[hscess]

I am wanting to extend the Y axis on my G0704. How much do I need to mill off of the inside of my mill base front and back. I would like to gain another inch or so without harming rigidity. I was thinking 1.75" in the front and 1/2" towards the back. Let me know how much to mill out. I have the standard length ball and screw.

[mikegiraud]

I am wanting to extend the Y axis on my G0704. How much do I need to mill off of the inside of my mill base front and back. I would like to gain another inch or so without harming rigidity. I was thinking 1.75" in the front and 1/2" towards the back. Let me know how much to mill out. I have the standard length ball and screw.

I left 0.5" in the rear, and 1.70" in the front of the base. For the rear, I pocketed to about 1.85" deep. This gave me just over 9" of travel. My Y-axis stepper is a front mount. A longer ball screw will be needed. The attached pic will show the finished base a bit more clearly.

Attachment 329148Attachment 329150

[arizonavideo]

Did you add a column spacer?

[hscess]

How much longer is the extended ball and screw than the regular standard length? Your base looks good.

[mikegiraud]

Yes, I added a column and head spacer. Mike Sherman here on the forum made them. Search his threads, and you'll see a pic of my G0704 with his nice spacers in place.

For the longer ball screw, you simply need to increase its length to get the end within .2 - .25" or so of the back wall of the pocket that you machined in the base. I can't recall the added length, as I provided Chai on Ebay with the overall length and end machining. This will vary on your machine due to your end machining requirements. Basically, if your existing screw length is 2" from the back of the base now, you need to add 1.3" to allow for the new ball screw to be .2" from the pocket wall.

The pics of the base aren't mine, but another forum member's. The dimensions are mine. This is the instructional sketch that I gave to the local machine shop to machine my base. Mine looks identical however. The local shop charged me about $200 to machine the base, the z-column and the z-slide. I added about 3.5" of z-travel as well.

[hoss2006]

If you're into doing things yourself you can get all the information on my site since I originated the extended Y axis years ago.
g0704.com
Hoss

[hscess]

Thanks Hoss, I will check into that. Thanks for your help.

[hscess]

This the kind of info that I need. Thanks for your help.

[Fastest1]

You can also bore a hole thru the rear of the casting as Hoss did with the rear mounted stepper. Even if you dont mount the stepper in the rear, the fact the ballscrew can pass thru makes length less of an issue. if the ballscrew passes thru the rear (or past the inner wall) there is no way for the nut to fall off it merely hits the wall and stalls.