[xaitmaikur]

Hey Everyone. Newbie here. I am a experianced Product Design Engineer that does a lot of Solidworks modeling. I am trying to set up a G0704 for doing basic prototyope work on small aluminum parts. I am really interested in true 3D contour milling. I found BobCAD V25 Mill Pro selling for $625 with training videos and bought it. I also Made a deal trading contract Engineering hours for stepper controller and motors and just recieved a G0704. So I am into this project for about $1900 so far and want to design my own motor mounts etc.

I am getting ready to convert the G0704 and have a few questions.

-Direct drive vs. belt drive off the servo motors? I am liking the reduction I can get from the belt drive. is one better than the other?

-On the Z axis, is there any reason to not use the turn handle shaft exiting the side of the main column as the pully for a belt drive servo? I see a lot of direct drive motors for the z axis and even belt drives but none of them use the side.

I have a lot of questions and am reviewing a few sites but I am pretty sure there is a ton of experiance here.

[Fastest1]

I will take a stab at a few of your questions.

First regarding the belt drive. I believe this is used for optimizing the speed and torque of the servo or stepper. Resolution could be changed too, if needed.

Using the handle on the side of the column as a method of raising and lowering the Z brings quite a bit of backlash into the system. The Z screw is crude at best to be reused, then to add in the slop of that bevel gear. Sounds like you are just asking for problems. Does the bevel gear have any provisions for adjustment?

[xaitmaikur]

Thanks for the reply. I think you are right about the added backlash. I am not too impressed with the gear in there. I am 100% going belt drive. I like the options it gives me for mounting.

[Fastest1]

The mill is small enough where stepper placement is more of a personal thing than necessity. Mine are direct on every axis, 34 on the Z, 23's on X & Y. No problems. That being said. I might make my Y axis stepper mount in the back.