DC Treadmill motor for servo?

In response to below...
1. Agree with the brush observations - this is an issue that becomes
serious
when brushes are worn-in; it's wear that creates the bad angles. Result
can
be a chunk of brush material chipping off when reversing (sharp edge
catches
a commutator groove) and doing damage.

2. Don't agree with lumpy operation statement for "real" DC motors and
controllers. The earlier-available GE units were, like the early
Sherline
motors, triac-based (or whatever) and had badly reduced torque at lower
speeds. The more modern, pulse-width type of controllers (new Sherline,

more recent treadmill) such as the KB Electronics units, provide
excellent torque and speed uniformity across a broad range of speeds.

Further to that, I suspect a belt reduction arrangement would be best to
get
speeds down into a better range than would be possible with direct
spindle
drive; encoder on the spindle.

Let's put it this way: I have all items in a box under the bench, and a
99.00
gecko will likely give me a lot better bang for the buck than, for
example,
200-300 for a 600 oz-in stepper and driver.

Thanks to all who replied / mark



mark wrote:

> Have a couple of the Permanent Magnet type, and some of the Electronic

> Goldmine encoders..... How would these go together with a Gecko 3XX?

Jon Elson wrote:
Note that some motors are not good as servo motors. They don't like to
run backwards (due to brush angle or shift) or they may have 'lumpy'
output at low speeds. For something like this, you have to test it to
know for sure.

Jon