My first cnc lathe - lcarrudajr

[lcarrudajr]

Hi all, this is the construction log of my first cnc lathe that i'm building with help of some friends.
It has a 1hp 3phase 220volts spindle motor, a 4 inch chuck and 70 centimeters x axis (about two feet).
The body is made of 5/8 mild steel welded with an arc welder, and then milled to archieve flatness.
any suggestions?

lcarrudajr

[LeeWay]

That is looking great. Nice size lathe. Are you going to use Vbelt drive, timing belt or gears?
For Vbelt or gears, you won't have to consider how difficult it would be to change the belt. Timing belt, however might require more work. I haven't yet wore out a timing belt though, but I am sure it can happen. Likely worth the trade off anyway with the compactness of your design.
I would suggest a few more ribs either bolted or welded. What type ways are you considering?
Ball screws?
I look forward to seeing how this turns out. Welcome to the Zone, BTW.

[lcarrudajr]

It has two welded ribs, but it is installed low in the "frame".
Im using a single pair of V Belt. The motor has 3500 rpm, but I'll get 2500. I'll install a frequency inverter in the motor.
I ordered today the linear rails and the ball screws (c7 grade - 0,05 mm error in 300mm, i think)

thank you.

lcarrudajr

[idtkid]

You guys and your crazy lathe builds! Love seeing these pictures, looks like a great build so far.

Is this your first machine build? Im always curious to know peoples professions as well. Keep posting!

[Guldberg]

Looking good. Looks a bit like mine, except I chose a slant bed design and a little bigger motor (3hp), so i beefed up the construction a bit using 15mm steel and a lot of ribs
Slant bed CNC lathe from scratch

A suggestion: Fill it with that epoxy granit stuff. Would defently dampen it and properly allow you to take some deeper cuts without vibrations.

70cm X axis? Sure you dont meen Z? :-)

[lcarrudajr]

Guldberg, You have a great lathe. I should have researched a bit before starting the construction of my lathe ...

Actually, I was referring to the z axis, however I'm thinking of doing the two axes of the same size to use gang tooling.

The epoxy granit stuff is a great idea.

Thank you.

update: the pulleys are installed and the running ok

[lcarrudajr]

I got so much involved in the project that I forgot to take pictures...
The first picture was made when the X axis was being built.
The others shows how the motor is linked to the ballscrew.
The stepper motors are 120 kgf or 12 nm. They're big...

Lcarruda.

[praetor]

Nice beast of a mchine!

[Guldberg]

Looking a bit crude, how big is the backlash in those couplings?

[lcarrudajr]

there is no backlash in the couplings. Each coupling has four bearings ... These couplings are used in cars of the Fiat brand, in the direction column (steering system).

This was built around as if it were forged. It was milled only where it is necessary to maintain alignment and squareness.

As the intention is to paint it after finished, I do not worry about finishing.

[Guldberg]

You fabricate like i do. My philosophy is that paint can fix most welds and joints:-) I must say though that FIAT is not a necessary a stamp for quality and precision:-D (I own a Grande Punto)

[lcarrudajr]

look maa... no hands...