420 motor bearings and motor failure

[Tridle]

I've had 3 motor failures due to bearings. I've read several threads about this and possible options including bocca bearings ceramic replacements. I've also heard waiting between flights especially on hot days helps as well. I'm wondering if anyone has tried the 440 motor with better success? I understand scorpion also makes a motor that has replacement parts available, but the power consumption suggests the need for a stronger ESC if you go that way.

.....Just looking for thoughts and ideas that are inexpensive and result in fewer replacements.

[Skidpad]

Welcome to the "toasted motor" club...I've gone through a 420 myself, and I'm currently running a 440. Unfortunately, it didn't take many flights on my 440 before the e-clip came off the bottom of the shaft. I figured since I had to pull the motor to install a new clip, I would separate the motor and have a look at the shaft. As I suspected...it was already showing signs of the same shaft wear as others have had on their 440's, and as I had on my 420.

My LHS guy asked if I was letting it cool down between flights, and I really haven't been. So, I've been trying that recently and I quickly realized this method isn't going to work long-term...when I have an opportunity to fly at home, I like to fly batts back-to-back. Nevertheless, I haven't flown enough to see if letting it cool a few minutes will help the shaft wear problem.

You can also use green Loctite at the point where the shaft passes through the lower bearing to help prevent the shaft wear. I haven't done mine yet.

As fas as parts for these motors, you can get replacement bearings from Boca, but nobody - including Blade - sells the shafts. So, we are out of luck using these motors as a long-term solution. Once my 440 is done, I will upgrade (either a Curtis Youngblood version of a Scorpion, or perhaps the new e-flite 450 motor...which you CAN buy replacement shafts, etc for).

As far as running a stronger motor with stock esc, look for posts on here by EEngineer - he's done some actual measurements on current draw. Jchandler is running a Scorpion 2221-6 on the stock esc without a problem, but I would encourage you to read as many threads as possible about the subject.

[runtim23]

I recently purchased the e-flite 450 since I got a deal and the aligns were out of stock. I heard of guys running both the Scorpion 2221-6 and Align 450 mx with the stock esc. If that's the case I'm not sure why the e-flite 450 3600kv 40a cont. requires a 40 amp esc since the mx 3400kv has 46a cont. but I installed a 60 amp esc with mine. Should the kv suggest something here? I only have 2 flights on it with a 12t pinion at 90% TC juiced off of stock batts. Both the esc and motor felt a little hotter than what I'm used to but it was rocketing around quicker than ever. Only complications so far is having to use align pinions which resulted in me drilling the frame to slide the motor back a little further so it would loosen up the fit.

[Eggbeatr]

Originally Posted by Skidpad

You can also use green Loctite at the point where the shaft passes through the lower bearing to help prevent the shaft wear. I haven't done mine yet.

I use "Loctite 680" you'll have to buy it on-line. it's specifically made for loose tolerance metal fittings. It holds up to the heat, and the bearing inner race will not move using this stuff.

[jdFin]

Originally Posted by Skidpad

Welcome to the "toasted motor" club...I've gone through a 420 myself, and I'm currently running a 440. Unfortunately, it didn't take many flights on my 440 before the e-clip came off the bottom of the shaft. I figured since I had to pull the motor to install a new clip....

I was going through and inspection and cleanup after a pretty hard crash and noticed that the clip is gone and the washer is wearing - "ovalled" out a bit. The bearings are still smooth, and the shaft looks okay.

I have confirmed with Horizon support that I can't get any motor parts through them, but your comment implies that you have found a place to get the little clip. True? And the washer?

(Toasted three 420s in my -3D; this is the original 440 in my -X.)

[Skidpad]

I went to my local fastener store (not Lowes, but a place that specializes in hardware) and found a clip that works. It isn't identical to the original, but it works.

Check your local area for an e-clip suitable for a 3.17mm shaft. If you don't have any luck, PM me your address an I'll send you a couple (I bought extras).

The washer...since these are essentially throw-away motors, I'd probably try and find a small washer or two that would work instead.

If all else fails, I have two new 420's that I'm willing to sell. :-)

When my 440 is done, I'm upgrading to the new 3600kv/450 e-flite motor as mentioned above.

[kavic5150]

You guys should upgrade to a 6s power system. I get 7 minute flights with brand new lipos and the motor is barely warm. Using the hyperion (same as scorpion just better looking) 2221-1630kv.

