Motors Swapped to T-Motor 2216-12 800kV

[RolandS888]

Cant fly at the moment Mudman, will be 2 weeks before I can get back to this.

 

[RichWest]

Not that my opinion matters, but the bell head section is extremely characteristic of Sunny Sky motors. Even the stator/base housing appears identical, not that it makes any difference. Like RolandS888, why would they use imperial measured components in today's world... I'd far prefer 4mm shaft than an 1/8". Could be T-Motors, but of SunnySky design...

Link to example SunnySky photos: Sunnysky V2216 12 800KV Outrunner Brushless Motor Multi Rotor Quad Copter HEXA | eBay

Sorry I have a hard time believing T-Motors built the Solo motors.

@RolandS888 , I'm most eager for your results as well.

 

[RolandS888]

Certainly the strock motor is the budget Tmotor version, if there is such a thing.
Running side by side there is a huge difference between the two.

 

[Mike Boland]

I was just wondering how you verified the motor direction after fitting them?
You don't mention it in your blog at all.

 

[David Weston]

Did you try the stock motors with new bearings at all? I have one new motor pod, one semi new about 2 months ago, and 2 from June 16 when I got Solo. The new one sounds like a gem, purrs. The other 3 are totally different sound,,definitely not purring. I know the last one I replaced had a bad bearing. I am replacing all the bearings with Boca Bearings (sealed as I am in Florida and micro silica sand everywhere). I got them yesterday but unfortunately on the smaller bearing I ordered one that had a flange on one side (didn't see it when I ordered). But, I think with the new bearings it's going to be totally different motor performance. Will report after I replace them.

 

[David Weston]

You can test all the motors individually with MP Motor test. That's when you can check for direction.

 

[RolandS888]

I was just wondering how you verified the motor direction after fitting them?
You don't mention it in your blog at all.

Did you try the stock motors with new bearings at all? I have one new motor pod, one semi new about 2 months ago, and 2 from June 16 when I got Solo. The new one sounds like a gem, purrs. The other 3 are totally different sound,,definitely not purring. I know the last one I replaced had a bad bearing. I am replacing all the bearings with Boca Bearings (sealed as I am in Florida and micro silica sand everywhere). I got them yesterday but unfortunately on the smaller bearing I ordered one that had a flange on one side (didn't see it when I ordered). But, I think with the new bearings it's going to be totally different motor performance. Will report after I replace them.

Mike, after soldering the new motor in I just plugged it back in and started the motors, the wires are long enought to sit the pod on top of the arm whilst plugged in. No need to go to the hassle of doing it with MP but that would certainly work as well. I worked on the assumption that the old and new motors are wound the same way and soldered the new motor wires in with the same orientation as the old motors. It was just a guess, but it paid off as they were all the correct direction on the first go.

David in the past I have found that the cheapest chinese motors usually scrimp on the bearing quality. I have changed bearings in other brushless motors (to Boca ceramic) and have then also had magnet and or winding failure as well. These days I'd rather just invest in good reliable gear. I have T-motors in most of my multirotors, and besides some minor balancing issues I am yet to have oine fail. The thing that got me with these stock motors is the difference in magnetic 'cogging' as you rotate the motor by hand. They were differences amongst the 4 motors on Solo. Why?!? They should be identical.
The bought T-motors are tight, smooth and identical, and they purr, exactly as I expected them too.
But a bearing change on the stock motors certainly cant hurt, it will smooth things out and may be all thats needed. I will be digging into my stock motors and will post what I find.

 

[RichWest]

@RolandS888 , Curious about your experiences with the ceramic bearings. I guess related to long term use. It is my understanding they require a higher frequency of maintenance; cleaning and greasing....

 

[AUsome]

I tried something at this point, I copied the wires phase rotation from the stock motors, making notes of what I pulled apart and soldering the new motors in the same way. I get every one right the first time and didnt have to resolder any wires to change direction of rotation.

Roland, can you explain what you meant by copying the wires phase rotation from the stock motors, etc.? Since the replacement motors' wires are all black, obviously just attaching red/blue/black in the same manner wouldn't alone be enough.

 

[RolandS888]

Roland, can you explain what you meant by copying the wires phase rotation from the stock motors, etc.? Since the replacement motors' wires are all black, obviously just attaching red/blue/black in the same manner wouldn't alone be enough.

OK.
Yes the new motors wires may all be black, but if you sit the old and new motors next to each other, they both have 3 wires. A left, a middle, and a right.
On the t-motor they are all black, on the stock motor they are red, black and blue.
And, the motor solder pads on the ESC are labelled A, B and C.
I just equated left / red (to A), middle / black (to B) and right / blue (to C), and made sure the new T-motor wires being soldered in are done in the same orientation as the old motor that was removed.
It helps to draw pictures of what is being removed before you start.
I hope that makes sense, Its kind of hard to explain.

