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

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.)
>

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