Nice video. I have the same 1800mm Ranger, and it does fly great! I flew my entire field inverted, and it performed flawlessly. Great job on the balance stands!
Thanks. I enjoy sharing what I'm learning along the way! Working with foam is one of those areas. Back in my previous life, when I did a lot of RC flying with my boys, everything was balsa, and the latest thing was the plastic shrink on covering to replace silkspan and proper silk with dope.
You have exposed rafters in your barn. This makes it very easy to put a sizeable screw into it to use a rope point. Heck, you could put a couple of hangar rail supports for a short piece of closet rail to hang from. Make a large loop out of heavier cord, I like to use boat throw rope that doesn't tangle. Loop needs to be big enough to go around your planes wing and for larger, heavier ones, the nose. We're looking to hang the plane level with the rope from the rail/nail from your ceiling. In between the loops of rope that go over the rail, hang a small, dent free plumb bob from kite string. I go all out there and sometime use a 1/4 x 20 metal nut. Just tie a small loop in one end, put it through the nut and pass the nut through it, slide it tight. You know have two plumb bobs hanging from the same center of the suspension point and their mass pointing to the center of the earth. Lower the plumb bob to just above the wing, let everything settle and it will hang directly over the center of the airplanes center of mass (current cg). Add necessary weight to place that in the correct, desired Center of Gravity. Bigger planes need bigger loops of cord. Cord is cheap. You can use lighter cord for small models but beware, surveyors cord will just turn itself into a big, loose ball if there isn't any pressure on it. I've not experienced any damage from the cord cutting into my models but my heaviest is 19 pounds and made of coroplast. Also, its' been in several unplanned arrivals BUT even new, it didn't occur damage. But if you have a nice heavier plane consider using larger rope. Yes, I'm aware of the other setup called by a silly girls name. Neither of these are my invention as I saw this CG Sling demonstrated in the 70s in my first RC club. I've always found the other being a more complicated version of the same thing AND seeings how most people have all the makings hanging around any home garage, no need to get all fancy however, a proper CG makes everything better. Gonna tie up a little one for my Volantex airplanes. They're CGs are all over the place, usually too far aft. The gyro package they have on them takes care of 10 mph gusts on a 2 ounces airplane, it can handle an aft cg HOWEVER it's fun to fly them on a calm day without the Gyro, WHEN the CG is in the correct place. Not without, no, Not then. Have you slamming the switch back into trainer mode real quick. Kept from hitting my house that way. Wouldn't hurt the house OR probably the plane BUT I'd have to get up on the house to get it back. Two big for Rope, some digital scales, a calculator and a how to on weight, balance and datum. CG is just a moment arm from a set point, you only have to have some basic Trig to figure that out. ADDENDUM!! Hey, this guy is demonstrating his Girl name rig and his is the more basic one, really just a further suspension point from the rafters. That's cool but I just use more rope, it's cheap and when done loops up and fits in a quart size ziplock bag with the plumb bob and a small c clamp that I can use to attach most places I want to run CG on an airplane from. BUT the method is the same. EXCEPT, did you see that huge WING STABBER of a plumb bob? Somebodies framed a house before. My fancy plumb bob is a little eye hook into the center of a small piece of dowel rod with a point sanded into the other end, it can hang sideways, that's why I switched to the 1/4x20 nuts cuzz they hang straight, have a little weight and will only go through the wing of a stick in tissue FF plane. Anyways, here's the link. th-cam.com/video/E-qcZahbxbI/w-d-xo.htmlsi=7R1kfopYtEJ7getu
Hi Bill, I'm not sure what you are describing. The method I have used was one that I found online, and Google is the source of all truth.... :-) I'm sure there are other ways of doing it, but this does appear to give a sensible result. My geometry is a bit of a past memory, so I'm not quite sure how to check it! And, we are also making the assumption that every square cm of wing area at a given position along a chord of the wing will produce the same amount of lift as you proceed out along the wing. At the end of the day we are working out a place to start that we are confident will allow the plane to fly. We will then adjust that based on actual flight characteristics.
Ty very much for your video but iwant to understand whtas the importance to know the cg during the design of the aircraft and will be the wight distrbuited around it? Or what? And there is cg for wing and another one for the aircraft totaly in general iam not understand why we know the place of cg during design can you rxolain to me please
No worries. The Centre of Gravity is the balance point for the entire aircraft. It's important because if it is too far forward or aft, you will not be able to control the plane. Too far forward and it will just dive towards the ground as the airspeed lowers. Too far backward, and it doesn't want to fly straight. As the weight of the plane needs to be supported by the wing, the point where the lift on the wing is centred needs to be close to where the weight of the whole plane is centred. When you balance a plane on your fingers, you are basically doing the same sort of thing - as long as your fingers are on the fore-aft location of where the lift is centred. I'll give this some more thought and see if I can do another video to explain it clearly.
Hi Tim, yes the battery is in place when you check the balance. The aircraft needs to be set up as it will fly. Then you know whether to move the battery forward or backward to get it right.
