Re: Yaskawa Motors

dave wrote:

> From: dave <daveland@...>
>
> Hello
>
> I found several Yaskawa Robots in a local junk yard. They use ball
> screws and what I think is a
> DC servo motor. On the motor nameplate it reads:
>
> Cup Motor
> Type UGCMED-04
>
> KW KG*CM rating RPM
> V A
> ----------------------------------------
> 0.4 22.3 cont
> 1750 67 8.2
> 2.0 112 inst
> 1750 40
>
> or
>
> cup motor
> Type UGCMED-08
>
> KW KG*CM rating RPM
> V A
> -------------------------------------------
> 0.75 41.7 cont
> 1750 144 6.7
> 3.75 209 inst
> 1750 33
>
> weight 25KG
>
> These also have "feedback units" attached
>
> Feed back unit
> Model TFUE-05Zc7
>
> Pin function
> ------------
> A=channel A
> B=channel B
> C=Channel Z
> D=common
> E=+12v
> F=gnd
> G= T.G+
> H=T.G-
> I=spare
>
> Here are my questions:
>
> 1) These appear to be DC servo motors.... What is a cup motor ???

Yes, Yaskawa makes VERY fine servo motors, and the specs definitely
look like servo motors, but unless you see brushes on it, it may not be
a DC servo motor. Probably the term cup refers to the design of an
ironless rotor. I would guess they use a disc to attach a cylindrical
winding to the shaft, making the whole assembly look a bit like a
cup. Ironless motors cost a LOT more, but they have very low
inertia. In a machine tool application, the low inertia is not much
benefit, as the table presents a great deal of inertia.

>
> 2) They are a bit rusty externally, and have been outdoors for 1-2
> years. The rubber brush caps
> are intact and there is no rust underneath the caps. The shafts are
> protected by th boots covering
> the ball screws. Could they still be in good condition internally???

(Ah, brushes, answers a question from above.)
Who knows what the condition is. You could probably hook a
flashlight battery to the motors and see if they move.

> 3)The encoder has 2 quadrature channles A and B but what is channel Z?

Z is the once-per-revolution index pulse. When used in conjunction with
a home switch on the linear axis, this can allow the machine to home to
an exact encoder pulse repeatably, for maximum accuracy.

> 4) is the T.G+ and T.G- leads on the encoder a tach ???

VERY good! I wasn't sure what these were, but I think you've got
it!

> 5) Would these make a good servo motors for large CNC mill (YCM-40) ?

I don't know what sort of machine you are talking about. These motors should
do quite nicely for a Bridgeport Series I or II machine. If you can find servo
amps to support the motors up to full power, then very likely they could
run a pretty good size machine. It depends on what maximum rapid traverse
speed you want to have. Weaker motors can always be used with a belt
reduction, but that sacrifices the high speed. Also, these motors would be
best for direct drive, as I gather from your description that the feedback
units are directly connected to the motor.

If you give me some more info on the specific size of the machine you have
in mind, I should be able to be more specific in recommendations.

Jon