What size Knuckle H quad for 2212 980 KV motors?

[Quad]

I was going to make a second electohub. I have the RTFQ motor and ESC kit for the ElectroHub. I also ordered the ElectroHub frame but it is not here yet. I am thinking of making a Knuckle H quad in the meantime. I was wondering what motor spacing I should use with the 2212 980 KV motors and 945 props?

 

[William A]

With a 9" prop, arms should be about 4.5" from edge of body.

 

[Samick]

i actually just built a knuckle h quad to similar specs. I made my booms that hold the motors 14" long, and clamp down my motors on the very edge. The booms that go the length of the copter are 12". This looks good and proportional compared the the 8" h quads with the bolt on motor mounts, and allows for 10" props if need be.

wow, i actually contributed with something useful!

 

[Quad]

i actually just built a knuckle h quad to similar specs. I made my booms that hold the motors 14" long, and clamp down my motors on the very edge. The booms that go the length of the copter are 12". This looks good and proportional compared the the 8" h quads with the bolt on motor mounts, and allows for 10" props if need be.

wow, i actually contributed with something useful!

thank You! Did you make any adaptations or did you stick to the plans?

 

[jhitesma]

When I rebuilt my knuckle I sized it so 10" props would just barely fit if I opt to go with lower KV motors in the future. So I went with 320mm long booms (about 12 5/8") which should leave about 1/4" between props if I go with 10" IIRC. I also resized the center booms to give the same 320mm between motors front/back. Cutting it close for 10"....but I figured I'll probably smash it a few times before I can afford lower KV motors anyway and with my 8" props I've got just over 3" of clearance between tips.

All with motors mounted straight to the booms - no motor mounts.

 

[Quad]

When I rebuilt my knuckle I sized it so 10" props would just barely fit if I opt to go with lower KV motors in the future. So I went with 320mm long booms (about 12 5/8") which should leave about 1/4" between props if I go with 10" IIRC. I also resized the center booms to give the same 320mm between motors front/back. Cutting it close for 10"....but I figured I'll probably smash it a few times before I can afford lower KV motors anyway and with my 8" props I've got just over 3" of clearance between tips.

All with motors mounted straight to the booms - no motor mounts.

Thank You! Sounds like I have a solid plan then.

Floating the idea of using strong zip ties to tie the booms to the frame. Make a rectangular frame and then tie to the 12 5/8" booms to the frame. When one breaks I simply zip tie a new one on...

 

[Samick]

thank You! Did you make any adaptations or did you stick to the plans?

the only major thing i did different was instead of using the motor mount landing gear combo i used the discs. which is why my arms are the same length as the body booms.... i also put some balsa dowels in the center hub so that it would be an extra 1/2" taller, giving me a little more room.