Motor shaft question

[FuntanaS]

I have a motor from the B450 that has a worn out shaft where the lower bearing rides on it. Do you guys think it would be possible to put some JB weld on the shaft to fill in the low spots on the shaft? I was thinking of either putting some JB weld on the shaft and then sand/file the excess off or just JB welding the bearing to the shaft and running it for as long as I can.

I got another stock 420 motor in my B450 right now so if it doesn't work it's not the end of the world but I thought I would try and get some more life out of it.

Also the motor currently in the heli has about 30 flights on it and has been oiled before it was put in. I just recently took it out to oil it again and noticed what seems to be the beginning signs of the shaft wearing again. The shaft has a dark ring around it where the lower bearing is but hasn't worn yet. So what can I do to stop this? The bearings seem to be good. They spin nice and smooth.

Any ideas?

[PauloG]

I'm interested to see the replies on this thread as I am in the same exact situation.

edit: Maybe there is another shaft from a diff company that would fit in the 440 motor?

[Blade120]

having the same issue here with a 440 motor shaft is wearing , bearings are still good. It's causing the pinion to wiggle a bit I know its the begining of the end for the motor but as long as its keeping cool and running smooth im still using it.

[FuntanaS]

Well I'm going to try out the JB weld in a little while. I'll see how it goes.
Does anyone know if JB weld is harder than the motor shaft? Would it take a longer/shorter time for the bearing to wear into the JB?

[Mikey2]

Originally Posted by FuntanaS

I have a motor from the B450 that has a worn out shaft where the lower bearing rides on it. Do you guys think it would be possible to put some JB weld on the shaft to fill in the low spots on the shaft? I was thinking of either putting some JB weld on the shaft and then sand/file the excess off or just JB welding the bearing to the shaft and running it for as long as I can.

I got another stock 420 motor in my B450 right now so if it doesn't work it's not the end of the world but I thought I would try and get some more life out of it.

Also the motor currently in the heli has about 30 flights on it and has been oiled before it was put in. I just recently took it out to oil it again and noticed what seems to be the beginning signs of the shaft wearing again. The shaft has a dark ring around it where the lower bearing is but hasn't worn yet. So what can I do to stop this? The bearings seem to be good. They spin nice and smooth.

Any ideas?

I know that some may disagree but given all the "motor" posts and absolutely "short-lived" motor components on these stock motors, there simply "has" to be an issue with the quality of these motors. Getting only 30 flights out of a stock motor is in my estimation, completely "unacceptable" even if you never lubed it. The basic "outrunner" design has been developed and marketed specifically as a "long life" component as compared with brushed inrunners and unless there is direct impact damage, I can't imagine why so many guys would suddenly be having so many issues with these stock motors. Just doesn't make any sense.

Unless HH wants to continue comping everyone for new motors, it sounds like a decent aftermarket motor is the only good solution. Regardless of whether JB Weld might provide even a temporary fix, I'm wondering if you should risk it? If the motor shaft is already heat scored, sounds like things are ready to grenade and who knows what impact that may have on your heli if and when it does..............especially if it comes apart in the air and the shaft were to seize. I know these are hard times economically for most of us but for all the fartin' around that folks are doin' with their motors, seems like the best bet would be to pop for a "quality" motor from the aftermarket. The motor is the "heart" of the heli, it's probably the single most expensive component and it simply has to be reliable in every respect. Just my two cents. Don't mean to sound too strident.

[Thalios]

Well, given that i'm closing on 100 flights with mine, over 30 crashes, and still on stock motor, i'd say something else might be the issue...

If the heli has never been crashed, no blade strikes, never overheated (run like 10 packs in a row in 100° outside temp without letting it cool down), etc, and still have these issues, then yeah, i might think there's an issue with the motor.

[FuntanaS]

Well the new motor I have in my B450 has about 40 flights on it now. It has never been in a crash/blade strike, and it has never been overheated (the outside temp here is in the 40's and 50's so the motor comes down after a 6 minute flight barely even warm. Probably around 100 degrees.)

Shortly after 100 flights is when my first motor started getting bad. Check to see if there is any lateral play in the shaft on the pinion end.

[Thalios]

Originally Posted by FuntanaS

Well the new motor I have in my B450 has about 40 flights on it now. It has never been in a crash/blade strike, and it has never been overheated (the outside temp here is in the 40's and 50's so the motor comes down after a 6 minute flight barely even warm. Probably around 100 degrees.)

Thanks FuntanaS.

What's the conditions of the weather? Near a water source (lake, ocean, etc that can cause fast bearing degradation?)

Keep the heli in a very humid place?

Just trying to find why it would have failed like that.

On the other hand though, you might just have got a bad one..

[Thalios]

Also, your motor might be out of balance. (removing the sticker has helped a few).

Even if stock, your head might be out of balance..

There's lots of stuff that can cause the motor shaft to wear down..

[FuntanaS]

Originally Posted by Thalios

Thanks FuntanaS.

What's the conditions of the weather? Near a water source (lake, ocean, etc that can cause fast bearing degradation?)

Keep the heli in a very humid place?

Just trying to find why it would have failed like that.

On the other hand though, you might just have got a bad one..

Well there are 10,000 lakes here in Minnesota but I am not very close to one. There aren't any oceans nearby that I know of. I always keep the heli indoors so humidity should be an issue there. On the first motor the lower bearing went bad which I assume was why it wore out.

