Hi folks, as you may know from watching the videos, I put my Twist 60 into mother earth a couple of weeks ago which resulted in some damage to the brushless electric motor I use to power it. I made a video on how to replace bearings in a brushless motor. While motors vary quite a bit this should give you a good idea on what’s involved and what to look out for.

As a brief history note, you may recall I originally built the Twist 60 with a Saito 1.15 nitro-methanol power house and had a bit of fun with it. It was sort of my last attempt at trying to like glow engines again, I just couldn’t get back into again though. I love the smell of burnt nitro, but these days most of my fleet is electric so it meant having to carry around multiple sets of equipment, one for glow and one for electric every time I went flying with the Twist. Earlier this year I converted the Twist to a large brushless eFlite motor, the Power 90. I had asked e-Flite’s recommendation for a motor and one of their techs recommended the Power 60. I poked a bit more and said I wanted it to perform as good or better than my 1.15 4-stroke motor so they suggested the Power 90 instead. I don’t regret switching to that large brushless motor, but it has different types of maintenance issues as you can read below.

Most of the damage to the Power 90 was to the bearings, they sounded kind of crunchy and beyond even flyable.  I also replaced the main shaft and prop adapter to make certain it would run true again as I had detected a bit of run-out at the prop shaft but couldn’t identify the exact cause. Below is the footage of this so called ‘crash’ and further down is a quick video on the repair of the E-Flite motor.

I ordered the new main shaft and prop adapters from Horizon Hobbies for the Power 90 motor but they didn’t carry a bearing set for this motor model. In fact even individually I could not find the proper bearings on their website.

This is when I turned to a reliable bearing source.  Now truth to be admitted, I have purchased bearings from Boca Bearings in the past for one of my nitro-methanol powered radio controlled helicopters, but I have not ordered from them in a long time and not for a brushless motor.  Recently Boca Bearings friended me on YouTube which was pretty cool.  So when I thought of replacement bearings for the E-Flite Power 90, of course, I instantly thought to check the Boca Bearings website. Good marketing!

The bearing part numbers for the E-Flite Power 90 brushless motor from Boca Bearings (the ceramic variety) are SMR696C-YZZ NB2 for the larger ‘rear’ bearing and SMR626C-YZZ NB2 for the smaller ‘front’ bearing. (Rear and front are interchangeable terminology depending on the prop adapter and mounting of the motor.. smaller/larger is the better bet!)  They were 9.95US a piece, but high quality and I expect that they will last a long time until I perhaps crash the Twist 60 once again.

The E-Flite Power 90 brushless motor has been an excellent motor, so I wanted to replace the bearings with only the best quality substitution bearings for my motor. It’s not often you can spend so little for the something of very high quality in this hobby 😀  The bearings from Boca Bearings are probably much better than the original and will be more than sufficient for my flying needs.

I’ve posted a video of how to replace the bearings, motor shaft and prop adapter for the E-Flite Power 90 brushless motor below, please check it out and let me know what you think of it!  (Yes, I am aware it does move a little fast, please use the ‘pause’ button if you want to hold on a step and I’ll remember that in future video slide-shows 🙂 )

UPDATE: I just did a run-up on the motor tonight, it sounds great. I ran it up bare/unloaded and then I ran it up on a 16×8 3-bladed prop. While I know 3-bladed props aren’t preferred for 3-D I have a ground clearance issue with this plane. As it was I had to re-form the landing gear aluminum to fit this propeller.  The system is two 3700mAh 14.8 volt packs running in series for 29.6 volts at 3700mAh.  With the previous prop, a 15×7 3 bladed prop I would get about 10 minutes of flight, most of it full out. I expect the time to drop dramatically with the new prop, but I should be able to use less throttle with a larger prop if I’m not aiming for speed. It should be a lot of fun at any rate, I really love this plane and motor combination.

ANOTHER UPDATE: I managed to get a flight in on the Twist 60 with the Rebuilt Power 90 outrunner brushless motor the other day. The motor sounds great as it ever did, I don’t notice any additional performance difference between the steel and the ceramics, but we’ll see how they hold up over time.  This was the first time I had used a 16×8 3 bladed prop, flying the Twist originally on the 15×7 3 bladed prop ever since I removed the nitro-methanol 4-stroke and replaced it with the e-Flite motor.  The plane is not as fast with the larger and higher pitch prop, but it does have a lot more pull to it in vertical climbs.  This motor and prop combination runs incredibly quiet even at full throttle it is quieter than my Mini-Titan RC helicopter by quite a bit.  Check out the flight video below, there’s a very special ending to it (no it does not include a giant spider!)

If you have any thoughts or input, please comment before, I appreciate your voice.

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