Situation re Stepper Motors - Bryce??

[GeoffB17]

Hello all,

Bryce - any clues yet regarding the situation re the Stepper Motor problem for the 3" drives.

I don't know how many you've repaired so far?  Any indications regarding specific causes (age, use, environment), are there any variations in the degree of deterioration of the rubber?

Should we assume that ALL drives are going to suffer this problem?   Eventually?  Or are there batches of production that seem to be less troubled than others.

My drive was about 30 years old when it went.  Do others seem to be about that age too.

I accept that you're more concerned (or have been) in the fixing rather than the statistics.  However, it would be interesting to know any indications.

Any hints about anyone in the UK (i.e. NOT in the EU) that has been able to do the same fix as you've been doing.

Geoff

[Bryce]

Hi,
    nope I've never done any statistics on it (40% of me would love to be better in statistics, but the other 73% doesn't really care ).

I'm not sure if there are any factors that would cause this failure to happen faster, slower or not at all. It's most likely just the age of the nylon bushing. Similar bushings on other devices are known to fail regularly too. As for rubber parts, they will all eventually fail, rubber doesn't last for ever.

Bryce.

[GeoffB17]

Oh, are you saying that this problem is really to do with the failure of the nylon brushing, rather than the rubber thing turning to goo?   I understood at the time that you suggested that the rubber thing wasn't doing much, and I believe that your repair did not replace the rubber thing, is that so?

Could the rubber turn to goo, and the stepper motor continue to work, if the brushing did not crack (and so lose grip on the shaft)?

Geoff

[Bryce]

Oh, are you saying that this problem is really to do with the failure of the nylon brushing, rather than the rubber thing turning to goo?  I understood at the time that you suggested that the rubber thing wasn't doing much, and I believe that your repair did not replace the rubber thing, is that so?

Could the rubber turn to goo, and the stepper motor continue to work, if the brushing did not crack (and so lose grip on the shaft)?

Geoff

My guess is that the rubber has already turned to goo in most drives, but they continue working.

Bryce.

[GeoffB17]

That's good news, I guess.

The thought that yes, the rubber rot would be inevitable, and soon, was bad news.   If this alone is not necessarily fatal, then that's not so bad.  The nylon part may well be doomed too, but maybe this will be much more dependant on use factors?

Geoff

[SerErris]

Normally the nylon part is great after you cleaned of the rubber gump.

[GeoffB17]

Hm?

I don't know what happened with the other drives that Bryce has repaired, but in my drive, the nylon 'brush' - actually more a sleeve - had cracked along it's length, so it no longer gripped the shaft enough to operate properly.  Bryce glued the nylon part, so that it did grip the shaft again sufficiently to work again.  My drive is still working fine, 4 or 5 years (?) later.  I thought at the time that he'd glued the nylon part TO the shaft, but now I understand that this is not so. 

Geoff

[bene78]

Hello,

Are you talking about the EME-150A drives right?
Did you manage to disassemble the motor and see where the fault is? Are there photos of the process or of the piece that wears out?

I've searched the forum but I can't find a related post, only one that you talked about the bug but it's from 2017.

https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/the-end-of-the-eme-150a/msg140452/#msg140452

[Bryce]

Hello,

Are you talking about the EME-150A drives right?
Did you manage to disassemble the motor and see where the fault is? Are there photos of the process or of the piece that wears out?

I've searched the forum but I can't find a related post, only one that you talked about the bug but it's from 2017.

https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/the-end-of-the-eme-150a/msg140452/#msg140452

No, the drives with this problem are the non EME-150A drives (Thread with pics here: https://www.cpcwiki.eu/forum/amstrad-cpc-hardware/eme-156-mechanics/ ). The EME-150A has a different motor and different issue that I at least have never found a solution to repair them.

Bryce.

[bene78]

Ok. Thanks.