6s 1300ma brick packs will get you those longer flight times and 6s 1200ma packs are very light and will fit under any canopy.

[Imzzaudae]

Is anyone taking the E flight motor apart and lubing the lower bearings every few flights?
Does the set screw that holds the bell on the motor have lock tight from the factory?

I'd like to pull my motor, take it apart and do the lower bearing but I'm afraid to strip the stud trying to loosen it off. Any advice would be appreciated.

[Skidpad]

You don't need to remove that set screw at the top to disassemble the motor - its comes apart from the bottom easily.

Once you have the motor removed from the mount (as shown in the picture), you only need to remove the pinion (single set screw on the side of it), and then the small e-clip on the shaft. Once the e-clip is off, remove the brass washer from the shaft.

At that point simply separate the two halves of the motor by pulling them apart by lifting up on the "can" (the outer housing that rotates when the motor is running) and holding the bottom housing.

[Imzzaudae]

I have wanted to take the motor apart and give the bearings a good grease job for a while.
Will have at it before I fly again.
Ron

[Windmanquebec]

Originally Posted by Imzzaudae

Is anyone taking the E flight motor apart and lubing the lower bearings every few flights?
Does the set screw that holds the bell on the motor have lock tight from the factory?

I'd like to pull my motor, take it apart and do the lower bearing but I'm afraid to strip the stud trying to loosen it off. Any advice would be appreciated.

https://www.helifreak.com/attachment...9&d=1277253347

[kavic5150]

Get some tri-flow synthetic lubricant. It comes with an applicator tube that should be able to reach both bearings without disassembling anything.

Just make sure to get the regular tri-flow, not the dry formula which has an additive that will create drag in high speed bearings.

[spykez]

How does one properly prolong the life of an Eflite 420/440 motor?

Just took apart my 420 motor and I found that there was some wear on the shaft around the lower bearing.

I have a brand new 440 I got somewhile back but never got round to putting it in, I'm thinking I might use it (since it's there) but a lot of indications here seem to suggest either swapping the motor for a scorp or doing something to the lower bearing/shaft.

1. What is the best thing to do to the lower bearing and shaft?

I just experimented on the 420 by cleaning off all the lube on the inner surface of the inner race and dabbing some medium zap CA with a toothpick on the same surface and reassembling the motor. I don't think I f'ed it up as the inner race seems to be stuck to the shaft now and moving reasonably freely.

Is the CA a good choice or should I be using something else? I thought blue locktite would be a bit weak and was questioning if red loctite could hold in the heat, as was I questioning if CA was good enough. Should I have JB welded it? There was no appreciable 'wear' into the shaft at that point, just very very clear abrasion marks on the metal shaft, so I was humming and hawing about the JB.

Of course the acid test is a flight and I might not just yet while my hand is still splinted.

That was my 420 anyway.

2. What should I do to my brand new 440 never spooled up? Should I JB it or CA it or ?

I had a spare msh scorp 2580kv and did think of a 4S but the shaft was a bit long (eft over from a conversion). So I might change that shaft and try a 4S later - just dont know how this would balance cg wise... or just get a new scorp if my eflite 440 dies.

[Eggbeatr]

For holding the lower bearing inner race... CA won't hold nor the red locktite for very long. Use Locktight "680" made specifically for applications like this. Google it, you'll see

[FuntanaS]

I used the red locktite and it has been holding for quite a while now.

[spykez]

Originally Posted by Eggbeatr

For holding the lower bearing inner race... CA won't hold nor the red locktite for very long. Use Locktight "680" made specifically for applications like this. Google it, you'll see

Cheers for that reply, let me see what I have.....

@!#!##$! My red loctite I have is only a 263. Oh well, I'll try and source some. 680

Else, I'll just JB weld the thing, and accept the fact if that bearing ever gets knackered, the motor is f'ed..... Or wait, I can rob the shaft from the 420 maybe .. that's only CA'ed.

Thanks again guys

[Eggbeatr]

Loctite and other brands have whats called (retaining compounds). these are specifically for bearings or cylindrical fittings of bearing shafts, races, etc. We use them occasionally at my transmission shop anytime a bearing race doesn't press fit snuggly into the recess. Usually due to worn parts that have been replaced several times.
Loctite has a whole line of retaining compounds (the 600 series). Actually, Loctite 641 is designed for parts intended for future disassembly.