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#1
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I recently had to replace 2 of the blades on my KISS wind generator due
to small cracks which I found near the mounting holes. The blades were replaced with spares purchased at the same time that the generator was purchased. One of the replacement blades weighs a lot more than the other blades and none of the blades weighs the same, even in the complete spare set. This is causing a lot of vibration. KISS supplies a lead tape to place along the back side of the blades to balance them. I made a scale to balance the blades such that they all weighed the same. One blade ended up with 4" of tape, another with 12" and one with 18". Even though they weighed the same, it was even worse than before. So, does anyone have any ideas how to determine who to determine where the tape needs to be placed? -- Geoff P.S. I'll be out of Internet access for a few days. |
#2
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On 30 Mar 2005 15:22:25 -0800, "GeoffSchultz"
wrote: I recently had to replace 2 of the blades on my KISS wind generator due to small cracks which I found near the mounting holes. The blades were replaced with spares purchased at the same time that the generator was purchased. One of the replacement blades weighs a lot more than the other blades and none of the blades weighs the same, even in the complete spare set. This is causing a lot of vibration. KISS supplies a lead tape to place along the back side of the blades to balance them. I made a scale to balance the blades such that they all weighed the same. One blade ended up with 4" of tape, another with 12" and one with 18". Even though they weighed the same, it was even worse than before. So, does anyone have any ideas how to determine who to determine where the tape needs to be placed? -- Geoff P.S. I'll be out of Internet access for a few days. If you have 3 blades I would imagine that one of the blades should not require any tape. You should only need to match the 2 remaining blades to the heaviest blade. Am I wrong here??? So it would seem that you could start by removing the 4" piece from the one blade (heaviest one) and then cutting off 4" from each of the other 2. In any case, it would appear that they put the tape on the edge: http://www.kissenergy.com/TechnicalDescription.html Jeannette aa6jh Bristol 32, San Francisco http://www.eblw.com/contepartiro/contepartiro.html |
#3
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![]() "jeannette" wrote in message ... On 30 Mar 2005 15:22:25 -0800, "GeoffSchultz" wrote: I recently had to replace 2 of the blades on my KISS wind generator due to small cracks which I found near the mounting holes. The blades were replaced with spares purchased at the same time that the generator was purchased. One of the replacement blades weighs a lot more than the other blades and none of the blades weighs the same, even in the complete spare set. This is causing a lot of vibration. KISS supplies a lead tape to place along the back side of the blades to balance them. I made a scale to balance the blades such that they all weighed the same. One blade ended up with 4" of tape, another with 12" and one with 18". Even though they weighed the same, it was even worse than before. So, does anyone have any ideas how to determine who to determine where the tape needs to be placed? -- Geoff P.S. I'll be out of Internet access for a few days. If you have 3 blades I would imagine that one of the blades should not require any tape. You should only need to match the 2 remaining blades to the heaviest blade. Am I wrong here??? So it would seem that you could start by removing the 4" piece from the one blade (heaviest one) and then cutting off 4" from each of the other 2. In any case, it would appear that they put the tape on the edge: http://www.kissenergy.com/TechnicalDescription.html Jeannette aa6jh Bristol 32, San Francisco http://www.eblw.com/contepartiro/contepartiro.html The blades come with the lead tape already installed. About 8" or so along the leading edge at the root. To balance mine I removed about 1/16" at a time until it was balanced. Doug, k3qt s/v Callista |
#4
