bem

My Feedback: (1)

Hi,

I flew with my MythoS 125E with Hacker A60-7XS motor this morning and I had flown about 6 or 7 flights and when I landed and took the canopy off to change battery I noticed a metal part hanging out of one of the smaller holes inmotor case. I managed to get the metal part out after a while (had to mount off the motor from fuselage first).
After more careful examination of the metal part it seems to be some washer or clip.
See images below how the metal part look like.
Total run time on the motor is about120 flights = 850 minutes or ~14 hours.

I mounted back the motor on fuselage and tested it on ground at various RPM and it ran fine. I also made a 7 min flight and it was fine.
The metal part obviously is inside the motor for a reason but since I do not have an exploded view of Hacker A60-7XS I do not know where the metal part (washer/clip) is mounted and if it would be stupid to run the motor without it.
http://www.hacker-motor-shop.com/e-v...&t=3&c=32&p=32
I have e-mailed Hacker support earlier todaybut got no answer (maybe on Monday).

Anyonedisassembled a Hacker motor that know what purpose the metal part has and if it might be OK to run the motor without it (for a limited time)?
It is competition next week so I will not be able to repair the motor before that. I might be able to buy a new motor and get it shipped to me in time but I'm willing to take a chance with my current motor if it would be OK to run it maybe 10 flight (some more practice flightsand 4 competition flights).

And advice or if someone know what the metal part is for?

/Bo

Dansy

My Feedback: (53)

Have you try Aero-model? They have a service center for hacker, I would just call them....

flyboy91

My Feedback: (1)

I went and took an A60-6xs apart and it looks like its the spacer between the windings and the bell. I would probably see if you can find a washer to replace this. Mine was 12x8x.3

Andrew

bem

My Feedback: (1)

Hi
I bought the motor directly from Hacker in Germany so I e-mailed then yesterday (they had closed the telephone support already at lunch so it was to late to phone them).
I live in Sweden by the way.

I measured the spacer and it was 38 millimeter long (I formed a leadwire to same shape on top of the spacer and then straighten the wire and measured it) so I could calculate the diamter:

38 diveded by 3.14 (Pi) is about 12 mm.
With of spacer is 1.6 mm
Inner diameter would be about1.6 x 2= 8.8 mm
So my measurment is about in the neighbourhood of the spacer that Andrew have in his A60-6XS.

Thickness of spacer is 0.8 mm so that isabout same as 0.3 inch that Andrew measured on his spacer.

But one thing I find strange on my spacer is the it has rounded ends so it seems not to to have been a closed spacer. More like a clip?
See image below.
What do You think about the ends of my spacer, how can they be rounded?

And I can not understand how the spacer was able to get out of the original place between the windings and bell - it should be impossible?

Andrew: thanks a million for taking time to take a part Your A60-6XS to check what wasinside!

And Andrew -to run my motor as it i now without the spacer - what is purpose of the spacer as You understand it and what might happen to run without the spacer? Would the windings come dangerous close to front of bell so risk for windings to ge damaged without the spacer?
It is no play forward and back on drive shaft as it is now without the spacer. It is 1 millimeter / 0.4 inchspace now on my motor between bell and backplate.

What tools do one need to get an A60 apart (to get the bell of)? - can You give a brief step by step instructions how You do it?

/Bo

rm

My Feedback: (27)

I have no idea what it is, but some motors use a c-clip to hold the bell in place.

FinnSpeed

If you want to remove the bell, it looks like all you need to do is to remove the hex screw from the back end of the shaft. Then the bell will come out (but the magnets will resist, be careful). So no grub screws or clips in this motor, just like the O.S. brushless.

To me that part looks like it doesn't even belong in the motor. The washer in the other Hacker looks too different. I'd certainly open the motor and check for any damage inside. Also check that the necessary washers are in place. I suppose they are if there is no extra play.

bem

My Feedback: (1)

Hi,

I agree FinnSpeed that the metal "thing" seems to not belong in the motor. But its has similar dimension as the spacer that Andrew has in his A60-6XS.

I tested the metal part with a magnet today and it was attracted to the manget so it is not aluminium.

Maybe it is just a "foreign object" that somehow has got into the motor (and been stuck there by the magnets?).

Do I need a puller to get the bell of or should it be possible to pull it off by hand force?

/Bo

bem

My Feedback: (1)

Hi,

OK guys, I have zoomed in to the pictures that Andrew took of inside his A60-6XS and I think I have found the metal part and where it is mounted.

It seems to be the clip that is on the outside of bearing on the part that carry the windings (the stator), see my zommed in picture below.
Notice the rounded end of the clip, just like on my clip.

So what is the purpose of that clip?

Can I safely run the motor without the clip, at least for maybe 10 more flights?

That clip is obviously not safe, at least not in my motor since it came loose by itself.
A clip like that that come loose can damage the windings for sure.

/Bo

bem

My Feedback: (1)

OK, I took my Hacker A60-7XS apart now and the clip was missing on the stator.
Images below is on my own A60-7XS.

The windings had got some beating but no copper wire is broken, I examined them with a magnifying glass.

I have got some advice to just brush on some protective varnish on the copper wires that has some chafe on it.

I'm thinking of mounting a more ordinary black lock ring for axel- retaining ring(see image below for an example) on the motor instead of the type that Hacker use as standard.
I think it would be safer since it would be harder for such ring to come off.
Good or bad idea?

The slot in the black part on the stator where the clip is suppose to be is 17.40 millimeter diameter (and the original clip is 1.6 mm wide and 0.8 mm thick) so I will se if I can find ablack lock ring for axel with thatinner diameter, width andthickness.

