[kemeris]

Hi,

I am totally new to CNC world and want to build rigid CNC primary for aluminum and steel work, sometimes wood.

So, my axis: X = 78" / Y = 39" / Z = 30-35"

I am considering dual “Skate bearing” homemade system for my Y axis.
Can someone comment on such a design, any cons, pros?

Thanks in advance

[LeeWay]

If you are wanting to do any work in steel, you need a completely different design. A heavy duty router might be able to do some light milling in aluminum. No problem in wood, but steel? Not really. There are many reasons why.

Take a look in the forums here.

http://www.cnczone.com/forums/forumdisplay.php?f=48

That link shows routers and build logs for them. Stroll through those to see what different types of designs have been used.

Now look at mills here.
http://www.cnczone.com/forums/forumdisplay.php?f=221

You will see that they are decidedly different designs and parameters.

Welcome aboard.

[Phife]

you'll never be able to mill aluminum with a 30-35" long skate bearing Z axis, you'll probably have alot of trouble with wood even.

Why do you need that much Z travel?

[kemeris]

No problem in wood, but steel? Not really. There are many reasons why.

Thanks. At last I have found one thread about steel milling machine. They are huge

So for now I will limit with aluminium and wood.

[kemeris]

you'll never be able to mill aluminum with a 30-35" long skate bearing Z axis, you'll probably have alot of trouble with wood even.

Why do you need that much Z travel?

I am producing some wooden 67" benches from 1.5" planks, I am using only hand tools at the moment Also I am very interested in small aluminium parts for RC helicopters.

At this moment I am new to CNC world, but I am learning I have found lots of threads about linear motions systems but unfortunately found no information about skate bearing.

So why skate bearing is bad choice?

What is your suggestion?

[UUU]

So you need three machines. One giant saw bench and a drill press for making the benches. And a benchtop mill for the helicopter parts.

Benchtop mills come in different flavours. For steel - my benchtop mill has a Z travel of about 6 inches and weighs 400 pounds. The bench is another 150 pounds. I have a friend who does well with plastic and aluminium with a Taig, which is lighter. Up at your sizes it will be tons, many tons.

[kemeris]

So you need three machines. One giant saw bench and a drill press for making the benches. And a benchtop mill for the helicopter parts.

Benchtop mills come in different flavours. For steel - my benchtop mill has a Z travel of about 6 inches and weighs 400 pounds. The bench is another 150 pounds. I have a friend who does well with plastic and aluminium with a Taig, which is lighter. Up at your sizes it will be tons, many tons.

I got it

The reason for such a high Z axis was thought to upgrade my machine to 5-axis with B/C Drive in the future, at this moment I don't need such high Z-axis.

My bench have a lot of shaped parts, please take a look what I am talking about http://pdfcast.org/pdf/swing
I need CNC only for shaped parts, straight parts not a problem for me.

Maybe such a machine would be capable for such a wooden shapes and for small aluminium parts? http://www.cnczone.com/forums/showth...=522970&page=3

P.S. Sorry for my poor engligh

Thank you