update on recent mod to front arms of MM

[old man mavic]

this is a follow up to a thread started by Starz @Starz Checked your props?
it was mentioned that a lot of us were having prop strikes on the body of our MMs this was causing possible damage to the props and the body of the drone
it was noted that due to the design of the front arms which only have a soft foam filling they were very easy to twist
@Starz mentioned his idea to attach a plastic stiffener to the back of the arm to prevent it from twisting
i liked his idea and set about finding something that was light and strong ,i came up with an old credit card and i used it to make two pieces which i glued to the back of the arms and once it was dry i was amazed how stiff it made the front arms
i was asked to let the forum know the results of this mod so today i was able to fly and here are my findings
during the tests there were no prop strikes, and the drone handled as it should it was very gusty and the wind at ground level was around 12 to 18 mph i would not have flown in that sort of wind normally and i only went up to 20 ft as the MM was being buffeted around a lot
while i can not say that the mod is the answer to the prop strike problem i can say that it did seem to help a lot keeping the front arms level during flight
i took a couple of pics to show my flight
thanks for you attention OMM

 

[GregE]

Interesting landing gear and nice Wrap.
Staying under 250 g is apparently not an issue for you

 

[old man mavic]

not an issue at all,i have to register my MPP so just use the same no on my MM thanks for your comments

 

[Spin]

try using a popsicle stick cut to size and paint it.

 

[WooZie]

So, my friend Omm, do you think the stiffening of the arm is enough to stop the arm shaking in the wind and the prop will not touch the upper shell anymore? Thanks

 

[TDZHDTV]

this is a follow up to a thread started by Starz @Starz Checked your props?
it was mentioned that a lot of us were having prop strikes on the body of our MMs this was causing possible damage to the props and the body of the drone
it was noted that due to the design of the front arms which only have a soft foam filling they were very easy to twist
@Starz mentioned his idea to attach a plastic stiffener to the back of the arm to prevent it from twisting
i liked his idea and set about finding something that was light and strong ,i came up with an old credit card and i used it to make two pieces which i glued to the back of the arms and once it was dry i was amazed how stiff it made the front arms
i was asked to let the forum know the results of this mod so today i was able to fly and here are my findings
during the tests there were no prop strikes, and the drone handled as it should it was very gusty and the wind at ground level was around 12 to 18 mph i would not have flown in that sort of wind normally and i only went up to 20 ft as the MM was being buffeted around a lot
while i can not say that the mod is the answer to the prop strike problem i can say that it did seem to help a lot keeping the front arms level during flight
i took a couple of pics to show my flight
thanks for you attention OMMView attachment 92509View attachment 92510View attachment 92512

I just can’t quite make out your credit card CVV number and signature ?

 

[old man mavic]

So, my friend Omm, do you think the stiffening of the arm is enough to stop the arm shaking in the wind and the prop will not touch the upper shell anymore? Thanks

well lets put it this way i had no prop strikes during the flights of 3 batts so for me at this time i think it was a success, it also did not affect the camera or cause it to shake i cant promise that it is a fix, but as i fly it more and more i will know if it a long term fix,i do believe that the props flexing combined with the flex of the arms is what causes the issue

 

[WooZie]

i am thinking of putting that 3d printed plastic models inside the arms, do you know what i am talking about?

 

[old man mavic]

i am thinking of putting that 3d printed plastic models inside the arms, do you know what i am talking about?

yes i do you will need to remove the foam first then just put some spots of super glue on the inside part of the arms and then quickly insert the stiffeners and hold till the glue goes off
i would do a practice fitting first to make sure it all fits nice take your time good luck

 

[WooZie]

yes, i know, i want to prevent this issue if i can, mine have not yet any marks on it, but i don't want to have )))

 

[WooZie]

i would do a practice fitting first to make sure it all fits nice take your time good luck

of course i will do that training before ) thank you very much

 

[RadioFlyerMan]

this is a follow up to a thread started by Starz @Starz Checked your props?
it was mentioned that a lot of us were having prop strikes on the body of our MMs this was causing possible damage to the props and the body of the drone
it was noted that due to the design of the front arms which only have a soft foam filling they were very easy to twist
@Starz mentioned his idea to attach a plastic stiffener to the back of the arm to prevent it from twisting
i liked his idea and set about finding something that was light and strong ,i came up with an old credit card and i used it to make two pieces which i glued to the back of the arms and once it was dry i was amazed how stiff it made the front arms
i was asked to let the forum know the results of this mod so today i was able to fly and here are my findings
during the tests there were no prop strikes, and the drone handled as it should it was very gusty and the wind at ground level was around 12 to 18 mph i would not have flown in that sort of wind normally and i only went up to 20 ft as the MM was being buffeted around a lot
while i can not say that the mod is the answer to the prop strike problem i can say that it did seem to help a lot keeping the front arms level during flight
i took a couple of pics to show my flight
thanks for you attention OMMView attachment 92509View attachment 92510View attachment 92512

Billiant! And you can "charge it!"

 

[old man mavic]

Billiant! And you can "charge it!"

brilliant only you could come up with that love your sense of humour

 

[sirbadger]

of course i will do that training before ) thank you very much

Is it worth securing with rubber bands first to see what difference it makes?

 

[old man mavic]

Is it worth securing with rubber bands first to see what difference it makes?

if you just fit the stiffener and just hold it in you can feel the difference if you try to twist the arm gently

 

[WooZie]

if the stiffener will fit perfectly, i think of the glue, would be better a silicon glue insteed of a hard one?

 

[sirbadger]

if the stiffener will fit perfectly, i think of the glue, would be better a silicon glue insteed of a hard one?

I'd be inclinded to use double sided tape, easier to remove in future.

 

[WooZie]

i thought about it too, i don't want to remain marks in any case of warranty, but i don't believe the double side adesive will be strong enough to keep them together on these vibrations, i am still thinking

 

[JoostGT3]

Nice example of applied mechanical engineering! The stock shape is an open "U"-profile, which has hardly any torsional rigidity. By supergluing a structural load carrying backside to the legs, you created a torsionbox with dramatic increase of torsion stiffness... awesome!

 

[sirbadger]

Maybe, you can get some pretty strong stuff.