More on battery an cg changes they creat. Mistakes made.. larger-smaller size/same plane, placement at field being off slightly causes what if my plane does this. How maybe to fly it back down fast if I see your red flags for tail heavy. Y I ask. My glider flys great under power but when slow I have only 10% controlling humph. No turn. No up. loves down but no left/right until speed is up.
Hi Tim, it's hard to know what's happening without being at the field with you. It would be natural for the control response to be lower when the plane is flying slower, but it should still be there for all controls.
6:46 aka mean aerodynamic chord cg at 30% of mac.!!! after the mac is identified, its 'thirty percent' point is located and 'transferred' to the root chord. thus, thirty percent of mac 'becomes' about 45 percent of root chord for a swept wing; and, about 50 percent for a delta wing. d
Thanks for your helpful comments and observations. Certainly swept and delta wings come in a great variety of degrees of sweep, angle of the leading edge, etc. My concept is to work it out at the MAC (thanks for sharing that terminology) and then anywhere along the line perpendicular to the centreline of the fuselage going through that point it can be balanced fore and aft. It makes no difference whether the balance supports are close or far away from the root of the wing as long as they are along that line.
I have no problem with making it 30% of the MAC. The range of 25% to 33% is what I have heard is the typical range. Given that the centre of lift is going to move forward and back along the profile of the wing with different angles of attack, etc. and that different profiles and airspeeds can also make it change, there is room for the preference of the pilot to make the fine adjustment.
Also I have no problem transferring the mark to the root chord, given that it is brought in along a line perpendicular to the fuselage centreline. I suppose the main reason for having it there would be that if you are balancing it with your fingers, you have the fuselage there to hold onto during the procedure to keep from dropping your plane!
![แฉกลโกงงานวัด 2024 [ โกงมั้ยครับ ep.106 ] | DOM](http://i.ytimg.com/vi/taC5dpP3HXA/mqdefault.jpg)
I Love your shop,it reminds me of my late grandfathers and my uncles shops at there homes.I miss them,there were industrial designers.
Thanks, Steven. It gets a bit cluttered at times, but it works pretty well for me. Just has the issue of a boat getting in the way! :-)
Thankyou and God bless for the tutorials
I finally worked it out.
Excellent! Glad to hear that and especially encouraged to seeing God get the glory!
Nice video. I have the same 1800mm Ranger, and it does fly great! I flew my entire field inverted, and it performed flawlessly. Great job on the balance stands!
Cool, thanks
Thanks. This got me a starting point to make it flyable and adjust from there.
Excellent!
Big Help.. looks like you have taking your front wheel out to, and love your improvements on the lid cheers Robbie
Thanks. I enjoy sharing what I'm learning along the way! Working with foam is one of those areas. Back in my previous life, when I did a lot of RC flying with my boys, everything was balsa, and the latest thing was the plastic shrink on covering to replace silkspan and proper silk with dope.
You have exposed rafters in your barn. This makes it very easy to put a sizeable screw into it to use a rope point. Heck, you could put a couple of hangar rail supports for a short piece of closet rail to hang from. Make a large loop out of heavier cord, I like to use boat throw rope that doesn't tangle. Loop needs to be big enough to go around your planes wing and for larger, heavier ones, the nose. We're looking to hang the plane level with the rope from the rail/nail from your ceiling. In between the loops of rope that go over the rail, hang a small, dent free plumb bob from kite string. I go all out there and sometime use a 1/4 x 20 metal nut. Just tie a small loop in one end, put it through the nut and pass the nut through it, slide it tight.
You know have two plumb bobs hanging from the same center of the suspension point and their mass pointing to the center of the earth. Lower the plumb bob to just above the wing, let everything settle and it will hang directly over the center of the airplanes center of mass (current cg). Add necessary weight to place that in the correct, desired Center of Gravity.
Bigger planes need bigger loops of cord. Cord is cheap. You can use lighter cord for small models but beware, surveyors cord will just turn itself into a big, loose ball if there isn't any pressure on it. I've not experienced any damage from the cord cutting into my models but my heaviest is 19 pounds and made of coroplast. Also, its' been in several unplanned arrivals BUT even new, it didn't occur damage. But if you have a nice heavier plane consider using larger rope.
Yes, I'm aware of the other setup called by a silly girls name. Neither of these are my invention as I saw this CG Sling demonstrated in the 70s in my first RC club. I've always found the other being a more complicated version of the same thing AND seeings how most people have all the makings hanging around any home garage, no need to get all fancy however, a proper CG makes everything better.
Gonna tie up a little one for my Volantex airplanes. They're CGs are all over the place, usually too far aft. The gyro package they have on them takes care of 10 mph gusts on a 2 ounces airplane, it can handle an aft cg HOWEVER it's fun to fly them on a calm day without the Gyro, WHEN the CG is in the correct place. Not without, no, Not then. Have you slamming the switch back into trainer mode real quick. Kept from hitting my house that way. Wouldn't hurt the house OR probably the plane BUT I'd have to get up on the house to get it back.
