How To Replace Solo Motor Bearings!

[Del]

I was wondering the same thing, all three sound bad...less for the RCTimer ones. Personally it sounds like the shafts are spinning in the bearings, which is not good. Preloading bearings will help.

Since your on the trail for discoveries in replacing bearings. First, for you USA people, AVID bearings seems to be good quality and at a buck a piece. They have a good rep in the RC car/truck community, so can't be all that bad.

Here are some pictures for my DIY bearing press, assembled and disassembled. Similar to what DavidWeston had mentioned. The key is not pressing the inner race when seating the bearings, only the outside race. The tool presses the bearings straight in, no need for lube to install. The bearing adapters were machined from aluminum, with .005" smaller OD than the bearing and then the hole's ID was slightly larger than the inner race's OD.

T-Motor cir-clips and thrust washer, I highly recommend buying both. Preloading the installed bearings will improve performance and bearing life, the T-Motor nylon thrust washer is slightly thicker than the stock brass washer but they will compress.

Then in the picture are two tools I use for removing and installing the cir-clips. Both tools can be had through McMaster-Carr and are a bit tricky to use, but once mastered makes the task easier. The plier looking tool, is a cir-clip spreader, very valuable for these odd shaped cir-clips. On second thought, the tools are a little pricey, I'd only purchase if your doing bearing replacement as a biz. Me, I have a weakness for specialty tools...no biz need.

View attachment 2374 View attachment 2375

Thank you Rich for sharing your info and posting some pics..very appreciated

It seems like there is a few good name Quality bearings to choose from and even the option of stainless steel !
I ordered the Sunnysky bearing for now and just waiting for them to come in the mail!
I guess they might not be the best on the market..but I hear that they will do for someone like me who is just starting out and in the process on doing my first bearing replacement
But I'm sure the more experience I get over time the more I'll have an understanding on choosing My bearing more wisely

Cheers

 

[RichWest]

FWIW, NMB bearings are the very best that can be had, high precision bearings. If they don't have NMB on them, then they are not NMB no matter what a dealer tells you.

Regarding lube and bearings from bearing dealers, most bearings of this size come un-lubed unless specified. The same bearings could be used in medical or food processing tools is the reason. So pick an oil or grease of your choice and lube the bearings.

 

[Del]

FWIW, NMB bearings are the very best that can be had, high precision bearings. If they don't have NMB on them, then they are not NMB no matter what a dealer tells you.

Regarding lube and bearings from bearing dealers, most bearings of this size come un-lubed unless specified. The same bearings could be used in medical or food processing tools is the reason. So pick an oil or grease of your choice and lube the bearings.

I'll have to definitely keep the NMB bearing in mine...would the NMB bearings have the option to be ordered in stainless steel ?

Cheers

 

[RichWest]

I'll have to definitely keep the NMB bearing in mine...would the NMB bearings have the option to be ordered in stainless steel ?

Yes.

Ball bearings are machined components that include an outer ring, inner ring, balls, retainers, shields and snap rings. NMB’s miniature ball bearings are available in inch and metric sizes, open or shielded and flanged or unflanged. For extreme noise sensitive applications, superior hardness and corrosion resistance our ball bearings are manufactured with DD400™ stainless steel material. Chrome steel is available for applications in uses and environments where corrosion resistance is not a critical factor.

Everything you wanted to know about bearings and more - Miniature Ball Bearings

 

[Del]

Yes.



Everything you wanted to know about bearings and more - Miniature Ball Bearings

Awesome..thanks Rich

Cheers

 

[Del]

Mine were the same also, smooth as a baby's butt after changing. I also got the same app and in my opinion it was useless. Using your touch with the MP motor test is much better.

In case anyone's interested, these are the Boca Bearing P/N's

These are the Boaca Bearing P/N's for SEALED bearings: SR2-LL/C3C and SR2-5UU3. I apologize for the previous P/N/s but there are correct for sealed bearings.

Hey Dave...I found these Boca Bearing On there site and wanted to order a couple of sets! Iv use the Part number that you posted and this is what I've found!
I'm assuming that the SR2-LL/C3C bearing would be for the bottom of the motor! And theNSR2-5UU3 would be for the Top?

