News - 07.08.2020:
I flew my second Boxfat and it exhibited oscilations with the gear down at low speed. I think I need a gyro on roll and/or yaw to control this. I plan to add a gyro to the roll axis first.
https://youtu.be/oo1T4S5kAPE
I also discovereed that flaps require quite a lot of up elevator mixed in compared to normal planes as the plane will nose dive when flaps are lowered otherwise.
News - 20.06.2020:
I added a doubled for the rear face of the tail where the elevon servos are mounted to give a stronger mounting point. I also added new EDF extensnions for the EDF-bay so that the EDF can be mounted farther back in the bay.
News - 18.06.2020:
Added a new hinge piece for the main gear doors to provide more leverage to the servo linkage in the open position. Maingeardoor03.stl
NEWS - 01.07.2019:
Added drum brakes for the main wheels. The files for this are in drumbrake.zip. The brakes require the following parts:
2x M6x50 mm bolts for the wheel axles
4x 6x15x5 mm ball bearings
2x M2x6 mm screws for the servo mount
3x M3x25 countersunk screws
2x 5,6 g JX hv servos: https://www.banggood.com/custlink/m3vmtBnV51?custlinkid=173937
4x 47ODx3,5 mm O-rings: https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575353675&campid=5338226872&mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2F253621698783
I have also maidened the prototype, and it flies great, but the ESC died and caused it to crash:
https://youtu.be/nmjtMjbHrrk
Pre-release of my new sports jet design. Inspired by cold war jets. I call it MIR-25 Boxfat. It is not designed to be an exptreme speed model, but rather a high performance low to mid speed jet, up to 250 km/h, with exceptional low speed and high alpha performance.
It should be regarded as an experimental model, and CG might need adjustment. CG is calculated to be as specified below, and the range indicates a CG at 25-30% of MAC. Control throws should probably be in the range of 16-20 mm. These are things I will test and tune in the first few flights. I am releasing it early as I probably won't be able to test fly it in a few months due to the arctic climate I live in. Requires at least 300x300x320 mm printer.
Length: 2065 mm
Wingspan 1422-1610 mm
All up weight: 8,6 kg
Required power: 3,8 kW
Suggested control throws. Same as used on the prototype maiden flight:
Elevator throws (measured at the leading edge point)
Low: 23/20 mm (stick back/forward)
High: 35/26 mm (stick back/forward)
Aileron throws
Low: 20/20 mm
High: 30/30 mm
Rudder throws
Low: 20/20 mm
Calculated CG-range: 182-206 mm aft from the break between wing and leading edge extensions. The wing has two dimples on the underside to indicate this range. The prototype was stable when balanced on the front dimple, indicating 25%.
The wing can be printed with two perimeters for extra strength, or one perimeter for lightness. They wil lbe about 350 g with one perimeter and about twice that for two perimeters, which is still light.
Safety warnings:
-The EDF is a very highly loaded assembly at high speed so it's important that you know what you are doing.
-Make sure the integrity of the printed impeller is good before trying to run it.
-Always wear protective glasses when test runnin the fan. Always protect your eyes.
-Do NOT run the fan at high power while holding in your hand.
-Keep your hands and any loose items away from the fan when running. It WILL shred your fingers if they get sucked in, and the suction force is very strong. If something gets sucked in it can damage the impeller and potentially shatter, throwing loose debris out.
Electronics:
2x 22 g servos forthe rudders:
4x 58g standard servos for the elevons and flaperons.
5x 9g micro servos for the nose gear steering and wheel doors.
145 mm EDF (For example Vasa 145) 3D printable fan will be developed soon for it.
3x retract units. Either from JP or Hobbyking:
http://www.hobby-china.com/alloy-electric-retracts-set-3pcs-and-control-box-for-7-8kg-rc-plane-model.html
https://hobbyking.com/en_us/turnigy-90-degree-all-metal-servoless-outward-operating-retract-unit-90-size-1pc.html?affiliate_code=BSFWYBUNYWDKXJN&_asc=9928784058
Obviously batteries, receivers, cables and such...
-HET-800-83-510 motor with heatsink for the printable fan.
Required hardware:
1x 12mmx780 mm carbon wing tube: https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575353675&campid=5338226872&mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2F3K-Carbon-Fiber-Tube-12mm-x-8mm-x-1000mm-For-Airplane-Roll-Wrapped-Carbon-rod%2F152595464648
1x 10mmx780 mm carbon wing tube: The 12mm tube aboveshould b thick walled, or if it's not it should be filled in with a 10x8 mm or 10x7 carbon tube inside for increase its' strength.
https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575353675&campid=5338226872&mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2F800mm-Carbon-Fiber-Tube-8-10-12-13-14-15-16-18-19-20-21-22-24-25-26-27-28-30-32%2F124199011494%3Fhash%3Ditem1cead684a6%3Ag%3APNYAAOSw4~Fc7sN6
2x 8mmx230 mm woven carbon tubes for the elevons.
Various lengths of 3mm carbon rod for the hinge pins.
Short lengths of 4mm carbon rod for the wing pegs and as indexing for joining of parts.
Assorted M3 screws.
M3 grub screws.
Long M6 screws for the main gear.
1x short shock absorber for the nose gear: https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575353675&campid=5338226872&mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2FBLACK-Shock-Absorber-102004-RC-1-10-On-Road-Drift-car-02002-02175-HSP-122004%2F272113528144
85mm HSD shocks for the main landing gear: https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575353675&campid=5338226872&mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2F2pcs-Titanium-90mm-F104004-Adjustable-Shock-Absorber-for-RC1-10-Off-Road-Car%2F152475343522
6x 3x6x2,5 mm ball bearings for landing gear hinges and nose wheel:
https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575353675&campid=5338226872&mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2F10pc-MR63ZZ-Miniature-Model-Double-Shielded-Ball-Bearing-Bearing-Steel-3x6x2-5mm%2F232308880020%3Fhash%3Ditem3616b03294%3Ag%3AlN8AAOSw3ZRY-bD3
2x 12x18x4 mm ball bearings for nose wheel steering:
https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575353675&campid=5338226872&mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2F6701ZZ-6701-Metal-Shielded-Ball-Bearings-Miniature-Bearings-12x18x4mm-x-5PCS%2F151958105165%3Fepid%3D859232886%26hash%3Ditem236168ac4d%3Ag%3A9okAAOSwZ8ZW-Hkv
4x 6x15x5 ball bearings for the main gear: https://rover.ebay.com/rover/1/711-53200-19255-0/1?ff3=4&toolid=11800&pub=5575353675&campid=5338226872&mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2F5-10-20pcs-Rubber-Sealed-Ball-Bearing-605-2RS-To-699-2RS-Deep-Groove-Bearings%2F302178377251
6c 8x16x5 bearings for the elevons