 

[RolandS888]

@RolandS888 , Curious about your experiences with the ceramic bearings. I guess related to long term use. It is my understanding they require a higher frequency of maintenance; cleaning and greasing....

Rich, I use the boca ceramic bearing as replacements on my Mikrokopter Hexas. They are sealed so I find them no more needy than any other bearing. They do have a different sound about them though. Those little ceramic balls must be hard as diamonds, because they sure sound that way.
The only thing I do once in a while (and this is to most of my brushless motors) is a tiny drop of Tri-flow onto the top of the bearing seals and wait for it to sink through. It is a super thin synthetic teflon lube and I feel it helps keep everything moving.

 

[AUsome]

OK.
Yes the new motors wires may all be black, but if you sit the old and new motors next to each other, they both have 3 wires. A left, a middle, and a right.
On the t-motor they are all black, on the stock motor they are red, black and blue.
And, the motor solder pads on the ESC are labelled A, B and C.
I just equated left / red (to A), middle / black (to B) and right / blue (to C), and made sure the new T-motor wires being soldered in are done in the same orientation as the old motor that was removed.
It helps to draw pictures of what is being removed before you start.
I hope that makes sense, Its kind of hard to explain.

It does make total sense and I suspected this was what you were probably referring to, but this perfectly clears it up. Thanks muches.

 

[David Weston]

Replaced bearings with the Boca sealed bearings and tested motors. 2 motors are relatively new, two are the original motors. Definite sound difference between the new motors and the original motors. The new one's "hum", the older one's have a raspy sound, like a background growl. They are both CCW motors. The bearing change did not change the way the motors sound. I thought they would also "hum" but there was no noticeable difference. So, guess there is some mechanical difference between the older original motors and the newer one within the last month or so. No clue what it might be.

 

[RichWest]

Replaced bearings with the Boca sealed bearings and tested motors. 2 motors are relatively new, two are the original motors. Definite sound difference between the new motors and the original motors. The new one's "hum", the older one's have a raspy sound, like a background growl. They are both CCW motors. The bearing change did not change the way the motors sound. I thought they would also "hum" but there was no noticeable difference. So, guess there is some mechanical difference between the older original motors and the newer one within the last month or so. No clue what it might be.

Hmmm....you changed the only mechanical difference that's possible...bearings. Windings and magnets should be fairly consistent motor to motor. Again Cogging Torque is another issue and will make the motors sound different, in my opinion.

Curious, did you replace or re-use either the thrust washer and cir-clip?

 

[David Weston]

new clip, same washer as my Teflon ones don't arrive until tomorrow. Washers looked good, virtually no wear that was obvious.

 

[RolandS888]

@David Weston, are the bearings you replaced perfectly smooth when you rotate the bell?
I have replaced bearings before and I was a bit heavy handed with them, they were slightly damaged on the install and rumbled from the get go. Lesson learned.
Since then, I heat the stator and freeze the bearings, and the bearings ususlly drop straight into the recess.
Also, you are changing cheap Chinese bearings with what are probably cheap Chinese bearings as well, so it pays to check them thoroughly prior to install.

 

[David Weston]

the larger bearing seated with just thumb pressure. The smaller one I had to l lightly tap but used even pressure all around with a flat piece of (small) steel over the bearing. I took a Q-tip with dipped in soapy water, swabbed the inside of the bearing seat, went in easily.

 

[RichWest]

Also, you are changing cheap Chinese bearings with what are probably cheap Chinese bearings as well, so it pays to check them thoroughly prior to install.

That is the funniest thing I've read all day...thank you!!!!!!

 

[David Weston]

Roland, Mike, and others. Decided I would replace the thrust washers with new Teflon ones so I took my 1st spare, the original motor that had the bad bearing, and started taking it apart again. I was using a jewelers screwdriver to remove the (new) circ-clip when it slipped and ooops, broke a winding wire. Well, that's trash now,,or is it? BTW, the Boca bearing (sealed) are $17.00/pair. What do you think about replacing the motor I just trashed with the 900 kv MT2216 T-motor?

High Performance Brushless T-Motor MT2216 900kv for Copter

Will the ESC keep the shaft rpm in sync and make the correct changes for stable flight with the other 880kv motors? At $55 probably isn't worth the effort as I can buy a new 3DR pod for $70 and have a warranty in case of a failure that trashes SOLO. Guess this is why "tinkering" is part of owning a SOLO...lol

 

[RolandS888]

David, I wouldnt use a motor with broken wires internally, it will be less powerful and there is now a risk of it shorting out. It is trash, keep it for spares (bell, shaft, bearing etc.)
FYI, I measured the Kv of my stock motors and it is a little higher than the 880 stated, around 890.

Whilst I think the pixhawk will accomadate a motor of slightly different Kv, it isnt the optimum scenario and I would not deliberately put motors of different kv in the one quad. Just my opinion.