Tricopter - 660mm - CFRP & RP printed

grabcad

This is a simple and practical tricopter design, both forward legs are foldable and will easily snap into position, this makes it ideal for the traveling hobby photographer. The tricopter layout allows a wide FOW camera to be mounted high up on the aircraft without propellers obstructing the image. All 3d printed parts have been designed for manufacture using a FDM printing technique (hence all parts have a base plane to be printed from and there is no unsupported structure). A general 0.20mm offset has been applied on parts that require a slide fit, such as the feats to motor mounts. I printed all the parts on a Kossel style printer with a 100µ z-step size and approx. 35% model porosity. PLA was used due to availability and the internal porous structure were honeycomb shaped. The upper and lower frame plates are 1.50mm quasi isotropic CFRP sheets and the booms are 14x1mm, constructed from 3k fibre with 2/2 twill and UD prepreg plies. The sheets we laid using 5x 200g low temp cure (tooling) pre-preg carbon (due to availability at the time). The layup was vacuum bagged and cured in a conventional oven. The tubes can be sourced from http://www.easycomposites.co.uk/products/carbon-fiber-tube/glossy-3k-woven-finish-14mm-12mm-1m.aspx All parts on the rear boom has been printed apart from the pivot sleeve which is a simple turned aluminium tube with a M4 thread on the end for simple sleeve removal upon service. The pins on the kk2 flight controller have been inverted, this allows for a neater packaging. The flight controller itself is suspended on 4 off 60g AV’s, this in order to reduce high pitch vibration reaching the accelerometer on the flight controller. The mount for the KK2 also supports a “Suppo” OSD (v3.51) and 10Hz GPS unit. In hindsight I would say it’s a bit unnecessary with the OSD for this type of multicopter, and to be fear, the Suppo OSD is not very good either. To ensure a good quality picture a Quanum Q-2D gimbal was selected mainly due to mass, but also budget. Additionally the gimbal allows the camera pitch to be modulated from the transmitter. The gimbal has been positioned as close as possible to the tricopter roll axis, this in order to minimise the impact it will have on the dynamic response. To achieve this, the gimbal controller had to be relocated and a bespoke mounting plate had to be manufactured. I run 4 cell battery, in order to power the Skyzone TS353 400mw VTX, a hobbyking 12v 3A Ubec has been installed. The voltage supplied by the Ubec to the VTX is passed through a homemade LC-filter to ensure a clean video signal is achieved. The gimbal is great and the video quality is second to none! But I would strongly recommend fitting a standalone fixed 600/700tvl camera use for FPV. When I find time, I will remove my OSD and fit a fixed camera. Ready to fly weight: 1450g Motor PCD: 660mm Flight time: 11minutes Shopping list: Motor: 3 off - NTM 900kw - £10.69x3 = £32.07 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=25081 Motor prop drive: 3 off – 28 series – £1.25x3 = £3.75 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16719 Speed Controller: 3 off - Afro ESC 30Amp - £9.24x3 = £27.72 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=39708 Propellers: Graupner 9x5” – 1 off CW & 2 off CCW - £4.75x3 = £14.25 http://www.fast-lad.co.uk/store/graupner_elektro_prop_propeller_13269x5_right_hand_rotation-p-20900.html http://www.fast-lad.co.uk/store/graupner_elektro_prop_propeller_13269x5l_left_hand_rotation-p-20901.html Flight Controller: KK2.1.5 - £14.51 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=54299 Camera Gimbal: Quanum Q-2D - £65.99 http://www.hobbyking.com/hobbyking/store/__55238__Quanum_Q_2D_Brushless_GoPro_3_Gimbal_suitable_for_Nova_Phantom_QR_X350_and_others_.html Video Antenna: Boscam 5.8Ghz RP-SMA - £17.01 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=44643 Video transmitter: SkyZone TS353 400mW - £24.50 http://www.hobbyking.com/hobbyking/store/__27145__SkyZone_TS353_5_8G_400mW_FPV_Transmitter.html Ubec – 12V 4.5A - £5.28 http://www.hobbyking.com/hobbyking/store/__18788__12V_4_5A_UBEC_2_5S_Lipoly_7_2_21V_.html Servo – Turnigy TGY-211DMH - £13.13 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=23466 Battery: Zippy Flightmax 3000mAh 20c - £11.19 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8852 Radio receiver: FrSky TFR8 SB 8ch - £25.73 http://www.hobbyking.com/hobbyking/store/__24785__FrSky_TFR8_SB_8ch_2_4Ghz_S_BUS_Receiver_FASST_Compatible.html Flight controller AV’s: 65g - £0.69 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=40603 Motor arm: 14mm x 1mm x 1m - £15inc.VAT http://www.easycomposites.co.uk/products/carbon-fiber-tube/glossy-3k-woven-finish-14mm-12mm-1m.aspx Antenna adapter: 90° RP-SMA – £0.95 http://www.banggood.com/RPSMA-Male-to-RPSMA-Female-Adapter-Right-Angle-RF-Connector-p-924170.html Washer: M3 Socket caphead - £1.25 http://www.hobbyking.co.uk/hobbyking/store/__32022__Sockethead_Washer_Anodised_Aluminum_M3_Red_10pcs_.html Gopro cable: Video and charge cable - £1.25 http://www.hobbyking.com/hobbyking/store/__49451__Super_Slim_GoPro_3_A_V_Cable_And_Power_Lead_For_FPV.html Free: Bolts, Anchor nuts and Tappex thread inserts Missing from the shopping list is the GoPro and all the servo and power cables, TX60 and battery balance connectors. Total: £274.27 Optional: OSD: SUPPO Easy OSD Free Bird v3.51 - £44.95 My radio and FPV gear: Radio transmitter: Futaba T8FG – £180 second hand FPV goggles: SkyZone V2 - £250.79 http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=50228