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?
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.
On Mon, 19 Dec 2005 21:51:06 +0000, range_hood put finger to keyboard and composed:
Over here the trade price is AU$9 (= 5.6 euro).
If it were that easy, then why would there be (F)orward and (B)ackward versions of the same motor? Have you ever seen a left handed screwdriver? ;-)
Joking aside, these motors use electronic speed control, so reversing the supply could damage the built-in regulator. If your motor lends itself to disassembly, then I suppose you could reverse the motor wires at the regulator PCB. However, I suspect the motor's housing is probably a "crimp" type.
A & B are used for setting the speeds in a dual speed machine. FYI, yours is a 1600/3200 RPM motor.
See
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and
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- Franc Zabkar
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Please remove one 'i' from my address when replying by email.
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!
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.
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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:
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.
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