question on steppers

[bru]

Hi. First i'd like to say what a great forum! I have been researching home built CNC routers for a while and only recently stumbled upon this community.

I am in the process of gathering all the components for my router. I have the ball screws and linear guides and am looking now for the stepper motors. The ball screws have the following lengths of travel to give a size perspective of the machine. X,Y,Z respectively: 73", 42", 18". As a side note, I do not intend to use all 18" of Z height--I got a great deal on the screw and will cut it down to fit the design if necessary.

My main question is in regards to the size of the stepper motors needed. From looking at past threads it seems most people are in the 200-400 oz-in range, but it also seems most peoples machines have a smaller foot print. The motors i have had my eyes on are 990 oz-in. Is this complete overkill for my project? I had planed to couple them directly to the ball screw shafts (direct drive). I would guess the Y-Z gantry will weigh about 100-150lbs when complete.

Any input or suggestions would be appreciated, thanks.

[Oldmanandhistoy]

Hi bru and welcome to the zone,

Unfortunately you have started your thread in the wrong forum; maybe a moderator will kindly move it to the relevant forum.

As to your question, more information is required such as what you plan to cut, what speeds you would like to cut at, what are you using for linear rails and so on.

I would imagine that 990 oz in will be overkill especially if you are using ball screws but like I said more information needed.

If you get no more replies here I would repost in the “stepper motor and drives” forum with added information or research the forum for the relevant information. You could have a look through this forum and find a build with similar specifications to what you plan to build and see what they have used or ask question there.

I do recommend that you do a good search of the site and try to find the information that way. Very similar questions are asked very frequently and many members are reluctant to answer the same questions over again.

Hope this helps,

John