Re: [CAD_CAM_EDM_DRO] BALLSCREWS QUESTION

Braga,
If I have done my conversions correctly, 0,01mm will be ~0,00039"

IF you mount a 500 line (2000 quadrature) encoder on the END of the ball
screw, that will be a resolution of approximately 0,0004" (0,01016mm), a
1000 line encoder would be 0,0002"
Now, if you had a 1:1 ratio between your servo and the lead screw and the
encoder is mounted on the back end of the servo, all the math is still the
same. If however you add a reduction ratio between the servo and the lead
screw, then you would divide the ratio to figure your resolution. Example
if you had a 2:1 ratio and 500 line encoder on the servo; the 0,0004 /2 =
0.0002" resolution would be obtained. All of this will be figured with the
G340 set at X1 on the multiplier. If you choose the X2, the you will
MULTIPLY to get your resolution to the above figures.

Hope this helps. (and I have done my math correctly:})

At 12:04 PM 1/24/2005, you wrote:

>I'm older to this list but this is my first question to the forum.
>I'm looking at putting together my own CNC mill. I already have two
>superb 40" german x/y linear assemblies and the servo motors (54V, 7A,
>3000 RPM), everything saved from junk. I intend to use Gecko 340 and
>Mach2.
>
>The question I have regards to the TPIs of my ballscrews ­they are
>20mm - (0.8") - per revolution. This seems very large to my purpose.
>
>I would like to know if some of you kind folk would take a moment to
>figure the way I can use it with a minimum of acurracy, say 0,01mm,
>using belt reduction, I guess.
>
>Thanks very much,
>
>Manel Miranda
>Braga, Portugal
>
>

Bubba

OLDER THAN DIRT
Country Bubba
(Actually the inventor of Country and Bubba)
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LaGrange, GA

http://bellsouthpwp.net/A/r/Arts_home_page/cnc/

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