Welcome Inspire Pilots!
Join our free DJI Inspire community today!
Sign up

Correct motor mount angle

Joined
Jun 12, 2014
Messages
46
Reaction score
24
- @Jeff. Can you please tell in which condition you make your mesurement : 1 You take the drone in landing mode and you put it on a table or 2. you put it on a table in transport mode and active the landing mode and let the aircraft come alone in landing mode.
I place the I2 on a table in transport mode, I then convert it to landing mode and take the measurement. It’s pretty consistent every time.

As to your question about glue and screw tightening, I would never use glue unless it was designed to be there. As to screws, I use blue loktite on the threads and only tighten down until any unnecessary motion of the restrained component is removed.
 
Joined
Jun 12, 2014
Messages
46
Reaction score
24
to Clarify my loctite comment. Only use loctite on places that have metal receivers. Never ever Loctite to plastic it will eat it alive.
 
  • Like
Reactions: Advexure
Joined
Aug 30, 2016
Messages
4
Reaction score
0
Age
34
thanks jeff, also did you have the height of propeller at the center of the frame ? (around 21,cm) ?

Thanks
 
Joined
Dec 12, 2016
Messages
118
Reaction score
46
Age
46
I discovered my front props to be off a fair amount, so after aligning the front props to be the same, I checked the rear props..they were off even further than the front before I adjusted anything..seems Frank and company “Split the difference” on mine.
 
Joined
Feb 18, 2016
Messages
23
Reaction score
10
Age
47
Well I adjusted mine. Once side was one notch too high and the other, one notch to low. They are now 21.5 cm on both sides like above in landing mode but when I transform it for flight mode one side is slightly higher than the other by a couple of mm, so something is still a bit out. Will test fly later this week and report back.
 
Joined
Aug 23, 2018
Messages
17
Reaction score
8
Age
45
In my tinkering with the relevant angles of the motors, I've found that a 93-97 degree variance is tolerable. Just as long as the arms do not have a difference of more than a couple degrees between them. Anything further than that, you're bound to have some issues.
 
  • Like
Reactions: Phil DeVore
Joined
Oct 23, 2016
Messages
39
Reaction score
13
Age
62
Greetings!
Late to this party but still bearing gifts, I rebuilt my third Inspire 1 recently and can report setting a common anhedral angle of 3 degrees in all three builds.

I arrived at the number by
a) taking photos of my Inspires while in flight and when new.

As a long-time pilot, I noticed the anhedral set of the props immediately and thought there might well have been something wrongly set up with my bird.
However, more shots of other Inspire 1's confirmed that the unusual prop and motor angle was, in fact, designed that way.

b) the giveaway for me has been the set of the Inspire's feet when in landing/takeoff mode.

If I set up the drone on glass or other flat surface, the bottoms of the landing gear feet (its "soles", I.e.) have a slight but very definite angle to them. If I relax the prop angle screws and let the craft settle down on its feet properly, I can see that my prop angles also settle down to around 2-3 degrees anhedral. There's nothing tentative about it - it settles down with a solid "clunk". And stays there. Subsequent measurement with an RC heli prop angle tool yielded the 2-3 degree angle result.

BTW I use the same glass technique when building the booms/motor mounts to ensure that fore and aft motors are aligned and their drive shafts are in line.

Slightly political rant and thoughts follow:

DJI mystique and monopoly aside, these are, bottom line, R/C aircraft, and must follow all the rules of same, even if made in China by an company with delusions like Apple.

It would be very interesting to get the FAA to go after them to issue us with a manufacturer's POH with all the manufacturer's flight data clearly stated, since the FAA rules that we are rPICs and bear the responsibility of pre-flight inspection at the very least.
In fact I think the FAA's definition of a UAV and their licensing laws kinda mandate that, don't they?

Oh - sorry - pilot speak is a bore!
FYI if you need it:
FAA: the USA's Federal Aviation Authority
POH: pilot's operating handbook. Every real aircraft has one.
rPIC: remote pilot in command
UAV: unmanned aerial vehicle

Happy Holidays!
Chris
 

The Editor

Moderator
Staff member
Joined
Aug 7, 2013
Messages
9,762
Reaction score
5,106
Greetings!
Late to this party but still bearing gifts, I rebuilt my third Inspire 1 recently and can report setting a common anhedral angle of 3 degrees in all three builds.

I arrived at the number by
a) taking photos of my Inspires while in flight and when new.

As a long-time pilot, I noticed the anhedral set of the props immediately and thought there might well have been something wrongly set up with my bird.
However, more shots of other Inspire 1's confirmed that the unusual prop and motor angle was, in fact, designed that way.

b) the giveaway for me has been the set of the Inspire's feet when in landing/takeoff mode.

If I set up the drone on glass or other flat surface, the bottoms of the landing gear feet (its "soles", I.e.) have a slight but very definite angle to them. If I relax the prop angle screws and let the craft settle down on its feet properly, I can see that my prop angles also settle down to around 2-3 degrees anhedral. There's nothing tentative about it - it settles down with a solid "clunk". And stays there. Subsequent measurement with an RC heli prop angle tool yielded the 2-3 degree angle result.

BTW I use the same glass technique when building the booms/motor mounts to ensure that fore and aft motors are aligned and their drive shafts are in line.

Slightly political rant and thoughts follow:

DJI mystique and monopoly aside, these are, bottom line, R/C aircraft, and must follow all the rules of same, even if made in China by an company with delusions like Apple.

It would be very interesting to get the FAA to go after them to issue us with a manufacturer's POH with all the manufacturer's flight data clearly stated, since the FAA rules that we are rPICs and bear the responsibility of pre-flight inspection at the very least.
In fact I think the FAA's definition of a UAV and their licensing laws kinda mandate that, don't they?