When I took my replacement motor apart after 30 flights there wasn't any wear on the shaft and the bearing spun smoothly. The shaft was however a little bit darker where the bearing rides on it. After taking the motor apart and re-oiling it I cleaned the oil off from the bearing where it rides on the shaft with a q-tip. Maybe the oil was causing the bearing to spin on the shaft instead of turning?

[Thalios]

Originally Posted by FuntanaS

Maybe the oil was causing the bearing to spin on the shaft instead of turning?

Don't think so. Unless the bearing is too hard to turn (damaged), it should rotate with the shaft, and the shaft should be sorta snug in there.

[JohnnyV52]

Where's dribbe been on this one? I don't have 30 flights I don't think... I've oiled my bearings... If it goes out anytime soon... I won't be replacing it with eflite....

[FuntanaS]

Well yesterday I put some JB weld on the shaft. I applied some to the groove and then used a razor blade to scrape off the excess so that it was flush with the rest of the shaft. I put the motor back together and there is no play at all. I haven't been able to test it out yet but it should work just fine.

Hopefully it lasts a long time. But even if I have to do this ever 100+ flights it's not a big deal to me. Once I had the motor out and apart it probably took me 10-15 minutes to JB weld it. The JB weld took forever to dry though.

[Thalios]

Good to know FuntanaS!

Keep us updated. you might have a solution if someone wears a shaft prematurely!

[FuntanaS]

Originally Posted by Thalios

Good to know FuntanaS!

Keep us updated. you might have a solution if someone wears a shaft prematurely!

I plan to swap the motors and try it out. On a side note while I was doing a pre-flight I noticed that one of my servos had a notchy feel every time it went past a certain position. Turns out that on one of the gears like half of one tooth was missing. It had to have happened on my last crash. Which was 70+ flights ago!!!!! So I'm grounded until I get new gears.

I will for sure keep you guys posted on my results. Half the fun to me with these helicopters is tinkering and finding new ways to make things work. That's maybe why I'm going to school for mechanical engineering?

[Thalios]

haha, nice!

I make a living installing and programming giant servos and motors (I work stage automation).

I know what you mean! Messing with these is as much fun as it is flying them!

Now that i've completed my Protos 500, should i just sell it and get something else to build? i've not even flown it yet!

[2cants]

Today I removed my motor, as there was some play.

After taking the motor out - behold, completely worn shaft. Should have known the shrill noise wasn't good - just so hard to pinpoint.

Pretty gutted, as I've only had 50 flights, and since I'm beginning, it is mostly hovering, figure 8's and recently fast cirlces. Only 2 and bit months old!

As per the lubrication thread (https://www.helifreak.com/showthread.php?t=356837), I sprat the heli with silicone regularly - including the underside of the motor.

The motor bottom bearing seems to turn freely enough (used a small screw driver to turn it).

Q. Does anyone know if the motor shaft can be pressed out and replaced?

Or, a whole new motor?

Pretty dissapointed that the motor crapped out so soon.

[Mikey2]

Originally Posted by 2cants

Today I removed my motor, as there was some play.

After taking the motor out - behold, completely worn shaft. Should have known the shrill noise wasn't good - just so hard to pinpoint.

Pretty gutted, as I've only had 50 flights, and since I'm beginning, it is mostly hovering, figure 8's and recently fast cirlces. Only 2 and bit months old!

As per the lubrication thread (https://www.helifreak.com/showthread.php?t=356837), I sprat the heli with silicone regularly - including the underside of the motor.

The motor bottom bearing seems to turn freely enough (used a small screw driver to turn it).

Q. Does anyone know if the motor shaft can be pressed out and replaced?

Or, a whole new motor?

Pretty dissapointed that the motor crapped out so soon.

Knowing what I know now about the stock motors and the short lives so many are having with them, unless a guy's on a real budget, I don't know if I'd mess around in trying to repair what appears to be an already marginal design.

Although I didn't get out the calculator and go shopping, from what I can determine, there isn't that much difference in price between a stock motor and let's say an equivalent Scorpion. I might add that for comparison purposes, the ESKY brushless motor in my K3 was strong and silent for 3 years and flight after flight with nary an issue and ESKY stuff is really "bargain basement".

I think the HH tech service boys have been pretty good about chiming in here on the forum specific to other issues.............they've been very informational and helpful. They are, however, "noticably" silent with respect to what "seem" like a lot of motor issues so am guessing there's a problem with these motors. I read quite a bit here in Helifreak and with the exception of "Walkera" products, can't ever recall reading so many posts about motor issues with any one particular heli. Frankly, I'm tempted to just pull the stock motor outa my own 450 and replace it with something decent before there's any trouble.

[2cants]

3:30am hi in NZ, and I've put the heli back ready for tomorrow (if I don't sleep in in)

I think I mught have found the cause - thanks to one of the many threads and video on here).

When I took my motor out there was no circlip or washer. I simply undid the pinion and presto the motor came apart (ok - the magnets made it a little difficult).

So I guess the problem arose because no circlip. Don't know how it could have come loose - had'nt ever had a major crash (just copuple of tilt overs).

[Thalios]

To anyone that wanted to know.

Inspected my motor today. Shaft and bearings are good as new.