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Monday,August 19, 2019, 07:44:03

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DarkButterfly:
18 Aug 2019 19:13:57
Had another negative encounter, it's been a few years since the last one, just an uneducated ******, going on about drones being illegal yada yada yada.    :-/
Still that didn't spoil my flying time, had an absolute blast  ~~
Gaza07:
07 Aug 2019 19:52:01
ooooh mrs jones  :D
hoverfly:
30 Jul 2019 15:26:34
D.B. you tightwad.. :cool:
atomiclama:
29 Jul 2019 20:14:10
DB that just means you have shed loads of props in the first place ;-)
DarkButterfly:
29 Jul 2019 18:53:33
Just had a thought, even with all the crashing I've done, I haven't bought any replacement props in over a year ~~
ched:
09 Jul 2019 19:45:42
May the sun shine and winds be light for BFU#8. Son't forget lots of vids for those of us unable to attend.  :D
Gaza07:
09 Jul 2019 18:10:30
Hope you all have a great day  :beer2:
Andy7:
09 Jul 2019 14:05:28
BFU#8 details locked in for this saturday - see the head of the forum thread for all details.
hoverfly:
05 Jul 2019 21:51:05
Good for genital warts as well......or so I'm told.. :hmm
DarkButterfly:
05 Jul 2019 21:48:24
Just fixed a busted SMA connector on my TBS unity pigtail, it suffered badly in a recent crash and split in two, nothing a touch of the soldering iron couldn't fix  :D
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Printing 3d Forum

Sausagecopter 2 came down :(

Started by sausageroll, Tuesday,April 16, 2013, 22:17:27

Previous topic - Next topic

sausageroll

So today I was flying the big sausagecopter 2 hex, and all was fine, and all of a sudden, it shook, flipped over and fell. The Naza did well, righted it back up and it fell on its legs, stabbing the leg into the ground.

everything is fine apart from the mount the motor broke off, and two of the three legs. The chassis survived and so did the motor.

I do check these screws but not enough. The hex flew 40mins the other day (7km in a grid pattern) and the long flight must have backed out a few of the screws. This happened only a few mins into flight maybe 3mins.

Threadlock does not always work here because the heat from the motor can soften it. Im going to replace the screws for hex headed type bolts and laser cut a plate with four hexagon cut outs and then sit the plate over the screw heads. This will stop the bolts turning. Im going to design a little tab that sticks out of the side of the motor mount and part of the pre flight will be to waggle this tab and if its loose, you dont fly until you do the bolts up.

Anyway, I guess the real message in all of this is make sure your "mission critical" screws cannot come out. Lock wire would be good if they made lockwire bolts small enough, but loctite (222) on the screws at a min, and if its a part that gets warm, like a motor, then some other kind of mechanical positive lock on the screws would be a good idea.


Pete.

Gaza07

Sorry to hear about the crash Pete at least it didnt kill it  ~~  :beer2:

SimonS

A quick look at the Loctite website reveals that they do twenty different types of threadlock and that 222 is the weakest. I use 243 which is over four times stronger and is available from Halfords.

sausageroll

Yeah, im somewhat of a loctite nut. Ive even got the computer controlled dispensing machine haha, I use it a lot in daily work, but I dont trust it so much in this application. The constant heat of the motor and the vibration is enough to loosen it even with loctite.

Ive designed a plate with hexagon cutouts that sits over the top of the hex head nuts and locks them so they cant rotate. I feel thats a safer way of doing it.

Just had to do a bit of inspection on the motor with this cool machine to make sure I got the dimensions right for the lock plate


macspite

Quote from: sausageroll on Thursday,April 18, 2013, 18:10:03

Ive designed a plate with hexagon cutouts that sits over the top of the hex head nuts and locks them so they cant rotate. I feel thats a safer way of doing it.



Just had a vision of making, packaging and selling little M4 or M6 indicator tags that show if the nut has loosened - like they fit to truck wheels.



Who is up for a set?  :hmm:

sausageroll

hah, yeh its not a bad idea. For these though it wouldn';t help, as the bolts in question are not really visible.

sausageroll




This Family friendly diagram shows the anti crash plate to secure the motor bolts. the two 2mm holes at the side align with two holes in the motor mount plate and an M2 bolt and locknut are used to hold it down. The rounded tips of the anti crash plate stick out either side of the mount so you can feel if they are loose before flying. If that is loose, then you need to do the bolts up, but even if its loose it still wont allow the bolts to undo.

Its a good system. Inspired by a locking plate thing on one of Agent Jay Zs videos - http://www.youtube.com/user/AgentJayZ?feature=watch

Sent the drawing to the laser cutters will have them next week sometime.

Exciting.

Gaza07


sausageroll

If anyone is wondering, they were 77p each lol.