Oh - sorry - pilot speak is a bore!
FYI if you need it:
FAA: the USA's Federal Aviation Authority
POH: pilot's operating handbook. Every real aircraft has one.
rPIC: remote pilot in command
UAV: unmanned aerial vehicle

Happy Holidays!
Chris
This thread is regarding the Inspire 2 and the correct angle on both aircraft is achieved using a jig which is not available to the general public
 
  • Like
Reactions: Phil DeVore
Joined
Oct 23, 2016
Messages
39
Reaction score
13
Age
62
Sorry, Mr. Editor -
Really??
Is the Inspire 1 not an aircraft, under FAA regulations?
Doesn't it have an anhedral/dihedral angle like almost all winged aircraft?
Does the PIC not have command of his craft, not necessarily as a mechanic, but to do an accurate pre-flight?
Does the FAA not mandate that for its 107 pilots?

So - doesn't this apply to Inspire 2's as well?
Maybe the actual angle number itself might be different, but every other "real" vehicle on the planet has manufacturer's specs that are published.
"Not available to the public" is, IMHO, simply Apple-style nonsense.
If the FAA mandates PIC responsibilities in UAVs, especially upscale UAVs like the Inspires (not just the more expensive ones - let's forget about snobbery, shall we, just for a moment? And think about safety in flight, Rule #1 in any flight manual or rule book?
Which way do they want it? Is it a toy to be returned to the manufacturer every time it malfunctions by its owners/drivers?
Or is it a remote aircraft piloted by rPICs?
 

The Editor

Moderator
Staff member
Joined
Aug 7, 2013
Messages
9,762
Reaction score
5,106
Sorry, Mr. Editor -
Really??
Is the Inspire 1 not an aircraft, under FAA regulations?
Doesn't it have an anhedral/dihedral angle like almost all winged aircraft?
Does the PIC not have command of his craft, not necessarily as a mechanic, but to do an accurate pre-flight?
Does the FAA not mandate that for its 107 pilots?

So - doesn't this apply to Inspire 2's as well?
Maybe the actual angle number itself might be different, but every other "real" vehicle on the planet has manufacturer's specs that are published.
"Not available to the public" is, IMHO, simply Apple-style nonsense.
If the FAA mandates PIC responsibilities in UAVs, especially upscale UAVs like the Inspires (not just the more expensive ones - let's forget about snobbery, shall we, just for a moment? And think about safety in flight, Rule #1 in any flight manual or rule book?
Which way do they want it? Is it a toy to be returned to the manufacturer every time it malfunctions by its owners/drivers?
Or is it a remote aircraft piloted by rPICs?
Yup really.

Certain maintenance/set ups are not designed to be tinkered with by the end user (although many do) and have zero to do with air worthiness.
I fly a fleet of UAS by different manufacturers and am CAA authorised in various weight class of aircraft to operate commercially as well as certified for night flying.
My ops manual is submitted annually and in order to gain my qualifications I also underwent a practical flying examination (which I understand the US does not have/bother with). This included pre/post flight checks (under observation), mission planning, site survey, crew briefing and post flight de-brief.
At no point in my years of flying multirotors commercially have I been asked or required to know what angle the props should be set at.
So, to answer your question - yes really.
 
Joined
Feb 27, 2017
Messages
450
Reaction score
91
Age
64
Either here or in the DJI forum there is a post that shows a precise measurement chart, from the outside tip of the propeller to the surface (of course a flat balanced surface) This measurement includes aftermarket props of carious lengths. I just don't remember the post name or exactly which forum it's on, I don't find it here but will try a couple other key words. However, I think you are talking I2? chart is for I1
 
Joined
Dec 13, 2015
Messages
509
Reaction score
234
Age
71
Either here or in the DJI forum there is a post that shows a precise measurement chart, from the outside tip of the propeller to the surface (of course a flat balanced surface) This measurement includes aftermarket props of carious lengths. I just don't remember the post name or exactly which forum it's on, I don't find it here but will try a couple other key words. However, I think you are talking I2? chart is for I1
After all, the specific exact angle of propellers is not that critical. Propeller's tips must not collide with front OA sensors, providing reasonable and equal clearance on both sides. That's it.
 
Last edited:
Joined
Nov 17, 2017
Messages
376
Reaction score
128
Location
Australia & Europe
After all, the exact angle of propellers is not that critical. Propeller's tips must not collide with front OA sensors, providing reasonable and equal clearance on both sides. That's it.
I would personally not encourage people to be complacent about not having the angles of motors equal. IMHO they should be as close to perfectly equal as possible and adjusted if that is not the case. If the angles of motors are not equal on both sides that will cause all sorts of undesirable flight characteristics and aerodynamical issues. For starters the IMU will have to compensate for unequal lift vector on both sides of the craft and the craft will hover tilted to one side and thus the dynamic CG will be away from the CG of the craft. Yawing the craft while hovering will be unstable and will have tendency of exhibiting toilet bowl effect. (Otherwise also caused by discord between GPS true north and magnetic north). That is just one issue resulting from the different motor angles.
Anyway, without going too deep into other issues resulting from the unequal arm/motor angles I would encourage people to either adjust the angle themselves if the difference is close to or more than 1/2" between the prop tips facing each other. Or if not comfortable with tinkering, send it in for repair.
 
Last edited:
  • Like
Reactions: Mixchief

New Threads

Members online

Forum statistics

Threads
19,124
Messages
188,053
Members
28,183
Latest member
sgprieto