SK3 2822-1275 Motors for Anycopter Quad?

SeanDuffy

Junior Member
Hi!

I'm building a quadcopter using the anycopter quad kit from Flite Test's Rotor Bones series. So far I've assembled the frame, however due to the recommended motors (Turnigy Park300) being on backorder, my order for electronics from Hobbyking has been on hold for some time and I've been unable to progress with my build.

Today, I discovered the Aerodrive SK3 2822 1275Kv motors from David using them in his V-Tail Quad, which are in stock at the moment. I noticed that although these have a lower Kv than the Park300s (1275Kc vs 1380Kv), they are only slightly heavier at 31g and seem to be of a similar form factor. Also, a bonus is that they includes pre-soldered bullet connectors.

Since I'm not too experienced with choosing motors, I just wanted to know if these would be a good substitution for the Park300s, and if they would provide a comparable performance. Thanks in advance!
 

Cyberdactyl

Misfit Multirotor Monkey
They'll do fine.

Make sure you get appropriate sized props and adapters if not a threaded rod. My guess is somewhere around 9047.
 

SeanDuffy

Junior Member
It looks like these motors include the adapters. Will the 8045 props I was planning on using with the Park300s not suit these motors?
 

Johan

Senior Member
I have the same motors lying on my desk (also due to the backorder on the Park300's and according to e-calc it should work out), also some 8045's and 9047's, but I'm waiting for the frame to arrive.
I'm working on a tri however, that might change things, but in your advantage I think...
If the frame arrives anytime soon, I'll let you know my findings.
 

Johan

Senior Member
This is what you get with the adapter and the 8045's on it.

sk3.jpg

You maybe could reverse the motors (turn them upside down) and use the 3mm shaft (underneath the mount here, so a bit hidden) instead of the threaded shaft on the adapter and use the other adapter.

Then you'd get this:

sk3-2.jpg


The advantage might be that it is pushing the motor mount from below instead of pulling on it from the top, while lowering the point of gravity.
That feels like an advantage, but that is just a guess ...
 
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SeanDuffy

Junior Member
This is what you get with the adapter and the 8045's on it.

View attachment 12089

You maybe could reverse the motors (turn them upside down) and use the 3mm shaft (underneath the mount here, so a bit hidden) instead of the threaded shaft on the adapter and use the other adapter.

Then you'd get this:

View attachment 12090


The advantage might be that it is pushing the motor mount from below instead of pulling on it from the top, while lowering the point of gravity.
That feels like an advantage, but that is just a guess ...

Thanks for the top, I may well try this when my motors arrive.
 

Cyberdactyl

Misfit Multirotor Monkey
The advantage might be that it is pushing the motor mount from below instead of pulling on it from the top, while lowering the point of gravity.
That feels like an advantage, but that is just a guess ...

Yes.

The more mass of the multirotor you can get in the plane of the thrust, the less energy you expend on resisting the moment of inertia during pitch or roll changes. Which goes hand-in-hand with designing the components as close to the center of mass as possible.

So. . .a "perfect" multirotor, for flying performance, would ideally have 100% of the mass at a pinpoint at the center, in the plane of the thrust. Which of course is impossible.
 

Johan

Senior Member
Now I've received the flitetest motor mounts and frame, it looks as if mounting below the mount is bringing the spinning part of the motors very close to the edge of the wooden boom and the landing gear, therefore maybe not such a good idea...
There is only a few mm (~ 1/8th inch I estimate) gap.

View attachment 12090

Next problem I face at this moment: the screws that come with this motor have tapered heads and are just long enough to mount on the cross mount that comes with it (see picture), the G10 motor mount is thicker than this cross and does not have tapered screw holes....

I saw in the v-quad video David mounted them directly on the bat-bone mounts (other side up, so with the 3mm shaft protruding through the bottom, unlike in this picture), but probably with slightly longer flat-head screws, otherwise it would not work (too short). I'd rather not touch the G10 with a drill to have the original screws sunken since this would weaken the delrin...
I'll try to ask...
 
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SeanDuffy

Junior Member
Now I've received the flitetest motor mounts and frame, it looks as if mounting below the mount is bringing the spinning part of the motors very close to the edge of the wooden boom and the landing gear, therefore maybe not such a good idea...
There is only a few mm (~ 1/8th inch I estimate) gap.

View attachment 12090

Next problem I face at this moment: the screws that come with this motor have tapered heads and are just long enough to mount on the cross mount that comes with it (see picture), the delrin motor mount is thicker than this cross and does not have tapered screw holes....

I saw in the v-quad video David mounted them directly on the bat-bone mounts (other side up, so with the 3mm shaft protruding through the bottom, unlike in this picture), but probably with slightly longer flat-head screws, otherwise it would not work (too short). I'd rather not touch the delrin with a drill to have the original screws sunken since this would weaken the delrin...
I'll try to ask...

So do you think it would be necessary to buy some longer screws in order to attach these motors to the delrin motor mounts? Of course another option would be to do what Chad suggests, forget about screws and just mount the motors with a few zip ties through the screw holes.
 

Johan

Senior Member
So do you think it would be necessary to buy some longer screws in order to attach these motors to the delrin motor mounts? Of course another option would be to do what Chad suggests, forget about screws and just mount the motors with a few zip ties through the screw holes.

It looks like that the longer screws are the simplest solution because with the cross mount attached, the holes in the mount fall outside of the bat-bone mounting plate, but i'll try to ask the FT experts first