Quick servo vs stepper questions

[Hack]

When building a 3 axis router is there any thing other than the electronics and how to mount either type of motor that needs to be taken into account. I have been doing some drawings for a machine and haven't decided what type I want to use and don't want to get to far into the project if there is something else to consider.

Thanks

[Patrick2by4]

that's a big question. First ask yourself what are your needs, wood only? foam? aluminum? printed circuit boards?
what size work envelope do I want?
How much money am I willing to spend?
You also need to read about the different projects people built, what is your skill level, what do you think you can reasonably build?

[RotarySMP]

Marriss, the designer of Geckos suggests the following rule of thumb. Below 60W per axis drive power, choose steppers, above 100W use servos, between these values depends on the application.

[snaggletto]

No, it really doesn't matter. Just make sure you leave the motor mount areas big enough to accomodate smaller or bigger motors. Many servos and steppers have similar mounts. For example the NEMA23, and NEMA34 standards apply to both steppers and servos.

Steppers need to be oversized for the application, so that they have more than enough torque for almost any situation on the machine and thus will never/rarely loose steps. Steppers can be nice as they act like a brake when not in motion. This can come in handy with a heavy Z (vertical) axis.

Servos are definitely superior in terms of smoothness, speed, and a wide spread of torque.

[ger21]

Originally Posted by RotarySMP Marriss, the designer of Geckos suggests the following rule of thumb. Below 60W per axis drive power, choose steppers, above 100W use servos, between these values depends on the application.

I thought I read steppers below 100W, Servos above 200W, either in between? And I also read this from Mariss. Maybe the 200 was 150, but I'm pretty sure 100W was the low cutoff.

[RotarySMP]

Opps, Thanks for correcting that.

As Hack is looking at a three axis router, I would guess you will be in Stepper country.