KR> New wing skin idea or not so new....
Hi Gary, Many years ago a friend of mine acquired,(in a trade), a "stock" KR with trike gear and wood wings and turtle decks, even the canopy frame was wood. As I recall the builder, (completely unknown to me), used about a 3/32" or 3mm birch plywood, over wood ribs, bulkheads, stringers, etc. He was quite the craftsman. I lost track of it and even tried to find it again years later, but never did. I recall we did a weight and balance on it and I'm pretty sure it was fairly good for weight. No reason why it would not work and be perfectly fine. Lots of work to get all the ribs just right. Wayne After looking in the archive, I didn't find results for wood wings. Has there been discussion about wood wings similar to that of GP4 or Tailwind? Has anyone done this? Gary __ Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org please see other KRnet info at http://www.krnet.org/info.html see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options
KR> New wing skin idea - Fuel tanks
That's why I am going for welded ally tanks. I don't think you will get anything stronger and will give the highest capacity for a given outer dimension. Regards Dene Collett Avlec Projects cc Builders of award winning aircraft tel:27419560048 cell: 27845805003 Port Elizabeth South Africa -Original Message- From: KRnet [mailto:krnet-bounces at list.krnet.org] On Behalf Of Ronald Wright Sent: 17 February, 2014 9:45 PM To: KRnet Subject: Re: KR> New wing skin idea - Fuel tanks Don't you have a concern about cold weather and the vinyl?cracking?? I would think a thin wall aluminum tube would be a much better choice.. ions
KR> New wing skin idea - Fuel tanks
"I tested the PVC water pipes and found that the fuel would weep through the sealed pipe until it was all gone in about three months. I am also testing Vinyl fence posts. I brought the test items to the Gatherings at MVN several times" The proof is in the testing but it really begs the question of why the fuel would seep through PVC pipe but not through PVC fence posts. I would like to pursue the use of the vinyl posts but would like to know why there is a difference. I am just an aerospace engineer...not a chemical engineer, so if anyone knows please pass that on.
KR> New wing skin idea - Fuel tanks
I tested the PVC water pipes and found that the fuel would weep through the sealed pipe until it was all gone in about three months. I am also testing Vinyl fence posts. I brought the test items to the Gatherings at MVN several times. Larry always had me keep the gasoline outside the terminal building on the picnic table. The sealed Vinyl post has held automotive gasoline with 10 percent Ethanol for seven years and not lost a drop. I check the loss rate (zero) by weighing the Vinyl post test items on a digital scale. Apparently the glue used for the Vinyl stands up to gasoline and Ethanol quite well. I would have used the Vinyl posts in my KR-2 when I replaced the Vinyl Ester tanks, but would have required too much rework on the existing wing structure. Were I building from scratch, I would definitely use the Vinyl fence posts; they are available at Lowe's in 3, 4, 5 and 6 inch sizes. Sid Wood Tri-gear KR-2 N6242 Mechanicsville, MD, USA > -- >>>How fuel resistant is PVC, ABS? Drain pipe ABS is really strong and >>fairly light. Peter > + > > Bill Clapp used PVC pipe for fuel tanks and found the fuel would > slowly "weep" through the > pipe. http://www.krnet.org/mvn2004/040929277.jpg Someone else was > doing a test using the square vinyl post covers and indicate early > success. I don't recall who that was. > > I would suggest that there have been enough different things tried on > KR's to satisfy most builders curiosity. If you're building simply > to fly, go with proven ideas and save time. If you're building to > fulfill your desire to experiment, go for it.. > > Larry Flesner >--
KR> New wing skin idea - Fuel tanks
Don't you have a concern about cold weather and the vinyl?cracking?? I would think a thin wall aluminum tube would be a much better choice.. From: smwood To: krnet at list.krnet.org Sent: Monday, February 17, 2014 1:08 PM Subject: Re: KR> New wing skin idea - Fuel tanks I tested the PVC water pipes and found that the fuel would weep through the sealed pipe until it was all gone in about three months. I am also testing Vinyl fence posts.? I brought the test items to the Gatherings at MVN several times.? Larry always had me keep the gasoline outside the terminal building on the picnic table.? The sealed Vinyl post has held automotive gasoline with 10 percent Ethanol for seven years and not lost a drop.? I check the loss rate (zero) by weighing the Vinyl post test items