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![]() "GeoffSchultz" wrote in message oups.com... I recently had to replace 2 of the blades on my KISS wind generator due to small cracks which I found near the mounting holes. The blades were replaced with spares purchased at the same time that the generator was purchased. One of the replacement blades weighs a lot more than the other blades and none of the blades weighs the same, even in the complete spare set. This is causing a lot of vibration. KISS supplies a lead tape to place along the back side of the blades to balance them. I made a scale to balance the blades such that they all weighed the same. One blade ended up with 4" of tape, another with 12" and one with 18". Even though they weighed the same, it was even worse than before. So, does anyone have any ideas how to determine who to determine where the tape needs to be placed? -- Geoff P.S. I'll be out of Internet access for a few days. You can't balance them by statically weighing them. My KISS was able to be balanced by trimming maybe less than an inch of the tape from 1 or 2 of the blades. Did you try and balancing them according to the procedure in the manual? I had no trouble doing it that way. The balance of the blades depends not only upon the weight but the distribution of the weight along the length of the blade. ie a bit of weight further out on the blade has more affect than the same amount of weight close to the root. Also, replacing only 2 out of three blades may not be a good idea. My KISS blades after 3 years of service have clearly eroded. I do have a spare set and I suspect that the new blades probably weigh more than the original ones. My suggestion is to use a complete set of new blades and use the original balancing technique. Doug s/v Callista |
#5
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![]() Doug Dotson wrote: "GeoffSchultz" wrote in message oups.com... I recently had to replace 2 of the blades on my KISS wind generator due to small cracks which I found near the mounting holes. The blades were replaced with spares purchased at the same time that the generator was purchased. One of the replacement blades weighs a lot more than the other blades and none of the blades weighs the same, even in the complete spare set. This is causing a lot of vibration. KISS supplies a lead tape to place along the back side of the blades to balance them. I made a scale to balance the blades such that they all weighed the same. One blade ended up with 4" of tape, another with 12" and one with 18". Even though they weighed the same, it was even worse than before. So, does anyone have any ideas how to determine who to determine where the tape needs to be placed? -- Geoff P.S. I'll be out of Internet access for a few days. You can't balance them by statically weighing them. My KISS was able to be balanced by trimming maybe less than an inch of the tape from 1 or 2 of the blades. Did you try and balancing them according to the procedure in the manual? I had no trouble doing it that way. The balance of the blades depends not only upon the weight but the distribution of the weight along the length of the blade. ie a bit of weight further out on the blade has more affect than the same amount of weight close to the root. Also, replacing only 2 out of three blades may not be a good idea. My KISS blades after 3 years of service have clearly eroded. I do have a spare set and I suspect that the new blades probably weigh more than the original ones. My suggestion is to use a complete set of new blades and use the original balancing technique. Doug s/v Callista The problem with replacing all 3 blades is that the 3rd blade of the replacement set has a very large front to back warp to it which causes a lot of vibration on it's own. To explain further, when the blades spin the tips of the blades should rotate on the same "X" plane and have little "Y" plane variation. However, the 3rd replacement blade has about 5/8" of Y plane variation. All of the blades were stored together and wrapped in foam. The original set had some variation, but I was able to correct that by placing tape shims on the hub where the blades attach. The 5/8" variation is too much to correct that way, so I'm only using 2 of the spare blades. I suspect that this is due to differences in the manufacturing/curing process. They're made in Trinidad and I suspect that the process may have a lot of variables in it, and this has lead to the differences in the blades. In the past I've tried to use their prescribed method of balancing the blades, which requires turning the blades in a windless environment and determining which blade is heavier. That's great if you're somewhere where the wind isn't blowing, but in the Caribbean that's almost never. Moving the generator to a sheltered location would be a major project, so forget that. I thought that this would be similar to balancing a tire or a ceiling fan and I hoped that someone would have a good method to achieve this given my environment. -- Geoff |
#6
