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javawizard

22/10/2007 4:20 PM

Math Conversions for Woodworking

Hi Folks,
I'm adding some more converters to www.fast-math.org. I'm
wondering if woodworkers have need for any math conversions that are
not already there? If you have a good let me know, and I'll add it.
Thanks,
- Jeff
www.fast-math.org


This topic has 1 replies

Bn

"BobS"

in reply to javawizard on 22/10/2007 4:20 PM

22/10/2007 10:04 PM

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"javawizard" <[email protected]> wrote in message =
news:[email protected]...
> Hi Folks,
> I'm adding some more converters to www.fast-math.org. I'm
> wondering if woodworkers have need for any math conversions that are
> not already there? If you have a good let me know, and I'll add it.
> Thanks,
> - Jeff
> www.fast-math.org
>
How about a pulley calculator such as would be used for a wood lathe =
that uses two sets of pulleys (motor shaft, step pulleys, headstock step =
pulleys). Also add the rotational speed of the edge blank you're =
spinning such as a 10" bowl. The headstock shaft is spinning at XXX rpm =
and the edge of your workpiece is going - how fast you say.....?

Example from a Delta mini lathe with a variable speed motor:

Headstock Pulley - outside diameter - left to right (largest to smallest =
pulley) - readings in inches.=20
Pulley # Diameter=20
1 3.14"
2 2.74"
3 2.35"
4. 1.95"
5 1.575"
6 1.293"


Motor Pulley - left to right (smallest to largest pulley)
1 .83"
2 1.23"
3 1.60"
4 2.00"
5 2.40"
6 2.67"

Formula: (one example)

Motor Pulley Diameter / Headstock Pulley Diameter =3D Speed Ratio
Speed Ratio x Motor Shaft Speed =3D Headstock rpm

Using the low of 1525 rpm and a high of 3515 rpm at the motor shaft, an =
approximate rpm of the headstock shaft can be determined.

Lowest speed calculation: (Controller at minimum setting)

.83 / 3.14 =3D .264 Speed Ratio

.264 x 1525 VS low rpm =3D 403 rpm in theory and actual reading was 425 =
rpm - a 5% difference

Highest speed calculation: (Controller at maximum setting)

2.67 / 1.293 =3D 2.06 Speed Ratio

2.06 x 3515 VS high rpm =3D 7,240 rpm in theory and actual reading was =
6,600 rpm - an 8% difference


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<STYLE></STYLE>
</HEAD>
<BODY>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>"javawizard" &lt;</FONT><A=20
href=3D"mailto:[email protected]"><FONT face=3DArial=20
size=3D2>[email protected]</FONT></A><FONT face=3DArial size=3D2>&gt; =
wrote in=20
message </FONT><A=20
href=3D"news:[email protected]"><FONT=
=20
face=3DArial=20
size=3D2>news:[email protected]</FONT=
></A><FONT=20
face=3DArial size=3D2>...</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>&gt; Hi =
Folks,<BR>&gt;&nbsp;&nbsp;&nbsp; I'm adding=20
some more converters to </FONT><A =
href=3D"http://www.fast-math.org"><FONT=20
face=3DArial size=3D2>www.fast-math.org</FONT></A><FONT face=3DArial =
size=3D2>.=20
I'm<BR>&gt; wondering if woodworkers have need for any math conversions =
that=20
are<BR>&gt; not already there? If you have a good let me know, and I'll =
add=20
it.<BR>&gt; Thanks,<BR>&gt; - Jeff<BR>&gt; </FONT><A=20
href=3D"http://www.fast-math.org"><FONT face=3DArial=20
size=3D2>www.fast-math.org</FONT></A><BR><FONT face=3DArial =
size=3D2>&gt;</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>How about a pulley calculator such as =
would be used=20
for a wood lathe that uses two sets of pulleys (motor shaft, =
step&nbsp;pulleys,=20
headstock step pulleys).&nbsp; Also add the rotational speed of the edge =
blank=20
you're spinning such as a 10" bowl.&nbsp; The headstock shaft is =
spinning at XXX=20
rpm and the edge of your workpiece is going - how fast you=20
say.....?</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Example from a Delta mini lathe with a =
variable=20
speed motor:</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV>
<DIV><FONT face=3DArial size=3D2>Headstock Pulley - outside diameter - =
left to right=20
(largest to smallest pulley)&nbsp;- readings&nbsp;in inches. =
</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Pulley #&nbsp;&nbsp;&nbsp;=20
Diameter&nbsp;</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>1&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; 3.14"</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>2&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; 2.74"</FONT></DIV>
<DIV><FONT face=3DArial=20
size=3D2>3&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nb=
sp;&nbsp;&nbsp;&nbsp;&nbsp;=20
2.35"</FONT></DIV>
<DIV><FONT face=3DArial=20
size=3D2>4.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&n=
bsp;&nbsp;&nbsp;&nbsp;&nbsp;1.95"</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>5&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; 1.575"</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>6&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; 1.293"</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Motor Pulley - left to right (smallest =
to largest=20
pulley)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>1&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; .83"</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>2&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; 1.23"</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>3&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; 1.60"</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>4&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; 2.00"</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>5&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; 2.40"</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>6&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;=20
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; 2.67"</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Formula: (one example)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Motor Pulley Diameter / Headstock =
Pulley Diameter =3D=20
Speed Ratio</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Speed Ratio x Motor Shaft Speed =3D =
Headstock=20
rpm</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Using the low of&nbsp;1525 rpm and a =
high of 3515=20
rpm at the motor shaft, an approximate rpm of the headstock shaft can be =

determined.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Lowest speed calculation: (Controller =
at minimum=20
setting)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>.83 / 3.14 =3D .264 Speed =
Ratio</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>.264 x&nbsp;1525 VS low rpm&nbsp;=3D =
403 rpm in=20
theory and actual reading was 425 rpm - a 5% difference</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Highest speed calculation: (Controller =
at maximum=20
setting)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>2.67 / 1.293 =3D 2.06 Speed =
Ratio</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>2.06 x 3515 VS high rpm =3D 7,240 rpm =
in theory and=20
actual reading was 6,600 rpm - an 8% difference</FONT></DIV></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV></BODY></HTML>

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