/Bo

bem

My Feedback: (1)

Hi,

I sat down and have been thinking.
Why not reuse the old Hacker clip and after reshape to original shape use glue over the clip efter it is mounted back?
I managed to get back the shape of old clip rather good. Cleaned all surfacec with acetone and then mounted back the clip.
Then I know from past experience that Loctite Power Glue Extreme Repair is good - flexible, strong, handle vibration good and can handle temperatures between -50 to +120 deg celsius (-58 F to +248 F) and bond good to metal and various other materials. So that was the glue I used to make sure the clip will not be able to jump out of the notch.
I hope this will be enough and will last the life of the motor. Maybe I will mount a new clip later.

/Bo

Dansy

My Feedback: (53)

How long you had this motor?

Me I would have send it for repair......cost less then a plane and a new motor.....

bem

My Feedback: (1)

I bouht it from Hacker in Germany in April 2013. It is under warranty but it is competition now so I have to do what I can with the short time I have.
Sure I would send it in if it was another situation.
I just have to do the best I can now.
I will testfly tomorrow if weather permit.
If the motor should fail in flight it is not so much problem, the radio will work and plane will fly anyway,a landing on field should be possible in most cases.
Maybe I should get a spare motor (it is another 229 Euro / US $300) but my experience of brushless motors (I have only used Hacker motors in larger planes) is that thay are very reliable.
And I had 14 hours total run time (in flight) on my A60-7XS before it happened.

Why the clip came loose from it's notch during flight in the firstplace I suppose we will not be able to know unless more A60-7XS get same problem and then it should be design problem that Hacker have to solve.
I just can not undrestand what could cause the clip to come of the mounting notch - the stator part is just sitting there static, if t was a rotation part or someting that vibrate It could be a cause but nothing of that is the case here.

/Bo

bem

My Feedback: (1)

Hi,
Motor assembled and mounted in the model again, ready to fly again tomorrow.

/Bo

chuckk2

Please tell us how it went after the repair! Did the motor stay together?

Sessholvlaru

So your motor barfs out a piece of metal and you take it up for a flight without dissembling it first? Incredible.

fred985

many years ago i learned all about c-clips, retainer clips, small retainer springs etc,,they are known as JESUS clips. they usually goig BOING !! and disapare at supersonic speed to never be seen agin. so you say "where did that JESUS thing go and then treck of to the auto parts store trying to find another one that dosent exist because the one that went POING ! was the only one to exist in the entire world. this said, since your motor runs fine without it my sdvice is to fly it and go for broke with the competition !!!!! hell, i buy lotto tiks every week and hope i win,,,take your chance and maybe you will be surprised and win. by the way, my mom came over on the gripsholm from your area in 1917,,,,the sistership to the gripsholm is the stockholm which dam near cut the adriadoria in half and sent her to a watery grave dot far from block island ,,,both the ships are still going strong albet entirely new topsides. you blokes from the great frozen nort sure build tough ships. you should be able to handle a crummy out of place JESUS clip.

FinnSpeed

I hope the motor stays together! You'll be probably competing against my flying buddies in the F3A Nordic Championships, right?

While I don't fully understand the function of such a clip in that position, it sure looks like the bearing assembly is removable. The clip may have something to do with that. However, when the motor is fully assembled, the bearings cannot come out even if the clip is missing. Maybe they could move a bit but most probably will not cause a catastrophic failure.

I'd send the pictures you took to Hacker and ask for advice after the competition. I hope they understand that you had to make it work with a quick fix and won't void the warranty.

bem

My Feedback: (1)

I ran it on ground first. Then made one testflight.
My motor, my decision, nobody to blame but me if anything had happend to the motor.
I have reparied the motor with original clip now as You can read above, andwith some glue on the clip so it should not come loose again.
That is all I can do for now.
If the "repair" will not hold and motor fail we can have this thread as an example how not to do a repair and as an example of poor judgement.
If the motor will work today (plan to fly at least 10 flights) I see no reason it would not hold another 10 flights.
In retrospect I should have had a new spare motor but since I do not have that I do as best I can with what I have.
/Bo

bem

My Feedback: (1)

Yes.
(That is why I is kind of a hurry, and want to practice some more also before I go there).
/Bo

bem

My Feedback: (1)

It was luck that the clip was hanging out of one of the holes in the motor after the flight so I could see it. Suppose the clip had just flown out and disappeared and then I had never known the clip was missing in the motor.

/Bo

nonstoprc

My Feedback: (90)

It looks like the repair is sound, assume the glue can hold well under motor's operating condition. I would think if a permanent fix is sought, JB-weld can be used which can withstand up to 550ºF.

lopflyers

My Feedback: (12)

100% w you Ben. Now go fly and I hope you win the competition,

bem

My Feedback: (1)

Hi,
I'm back - after10 flights and motor runs like it used to before. I have drawn my conclusion from that, other may draw their own.
When I arrived at the field rain was pouring but I sat in the car (took a nap for about 1 hour) and sky cleared up.
Last flight was in light rain as rain started again on my 10th flight.

/Bo

bem

My Feedback: (1)

Hi,

Competition went well. Motor ran fine (6 more practice flights the day before competition and 4 rounds in competition).
So it has total 20 flights (20 x 7 minutes= 2 hours and 20 min runtime) since "repair".
I came 7th in my class, Nordic class(and I was also part of my country national teamthat took 2nd place).

In my opinion a MythoS 125E can be competitive in FAI Advanced class - the class Nordic, N-13,I'm competing in is
basically Advanced schedule A-12 with just some slight modifications.
MythoS 125Ecan withoutdoubt fly P-13 schedule also with OK results I'm sure.

/Bo