[dbsharp]

Shooting for 4'x3'x1' milling area. 3 axis operation, and maybe a 4th at some point!

Right now I'm looking at using a diy linear bearing similar to whats available at cncrouterparts. Their price is quite good, but I found a nice chunk of aluminum at the scrap yard and I can make some fairly cheaply myself.

The current plan is to use
-1/2-10 acme for the shorter axis, and a larger (.75-1) screw for the long axis.
-nema 23 steeper motors
-usb cnc controller
-gecko g250x or g251x, not sure of the difference here.
-Bosch 1619 3.25hp router

Here's what Iv'e got on the design do far.

[ger21]

You'll want to use multi start acme with 2-4 turns/inch. 1/2-10 single start is much too slow.

Also, you'll want the G251, as the G250 doesn't have screw terminals or a heatsink. Otherwise they're the same. However, A G540, which contains 4 G250's, is usually cheaper.

[dbsharp]

what kind or rpm's can do people typically get from a diy setup like this?

My current frame design looks like it is going to give somewhere around 20,000 pounds of force per inch of deflection. That's getting into the recommended stiffness range for cutting AL. Iv'e been thinking about using ball screws to limit compliance for more accuracy.

[dbsharp]

i just bought 3 ball screws off ebay. they look a little dirty, but I should be able to clean em up and make em work. I should be able to get my 3'x4'x1' routing area I wanted with these and maybe a little more! the big ones look like they are .2-.25 lead per revolution and the little one for the z axis is .125.
I have less than $200 in all 3! They all come with bearings and the ball nuts.

[dbsharp]

I'm ditching the ball screws I have and I bought all new ball screws and linear bearings.

I have purchased pretty much everything I need to build it except a little bit of raw material and a solid computer to run it.

I should be able to get 300in/ min+ feed rates and a resolution of .0002".

[dbsharp]

Got the rotary table working, and made a motor mount for my cnc project.





More to come