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Skynetic Huntsman V2 Glider

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  • Skynetic Huntsman V2 Glider

    Very poor printed instruction manual. The pdf is much better.

  • #2

    Comment


    • #3
      Hi, all.

      This is my first pusher airplane. I've built kits, ARFs, BNF/PNP, you name it, for more than 25 years. But I cannot get this airplane to fly.

      It won't climb, even with 125% elevator throw. Whether I launch it straight ahead as the manual says, or at about a 45-degree up angle, it will not climb. After about 15 feet it noses into the ground with a consistent right roll. No damage, because I'm standing in 5-foot-tall pasture grass as a cushion.

      I've played with the CG by moving the battery as far back as I can...even reversed the prop. All to no joy.

      One of my flying buddies, who hasn't seen the plane since we've only texted each other, thinks it may be a thrust line issue with the pylon-mounted motor. I don't want to start digging into foam and "let's try this" until I get a response to my support ticket with Motion. So far, they've kicked the can down the road.

      I believe I might have been the first person to purchase the airplane. I couldn't get a copy of the PDF manual ahead of purchase but I went ahead and bought the plane anyway. After I received it, I told Motion that their website description was really off. They listed the airplane as having a rudder, but it doesn't. They recommended an Admiral 2S with XT-30 connector, but the ESC has a T connector. There were a couple of other issues as well, and they've since corrected the website description after I pointed out the errors. They claimed that they just put up what the manufacturer sent them.

      The airplane also is labeled Bancroft on the printed manual that came with the airplane, not Skynetic as advertised.

      I've never had an airplane that simply would not fly.

      Ideas? Thanks for any thoughts.

      Comment


      • #4
        If you've been at it for 25 years you probably already know all this, but...

        Here's what I'd do:
        • Set the CG at the 1/3 chord length from the leading edge (or in accordance with the manual).
        • Ensure the horizontal stab is mounted flush to the fuse with an incidence angle parallel to the fuse and slightly downward relative to the wing. (An H-stab angled upwards is bad news and may cause a nose dive.) Also ensure that the wing is flush on its mount with a slight upward incidence relative to the fuse.
        • Set the mechanical elevator trim so that the elevator is parallel to the horizontal stab or with a very slight upward value in accordance with the manual.
        • If you have installed a stabilizing controller, turn off all stabilization!
        • Take it out to a grass field and give it a few good power-off test glide tosses (toss it horizontally with the fuse horizontal). With your hands off the controls, it should settle down into a nice steady glide with constant speed at a nice gentle downward angle with no tendency to nose up or down.
        • Adjust the CG as required to get that power off glide working correctly.
        • Ensure the prop is mounted correctly with its convex side facing forward and the concave side facing rearwards.
        • Make sure the prop is rotating in the correct direction! While holding it in your hand, apply some throttle and ensure that the thrust is in the forward direction.
        Note that for best performance, gliders should be trimmed with a CG that is as far aft as you can comfortably control (i.e. trim speed should just be kissing a stall - this is where the minimum sink speed on the performance curve lives). If the CG is forward, a lot of up-trim is required and this is not aerodynamically efficient (but does make the aircraft more pitch stable).

        Cheers and keep us posted as to your progress!
        Hope this helps!
        rr

        Comment


        • #5
          Thanks for the general glider ideas. While I've had decent experience with gliders, they've all been either motor gliders or entry-level ships. I'll save the tips you offered for later as I get into gliders in a bigger way (want to do slope soaring).

          The problem with this glider is that it's very cheap and very cheaply made. (If I could do it all over, I'd never buy it). The tail feathers are loose. The stab and elevator are part of what Skynetic calls a "vertical landing system." Stab and elevator assembly together are on a separate servo apart from the elevator so that, in the event of a "vertical landing," you can trip a Tx switch to activate the servo and pop up the entire stab/elevator assembly. Because of that design feature, everything in the empennage is loose. The vertical stab is a pressure fit with one screw, and it, too, is slightly loose.

          Motion has been good about it, and today they said they're sending me another wing and motor pylon assembly. We shall see what happens.

          I'll take it to the flying field Saturday and have a couple of the guys look at it, and I'll report back. Motion said they've had no other complaints on the glider, but it's very new.