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![]() "GeoffSchultz" wrote in message oups.com... Doug Dotson wrote: "GeoffSchultz" wrote in message oups.com... I recently had to replace 2 of the blades on my KISS wind generator due to small cracks which I found near the mounting holes. The blades were replaced with spares purchased at the same time that the generator was purchased. One of the replacement blades weighs a lot more than the other blades and none of the blades weighs the same, even in the complete spare set. This is causing a lot of vibration. KISS supplies a lead tape to place along the back side of the blades to balance them. I made a scale to balance the blades such that they all weighed the same. One blade ended up with 4" of tape, another with 12" and one with 18". Even though they weighed the same, it was even worse than before. So, does anyone have any ideas how to determine who to determine where the tape needs to be placed? -- Geoff P.S. I'll be out of Internet access for a few days. You can't balance them by statically weighing them. My KISS was able to be balanced by trimming maybe less than an inch of the tape from 1 or 2 of the blades. Did you try and balancing them according to the procedure in the manual? I had no trouble doing it that way. The balance of the blades depends not only upon the weight but the distribution of the weight along the length of the blade. ie a bit of weight further out on the blade has more affect than the same amount of weight close to the root. Also, replacing only 2 out of three blades may not be a good idea. My KISS blades after 3 years of service have clearly eroded. I do have a spare set and I suspect that the new blades probably weigh more than the original ones. My suggestion is to use a complete set of new blades and use the original balancing technique. Doug s/v Callista The problem with replacing all 3 blades is that the 3rd blade of the replacement set has a very large front to back warp to it which causes a lot of vibration on it's own. To explain further, when the blades spin the tips of the blades should rotate on the same "X" plane and have little "Y" plane variation. However, the 3rd replacement blade has about 5/8" of Y plane variation. Order a new blade or a new set. I'm sure Doug weill make good on the defective set. All of the blades were stored together and wrapped in foam. The original set had some variation, but I was able to correct that by placing tape shims on the hub where the blades attach. The 5/8" variation is too much to correct that way, so I'm only using 2 of the spare blades. I would have contacted KISS when the original set didn;t work. I suspect that this is due to differences in the manufacturing/curing process. They're made in Trinidad and I suspect that the process may have a lot of variables in it, and this has lead to the differences in the blades. I have friends that have visited the factory. Small, but well organized. My original and replacements were fine. Again, contact the factory for advice. I've had nothing but experiences with them. In the past I've tried to use their prescribed method of balancing the blades, which requires turning the blades in a windless environment and determining which blade is heavier. That's great if you're somewhere where the wind isn't blowing, but in the Caribbean that's almost never. Moving the generator to a sheltered location would be a major project, so forget that. Balanceing the blades has never required doing it on the generator itself. Only the blade assembly (hub + blades) using the supplied balancing shaft is necessary. I thought that this would be similar to balancing a tire or a ceiling fan and I hoped that someone would have a good method to achieve this given my environment. I'm sure you can find an environment that will be sufficent. It doesn;t require much. -- Geoff Doug |
#7
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Balanceing the blades has never required doing it on the generator
itself. Only the blade assembly (hub + blades) using the supplied balancing shaft is necessary. Call me confused. What "supplied balancing shaft" are you talking about. I never received anything like that. -- Geoff |
#8
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Geoff,
You should have received a short tapered threaded shaft that is identical to the shaft on the generator itself. You install it into the hub with the blades attached (hub/blade assembly not installed on the generator). Then you arrange a couple of horizontal surfaces close enough together to allow the assembly to rest with the shaft with one end on each surface. Two tables moved close together is what I used. That way the hub/blades can rotate almost frictionless. Then you observe the heavy blade drop and incrementally remove the tape until you can give the blades a spin and have no particular blade end up at the bottom. Take a look at the section entitled "Rotor Balancing" in the manual. It describes the entire process. Doug s/v Callista "GeoffSchultz" wrote in message oups.com... Balanceing the blades has never required doing it on the generator itself. Only the blade assembly (hub + blades) using the supplied balancing shaft is necessary. Call me confused. What "supplied balancing shaft" are you talking about. I never received anything like that. -- Geoff |
#9
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Just an afterthought: You CAN'T balance the blades on the generator itself.
