05-04-2023, 05:51 PM
KMart sell a large foam glider, and the same product is sold in Europe via Lidl. There's a huge community around converting them to RC, whether as RC gliders, powered aircraft or even ducted fan swept wing jets!
My son and I picked one up from KMart last week and set about converting it. I bought tiny little 4.5g servos, a 2306 motor and I've ordered a 20A ESC (motor draws 10A with the 5x4.3x3 prop) While I wait for the 20A ESC to arrive I've used my 35A ESC out of my Bix3.
I went to Jaycar and bought some nichrome wire, and I made up 2 hot wire foam cutters. a bow shaped one for making big straight cuts and a scoop shaped one for scalloping out the inside of the nose of the glider,a nd for making tube shaped grooves where reinforcing rod is to be added.
I used my bench power supply to send the appropriate current through them.
I then cut the nose off the glider using the bow cutter, and traced out the cut shape onto plywood to serve as a template. I cut out the plywood, drilled the necessary holes, and then screwed it to some large standoffs, which I hot-glued into the plane nose. I can now remove this motor mount when desired by unscrewing it from the standoffs.
I then scooped out the foam from the nose, and then inserted my battery, receiver and speed controller.
I installed 1 servo in each wing, and cut out ailerons (the plane has moulded in lines at this point, more where you'd expect flaps to be, but they still give great control authority). I also cut out the back of the horizontal tail surface to make an elevator and used a servo in the vertical stabiliser to control it. I cut a chamfer on the bottom front of the control surfaces and used packing tape on the topside as a hinge. I installed the servos on top of the wing to keep them out of harm's way when belly landing.
I installed a 5mm carbon tube in the wing and fuselage, and a 4mm carbon rod in the horizontal stabiliser to stiffen it all, and it was 'ready to fly'
I set the CG to the same as it was out of the box as a chuck glider (50mm from the leading edge of the wing) but I found that was incredibly pitch sensitive (probably because it's design to do easy loops when chucked by a kid), so I moved it forward about 10mm by repositioning the battery. It flies much more balanced now.
I found that at speed the nose and tail would flutter a lot, leading to control issues and a rapid unscheduled dissassembly. 10 minutes with the hot glue gun and it was back together, and I added more 5mm carbon tube from the underside of the fuselage to the underside of the tail, and I glued 2 tongue depressors to the sides of the 'cockpit' to stiffen that too. It flies beautifully now, and it can cruise around for about 8 to 10 minutes on half throttle with the 850mAh 3s battery I'm using.
I've learned some lessons for if (when) I make another one. I'll put the servos on the underside of the wing, and scoop out far less foam from the nose.
All in all, a fun little weekend project with my kids, and now we have a very robust, easy to repair plane for quick lunchtime flights.
My son and I picked one up from KMart last week and set about converting it. I bought tiny little 4.5g servos, a 2306 motor and I've ordered a 20A ESC (motor draws 10A with the 5x4.3x3 prop) While I wait for the 20A ESC to arrive I've used my 35A ESC out of my Bix3.
I went to Jaycar and bought some nichrome wire, and I made up 2 hot wire foam cutters. a bow shaped one for making big straight cuts and a scoop shaped one for scalloping out the inside of the nose of the glider,a nd for making tube shaped grooves where reinforcing rod is to be added.
I used my bench power supply to send the appropriate current through them.
I then cut the nose off the glider using the bow cutter, and traced out the cut shape onto plywood to serve as a template. I cut out the plywood, drilled the necessary holes, and then screwed it to some large standoffs, which I hot-glued into the plane nose. I can now remove this motor mount when desired by unscrewing it from the standoffs.
I then scooped out the foam from the nose, and then inserted my battery, receiver and speed controller.
I installed 1 servo in each wing, and cut out ailerons (the plane has moulded in lines at this point, more where you'd expect flaps to be, but they still give great control authority). I also cut out the back of the horizontal tail surface to make an elevator and used a servo in the vertical stabiliser to control it. I cut a chamfer on the bottom front of the control surfaces and used packing tape on the topside as a hinge. I installed the servos on top of the wing to keep them out of harm's way when belly landing.
I installed a 5mm carbon tube in the wing and fuselage, and a 4mm carbon rod in the horizontal stabiliser to stiffen it all, and it was 'ready to fly'
I set the CG to the same as it was out of the box as a chuck glider (50mm from the leading edge of the wing) but I found that was incredibly pitch sensitive (probably because it's design to do easy loops when chucked by a kid), so I moved it forward about 10mm by repositioning the battery. It flies much more balanced now.
I found that at speed the nose and tail would flutter a lot, leading to control issues and a rapid unscheduled dissassembly. 10 minutes with the hot glue gun and it was back together, and I added more 5mm carbon tube from the underside of the fuselage to the underside of the tail, and I glued 2 tongue depressors to the sides of the 'cockpit' to stiffen that too. It flies beautifully now, and it can cruise around for about 8 to 10 minutes on half throttle with the 850mAh 3s battery I'm using.
I've learned some lessons for if (when) I make another one. I'll put the servos on the underside of the wing, and scoop out far less foam from the nose.
All in all, a fun little weekend project with my kids, and now we have a very robust, easy to repair plane for quick lunchtime flights.