          Comment


          • #6
            Here's a photo from the manual showing the entire horizontal stab/elevator assembly in its "vertical landing" position after the servo has been activated. As you can imagine, this means things are going to be loose.

            Comment


            • #7
              I took it to the flying field today and had several other experienced flyers take a look at it. All agreed that, with its severe nose-down pulling tendency, even when it's in your hand prior to launch, the problem is the motor thrust line. They all suggested, as I'd thought myself, that shimming the motor so that the thrust line is less severe on the lateral (pitch) axis might be the solution. As it is, the airplane will not climb.

              I'll see what the new wing/motor mount does but, as it is, the airplane simply won't fly.

              Comment


              • #8
                Originally posted by WillCorsair View Post
                Here's a photo from the manual showing the entire horizontal stab/elevator assembly in its "vertical landing" position after the servo has been activated. As you can imagine, this means things are going to be loose.
                In the old days we called this a "de-thermalizer," meaning that it was something to ensure you could get the airplane out of a fast-elevator thermal.

                Comment


                • #9
                  Well, I had one final brain storm (brain fart??) this morning. I tossed the glider with the battery at the recommended CG (without motor running), and it just nosed over. I removed the battery completely, tossed it, and it flew beautifully for almost 50 feet!!! The CG with battery removed seems to be another 40mm rearward from the recommended CG.

                  The problem is that the battery will have to be inserted way back under the wing, and the Rx and ESC located toward the front. Meaning that I'll have to remove the Rx and ESC every time I want to insert/remove the battery.

                  I have another email into Motion to see if there's a different battery (form factor and/or weight), and also if they can have one of their pilots outfit and fly the glider. There's something very wrong with the recommended CG.

                  Comment


                  • #10
                    A couple of days ago I started digging through my shop for metal washers that I can use as balance weights. I'm no stranger to coins or washers on the lateral/pitch axis and small nails or pieces of wire in the wingtips for longitudinal axis.

                    I got a reply from Motion (Derek). He says the following:

                    "I am very puzzled, Joysway has been making this plane for years. Hundreds have been sold. Here is a video of the plane flying with the battery all the way forward. Again. no complaints like yours. Others are not running into this issue as far as I can tell."

                    There was no video included. I reiterated to him that there was nothing at all about this airplane on rcgroups, HobbySquawk, Youtube.....nothing. I said I figured maybe the manufacturer re-badged an airplane because my manual said the model was from "Bancroft," while the website said Skynetic. I know the Chinese are infamous for re-badging the same product. Banggood, anyone?

                    The website copy for the model was really poor, as noted above. They've since corrected the listing based on my feedback (complaint). Derek said they only put up on the website what the manufacturer sends them, which is often erroneous. I can understand web copy being erroneous, particularly when it's written by non-native English speakers. What I can't understand is why Motion doesn't check out a model before putting it up on the website. It's as if nobody at Motion has outfitted and flown it, yet they just accept what the manufacturer says.

                    Amazing.

                    Okay. Done venting. Now I have to figure out how to get this dog to fly since I'm out 140 bucks plus tax.

                    Comment


                    • #11
                      I tried to upload these videos of the plane flying, but was unsuccessful so I'm providing links to them. You can see the battery placement in the longer video

                      https://www.youtube.com/watch?v=QypyBmnaBEw

                      https://www.youtube.com/watch?v=VdBse-mmJME

                      Comment


                      • #12
                        Hey davecee. you can't upload videos here, but you can embed them by clicking this button in the reply section

                        Click image for larger version  Name:	video.JPG Views:	0 Size:	28.4 KB ID:	328789
                        So your Videos then show up like this:



                        Comment


                        • #13
                          I took it out again last evening after positioning the battery under the wing as well as I could. I could tell on throttle up, however, that it wasn't going to work because the severe nose down pull while the glider was in my hand was still bad. I tossed it at a slight up angle, but it did what it always has: after about 15 feet or so, it nosed into the ground.

                          It has to be a thrust line issue. Holding the glider level in my hand, applying full throttle, and the nose pulls severely down. It will not climb.

