HolyStone HS720 & HS720E Replacement Rear Arms

thingiverse

This design was inspired by the only other rear arm I could find here on Thingiverse "that were slightly too long to fit my drone". There are NOT remixed from the original but totaly designed from scratch in 123D 2 designs are uploaded for both Left & right sides. 1 vers has a reduced amount of plastic to try and save weight & try to help balance the drone during flight. ** Important ** My drone does fly with a replacement arm printed and fitted but !! the difference of 0.8 g is enough to make it slightly unstable and instead of a clean stable hover it does slide in the direction of the replacement arm, If you crash and burn with 1 busted arm then please remember this if you plan to print your own parts. ( I would poss suggest to replace both rear arms to keep the weigh equal on each side but it`s your drone not mine & I take no responsibility for anything that may happen to it. If in doubt buy genuine replacements direct from Holy Stone My replacement arrived in 6 days direct from china) The arm has been designed to use the original bottom part of the arm with the led window if you can salvage this from your broken arm. The motor & Ariel wiring will sit in the channels either side of the led board mount platforms to keep the wiring snug. Inside is a space for the led board and screw holes are provided (I suggest you put screws into the holes first to make threads before you final fit the led board) Printing material and speeds are up to you, Here are the settings I used for printing in Petg :- 2 shells / walls 15% infill Supports are required and are minimal to save printing time & plastic. Part orientation for printing is suggested as horizontal to the build plate to save on support material. NOTE Not every printer is calibrated for precision printing and not every plastic prints equall, I have tried to allow for this during design, but as with all things 3d printed You may have to scale the part slightly to get a good fit. NOTE There are 4 files uploaded. 2 left arms & 2 Right arms The rev3_1.stl are slightly stronger versions of the arm & they weigh slightly more than the other rev3_2 ones The rev3_2.stl have slighlty less plastic on the inside & may have a little more flex but are lighter in weight. The picture of the printed arms are from test versions with draft qualty printing so are not the best looking and at some point will be updated to final print quality versions ** Update 12-10-21 ** Removed the Rear Right side arm files as the retaining pin was incorrectly placed. ** Update 13-10-21 ** Uploaded fixed Rear Right side arms with the corrected retaining pin location (was 1.2mm out)