Re: [CAD_CAM_EDM_DRO] swiss turning in minature?

In a message dated 5/12/2003 7:36:48 AM Central Standard Time,
eexgs@... writes:

> I think a dremel might even do the trick.<<

NO WAY! ForGET about that!

The > headstock could then be moved back and forth under stepper control as

> could the tail stock. Between the two

would be the bearing unit. Here I need ideas, what sort of bearings?
Bushes? <<

You say "on the cheap"??? A MOVING headstock? NO WAY! This is MUCH too
sophisticated a concept for you to even begin to IMAGINE doing it
"cheap"! If you MUST build your machine with the moving headstock for the Z
axis, it will have to be done VERY precision, and that will cost MORE than a
good well-done conversion of an extant conventional lathe design!

Spindle bearings? For a smallish lathe spindle? Double-row angular contact
ball bearings. Linear? I have used Thomson linear ball bearings for years
with success in most applications, but the THK stuff looks good for such
home-brew machine-cobbling! Get the THK catalogs and gawk!

I have never personally seen one myself, but the Sherline is available for
the direct attachment of size-23 steppers, I am led to believe, and that
would be a good learning experience, and might even WORK, if you are careful
as you go!

>
> Then there would be a cross slide, another linear rail again under stepper
> control. Built solid with absolute minimum over hang.
>
> So, am I daft? Would it be better just to build a normal lathe?<< Yes,
> certainly! Maybe after ten to twenty years of tinkinering with that, you
> may by then have enough experience to 1)realize the moving headstock idea
> was daft, not YOU; and 2)if you still MUST do it that way, you might have a
> clue by then how to go about it.
>
> One other thing it has to be on the cheap. I have rails and leadscrews,
> steppers and drivers. I don't have decent spindles etc. THen you have
> your work cut OUT for you!
>

Jan Rowland


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