Tricopter - Scratch Build

[FlyingMonkey]

Balance your props. I hate doing it but it makes a huge difference. Especially with the larger props.

 

[Glademist]

Hey guys.

I am starting to buy parts for my tricopter build and while reading the forum i found something about "shimming a motor" to avoid having different rotations for propellers. The person also wrote that doing such thing is not recommended for a rookie and i took it for granted. Therefore:

Without having the HK Control board V.3 in my hands yet, for the tricopter is there a manual to know which prop should rotate which way? Will the board know from factory? Or do i need to flash the board to get it know it powers a tricopter?

I am buying flashed ESCS with SimonK (F-20A HK) and the guy who sells them asks me whether he should flash them to spin a certain direction. Do i need this? I thought i just switch 2 of 3 cables of motor and change spin direction, am i right?

Thanks a lot for answering.

 

[lankyjames]

Hey guys.

I am starting to buy parts for my tricopter build and while reading the forum i found something about "shimming a motor" to avoid having different rotations for propellers. The person also wrote that doing such thing is not recommended for a rookie and i took it for granted. Therefore:

Without having the HK Control board V.3 in my hands yet, for the tricopter is there a manual to know which prop should rotate which way? Will the board know from factory? Or do i need to flash the board to get it know it powers a tricopter?

I am buying flashed ESCS with SimonK (F-20A HK) and the guy who sells them asks me whether he should flash them to spin a certain direction. Do i need this? I thought i just switch 2 of 3 cables of motor and change spin direction, am i right?

Thanks a lot for answering.

When you use props that rotate in the same direction the 'level flight' of a tricopter is actually a slight angle - due to motor torque - which is counteracted with the yaw of the tail motor. Shimming a motor is done to off-set this angle, to return to level flight and use less counter acting torque. Unfortunately I have no idea which motor you should shim or by how much - sorry!

The KK2.1 actually shows you an example of which rotation each motor should be, shown below;


In truth, it doesn't really matter, the flight controller really doesn't care - so long as the front two motors are rotating alternately to each other the tail can be which ever way you want. You will not need to flash the FC to have the pictures rotating the other way. When a side dips lower than the other it just knows to speed up the dipped motor, it doesn't 'know' which way it is rotating. I hope that makes sense!

There is some debate about which way the front propellers should rotate, some argue outside edges going forward (such as the picture above) some argue outside edges going backwards - I haven't been convinced which is better yet, or if it is just personal preference.

I don't believe I've ever heard of an ESC being flashed for a specific direction - as you mention swapping 2 leads changes direction.

 

[Andre]

Hi guys quick question. The Original Tricopter Body does that come with 1 or 2 pieces?

Thanks.

Andre.

 

[Andre]

Hah tip of the week.

When using epoxy to seal the wires down on the motors. Keep an eye on where the glue goes.
Had to take apart 2 motors and chip out pieces of glue. Rookie mistake.

 

[Foam Addict]

Hi guys quick question. The Original Tricopter Body does that come with 1 or 2 pieces?

Thanks.

Andre.

Two, although it isn't hard to make your own with a drill and Dremel.

 

[Andre]

Supplier and I sorted out the issue.
2nd piece is on route.

I ordered it from Great Hobbies which is now selling Flite Test gear.

For now I've made up a wood frame so I can learn without fear

 

[Foam Addict]

I did the same thing! Have fun Andre, I know I did.

 

[Andre]

Yes chipping the glue out of the bell and magnets was a great way to waste an hour of my afternoon.
But it was pouring rain.

Wood bbq skewers work great, then some brake cleaner to remove any last pieces.
All 3 motors spin well again.

 

[Andre]

I've noticed my servo is making a lot of noise at idle.
What can I do about this?

Thanks.

 

[lankyjames]

I've noticed my servo is making a lot of noise at idle.
What can I do about this?
Thanks.

Two things, its most likely to because it is an Analog servo- need to be sure to set servo channel for low rates.

Next is jitter, and this is just setting the servo filter in increments of 10 or so until it quietens down.

 

[Andre]

Yes great points.
I had flashed the KK and forgot to reset all of this.

I'll have to adjust the setting because now she is rotating to the right.

 

[Andre]

Killed my new $20 digital servo.
Looks like a gear got crunched on a hard landing.

Nuts. I'll have to order a replacement kit.

Anyone suggest a less costly servo then the BMS-385DMAX Digital Servo?

I guess running a normal 9G is a bad idea?

The flight was semi nice for the first few minutes then it all went south

Thanks.

 

[Foam Addict]

I've been flying with a 20+ yo Futaba standard servo with nylon gears, and it works fine for me.
Maybe a park sized hobbyking servo would work?

 

[Andre]

Looks like a broken tooth on the top gear.

I've ordered a kit but in the mean time I'm going to see if I can flip the gear 180 since it does not do a full rotations.

When I rebuild the tail section I'm going to use smaller zip ties. I guess putting my good ones on was a bad idea.

I have a few 9Gram metal gears servos on hand. I might try one so I can keep flying until a repair stuff come in...

 

[e_lm_70]

Killed my new $20 digital servo.
Looks like a gear got crunched on a hard landing.

Nuts. I'll have to order a replacement kit.

Anyone suggest a less costly servo then the BMS-385DMAX Digital Servo?

I guess running a normal 9G is a bad idea?

The flight was semi nice for the first few minutes then it all went south

Thanks.

I'm using Corona MG939 Digital ... it cost around 5$ .. and it has never let me down on my tricopter.

 

[Andre]

Great stuff. I'll keep that in my notes for the future.

Andre.

 

[Andre]

 

[Andre]

For reference I was not planning on going above the tree line but things escalated quickly and ended poorly.

Multi-rotor rookie. I should know better.

 

[Andre]

Got tired of trying to make a pin connector to flash the ESC with.

Soldered on connectors instead.

Much easier.