on a digital scale.? Apparently the glue used for the Vinyl stands up to gasoline and Ethanol quite well.? I would have used the Vinyl posts in my KR-2 when I replaced the Vinyl Ester tanks, but would have required too much rework on the existing wing structure.? Were I building from scratch, I would definitely use the Vinyl fence posts; they are available at Lowe's in 3, 4, 5 and 6 inch sizes. Sid Wood Tri-gear KR-2 N6242 Mechanicsville, MD, USA > -- >>> How fuel resistant is PVC, ABS? Drain pipe ABS is really strong and >> fairly light. Peter > + > > Bill Clapp used PVC pipe for fuel tanks and found the fuel would > slowly "weep" through the > pipe.? http://www.krnet.org/mvn2004/040929277.jpg Someone else was > doing a test using the square vinyl post covers and indicate early > success.? I don't recall who that was. > > I would suggest that there have been enough different things tried on > KR's to satisfy most builders curiosity.? If you're building simply > to fly, go with proven ideas and save time.? If you're building to > fulfill your desire to experiment, go for it.. > > Larry Flesner > -- ___ Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org please see other KRnet info at http://www.krnet.org/info.html see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options
KR> New wing skin idea - Fuel tanks
At 02:15 PM 2/16/2014, you wrote: >How fuel resistant is PVC, ABS? Drain pipe ABS is really strong and >fairly light. Peter + Bill Clapp used PVC pipe for fuel tanks and found the fuel would slowly "weep" through the pipe. http://www.krnet.org/mvn2004/040929277.jpg Someone else was doing a test using the square vinyl post covers and indicate early success. I don't recall who that was. I would suggest that there have been enough different things tried on KR's to satisfy most builders curiosity. If you're building simply to fly, go with proven ideas and save time. If you're building to fulfill your desire to experiment, go for it.. Larry Flesner
KR> New wing skin idea - Fuel
Nope. http://www.gilsoneng.com/reference/ChemRes.pdf peter One idea that occurred to me, was that a sufficiently large-diameter PVC pipe,
KR> New wing skin idea - Fuel
How fuel resistant is PVC, ABS? Drain pipe ABS is really strong and fairly light. Peter One idea that occurred to me, was that a sufficiently large-diameter PVC pipe,
KR> New wing skin idea - Fuel
One idea that occurred to me, was that a sufficiently large-diameter PVC pipe, properly sealed & run through the space between the leading edge and the front spar would make an ideal fuel tank... However, since I got my KR project with the wings prebuilt and a large header tank in place, I'm going with that for now... On 2/15/2014 6:27 AM, joemalsack at charter.net wrote: > Larry > How long is the fuel tank to get 12.5 gals. I was calculating mine in > the same location and found 48 inches long and 10 inches wide would > give me 12 gals. > Joe > > > On Fri, Feb 14, 2014 at 7:08 PM, Larry Flesner wrote: > >> At 01:41 PM 2/14/2014, you wrote: >>> I might not make the >>> tanks the full span between the spars but I would like to keep them >>> full >>> span for the stiffness it will give the wing being bonded to both >>> the top >>> and bottom skins. >>> Dene Collett >> + >> >> A long slender tank from root to tip, located immediately behind the >> forward spar helps to keep the CG shift to a minimum from full to >> empty on fuel. My tanks are just 10 inches front to rear behind the >> spar, full length of the outer wing panel and hold 12.5 gallon per >> wing. The CG shifts forward 1 inch from 25 gallon to empty. My >> tanks, while not connected from spar to spar, still add torsional >> stiffness to the wing, which, when built to plans, is already stiff >> enough. >> >> Larry Flesner >> >> >> ___ >> Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. >> To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org >> please see other KRnet info at http://www.krnet.org/info.html >> see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to >> change options > > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to > change options
KR> New wing skin idea
At 08:27 AM 2/15/2014, you wrote: >How long is the fuel tank to get 12.5 gals. >Joe My tanks are the length of the spar http://myplace.frontier.com/~flesner/22.jpg less about 8 inches (baffles and end foam), 10 inches front to rear and average about 4 1/2 inches deep (3 1/2 inches at the tip, 5 1/2 inches at the root). I calculated them to be 12.5 gallon and that came within about 2 tenths when confirmed at the fuel pump. Larry Flesner
KR> New wing skin idea