But before I order them..I want to double check with you or anybody els that would know if these are the right ones or size I should be ordering for the replacement bearing for the stock motor for the solo?


Cheers

 

[Maddog]

I was wondering the same thing, all three sound bad...less for the RCTimer ones. Personally it sounds like the shafts are spinning in the bearings, which is not good. Preloading bearings will help.

Since your on the trail for discoveries in replacing bearings. First, for you USA people, AVID bearings seems to be good quality and at a buck a piece. They have a good rep in the RC car/truck community, so can't be all that bad.

Here are some pictures for my DIY bearing press, assembled and disassembled. Similar to what DavidWeston had mentioned. The key is not pressing the inner race when seating the bearings, only the outside race. The tool presses the bearings straight in, no need for lube to install. The bearing adapters were machined from aluminum, with .005" smaller OD than the bearing and then the hole's ID was slightly larger than the inner race's OD.

T-Motor cir-clips and thrust washer, I highly recommend buying both. Preloading the installed bearings will improve performance and bearing life, the T-Motor nylon thrust washer is slightly thicker than the stock brass washer but they will compress.

Then in the picture are two tools I use for removing and installing the cir-clips. Both tools can be had through McMaster-Carr and are a bit tricky to use, but once mastered makes the task easier. The plier looking tool, is a cir-clip spreader, very valuable for these odd shaped cir-clips. On second thought, the tools are a little pricey, I'd only purchase if your doing bearing replacement as a biz. Me, I have a weakness for specialty tools...no biz need.

View attachment 2374 View attachment 2375

?I thought the RC motor sounded really good- do you have a recording of a "good" motor for us rookies to listen to?

How are you pre-loading the bearings?

You mention Avid bearings- lots of talk here about Boca bearings. I don't know anything about these bearings. Feelings about Boca?
The last set af bearings I bought were for my former deuce-and-a-half. (2.5 ton military 6x6. Each bearing set weighs more than Solo!)

I presume that tool is custom made, eh?

 

[RichWest]

I presume that tool is custom made, eh?

No tool for that I'm aware of....funny man.

I have no video of good bearing sounds, Roland did link to a T-Motor test video of his. Use that as a benchmark for what a motor should sound like.

The link above has quite a bit of info, but here's the one regarding preloading - Bearing Preload

I have no experience with Boca, I'm sure they offer fine quality ball bearings. Do they actually make the bearings?

 

[RolandS888]

Brand new T-motor 2216 800kv motors run singularly and together using mission planner.

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[Maddog]

No tool for that I'm aware of....funny man.

I have no video of good bearing sounds, Roland did link to a T-Motor test video of his. Use that as a benchmark for what a motor should sound like.

The link above has quite a bit of info, but here's the one regarding preloading - Bearing Preload

I have no experience with Boca, I'm sure they offer fine quality ball bearings. Do they actually make the bearings?

Thanks Rich! Good point- I don't know who actually makes Boca bearings.

The tool I was referring to was the one you showed to install the bearings- did you make it or buy it?

 

[RichWest]

Thanks Rich! Good point- I don't know who actually makes Boca bearings.

The tool I was referring to was the one you showed to install the bearings- did you make it or buy it?

Home made for the most part. I bought the aluminum spacers (and other hardware) from McMaster in the two bearing sizes needed. Chucked up in a drill press and filed the reliefs on the faces of the spacers to fit the bearings outer race. Thereafter, I chucked up the spacer on the M3x50 cap bolt to sand down the OD of the spacer to be slightly undersized. Then I counter sunk a hole larger than the inner race's OD, depth was just enough to clear the inner race's height when everything was assembled.

I had pondered building and offer these, but once I got to the labor side of things it made no sense. It would have been $20 shipped, rip-off. Further most had various methods in mind to complete the bearing install at the time of my discoveries for bearings. Setting up a production run with lathe would create economy, dropping by about $5. Further, everything from McMaster is in semi-bulk package quantities, so I spent about $45 for parts needed to make my set (+2) cost around $7, less my time. The thumb nut was $1.50 by itself. In the real world this should cost no more than $5 retail.

Again the tool works extremely well, bearings set with very little effort since they are aligned.

