Kunlun
10-31-2009, 08:24 PM
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Kunlun
My Kunlun Sailplane instructions for CG say to set it at 51 to 55mm. With the 8.23oz battery I need to add 12+oz of weight to make CG. I cant believe this is right. has there been a correction ? has this been an issue with the Kunlun?
11-01-2009, 01:11 PM
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RE: Kunlun
Most sailplanes are designed around heavier NiCD battery packs and heavy motors, so if you are putting in a LiPo pack it is not unusual to find that you have to add a lot of weight to the nose to offset the long tail.
If possible make the additional weight "usable" weight, by using a larger heavier pack, and moving things as far foward as possible.
Also remember that weight added to the nose ( e.g. a heavier spinner ) has a larger lever moment, requiring less overall weight to move the C.G. forward.
If possible make the additional weight "usable" weight, by using a larger heavier pack, and moving things as far foward as possible.
Also remember that weight added to the nose ( e.g. a heavier spinner ) has a larger lever moment, requiring less overall weight to move the C.G. forward.
11-02-2009, 08:43 AM
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RE: Kunlun
BE REAL HERE.......WHO USES NICAD ANYMORE!! I am using a Lipo battery that is as stated 8.23 oz.. What I have determined is that I will have to switch the location of the battery, reciever and ESC by building a ramp forward (over the reciever/ESC location) to support the battery and use the designed battery tray for the reciever/ESC. That will get me closer to the correct CG.Unfortunately I have to correct this design on an ARF. One would think that CMP designers would design around Lipos over Nicad since technology has advanced to that level and Lipos are the battery of choice. CMP needs to get with the times.
11-05-2009, 12:30 PM
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RE: Kunlun
Actually NiCD's are in fairly heavy use for sailplanes. And most ARF sailplane designs still allow for their use.
In the "get real" department I would suggest that you remember that Nano-Phosphate cells are the current "up and coming" technology, and they have heavier weights than LiPo's.
Since adding a bit of weight is easy, be it with bigger packs, etc.... better that the plane be designed around this type of thing, and let the end user adjust as needed.
In the "get real" department I would suggest that you remember that Nano-Phosphate cells are the current "up and coming" technology, and they have heavier weights than LiPo's.
Since adding a bit of weight is easy, be it with bigger packs, etc.... better that the plane be designed around this type of thing, and let the end user adjust as needed.