To determine any fluid capacity all you need to remember is that it is 231 cubic inches to the gallon, although that will give you total liquid not useable liquid. Mark W. N952MW res. -Original Message- From: KRnet [mailto:krnet-bounces at list.krnet.org] On Behalf Of joemalsack at charter.net Sent: Saturday, February 15, 2014 8:28 AM To: KRnet Subject: Re: KR> New wing skin idea Larry How long is the fuel tank to get 12.5 gals. I was calculating mine in the same location and found 48 inches long and 10 inches wide would give me 12 gals. Joe On Fri, Feb 14, 2014 at 7:08 PM, Larry Flesner wrote: > At 01:41 PM 2/14/2014, you wrote: >> I might not make the >> tanks the full span between the spars but I would like to keep them >> full span for the stiffness it will give the wing being bonded to >> both the top and bottom skins. >> Dene Collett > + > > A long slender tank from root to tip, located immediately behind the > forward spar helps to keep the CG shift to a minimum from full to > empty on fuel. My tanks are just 10 inches front to rear behind the > spar, full length of the outer wing panel and hold 12.5 gallon per > wing. The CG shifts forward 1 inch from 25 gallon to empty. My > tanks, while not connected from spar to spar, still add torsional > stiffness to the wing, which, when built to plans, is already stiff > enough. > > Larry Flesner > > > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to > KRnet-leave at list.krnet.org please see other KRnet info at > http://www.krnet.org/info.html see > http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options ___ Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org please see other KRnet info at http://www.krnet.org/info.html see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com
KR> New wing skin idea
Larry How long is the fuel tank to get 12.5 gals. I was calculating mine in the same location and found 48 inches long and 10 inches wide would give me 12 gals. Joe On Fri, Feb 14, 2014 at 7:08 PM, Larry Flesner wrote: > At 01:41 PM 2/14/2014, you wrote: >> I might not make the >> tanks the full span between the spars but I would like to keep them >> full >> span for the stiffness it will give the wing being bonded to both the >> top >> and bottom skins. >> Dene Collett > + > > A long slender tank from root to tip, located immediately behind the > forward spar helps to keep the CG shift to a minimum from full to > empty on fuel. My tanks are just 10 inches front to rear behind the > spar, full length of the outer wing panel and hold 12.5 gallon per > wing. The CG shifts forward 1 inch from 25 gallon to empty. My > tanks, while not connected from spar to spar, still add torsional > stiffness to the wing, which, when built to plans, is already stiff > enough. > > Larry Flesner > > > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to > KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to > change options
KR> New wing skin idea
Hi Sid I hear you but I have not done my final calcs yet, I might not make the tanks the full span between the spars but I would like to keep them full span for the stiffness it will give the wing being bonded to both the top and bottom skins. Regards Dene Collett Avlec Projects cc Builders of award winning aircraft tel:27419560048 cell: 27845805003 Port Elizabeth South Africa -Original Message- I have since installed smaller aluminum tanks. Think it through on the full length dimension for wing tanks. Sid Wood Tri-gear KR-2 N6242 Mechanicsville, MD, USA --- >
KR> New wing skin idea
At 01:41 PM 2/14/2014, you wrote: >I might not make the >tanks the full span between the spars but I would like to keep them full >span for the stiffness it will give the wing being bonded to both the top >and bottom skins. >Dene Collett + A long slender tank from root to tip, located immediately behind the forward spar helps to keep the CG shift to a minimum from full to empty on fuel. My tanks are just 10 inches front to rear behind the spar, full length of the outer wing panel and hold 12.5 gallon per wing. The CG shifts forward 1 inch from 25 gallon to empty. My tanks, while not connected from spar to spar, still add torsional stiffness to the wing, which, when built to plans, is already stiff enough. Larry Flesner
KR> New wing skin idea
Dene; Make sure that the airloads don't travel through the full-span box structure of the tanks, rather than through the box structure of the spars. Probably would delaminate from the skins over time. Thermal loads also concern me. Wood, aluminum, and fibreglass expand differentially with heating. Peter I hear you but I have not done my final calcs yet, I might not make thetanks the full span between the spars but I would like to keep them fullspan for the stiffness it will give the wing being bonded to both the topand bottom skins.