 

[Maddog]

Home made for the most part. I bought the aluminum spacers (and other hardware) from McMaster in the two bearing sizes needed. Chucked up in a drill press and filed the reliefs on the faces of the spacers to fit the bearings outer race. Thereafter, I chucked up the spacer on the M3x50 cap bolt to sand down the OD of the spacer to be slightly undersized. Then I counter sunk a hole larger than the inner race's OD, depth was just enough to clear the inner race's height when everything was assembled.

I had pondered building and offer these, but once I got to the labor side of things it made no sense. It would have been $20 shipped, rip-off. Further most had various methods in mind to complete the bearing install at the time of my discoveries for bearings. Setting up a production run with lathe would create economy, dropping by about $5. Further, everything from McMaster is in semi-bulk package quantities, so I spent about $45 for parts needed to make my set (+2) cost around $7, less my time. The thumb nut was $1.50 by itself. In the real world this should cost no more than $5 retail.

Again the tool works extremely well, bearings set with very little effort since they are aligned.

Wow- you are certainly handy! That's very ingenious. I know what you mean about trying to sell something that's very labor intensive- it's usually not worth it.

 

[RichWest]

Wow- you are certainly handy! That's very ingenious. I know what you mean about trying to sell something that's very labor intensive- it's usually not worth it.

Not really ingenious, this is old school DIY...100's of years old.

Labor, machine time, and shipping...just crazy.....

 

[SurfnSkate81]

Could someone please give me a run down of how you actually use the vibration app? Am I using the 'Time Series' page and pressing sample? When I do that it seems that the sample is only about 5 seconds long. Is there some settings in the app I need to change?

 

[Maddog]

This video will 'splain everything!

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[RolandS888]

Some fundamental oversights in there, but the idea is on the right track, and any vibe reduction cant hurt.

 

[Maddog]

Some fundamental oversights in there, but the idea is on the right track, and any vibe reduction cant hurt.

Yep- I was just trying to provide the settings, etc. for the app.

 

[SurfnSkate81]

Some fundamental oversights in there, but the idea is on the right track, and any vibe reduction cant hurt.

Roland what suggestions do you have that differ from the video? I have never balanced my motors so any insight as to the right and/ or wrong way?

 

[RolandS888]

Whats hes doing there is good enough to start with, especially if you have never balanced a motor before, if you can reduce the vibes that are read by a phone app then you have made some improvement. So its all good, follow his lead and you should be able to see and reduce some vibes.

Have a good look at your gimbal mounting as well, it needs to be free to move on the balls in all directions, once it does that the quad will be more tolerant of vibes as well.

 

[RolandS888]

For anyone that wants to get really pedantic, consider the following...

Motor RPM. You cant just use any RPM, or max RPM, vibes are RPM specific, a motor will have zones or bands of vibes as it increases in RPM.
Put your motor and prop in a thrust tester and work out the RPM at which the motor is producing the thrust it will need to hover. Eg, a 2kg quad needs 500gr on each motor. record this RPM figure at the 500gr thrust point.
Use this RPM as the speed you are bringing the motor to for balancing. Spin it up to +/- 20% and check the balance in this range, not some arbitrary figure like full throttle or 2/3 throttle.
Did you know that the stock Solo motor cant even take a stock prop to 100% throttle. The motor loses sync and fails, its not powerful enough. BUT it will never ever need to get to 100% throttle RPM so why bother balancing a motor there.

Freedom of movement
Take the motor off the craft, why bother trying to read vibes when its bolted to a structure, any structure, it needs to be free to move. Bolt it to one thing only - the device taking the readings.

Instrumentation - Phones accelerometers and apps vary, you may get great results, poor results, or no results. Do you understand the units you are supposedly measuring on a phone app? And in which dimension are you measuring.?

I'll stop there. One day I'll put the whole lot in a video.
It is possible to balance some brushless motors ZERO vibes with the right equipment, and when they are there they are amazing to hold. they just sit in your hand and spin and you cant feel anything. Like a perfectly balanced spinning top, you can see it spin and you can hear it, but you cant feel it.

Like I said though, if you can read vibes with a phone app and do something to reduce that reading then you have done some good and will improve your video.