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Old Jun 23, 2014, 06:21 PM
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FMS BBD 1450mm ARF - FMS Motor Issues

I purchased an FMS 1450 BBD and the gold PAEP 4250-540kv motor that came with was bad so the shop I bought it from replaced it.

They were kind enough to replace is with an FMS gold PAEP 4250-580kv (which as it turns out is the exact same dimensions), but after two flights with it a magnet slipped in the cylinder so it was again replaced by the shop. So I'm now on my 2nd FMS 4250-580kv motor, I get it rewired etc, take it on two flights and it also throws a magnet... The tell tail sequence of events is the plane starts making a rattling noise & starts loosing power.

The shop I purchased it from happened to send me 2 replacements by accident for the first 4250-580kv that went bad (lucky for me), so I have a 3rd to try, but concerned it'll just throw a magnet too.

I did take apart the first 4250-580kv replacement after it threw a magnet and the magnets had definitely shifted out of their slots and it's clear they are not glued in place. I'm thinking I should just glue the magnets in place and keep using the motor, but wondering if I should just go buy a quality motor.

Anyone else having FMS PAEP 4250-580kv issues?

Anyone know a top quality motor that'll fit properly in this plane?

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Old Jul 03, 2014, 12:10 AM
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I sent back the 540kv (bad bearing) and the other two 580kv motors (bad magnets). So the 3rd PAEP 4250-580kv threw some magnets...

This time the shop I received the replacements from were very suspicious that I was causing this issue stating it was "unprecedented" in the number of failures. They then told me they would not send me another 580kv, that 540kv was what the model came with (even though they sell the 580kv as an upgrade). I told them if they had a bad batch of 580kv motors lets just want for another shipment, but they refused to guarantee me this replacement and told me to ship back the last 580kv motor for replacement. So let me get this straight. I get used to flying the model on a 580kv, it fails consistently on the 2nd flight for 3 580kv motors, but now you want me to fly a 540kv? What so I buy a 580kv for $38??? I then learn that some people repair their own motors, so I suggest I'll just keep the last 580kv and fix it and I then get an email that this part and all liability are mine since I've repaired the motor myself. Well GEE it's not like we're not repairing and modeling every single model we ever receive, what's their point... I'd prefer a properly constructed new motor... but downgrading me isn't an acceptable option.

So I took apart the last 580kv and every single magnet but 1 was not cemented in place. I re-glued them all back (including the one that was still attached) with quality metal to metal epoxy which will endure up 300 degrees F. I guess I need to start gluing my own magnets now...

I've refrained from publically stating who the distributor is, but it's a shame they're giving a good customer a hard time over a $38 motor that keeps failing. It's not the distributor's fault the part keeps failing, but treating me like I'm the problem is the distributors fault. First they make me happy by giving me a free upgrade, then when the upgrade is faulty they tell me they're not willing to honor it further.

I'll say this, the batteries I am using are larger than the 4s 3600mah spec'd for the model, they are a 4s 4000mah (Shock Value 30c) and a 4s 5000mah (Turnigy Nano-tech 35c-70c). I am curious to know if the larger size can cause motor failure.
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Last edited by Undermoose; Jul 03, 2014 at 12:15 AM.
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Old Jul 04, 2014, 12:07 AM
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FMS P51 1450mm V8 BBD back ready to fly. RPM tested the motor via Spektrum Telemetry on 4s battery without prop and it made +/-10150 rpm, right on target for my baseline I'd done prior ever flying a 580kv. Looks like the magnet re-glue works, but the real test will be under load Saturday morning.
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Old Jul 04, 2014, 02:20 AM
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Prop tested, no significant shudder / wobble, seems to be still reasonably balanced.

So it is possible to reseat magnets
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Old Aug 24, 2014, 09:04 PM
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the same here

I have got the same problem as you did.

I have bought the same plane (P51 BBD) from (I start to believe) the same online store. The only difference is that I am flying Admiral 4S 3600 mAh batteries. I have got TWO 580 motors fail the same way: at their second flight I heard a rattling noise, checked it out and magnets were displaced. Again, the same story: when the first 580 motor broke, the store sent me a replacement but notify me that it was the last time! They were not going to support this motor as it is not the stock motor that the FMS P51 comes with. I know ... the 580 is on their website's upgrade list

It is now obvious to me that the 580 batch this supplier has got is bad. I am glad I found your post because before I had started to believe it was my ESC's timing set wrong. I have a Castle Creations 100A ESC...again, ordered from the store's website "upgrade"list. So it is clear it is not the ESC...

So how is you repaired 580 motor holding up? What glue would be best to re-glue the magnets? Is CA good enough?

Cheers!

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Originally Posted by Undermoose View Post
Prop tested, no significant shudder / wobble, seems to be still reasonably balanced.

So it is possible to reseat magnets
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Old Aug 26, 2014, 04:33 PM
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Interesting. I got the Petie 2nd with the same motor just after 4th of july and I did the 1mm zip tie mod and flew it once. I felt it needed more power so I upped the timing on the ESC. 2 more times out and all the magnets came loose. I pulled it apart and ca'ed them back in place and wrote Motion about it who graciously said they would replace it if I sent it in. I did fly it once with the ca'ed magnets without issue and then pulled it and sent it in. Since they were out of stock I didn't get a replacement until last week. Interesting there is a red version of the motor available from Hobby King for $20. I put it in and haven't had any issues so far from the HK motor.
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Old Aug 26, 2014, 04:42 PM
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okay, I have managed to glue the magnets back in (what an ordeal!!). I used a 300 degrees F rated metal-to-metal Epoxy glue. The plane is now ready to fly. I just wonder whether I should leave the Castle Creations Phoenix ESC timing advance on "medium" (default) as I have had it set to or I should downgrade it to "low".
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Last edited by scoris; Aug 26, 2014 at 04:48 PM.
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Old Aug 26, 2014, 05:01 PM
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I tried a 100a Castle Edge Lite and it acted like high timing when on standard timing (hotter motor). I put the original FMS ESC back in.
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