Re: greetings from new member

On 13 May 99 , CAD_CAM_EDM_DRO@onelist.com entreated about
"[CAD_CAM_EDM_DRO] Digest Number 8":

Hi Dan

} Message: 7
} Date: Wed, 12 May 1999 06:18:08 -0700
} From: "Dan Mauch" <dmauch@...>
} Subject: Re: greetings from new member
}
} I can save you a lot of pain. The floppy drive motors are way to
weak. You
} will need stepper motors with a torque of at leats 60 oz inches.
That
} coupled to a fine 20 threads per inch lead screw will give you
plenty of
} power.

hmmm, I had one big one (NEMA 23 size) from one of the printers, and
was going to use it for the Z axis, but found (to my disgust) that 2
windings were burnt out. the ones I have at NEMA 17 size, not those
tiny ones on newer drives.

how does one measure torque on these things?

} If you are planning to use a those polished rods with bearing for
the X axis
} then I would suggest that you check the deflection under a load. You
will
} find that surprisingly little force cause deflections of .005-.010.

these rods are .5 inch, and about 9 inches long. a .005 deflection
(or less) will not worry me much, since that is equiv to one motor
step. bear in mind this thing will run slowly, and on soft materials
on harder materials, I'll just run it even slower... the point here
is not to make a machine to make things faster, but one to make things
I could not make without it (and without spending money, if I had
money, I'd order a Sherline or similar)

} I have built about tenty different cnc machoines so I think I can
speak with
} some authority. My first CB drill machine used kitchen cabinet ball
bearing
} draw slides. It worked fine for light duty work. See my web page at
} www.seanet.com/~dmauch for other tips and solutions.

I think I have seen it, yes I have....
for reference, the motors I'm using are the same as the one pictured
on your PCB drill, driving the Zaxis.

steam and wind

--
David Forsyth DaForce A-T Iwr.Ru.Ac.Za
Keeper of the listserver for South African Railways fans _|_ His
Part time gricer, kiter, photographer, father etc etc | Way
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