The bearing friction and just the nature of a PM generator do not allow the blades to freewheel. Doug "GeoffSchultz" wrote in message oups.com... Doug Dotson wrote: "GeoffSchultz" wrote in message oups.com... I recently had to replace 2 of the blades on my KISS wind generator due to small cracks which I found near the mounting holes. The blades were replaced with spares purchased at the same time that the generator was purchased. One of the replacement blades weighs a lot more than the other blades and none of the blades weighs the same, even in the complete spare set. This is causing a lot of vibration. KISS supplies a lead tape to place along the back side of the blades to balance them. I made a scale to balance the blades such that they all weighed the same. One blade ended up with 4" of tape, another with 12" and one with 18". Even though they weighed the same, it was even worse than before. So, does anyone have any ideas how to determine who to determine where the tape needs to be placed? -- Geoff P.S. I'll be out of Internet access for a few days. You can't balance them by statically weighing them. My KISS was able to be balanced by trimming maybe less than an inch of the tape from 1 or 2 of the blades. Did you try and balancing them according to the procedure in the manual? I had no trouble doing it that way. The balance of the blades depends not only upon the weight but the distribution of the weight along the length of the blade. ie a bit of weight further out on the blade has more affect than the same amount of weight close to the root. Also, replacing only 2 out of three blades may not be a good idea. My KISS blades after 3 years of service have clearly eroded. I do have a spare set and I suspect that the new blades probably weigh more than the original ones. My suggestion is to use a complete set of new blades and use the original balancing technique. Doug s/v Callista The problem with replacing all 3 blades is that the 3rd blade of the replacement set has a very large front to back warp to it which causes a lot of vibration on it's own. To explain further, when the blades spin the tips of the blades should rotate on the same "X" plane and have little "Y" plane variation. However, the 3rd replacement blade has about 5/8" of Y plane variation. All of the blades were stored together and wrapped in foam. The original set had some variation, but I was able to correct that by placing tape shims on the hub where the blades attach. The 5/8" variation is too much to correct that way, so I'm only using 2 of the spare blades. I suspect that this is due to differences in the manufacturing/curing process. They're made in Trinidad and I suspect that the process may have a lot of variables in it, and this has lead to the differences in the blades. In the past I've tried to use their prescribed method of balancing the blades, which requires turning the blades in a windless environment and determining which blade is heavier. That's great if you're somewhere where the wind isn't blowing, but in the Caribbean that's almost never. Moving the generator to a sheltered location would be a major project, so forget that. I thought that this would be similar to balancing a tire or a ceiling fan and I hoped that someone would have a good method to achieve this given my environment. -- Geoff |
#10
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![]() Doug Dotson wrote: "GeoffSchultz" wrote in message oups.com... I recently had to replace 2 of the blades on my KISS wind generator due to small cracks which I found near the mounting holes. The blades were replaced with spares purchased at the same time that the generator was purchased. One of the replacement blades weighs a lot more than the other blades and none of the blades weighs the same, even in the complete spare set. This is causing a lot of vibration. KISS supplies a lead tape to place along the back side of the blades to balance them. I made a scale to balance the blades such that they all weighed the same. One blade ended up with 4" of tape, another with 12" and one with 18". Even though they weighed the same, it was even worse than before. So, does anyone have any ideas how to determine who to determine where the tape needs to be placed? -- Geoff P.S. I'll be out of Internet access for a few days. You can't balance them by statically weighing them. My KISS was able to be balanced by trimming maybe less than an inch of the tape from 1 or 2 of the blades. Did you try and balancing them according to the procedure in the manual? I had no trouble doing it that way. The balance of the blades depends not only upon the weight but the distribution of the weight along the length of the blade. ie a bit of weight further out on the blade has more affect than the same amount of weight close to the root. Also, replacing only 2 out of three blades may not be a good idea. My KISS blades after 3 years of service have clearly eroded. I do have a spare set and I suspect that the new blades probably weigh more than the original ones. My suggestion is to use a complete set of new blades and use the original balancing technique. Doug s/v Callista The problem with replacing all 3 blades is that the 3rd blade of the replacement set has a very large front to back warp to it which causes a lot of vibration on it's own. To explain further, when the blades spin the tips of the blades should rotate on the same "X" plane and have little "Y" plane variation. However, the 3rd replacement blade has about 5/8" of Y plane variation. All of the blades were stored together and wrapped in foam. The original set had some variation, but I was able to correct that by placing tape shims on the hub where the blades attach. The 5/8" variation is too much to correct that way, so I'm only using 2 of the spare blades. I suspect that this is due to differences in the manufacturing/curing process. They're made in Trinidad and I suspect that the process may have a lot of variables in it, and this has lead to the differences in the blades. In the past I've tried to use their prescribed method of balancing the blades, which requires turning the blades in a windless environment and determining which blade is heavier. That's great if you're somewhere where the wind isn't blowing, but in the Caribbean that's almost never. Moving the generator to a sheltered location would be a major project, so forget that. I thought that this would be similar to balancing a tire or a ceiling fan and I hoped that someone would have a good method to achieve this given my environment. -- Geoff |
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