Cutting a piece to large for my mill

[BeerFizz]

Hi,

I have a mini mill which has an approximate Y of 3.5".

I want to cut a motor mount; square piece with a circular pocket and various mounting holes. This piece is symmetrical about the horizontal and vertical axis.

I drew this up in my cad program and then cut it horizontally in about 3/5ths or so with the idea of milling one half and then flipping it over and milling the other half, with a bit of overlap. I put a couple of holes in the horizontal line for pins to key it to when I flipped it over.

Has anyone done this?

Is there a way in OneCNC to do this?

Thanks for all help,
Phil

[SORCHEROR]

i have done similar parts that way,they were too big for my y axis which has 12 inches of travel,i modified my mini mill to get 4 inches out of it,alot of work for a small machine,i dont have it anymore since i got my hass

[BeerFizz]

Thanks for the response.

When you were doing larger parts on you mini mill, did you do the drawings in OneCNC and how did you manage the 'cutting only one half' thing?

[HuFlungDung]

The method really has nothing to do with the software in particular.

I would create a toolpath using one dowel pin as the work datum point and the other dowel lying along one axis, X or Y. You will need to use a work offset on your machine that sets the work datum quite far one direction, probably so the table starts from the extreme Y-. This means most all your toolpath would lie in the Y+ quadrants.

All you really need to do is to make sure that your toolpaths don't go beyond the travel of your machine. I don't know what you are using for toolpaths, but typically for 2d stuff, you will have to trim your 2d geometry to such lengths (in Y) that overtravel does not occur. Then create appropriate processes using the shortened geometry.

Since the part is symmetric with regard to the X axis, and hopefully this means the dowels, too, then just rotate the part 180° in Z and run the program a second time. Shift your work offset from the left to the right dowel hole before you do this.