Replacing stepper motor on FB-357A HD drive

[storhemulen]

The read/write head does not move on this HD-drive. I guess one reason could be the stepper motor is dead. Shouldn't it be possible to replace the motor with one from an ordinary Amiga DD drive? Or even any old PC drive?

Or could there be other more or less probable reasons for the head not moving?

Any input greatly appreciated as always!

 

[rkauer]

First re-lube the drive rails, then check if the motor is receiving voltage when a disk is inserted.

If the motor receives voltage, then it's dead for sure. I think you need to take a step motor from another drive that's equal to the one you have. Look for a dead FB-357A drive.

PROBLEM (yes, a big one):

The step motor is what control the track heads position, and moving/replacing it means you have to realign the heads, which is a very hard & time-consuming job.oh::banghead:

 

[storhemulen]

Thanks rkauer. I will check for voltage before anything else. I actually have an old FB-354 and the motor looks exactly the same and also have the same model# printed on it. That drive is not fully working but the motor seems OK (the head is moving anyway).

 

[storhemulen]

Success!

I removed the motor from the non-functional FB-354 and put it in the FB-357A. I tried to put it the same angle as the broken motor, with the "slider" at the same axial position in the spiral groove on the motor axis.
Lo and behold, it worked right away! :arms

So far at least, only had time to test it in the A500 that the donor floppy came from and it booted WB 1.3 just fine. Will try it tomorrow in the A1200 to see if it can format and read HD disks as well.

Then I'll grease it up with some lithium grease and seal the screws with nail varnish. The wifes nail varnish, that is.

Only need to put grease on the motor axis, right?

 

[ddni]

Would it have been possible to leave transplant the FZ357A electrics into the FZ354 mechanics? That way removing the head alignment issue?

 

[storhemulen]

Would it have been possible to leave transplant the FZ357A electrics into the FZ354 mechanics? That way removing the head alignment issue?

I guess. But in my case the donor floppy was supected badly mis-aligned, and possibly some other fault also.

Maybe I will try to fix that one as well, using the stepper motor from a PC-floppy and then getting it aligned.

 

[cosmicfrog]

but it works \o/

 

[storhemulen]

Tiny update: The drive seems to be working perfectly now, both DD and HD.

Now the question is, should it be put as df0 or df1? If it behaves 100% as a DD drive when starting games from disk then I guess it won't really matter. Maybe I'll set it as df1 just to be sure.