KR> New wing skin idea
Hi Wayne I appreciate your good advice and wisdom, however, I have experience with polystyrene foam in a KR wing being dissolved in flight and it is not good for the heart! I personally know a cozy builder that has had his tank spring a leak and had to replace a lot of foam in the wing, a very delicate operation. I build Whisper motor gliders for a living and their wings are 8m long each. The cores are cut on a CNC hotwire cutter in 1m segments with the washout already set. We join them with micro on a perfectly level table around the spar and glass over one side at a time. I have no worries about compromising the tortional strength of the wing as the tank will be bonded to the inside of the wing skins. This will offer much more ridgidity that the traditional methods. The bond between the different pieces is not a concern for me, if it is dome properly the bond will be at least as strong as if it was one piece. I plan on using 2mm or 3mm coremat as the core material Regards Dene Collett Avlec Projects cc Builders of award winning aircraft tel:27419560048 cell: 27845805003 Port Elizabeth South Africa -Original Message- From: KRnet [mailto:krnet-bounces at list.krnet.org] On Behalf Of Wayne Tokarz Sent: 14 February, 2014 5:58 PM To: 'KRnet' Subject: Re: KR> New wing skin idea I think you will be compromising the torsional rigidity of the wings with three pieces and relying on a bonded joint, ( I could be wrong here
KR> New wing skin idea
I built in wing tanks per the Diehl plans between the forward and aft spars, and from the WAF out to the first wing rib. Turned out to be 10.8 gallons per side. That 21.6 gallons would provide over 6 hours endurance plus reserve. Way longer than I care to sit in my tiny cockpit for one flight. I have since installed smaller aluminum tanks. Think it through on the full length dimension for wing tanks. Sid Wood Tri-gear KR-2 N6242 Mechanicsville, MD, USA --- > > Hi guys > It is my plan to put full length wing tanks inside my wings between the > spars ... > Dene Collett >
KR> New wing skin idea
Just remembered this one, did it years ago on a special project. Use any core you wish for front and back half of wing, and last a foam in the center area. Cover the spars with a releasable covering, (please don't laugh, but duct tape works really well for this!), lay up the whole wing as per normal. Cut the leading edge and slice the trailing edge, remove only the top or bottom half. Do your backside layups on the two skins and bond it all together. This is just the basic idea, I'm very sure you are more than capable working out the details, ( gas cap, lines, baffles, etc.). Just my humble two cents worth. Wayne -Original Message- From: KRnet [mailto:krnet-bounces at list.krnet.org] On Behalf Of Dene Sent: February-13-14 10:48 PM To: 'KRnet' Subject: KR> New wing skin idea Hi guys It is my plan to put full length wing tanks inside my wings between the spars but because it is common practice here to use polystyrene for a core and we all know what happens to poly foam when it even smells fuel, I have been trying to come up with a way to get rid of foam all together without having to produce a set of molds. I think I have a plan. The cores are hot-wired from foam blocks as usual but the core that we would normally use is discarded. The "female" form, which is cut with the washout already set in it laid out on a flat table. A thin sheet of mylar or similar is cut to the required dimensions and laid inside the foam form. Glass is then laid up on that with a core material. The skins can be made in three pieces: D box, centre section and trailing edge, all with "overlap" for bonding over the spars. All these can be bonded together over the spars. This method, if done carefully and accurately should produce a pretty fair wing skin that is strong, light and need very little fairing. Final washout can still be tweaked at final bonding. Any thoughts? Regards Dene Collett Avlec Projects cc Builders of award winning aircraft tel:27419560048 cell: 27845805003 Port Elizabeth South Africa ___ Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org please see other KRnet info at http://www.krnet.org/info.html see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options
KR> New wing skin idea
Hi guys It is my plan to put full length wing tanks inside my wings between the spars but because it is common practice here to use polystyrene for a core and we all know what happens to poly foam when it even smells fuel, I have been trying to come up with a way to get rid of foam all together without having to produce a set of molds. I think I have a plan. The cores are hot-wired from foam blocks as usual but the core that we would normally use is discarded. The "female" form, which is cut with the washout already set in it laid out on a flat table. A thin sheet of mylar or similar is cut to the required dimensions and laid inside the foam form. Glass is then laid up on that with a core material. The skins can be made in three pieces: D box, centre section and trailing edge, all with "overlap" for bonding over the spars. All these can be bonded together over the spars. This method, if done carefully and accurately should produce a pretty fair wing skin that is strong, light and need very little fairing. Final washout can still be tweaked at final bonding. Any thoughts? Regards Dene Collett Avlec Projects cc Builders of award winning aircraft tel:27419560048 cell: 27845805003 Port Elizabeth South Africa
