Ran D. St. Clair
Member
The Gremlin as a Tiny Trainer – How a 58 year old fixed wing pilot learned to fly FPV.
My Gremlin has served me well, but I thought I would share some of what I learned along the way. I am not a great FPV pilot, but I am flying under and around trees, occasionally through the branches, and doing flips and rolls now. The process only took about 50 years, plus 3 weeks….
I am a long time fixed wing pilot, though never a 3D pilot. I learned to fly quads line of site a few years back though not in a spectacular way. I also fly a lot of VTOL stuff that hovers, though usually with the aide of some sort of Autolevel. I tried FPV in a Bixler a year or so ago, and with the help of a Guardian flight stabilizer it was pretty easy, but it didn’t really grab me. Finding a suitable pair of goggles was a problem and dealing with the tangle of FPV video frequencies wasn’t much fun.
I eventually purchased the Quanum DIY FPV Goggle V2-Pro as well as a diversity receiver and some circularly polarized antennas. My intention was to use it with my glasses but being near-sighted it works best with the glasses off. I didn’t want to spend a hundreds of dollars on fancy Fat Shark style goggles or similar without knowing if they would work for me. The Quanum Goggle was a good choice as it allowed me to easily modify both the way it fit my face and the optics, and at $31.35 for the kit I wasn’t risking much. It may not be stylish, and I can’t say how the experience compares to more expensive goggles, but it works.
I tried flying in the house with an upgraded Inductrix AKA Tiny Whoop, but it wasn’t that much fun. The space was too small for flying in rate mode at my skill level, and the video quality through walls was pretty bad. Flying in AutoLevel mode was more successful, but it never grabbed me. The Inductrix could not handle much wind and I was beating it to death in the driveway, so I lost interest.
When the Gremlin came along I bought one mostly on impulse. The price was right, and the performance seemed impressive so I let the FT guys build one for me. It turns out I could have built it myself as soldering is not a problem, but the cost to let the FT guys do it for me was worth my time. I got the T.J. Williams Carbon Fiber frame so no complaints there. IMHO, some of the other frame designs block too much of the rotor disk and are vastly stronger than they need to be, especially when made from CF.
When I got it I was NOT a happy camper. Physically it was fine, but they forgot to send me the propeller mounting screws, so I could not fly it until I scrounged some from work. The part that made me frustrated and angry was the build video. It was great for all the physical build stuff, but really sucked in terms of how to deal with the computer and set it up. I eventually stumbled my way through it, but the level of information provided compared to what I needed was grossly lacking. They just assume you have all the necessary applications loaded and working properly, that you have the right drivers and cables, and they flew through the menus so fast it was hard to follow even with pause and rewind. I give them an A on the physical build and a D- on the computer setup portion.
IMHO the Gremlin frame designs are not great either. None of them provide any protection for the cloverleaf antenna. I made a few simple modifications which have served me well. I wanted to place the top plate above the cloverleaf antenna to protect it, but that meant that the CF top plate they provided was of no use as it would block the RF signal. I made a simple replacement top plate out of 1/16” plywood. I could not find nylon standoffs and screws that were tall enough but I found an even better solution. I made some standoffs out of blue Nyrod outer housing. I was also able to sand a slight bevel into the ends of the Nyrod so it was angled to miss the antenna. The top plate is held on with 4 small cable ties stretched tight through the center of the Nyrod. The result is light weight, plenty strong, but still a little flexible.
A 2nd less critical modification was a small 1/32” plywood plate over the bottom of the battery with a couple of small sponge rubber pads. This allows the Gremlin to sit level on the ground for easier takeoff, and protects the battery from direct impact and abrasion. The original O ring they provided was WAY too tight, so I replaced it with a rubber band, and later a pair of O rings that stay on the quad. Now I just lift the plate and push the battery in underneath.
I considered adding a hoop to protect the propellers, but I don’t think it is a good idea. Such a thing would allow it to get hung up in trees and it doesn’t seem to be necessary. The stock props are incredibly durable. I have bent them many times, but have yet to break one and I am still flying on the originals. More armor would also be extra weight, and with a 2S battery it doesn’t need any more weight. They say you can use a 3S battery for race quad performance, but the specifications for the motors and ESCs don’t support it.
Some other minor details… I taped down the ESC’s as they were unsecured except for the wiring and could shift outward to rub on the motors. I also protected the receiver antennas with a couple of pieces of inner Nyrod. I really think these frames would be better if the arms were just 1/8” longer. The CF frame is VERY strong. I doubt it will ever break. IMHO, the arms on the CF version could be made a bit thinner to block less of the rotor disk, but now I am picking nits.
Later, after flying a bit, I colored the top plate and the rear propellers red with a permanent marker. This made the Gremlin easier to find in the green grass. It is so tiny, it can easily disappear in even short grass so the red really helps, especially when I am not sure exactly where I landed (crashed).
