First Router...need help with motor sizing.

[BWay]

I am currently planning my first router build using a 4 axis gantry approach. I will be using the router for woodworking only. Attached is a drawing on my initial design. Here are the stats:

X Axis (long): Tolomatic linear actuators driven by a direct belt drive. The actuators has a 10:1 reducer with a mount for a Nema 23 motor. With the inline reducer the travel is .551in/rev. I will be driving both sides of the gantry with its own motor.

Y Axis: Tolomatic linear actuator driven by a ballscrew. The travel is .5in/rev. The actuator has a Nema 23 mount.

Z Axis: Parker Daedal Linear Actuator driven by a ballscrew. The travel is .393in/rev. The actuator has a Nema 23 mount.

The total travel of the machine will be 36 x 24 x 6.

I don't have the final weight of the gantry but I would guess it might be around 75-100 lbs when complete.

I have been reading old threads about motor sizing but am still trying to get it all figured out. A friend strongly recommended using Servo motors but many are using stepper motors. Based on this design what should I be considering when selecting the motor size and type? What kind of rapids would be reasonable?

Thanks!

[braidmd]

Motor sizing has been one of my concerns for quite some time. In fact, I'm still mulling it over... However, motor size, IMO, is only part of the equation. You really have to look at the drivers & power supply too. Many of the DIY builders have started out with hobby-type packages from outfits like Xylotex or HobbyCNC because they are a less-costly means to getting a machine up and running. But with most/all of them, the drivers are the weak link that limit your overall speeds. Gecko has a new driver - the G540, which sounds like an excellent option for the DIY'er on a budget... a product I'm very seriously looking at for my build. With that, here's two links that might help you figure out what you need for your application. My recommendation: Gecko drives (G540 or better), ~425 oz motors (+/-), and an appropriate power supply (see second link). I think you'll get better results with this arrangement over a package kit - with the drives being the key to success. Best of luck!!!

Motor sizing & drive choice:
http://www.geckodrive.com/support.aspx?n=520301

Good info from another thread:
http://www.cnczone.com/forums/showthread.php?t=71754

[BWay]

Braidmd....Thanks for the information and links. I am leaning heavily towards servo's but if I did use steppers the G540 looks great. In either case I am sold on using Mach 3 with the Gecko motor drivers. For Servo's I am favoring the G320's. I noticed that Keling has a 4 axis package that has 4 Nema 23 servo's, Gecko 320's and a power supply. Do you have any thoughts on this package?

[braidmd]

Glad I could be of some help. I really don't know much about servos, though the package you are looking at sounds good. I think the drives are the critical component for getting optimal performance out of your motors. Gecko makes very good stuff... can't recall reading a complaint in the forums here. Perhaps one of the more knowledgeable posters will chime in on your setup???