacket. The modulus for that item would be17.5x10E6 psi (conditioned rope value).In 1990 a second generation product was introduced known as HPTG2100I.Also made from the Kevlar 49 but a stranded resin impregnated rope withextruded PU jacket. Modulus is 15.0x10E6 psi.The HPTG-I version is an inventoried item whereas the HPTG is made toorder with a 5K min.Kenneth KnightPHILLYSTRAN, INC.Manager, Industrial Sales215-368-6611 *107fax: 215-362-7956cell: 267-614-5623kknight(at)phillystran.com"Is 15.0x10E6 psi a useful value in determining the cable usefulness?Regards,Tom Bernie-----Original Message-----
> Re: Pietenpol-List: Kevlar Drag Wires
Original Posted By: Gary Gower
RE: Pietenpol-List: Kevlar Drag Wires
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Group,I received this generous and informative email."I'm not on the Pietenpol List, but I am on the Kolb List, and wentbrowsing this morning. Saw this discussion and your email address and ifyou care to pass this along, feel free to do so.I am both an aerospace structural analyst and a sailor, as well asowning a Cessna Skywagon and Kolb Firestar.In the multihull sailing world, we often use what we call the"high-tech" ropes for rigging.1. They all have varying degrees of UV resistance. Covering extendsthat. With no data available, I'd guess that the UV protection for thewing covering would suffice for the drag and anti-drag cables, if youused Kevlar or other ropes for that, and especially if you used coveredrope.2. The applicable ropes are Vectran, Dyneema, or one of the aramids likeKevlar (another is Technora). They all have roughly the Young's modulusof about five million psi, so their area will have to be increased tohave the same stiffness performance as steel cable. Interestinglyenough, steel cable has an effective Young's modulus of about 11 million- so if the rope is twice the area, or about 50% bigger nominaldiameter, it's equivalent stiffness to the steel cable. Remember thatsolid tie rods have a Young's modulus of about 29 million psi, so ifyou're replacing those, you'll need about 2 1/2 times the diameter forthe rope.3. All these ropes creep. The initial creep is the most severe. Peopletypically make the end terminations and then apply a large load forabout 12 hours to prestretch them. If the prestretch tension is greaterthan the limit load (limit load is the maximum load the rope will eversee in service, without any safety factors - the real load) it shouldnot creep much after that in that load range. Dyneema has the mostcreep, the aramids next, and Vectran the least.4. The various rope manufacturers publish splicing information, and youcan buy "sailmaker's thimbles" for the ends. The "Brummel" splice iseasy to make, and makes a neat eye at the end. Knots, in general, failat 50% of the ropes breaking load or less. Use only splices for the ropecables you make.5. The end terminations, from the eye to the aircraft, can be made bylashing thin rope multiple times. Get something like 1/16" Vectransingle braid and tie it to the aircraft. Make the rope cable itself withboth eyes spliced in, but make it about six inches short. Lace the smallline from the aircraft through the rope cable eye and back to theaircraft, repeating several times, and finally pull tight and tie a knotin it to terminate it. Since each strand of the small rope is onlyminimally loaded, the knot is practical.6. In one case on my trimaran, I placed a turnbuckle between the hulland the small rope lashing. Once the final knot was made, the turnbuckleprovided adjustment. This might be most suitable for rope cables - andyou could even skip the lashing, with the final assembly being theaircraft fitting, the rope, and the turnbuckle to the other aircraftfitting. But the lashing does allow take-up of large gaps.7. Ensure that you avoid chafe.8. Sources are www.layline.com, Annapolis Performance Sailing, and WestMarine.9. Splicing links are: http://www.neropes.com/splice/default.h ... s.htmlGood luck!David Paule"-----Original Message-----
Group,I received this generous and informative email."I'm not on the Pietenpol List, but I am on the Kolb List, and wentbrowsing this morning. Saw this discussion and your email address and ifyou care to pass this along, feel free to do so.I am both an aerospace structural analyst and a sailor, as well asowning a Cessna Skywagon and Kolb Firestar.In the multihull sailing world, we often use what we call the"high-tech" ropes for rigging.1. They all have varying degrees of UV resistance. Covering extendsthat. With no data available, I'd guess that the UV protection for thewing covering would suffice for the drag and anti-drag cables, if youused Kevlar or other ropes for that, and especially if you used coveredrope.2. The applicable ropes are Vectran, Dyneema, or one of the aramids likeKevlar (another is Technora). They all have roughly the Young's modulusof about five million psi, so their area will have to be increased tohave the same stiffness performance as steel cable. Interestinglyenough, steel cable has an effective Young's modulus of about 11 million- so if the rope is twice the area, or about 50% bigger nominaldiameter, it's equivalent stiffness to the steel cable. Remember thatsolid tie rods have a Young's modulus of about 29 million psi, so ifyou're replacing those, you'll need about 2 1/2 times the diameter forthe rope.3. All these ropes creep. The initial creep is the most severe. Peopletypically make the end terminations and then apply a large load forabout 12 hours to prestretch them. If the prestretch tension is greaterthan the limit load (limit load is the maximum load the rope will eversee in service, without any safety factors - the real load) it shouldnot creep much after that in that load range. Dyneema has the mostcreep, the aramids next, and Vectran the least.4. The various rope manufacturers publish splicing information, and youcan buy "sailmaker's thimbles" for the ends. The "Brummel" splice iseasy to make, and makes a neat eye at the end. Knots, in general, failat 50% of the ropes breaking load or less. Use only splices for the ropecables you make.5. The end terminations, from the eye to the aircraft, can be made bylashing thin rope multiple times. Get something like 1/16" Vectransingle braid and tie it to the aircraft. Make the rope cable itself withboth eyes spliced in, but make it about six inches short. Lace the smallline from the aircraft through the rope cable eye and back to theaircraft, repeating several times, and finally pull tight and tie a knotin it to terminate it. Since each strand of the small rope is onlyminimally loaded, the knot is practical.6. In one case on my trimaran, I placed a turnbuckle between the hulland the small rope lashing. Once the final knot was made, the turnbuckleprovided adjustment. This might be most suitable for rope cables - andyou could even skip the lashing, with the final assembly being theaircraft fitting, the rope, and the turnbuckle to the other aircraftfitting. But the lashing does allow take-up of large gaps.7. Ensure that you avoid chafe.8. Sources are www.layline.com, Annapolis Performance Sailing, and WestMarine.9. Splicing links are: http://www.neropes.com/splice/default.h ... s.htmlGood luck!David Paule"-----Original Message-----