Author Topic: AXI 5325/24 Bearings  (Read 381 times)

Offline Graham Stephens

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AXI 5325/24 Bearings
« on: 07, November 2017, 08:56:07 PM »
Hi,
Has anyone had to change the bearings on an AXI 5325/24?  If so, can you tell me what they are?
Are there any particular problems associated with stripping and re-assembling this motor?
Mine sounds as though a bearing is breaking up and I would like to get hold of a new set of bearings before I strip the motor down.
Thanks in advance.
Graham

Offline Stuart Mellor

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Re: AXI 5325/24 Bearings
« Reply #1 on: 08, November 2017, 04:01:48 PM »

Hi Graham,
I know this won't be terribly helpful... I was faced with a similar problem recently - in that I thought the back bearing on my AXI was grumbling. Initial strip of the motor is easy... Remove the circlip with circlip pliers. Then the motor can then be pulled apart. You can use brute force but better is to use a machine mart battery terminal puller. This also fits a YS!
Then once apart -insert the shaft into each bearing in turn & spin the case. Keep your fingers out of the way! in case it snaps shut.
In my case, there was a small piece of metal stuck to the magnets, making an awful noise. The bearing test did indicate though, a slight roughness in 1 bearing, but having made enquiries though Electric Wingman - he said bearing replacement is not for the faint hearted - but he could get the bearings. Don't know how the bearings are fastened in but just look like ordinary shielded bearings - 8mm inner, 6mm thick (forgot the outer).
I know someone who sent back his motor to Axi for bearing replacement & it was then remarkably cheap.


regards


Stuart
« Last Edit: 08, November 2017, 07:57:41 PM by Stuart Mellor »

Offline Graham Stephens

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Re: AXI 5325/24 Bearings
« Reply #2 on: 08, November 2017, 09:16:28 PM »
Thanks Stuart.
Graham

Offline Graham Stephens

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Re: AXI 5325/24 Bearings
« Reply #3 on: 12, November 2017, 03:32:03 PM »
Hi Stuart,

I just thought I would give you an update.

I stripped the motor and the bearings were as follows:

Front - one 698Z 8x19x6mm shielded deep groove ball bearing

Rear - two 688Z 8x16x5mm shielded deep groove ball bearing.

Simply Bearings Ltd delivered replacements in about 20 hours.

I was able to drift the old bearings out quite easily.

There was a further problem which I discovered which was that the magnets had been rubbing against the stator laminations in a couple of places.

Arnie Mansell kindly made up a tool for pressing the new bearings into the housings and after some head scratching, we discovered that the cylindrical part of the rotor had moved slightly on the rotating end cap.  We have secured it again and the motor now runs much more sweetly.

For anyone contemplating replacing the bearings in one of these motors, it's not that difficult at all.

regards,
Graham.

Offline Stuart Mellor

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Re: AXI 5325/24 Bearings
« Reply #4 on: 12, November 2017, 06:42:38 PM »

Hi Graham,
Good info!  How did the insertion tool work?


Also - did you mean the end cap had come loose? I can remember trying to undo an end cap once - it was way too tight!




Offline Graham Stephens

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Re: AXI 5325/24 Bearings
« Reply #5 on: 12, November 2017, 08:30:10 PM »
Hi Stuart,

The insertion tool was a short length of bar stock turned down to 19mm at one end and 16mm at the other with the faces made concave so that they would press on the bearing outer without causing damage by pressing on the inner.
The whole lot was then pressed together in a vice, pressing the bearings into their housings.

Looking at the attached photo, the arrows show the two parts that had separated slightly allowing the magnets to rub against the stator.
Arnie had an old motor with a defective winding from which we had intended to swop the rotor for mine.  However, he had cut the output shaft off short and so we needed to remove the cap and spindle.  Like you we found that this was too difficult.  The screws would not come out and even when we drilled out the heads, we could not remove the shanks of the screws.

Offline Adrian Mansell

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Re: AXI 5325/24 Bearings
« Reply #6 on: 13, November 2017, 09:53:22 PM »
Hey Stuart! Have you noticed it getting dark early yet?


Graham has provided a good description.  Not sure why Paul @ electricwingman thought swapping the bearings was a pain, they are a straight interference fit and easily drifted out and new ones pressed in as Graham described.


I'd love to know what the shaft retaining bolts are put in with.  We tried a good fitting allen key followed by a real whack with an impact driver - no good.  Drilling the heads off got the shaft out but the shanks are stuck tight.  I drove a torx bit into a drilled out shank which bit tight enough for me apply enough force to snap it off!  Can't really try heat due to not wanting to knacker the magnets.  If we get desparate I'll have to drill them out completely and retap to M3.5 or M4.




Offline Phil Lewis

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Re: AXI 5325/24 Bearings
« Reply #7 on: 13, November 2017, 11:18:27 PM »

Hi Adrian,


I seem to be the club repair man and have done many AXI's but mostly the smaller ones so can answer your question, it's called thread lock, as you say you need a really good quality allen driver which turns into a fight, a couple of times I thought the driver had broke but luckily it was the thread lock giving in.


They appear to be the only make that does this I haven't come across any others, why they feel the need I haven't a clue.


Just a thought, maybe it is to protect their oversize bearings (oversize from what  :D ).


Phil

Offline Ashley Hoyland

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Re: AXI 5325/24 Bearings
« Reply #8 on: 14, November 2017, 08:25:51 AM »

Just a thought and I know nothing about the access to these screws in the AXI. 


Would it not be possible to rest a soldering iron on top of the screw head to transfer heat to the problem area (glue on the threads) without too much heat getting to the heat sensitive part of the motor.


Ashley

Offline Stuart Mellor

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Re: AXI 5325/24 Bearings
« Reply #9 on: 14, November 2017, 04:27:52 PM »



Hi Adrian, Ashley,
Yes, I've noticed it getting dark - so I've swapped my sunglasses for a lighter shade! ( Makes an hours difference)


Re the Axi - one thing's for certain - Axi never intended the shaft/rotor to be separated! Its not locktite, probably a bearing fit or similar - but you will never undo them. I reckon the assembly is probably located on a jig, fastened in & that's game over. Probably makes sense, since the last thing a user wants is the rotor rubbing or worse & there would be no point in separating the two for normal maintenance.


Adrian, - now you've sorted that! I've got a problem with my Align outrunner helicopter motor. I need to strip it - but how. It differs from the Axi in that there is no circlip -instead there is a collar on the shaft (probably pressed on). The end cap looks like it should be removable - there are 2 grub screws, which are easily removable  - but the end cap won't shift - so don't know what to do next. The distributers can't help & seen nothing on t'internet. I've tried some force, but nothing shifting - it looks like the end cap should come off & the stator pulled out from the shaft end.


regards


Stuart


ps - attached photos of generic motor - not actual one,




« Last Edit: 15, November 2017, 06:45:28 PM by Stuart Mellor »

Offline Stuart Mellor

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Re: AXI 5325/24 Bearings
« Reply #10 on: 15, November 2017, 07:02:38 PM »

Found the video! - easy when you know how.


Undo the grub screw - tap the shaft through. Pull apart. Just got to do it now!

Offline Stuart Mellor

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Re: AXI 5325/24 Bearings
« Reply #11 on: 16, November 2017, 08:09:53 PM »
See separate post -Align motor strip 2