Re: capstan motor in reversed direction


Thanks alot Arfa.
Great tutorial!

Richard


Arfa Daily Wrote:
> "range_hood" range_hood.20dyag@xxxxxxxxxxxxx wrote in message
> news:range_hood.20dyag@xxxxxxxxxxxxxxxx
>
> Stein-Olav Lund Wrote:
> Arfa Daily wrote:
>
> "range_hood" range_hood.20b6ag@xxxxxxxxxxxxx wrote in message
> news:range_hood.20b6ag@xxxxxxxxxxxxxxxx
>
> Hello there,
>
> got a track recorder (tascam 488) with a dead capstan motor (mabuchi
> EG-530KD-2B). Looked for replacement and contacted the service here
> in
> Vienna - still waiting for response. In America they go for about 18
> U$
> on the official service departments, so I imagine here in europe they
> go
> for more.
>
> Looked on ebay and found the same motor (EG-530KD-2F) with just one
> difference - the direction, it goes clockwise.The ebay price is ?2,
> including the shipping I could get two additional spare motors for
> the
> same money the service would take.
>
> My question: Will there be problems, if I just reverse the plus and
> minus poles to drive this unit counter clock wise? Specs and
> dimensions
> are the same.
> It has 4 pins (A B + -), do I have to change A and B too?
>
> Thanks in advance
> Richard
>
>
> --
> range_hood
>
>
> If this is the standard Mitsumi type motor, ( and looking at a
> picture
> of it
> on the web, it is ) which has AB+ and - all on a small piece of PCB
> material
> sticking out from the back of the motor, then the simple answer is
> no,
> you
> cannot reverse the motor by simply reversing the + and - connections.
>
> Inside the motor is an IC based speed governor circuit, which must
> have the
> supply voltage connected the right way round to it. A and B go out to
> the hi
> and lo speed adjustment circuit ( for normal and dub speeds ) which
> with
> this type of motor, usually comprises externally mounted pots.
>
> It / is / possible to reverse the direction of such motors, and I
> have done
> it on many occasions when I have not had the correct direction in
> stock.
> However, doing so involves prying off the motor rear cover, cutting
> the
> print tracks to the actual motor pins, and rewiring the opposite way
> about
> using thin rework wire. The governor circuit then continues to
> receive
> correct polarity DC, whilst the polarity of the drive to the motor
> proper,
> is reversed.
>
> However, as far as I can see, this is an absolutely standard CCW 12v
> dual
> speed cassette motor, and many general component suppliers stock
> generic
> pattern replacements for these motor types.
>
> Arfa
>
> One other thing is the brushes are offset to make lower friction in
> the
> direction of rotation.
> If you reverse the rotation, the motor's brushes and commutator wear
> off
> real fast---I have tried it!
>
>
> Stein
>
>
>
>
> Thanks alot for your input Arfa Daily, Franc Zabkar, Stein-Olav Lund.
>
> I decided to support the local area service this time. The motor
> costs
> about ?15 there. Sidenote: They are the one and only afaik here in
> Vienna (aut) to sell Minidisc Data (MD-Data) for ~?15.
> (http://ourworld.compuserve.com/Homepages/hanten/).
>
> Anyway, next time I'gonna try to get it elsewhere. Generic pattern
> replacements for this motor are hard to come by in my area, so I'm
> going to try to reverse an CW one. Even with a halved lifetime caused
> by increased friction of the wear parts it would be economical.
> Stein,
> have you tried this on a comparable motor (capstan unit)?
>
> Could you please give me a hint where to cut and resolder?
> Sorry, I do not own a digital camera.
> [image: http://img378.imageshack.us/img378/3357/tascam61qu.jpg]
> http://img378.imageshack.us/img378/3357/tascam61qu.jpg (picture is
> 16k)
>
> Thanks again
> Richard
>
>
> http://www.diybanter.com/showthread.php?p=1082374#post1082374
>
>
> --
> range_hood
>
> You will need a small flat blade screwdriver for a start. Insert it in
> the
> gap between the small connector PCB and the motor back plate, then
> twist
> VERY gently, being careful not to break off the PCB stub. Once the
> regulator
> PCB is exposed, you should be able to quickly spot the two motor
> connections. From your photos, I guess that you've already managed to
> get
> the back off. The motor pins are at 2 o'clock and 8 o'clock.
>
> Remove all traces of solder from around them using a solder sucker or
> solder
> wick, until you have nice flat print surrounding the motor pins.
>
> Now, using a fine, sharp modeller's scalpel, you must isolate each
> motor pin
> pad from the surrounding print. Make sure that if connections approach
> the
> pad from two sides at once ( and I seem to remember that at one of the
> connections, they usually do ) that the print between the two
> approaching
> tracks, stays joined together, or gets reconnected together when you
> rewire.
>
> Once you have cut around the motor pins, it is a simple job to
> crosswire the
> print back to the motor pins ie print pad ' x ' formerly connected to
> motor
> pin ' x ' now gets connected to motor pin ' y ' , and print pad ' y '
> formerly connected to motor pin ' y ' now gets connected to motor pin '
> x '.
>
> It's probably easier to do than describe.
>
> Once you have got it all done, you can usually even refit the motor
> back
> cover if you're careful.
> Position it correctly, then either tap it back in with a heavy pair of
> pliers or similar, or carefully press it back in using a vice and a
> block of
> wood with a hole drilled in, to protect the motor shaft.
>
> Incidentally, if the original motor has a heat interference fit brass
> pulley, rather than a plastic one, this is easily removed and fitted to
> the
> replacement motor, by heating the pulley with a small blowtorch whilst
> holding it with a fine pair of pliers. When the pulley gets hot enough,
> the
> motor will drop out of it by gravity. You then have about 15 seconds
> to
> position the pulley on the replacement motor shaft, before it cools
> enough
> to re-establish a shrink fit.
>
> Arfa


--
range_hood
.

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