More later....
My Gremlin has served me well, but I thought I would share some of what I learned along the way. I am not a great FPV pilot, but I am flying under and around trees, occasionally through the branches, and doing flips and rolls now. The process only took about 50 years, plus 3 weeks….
I am a long time fixed wing pilot, though never a 3D pilot. I learned to fly quads line of site a few years back though not in a spectacular way. I also fly a lot of VTOL stuff that hovers, though usually with the aide of some sort of Autolevel. I tried FPV in a Bixler a year or so ago, and with the help of a Guardian flight stabilizer it was pretty easy, but it didn’t really grab me. Finding a suitable pair of goggles was a problem and dealing with the tangle of FPV video frequencies wasn’t much fun.
I eventually purchased the Quanum DIY FPV Goggle V2-Pro as well as a diversity receiver and some circularly polarized antennas. My intention was to use it with my glasses but being near-sighted it works best with the glasses off. I didn’t want to spend a hundreds of dollars on fancy Fat Shark style goggles or similar without knowing if they would work for me. The Quanum Goggle was a good choice as it allowed me to easily modify both the way it fit my face and the optics, and at $31.35 for the kit I wasn’t risking much. It may not be stylish, and I can’t say how the experience compares to more expensive goggles, but it works.
I tried flying in the house with an upgraded Inductrix AKA Tiny Whoop, but it wasn’t that much fun. The space was too small for flying in rate mode at my skill level, and the video quality through walls was pretty bad. Flying in AutoLevel mode was more successful, but it never grabbed me. The Inductrix could not handle much wind and I was beating it to death in the driveway, so I lost interest.
When the Gremlin came along I bought one mostly on impulse. The price was right, and the performance seemed impressive so I let the FT guys build one for me. It turns out I could have built it myself as soldering is not a problem, but the cost to let the FT guys do it for me was worth my time. I got the T.J. Williams Carbon Fiber frame so no complaints there. IMHO, some of the other frame designs block too much of the rotor disk and are vastly stronger than they need to be, especially when made from CF.
When I got it I was NOT a happy camper. Physically it was fine, but they forgot to send me the propeller mounting screws, so I could not fly it until I scrounged some from work. The part that made me frustrated and angry was the build video. It was great for all the physical build stuff, but really sucked in terms of how to deal with the computer and set it up. I eventually stumbled my way through it, but the level of information provided compared to what I needed was grossly lacking. They just assume you have all the necessary applications loaded and working properly, that you have the right drivers and cables, and they flew through the menus so fast it was hard to follow even with pause and rewind. I give them an A on the physical build and a D- on the computer setup portion.
IMHO the Gremlin frame designs are not great either. None of them provide any protection for the cloverleaf antenna. I made a few simple modifications which have served me well. I wanted to place the top plate above the cloverleaf antenna to protect it, but that meant that the CF top plate they provided was of no use as it would block the RF signal. I made a simple replacement top plate out of 1/16” plywood. I could not find nylon standoffs and screws that were tall enough but I found an even better solution. I made some standoffs out of blue Nyrod outer housing. I was also able to sand a slight bevel into the ends of the Nyrod so it was angled to miss the antenna. The top plate is held on with 4 small cable ties stretched tight through the center of the Nyrod. The result is light weight, plenty strong, but still a little flexible.
A 2nd less critical modification was a small 1/32” plywood plate over the bottom of the battery with a couple of small sponge rubber pads. This allows the Gremlin to sit level on the ground for easier takeoff, and protects the battery from direct impact and abrasion. The original O ring they provided was WAY too tight, so I replaced it with a rubber band, and later a pair of O rings that stay on the quad. Now I just lift the plate and push the battery in underneath.
I considered adding a hoop to protect the propellers, but I don’t think it is a good idea. Such a thing would allow it to get hung up in trees and it doesn’t seem to be necessary. The stock props are incredibly durable. I have bent them many times, but have yet to break one and I am still flying on the originals. More armor would also be extra weight, and with a 2S battery it doesn’t need any more weight. They say you can use a 3S battery for race quad performance, but the specifications for the motors and ESCs don’t support it.
Some other minor details… I taped down the ESC’s as they were unsecured except for the wiring and could shift outward to rub on the motors. I also protected the receiver antennas with a couple of pieces of inner Nyrod. I really think these frames would be better if the arms were just 1/8” longer. The CF frame is VERY strong. I doubt it will ever break. IMHO, the arms on the CF version could be made a bit thinner to block less of the rotor disk, but now I am picking nits.
Later, after flying a bit, I colored the top plate and the rear propellers red with a permanent marker. This made the Gremlin easier to find in the green grass. It is so tiny, it can easily disappear in even short grass so the red really helps, especially when I am not sure exactly where I landed (crashed).
More later....