                          I can't tell what the thrust line looks like in the poor video of the yellow version. The version that's white with green trim appears to have a thrust line that is almost straight back along the fuse, compared to the Skynetic-badged version.

                          Comment


                          • #14
                            Originally posted by davecee View Post
                            I tried to upload these videos of the plane flying, but was unsuccessful so I'm providing links to them. You can see the battery placement in the longer video

                            https://www.youtube.com/watch?v=QypyBmnaBEw

                            https://www.youtube.com/watch?v=VdBse-mmJME
                            Thanks for the videos. I appreciate it.

                            Comment


                            • #15
                              Originally posted by WillCorsair View Post
                              I took it out again last evening after positioning the battery under the wing as well as I could. I could tell on throttle up, however, that it wasn't going to work because the severe nose down pull while the glider was in my hand was still bad. I tossed it at a slight up angle, but it did what it always has: after about 15 feet or so, it nosed into the ground.

                              It has to be a thrust line issue. Holding the glider level in my hand, applying full throttle, and the nose pulls severely down. It will not climb.

                              I can't tell what the thrust line looks like in the poor video of the yellow version. The version that's white with green trim appears to have a thrust line that is almost straight back along the fuse, compared to the Skynetic-badged version.
                              The videos are a bit old. The plane you have is the V2 version. There very well could have been a change in the motor thrust line. Generally these high motor pusher designs have good bit of angle to the motor. The higher the motor is mounted, the more upward angle is needed.

                              The pusher motor is positioned above center of gravity as well as behind the center of gravity. If the thrust line on such a plane is STRAIGHT back, it will push the nose DOWN as was mentioned previously in this thread.. Tilting the motor with the back of the motor higher is very NORMAL in these planes. Where you grasp the plane could affect how you perceive the thrust acting on the plane.
                              The fact that it glides well without the battery is puzzling. It should be tail heavy and porpoise in that condition.
                              What I'd check: Is the horizontal stab firmly in place and is it aligned with the fuselage datum line? Assuming that, does the wing have some positive incidence compared to the horizontal stab? Balance. Does the plane balance on the manufacturer's recommended point. Flex, is there very much flex in the rear fuselage, I've had cheap foamys that flexed so much that it would negate the control inputs from the tail surfaces. Launch, launch level only, launch with partial throttle and increase throttle after you pick up some speed.

                              Getting back to your glide test with no battery. I'd at least try one powered flight with tail weight added to replicate that center of gravity.

                              Comment


                              • #16
                                Originally posted by WillCorsair View Post
                                I took it out again last evening after positioning the battery under the wing as well as I could. I could tell on throttle up, however, that it wasn't going to work because the severe nose down pull while the glider was in my hand was still bad. I tossed it at a slight up angle, but it did what it always has: after about 15 feet or so, it nosed into the ground.

                                It has to be a thrust line issue. Holding the glider level in my hand, applying full throttle, and the nose pulls severely down. It will not climb.

                                I can't tell what the thrust line looks like in the poor video of the yellow version. The version that's white with green trim appears to have a thrust line that is almost straight back along the fuse, compared to the Skynetic-badged version.
                                I'm having trouble attaching pictures on this forum. Refer to your thread on RCG for my comment.

                                Comment


                                • #17
                                  Originally posted by James View Post
                                  Hey davecee. you can't upload videos here, but you can embed them by clicking this button in the reply section

                                  Click image for larger version Name:	video.JPG Views:	0 Size:	28.4 KB ID:	328789
                                  So your Videos then show up like this:



                                  I said upload, but I misspoke. I have embedded videos here before. When I tried multiple times for this thread. I'd get messages that the video was in an unapproved format . When I tried to attach a screenshot I got a message that my account had timed out and I had to log-in again event though I was still logged in.

                                  Comment


                                  • #18
                                    .OK, I tried the embed feature again and it worked. Perhaps I was doing something wrong. I still couldn't attach a screenshot though.

                                    addendum: Click image for larger version  Name:	image_75861.png Views:	4 Size:	108.8 KB ID:	328861

                                    Well, I clicked on remember me and the attachment worked now. Here's what I was getting before.

                                    It's all good. Thanks

                                    Comment

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