Xicoy CG scales
06-03-2019, 02:56 PM
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Xicoy CG scales
I have a simple question. I ordered the Xicoy CG system and just wondered what they mean by the 3rd distance of measurement. The 1st is center of mains to center of nosewheel. Second is center of mains to desired position of the cg. It's the 3rd where is says "center of mains to the correction point of where weight is added/removed". What are they talking about for the correction point. Tried to look on YouTube but didn't see any video. Thanks in advance.
Jason
Jason
06-03-2019, 03:23 PM
#2
I have a simple question. I ordered the Xicoy CG system and just wondered what they mean by the 3rd distance of measurement. The 1st is center of mains to center of nosewheel. Second is center of mains to desired position of the cg. It's the 3rd where is says "center of mains to the correction point of where weight is added/removed". What are they talking about for the correction point. Tried to look on YouTube but didn't see any video. Thanks in advance.
Jason
Jason
Hope this helps..
06-03-2019, 03:36 PM
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Yeah that makes more sense. I assumed but just wanted to verify. So it's not an exact measurement or super critical because it's more or less an educated guess, correct?
Jason
Jason
06-03-2019, 06:52 PM
#5
Be sure to zero all the pucks and ensure they all read the exact same weight of a test unit...bottle of scotch, bag of bbs, lead strip etc. I have a bad scale that drifts immediately after zero tare and I have tried several techniques to include readjusting set screw but to no avail.
06-04-2019, 05:43 AM
#7
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That third point of measurement (ie where to add weight) is not critical at all. The only reason that’s there is to give you an accurate amount of weight to add (ie: tailhwavy, add .69#s at your point).
If you want to simply carve off .69# and add it there and not think about it again, then that measurement matters. If you’re ok pulling out a weight that’s roughly .69, adding it and seeing where the cg then falls you’re just fine
If you want to simply carve off .69# and add it there and not think about it again, then that measurement matters. If you’re ok pulling out a weight that’s roughly .69, adding it and seeing where the cg then falls you’re just fine
06-05-2019, 02:50 PM
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Thanks for all the great info guys. Just got the system today from DreamWorks so I'm going to be putting it to use this evening. One last question for clarity. When measuring from the mains to the nosewheel, it says center of the puck if I remember correctly. Do you measure that or from the center of the wheels? Just wanted to make sure I'm right.
Jason
Jason
06-05-2019, 02:57 PM
#18
Thanks for all the great info guys. Just got the system today from DreamWorks so I'm going to be putting it to use this evening. One last question for clarity. When measuring from the mains to the nosewheel, it says center of the puck if I remember correctly. Do you measure that or from the center of the wheels? Just wanted to make sure I'm right.
Jason
Jason
06-05-2019, 07:48 PM
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I was going to do axle to axle. So 1st measurement is center of mains to center of nosewheel. 2nd is center of mains to the cg and 3rd is center of mains to the place you would add weight correct either nose or tail heavy. Correct? Is the 2nd measurement the factory recommended cg? Because doing the math and measurement on the 2.2M Pilot Predator the cg I come up with using 20% as the MAC is a full inch ahead of the factory marked cg. So just curious. I'll probably go off the more forward cg because I've been told the factory is too far back. Thanks again guys. I do appreciate it.
Jason
Jason
06-06-2019, 03:57 AM
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Shepga, I used the balance jig at first and I was not happy with the cg because the factory cg is too far aft. The plane has a few things, apparently all predators, have that need to be "tweaked" out. This thing acts very, very nose heavy on the factory cg with factory jig. I have everything as far back as I feel comfortable. I'm also pretty positive that the nose down issue in flight is due to the horizontal stab incidence being off which is why everyone has to have at least 3mm of up trim at neutral. So there's a couple things that can get a guy thinking it's one thing when it's truly another issue. I want to check it on the xicoy and see what that shows me for cg and balance as opposed to the factory jig. Nothing wrong with comparing the two. I'm not the only guy who had an interesting first flight and I don't want that again.
Jason
Jason
