Re: [CAD_CAM_EDM_DRO] Choosing stepper size

Mark,

The older round motors are now outdated. The newer square motors using the
rare earth metals are a lot better. One thing, the rotors are a lot larger
and some come with a 1/2" shaft.

I did some research and found a company that is importing motors from China.
I am now selling them. The one that I recommend has 640 oz/in and sells for
a little over $100.

In the past I have used 350 oz/in motors which sold for between $180 and
$200.

I now have three of my motors on a ShopBot CNC conversion and they are very
quiet and very fast. I am using Gecko G201 drives and they are running cool.
I can put my hand on them and they only feel warm not hot. For the next
conversion I will use the new G202 drives when they become available.



Bob Campbell
Bob@...
www.campbelldesigns.com
Breakout board
THC board sets
CNC router plans
Stepper Motors
VisualMill Basic

----- Original Message -----
From: "Mark" <mfraser@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Saturday, May 14, 2005 10:49 AM
Subject: [CAD_CAM_EDM_DRO] Choosing stepper size


> NEMA34 motors of up to 1200 or so oz-in can be had for just
> over 100.00.
>
> a 4x4 foot wood router has historically used 250-350 oz-in motors,
> and I'm wanting to build one about that size.
>
> There have been discussions about motor torque / inductance and
> speed limitations, but these seem to pre-date the availability of
> the newer hybrid motors, and I haven't found specs on the newer,
> inexpensive ones....
>
> For a given torque, is the inductance the same with the newre ones
> or lower? In other words, can I get more speed from a hybrid
> motor at the same CURRENT (more torque) as from an older motor?
> thanks / mark
>
>
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