Re:305oz Steppers! More torque, CNCresource laboratory??

Hello,

Lab results show up in our products. We have never sold a controller
or motor without ALSO "talkng" with the customer about his or her
needs and planned use(s). FWIW, additional info is in the site
architecture, without direct links. When warranted, those links are
shared.

It's also true that to provide really meaningful torque curves for
every motor/drive combination is a HUGE task. MORE importantly, the
curve for a drive which "seems" just like the one you have may not
be AT ALL like the one you may find posted somewhere.

Even drives using the exact same driver chip at the same power
supply voltage can have important differences.

Most is science, but there is still some "art" in making good DIY-
CNC decisions. Experience is not always easily put to paper.

Ballendo

--- In CAD_CAM_EDM_DRO@yahoogroups.com, R Rogers <rogersmach@...>
wrote:

>
> Phil,
>
> One of the reasons, many graphs don't exist for steppers is that

they aren't very encouraging when contemplating their use.

>
> Speed torque graphs for servos are plentiful. Almost every

seller makes them very available. When compared to stepper graphs,
the servos are the obvious choice. Having said all that, nothing
wrong with steppers. As long as they are implemented properly and
within their capability. If one designs a system with reduction and
high RPMs are expected from the step motor, they'll more than likely
be disappointed if torque is neccesary with the speed.

>
> Here's a page that explains it in greater detail.
>
> http://www.dynatorch.com/stepper.htm
>
> I was hoping Ballendo after doing testing of various drives and

motors in CNCresource' laboratory, would post his findings. Seems
odd that after all the testing nothing was even posted at their
site. Not even for their own motors or drives. Seems this would be
real deal makers for some.

>
> Ron
>
>
> Philip Burman <philip.burman@...> wrote:
> AS a novice I don't understand, with torque/speed curves

being so

> important, why is it that curves are so very often difficult to

find

> or apparently none existent. For example the cncresource web site
> doesn't have a curve for the stepper motor it offers as far as I

can

> find and the Keling site has very few. This seems to be the same

for

> so many sites selling stepper motors. No wonder us novices think

the

> holding torque is the only important criteria.
>
> Also I can't find either of the two listed motors on the

cncresource

> and the one stepper listed doen't even quote the holding torque.
>
> Am I going crazy or have I missed something.
>
> Regards
> Phil
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "ballendo" <ballendo@>
> wrote:
>
> > How FAR down, and how FAST the torque drops, and along

what "shape"

> > or "Curve" depends upon some things about the motor, AND some
> things
> > about the drive and power supply...................
>
> > So let's look at the numbers for the Motors Keling sells as

having

> > the specs listed on Daves HCNC website. (Where the new 305

oz.in.

> > motors are listed as 6v,2.0A) Here are links to both 305's and

the

> > 200's as formerly sold by hobbyCNC (and still available from
> > http://www.cncresource.com ):
> >
> > http://www.kelinginc.net/KL23H286-20-08B.pdf (2.15Nm, 305 oz.in.)
> >
> > http://www.kelinginc.net/KL23H276-30-8B.pdf (1.4 Nm, 200 oz.in.)
> >
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>