Two big for Rope, some digital scales, a calculator and a how to on weight, balance and datum. CG is just a moment arm from a set point, you only have to have some basic Trig to figure that out.
ADDENDUM!!
Hey, this guy is demonstrating his Girl name rig and his is the more basic one, really just a further suspension point from the rafters. That's cool but I just use more rope, it's cheap and when done loops up and fits in a quart size ziplock bag with the plumb bob and a small c clamp that I can use to attach most places I want to run CG on an airplane from. BUT the method is the same. EXCEPT, did you see that huge WING STABBER of a plumb bob? Somebodies framed a house before. My fancy plumb bob is a little eye hook into the center of a small piece of dowel rod with a point sanded into the other end, it can hang sideways, that's why I switched to the 1/4x20 nuts cuzz they hang straight, have a little weight and will only go through the wing of a stick in tissue FF plane. Anyways, here's the link.
th-cam.com/video/E-qcZahbxbI/w-d-xo.htmlsi=7R1kfopYtEJ7getu
Interesting thoughts. Thanks for sharing!
I adjusted the thingamabobby and everything is alright now! Thanks
Yes, Darryl, sometimes I'm at a loss for words, but fortunately there are universal ones to cover those times!
To determine the wing M.A.C., should you not extend the leading edge and trailing edge to the to the wing center root?
Hi Bill, I'm not sure what you are describing. The method I have used was one that I found online, and Google is the source of all truth.... :-) I'm sure there are other ways of doing it, but this does appear to give a sensible result. My geometry is a bit of a past memory, so I'm not quite sure how to check it! And, we are also making the assumption that every square cm of wing area at a given position along a chord of the wing will produce the same amount of lift as you proceed out along the wing. At the end of the day we are working out a place to start that we are confident will allow the plane to fly. We will then adjust that based on actual flight characteristics.
Ty very much for your video but iwant to understand whtas the importance to know the cg during the design of the aircraft and will be the wight distrbuited around it? Or what? And there is cg for wing and another one for the aircraft totaly in general iam not understand why we know the place of cg during design can you rxolain to me please
No worries. The Centre of Gravity is the balance point for the entire aircraft. It's important because if it is too far forward or aft, you will not be able to control the plane. Too far forward and it will just dive towards the ground as the airspeed lowers. Too far backward, and it doesn't want to fly straight. As the weight of the plane needs to be supported by the wing, the point where the lift on the wing is centred needs to be close to where the weight of the whole plane is centred. When you balance a plane on your fingers, you are basically doing the same sort of thing - as long as your fingers are on the fore-aft location of where the lift is centred. I'll give this some more thought and see if I can do another video to explain it clearly.
Was the battery in it when you balanced it?
Hi Tim, yes the battery is in place when you check the balance. The aircraft needs to be set up as it will fly. Then you know whether to move the battery forward or backward to get it right.
17:33 the supports should be about one-half that distance from the fuselage.!
See my first note above. Again, thank you for your observations and sharing your own knowledge and experience.
More on battery an cg changes they creat. Mistakes made.. larger-smaller size/same plane, placement at field being off slightly causes what if my plane does this. How maybe to fly it back down fast if I see your red flags for tail heavy. Y I ask. My glider flys great under power but when slow I have only 10% controlling humph. No turn. No up. loves down but no left/right until speed is up.
Hi Tim, it's hard to know what's happening without being at the field with you. It would be natural for the control response to be lower when the plane is flying slower, but it should still be there for all controls.
6:46 aka mean aerodynamic chord cg at 30% of mac.!!! after the mac is identified, its 'thirty percent' point is located and 'transferred' to the root chord. thus, thirty percent of mac 'becomes' about 45 percent of root chord for a swept wing; and, about 50 percent for a delta wing. d
Thanks for your helpful comments and observations. Certainly swept and delta wings come in a great variety of degrees of sweep, angle of the leading edge, etc. My concept is to work it out at the MAC (thanks for sharing that terminology) and then anywhere along the line perpendicular to the centreline of the fuselage going through that point it can be balanced fore and aft. It makes no difference whether the balance supports are close or far away from the root of the wing as long as they are along that line.
7:52 ummm the mark at 30% of mac SHOULD be 'transferred' to the root chord; NEAR 45% of root chord.!!!
I have no problem with making it 30% of the MAC. The range of 25% to 33% is what I have heard is the typical range. Given that the centre of lift is going to move forward and back along the profile of the wing with different angles of attack, etc. and that different profiles and airspeeds can also make it change, there is room for the preference of the pilot to make the fine adjustment.
Also I have no problem transferring the mark to the root chord, given that it is brought in along a line perpendicular to the fuselage centreline. I suppose the main reason for having it there would be that if you are balancing it with your fingers, you have the fuselage there to hold onto during the procedure to keep from dropping your plane!