Re: Z axis conversion

Hugh, I have had the same idea about the clamp on the quill. I
finaly decided it would have problems because of the clearance you
would loose. The clamp would be on the bottom of the quill and go
down with the quill. So if you are machining something that has to
get close to the quill there would be an interference problem. I do
think it would work most of the time though.

On the other methode of using a bolt in the front of the quill to
move the quill up and down. The bolt loosens up because it was never
designed to transfer power to the quill. I think the loosening is
because of the rocking motion on 1 little bolt causing it to stretch.



Wally K.




Hugh Currin wrote:

>
> I don't see how the screw could come loose from the quill? Any

scheme

> I think of restricts it from rotating, thus unscrewing.
>
> I've alternately thought of putting a split collar clamp around the

bottom of

> the quill. A ballscrew mechanism can then be attached to this

collar/plate.

>
> The ball screw itself could be attached to this collar/plate. It

couldn't

> extend below the quill though, so the ballscrew must move up and

down with

> the quill. If the motor is also mounted on this collar/plate (i.e.
> moves with the quill) a timing belt could drive the ballscrew. But

if

> the motor is mounted on the head, driving the ballscrew gets more

complex

> as the screw moves axially relative to the motor. One could drive
> the ballnut, but the bearings to mount the ballnut would get big.
>
> Alternately, a tube could be mounted to the split collar clamp/plate
> extending up alongside the head. The ballnut would be at the top

of this

> tube and the ballscrew extends down inside it. This moves the

ballscrew

> mechanism up so it doesn't extend below the quill. The ballscrew

is then

> mounted with bearings at its top to the head. It would be fixed on

only

> one end, similar to a bridgeport Y axis. Rotating the screw would

drive

> the quill up and down. The motor is fixed to the head. However,

it may

> be difficult to align and maintain alignment of the tube and

ballscrew.

>
> You'd only loose half to 3/4 of an inch in quill travel, the

thickness of

> the collar/plate.
>
> I hope this makes a little sense, I have trouble describing things

without

> sketches. You can see I also do not have a good solution for

this. :-(

> Be sure to let me know what you come up with. Thanks.
>
> Hugh Currin
> Klamath Falls, OR