Re: Re : minimum work CNC conversion

Hi Ken,

I've head successful applications of stepper motor mainly in
extremely slow feed rate. In slow speed steppers don't tend to miss
steps.

In the beginning I was planning the step motors too, and I did find
them cheaper but after seeing the fact that commercial CNC mills
mostly use servos (and more accurately AC servos) I changed my
course.

Regards,

Horace.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Ken Campbell"
<deltainc@...> wrote:

>
>
> ----- Original Message -----
> From: "Horace, T.L.Ho" <skyfroghorace@...>
>
> > I am still in early stage sourcing parts, my XY servos would be
> > 850oz-in peak torque, 72VDC, 8.5A, Z servo would be smaller as I

am

> > motorizing the quill. Not much calculation is done I am just
> > following others' steps. I forgot to mention that I will use
> > ballscrews, 32mm dia and 10mm lead. I want them be zero backlash

but

> > it depends on the results of sourcing.
> >
> > Why ? the reason is quite the same with most garage engineers,

but I

> > don't know really as my works need high precision I probably

should

> > get a new CNC mill 12000rpm fanuc 18Mi controller and other
> > expensive stuffs, and treat this project as a learning process.
> >
> > What best results in precision we can get for such a converted
> > machine ?
> ***********
> Just a thought, but take a serious review of obtaining a boss

bridgeport and

> using the factory or replacement steppers with a new controller

box and

> drivers ... we have run ours for days non-stop routing

fiberglas/carbon

> fiber with a gear speeder , and never missed a step ..... in fact,

I just

> drilled 1200 holes, each one indexed in a roto indexer, the table

had to jog

> x & y in between the drill cycle, to clear the index handle ...

other than

> boring me to death, it didnt miss a step the whole run. control

was open

> end, no feedback. software is ahah.
> regards, ken campbell, deltawerkes
>
>
>
>
>
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