Help with Tan()!

[zach454]

I have been working on this particular problem for some time now. I work in a machine shop and I'm trying to use some forumla's to make our lives easier, but my anwser don't come out the same as theirs.

If you go to:

http://www.zakgear.com/Over_Pins.html

You will see there is several calculations, and I have most figured out except for when you get to the:

<TABLE border=1 cellSpacing=0><TBODY><TR><TD>Pressure angle to pin center Bd:</TD><TD><CENTER>InBd=Tan(Bd)-Bd*pi/180 </CENTER></TD></TR></TBODY></TABLE>

For some reason my anwser doesn't come out the same as theirs?
Any suggestions?

Thanks!
-Zach

 

[Michael M]

As we don't know either what angles your using OR the result OR their result it's hard to say who's incorrect
You need to provide us with your calc data and the result given / expected
Also, what are you using for Pi ?
From memory 3.1417 was adequate, but they could be using 3.14159265358979

 

[zach454]

Ok I posted a copy of my entries so far. Everything works as it should until I get to Pressure angle to Pin Center. All the required entries are at the top 6 feilds.

<TABLE style="WIDTH: 616pt; BORDER-COLLAPSE: collapse" border=0 cellSpacing=0 cellPadding=0 width=820><COLGROUP><COL style="WIDTH: 257pt; mso-width-source: userset; mso-width-alt: 12544" width=343><COL style="WIDTH: 14pt; mso-width-source: userset; mso-width-alt: 658" width=18><COL style="WIDTH: 11pt; mso-width-source: userset; mso-width-alt: 512" width=14><COL style="WIDTH: 11pt; mso-width-source: userset; mso-width-alt: 548" width=15><COL style="WIDTH: 14pt; mso-width-source: userset; mso-width-alt: 694" width=19><COL style="WIDTH: 242pt; mso-width-source: userset; mso-width-alt: 11776" width=322><COL style="WIDTH: 67pt; mso-width-source: userset; mso-width-alt: 3254" width=89><TBODY><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; WIDTH: 257pt; HEIGHT: 15pt; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: #f0f0f0" class=xl67 height=20 width=343>Number of Teeth</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; WIDTH: 14pt; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: #f0f0f0" class=xl71 width=18> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; WIDTH: 11pt; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: #f0f0f0" class=xl71 width=14> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; WIDTH: 11pt; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: #f0f0f0" class=xl71 width=15> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; WIDTH: 14pt; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: windowtext 0.5pt solid" class=xl72 width=19> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; WIDTH: 242pt; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 width=322>N</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; WIDTH: 67pt; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: windowtext 0.5pt solid" class=xl74 width=89>50</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl70 height=20>Diametral Pitch</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl72> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66>DP</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl74>10</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl70 height=20>Helix Angle/Pitch Diameter</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl72> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66>h</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl74>31.5</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl70 height=20>Normal Pressure Angle</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl72> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66>An</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl74>30</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl70 height=20>Normal arc Tooth Thickness on Pitch diameter</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl72> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66>Tn</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl74>0.1544</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl70 height=20>Ball/Pin/Wire Diameter</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: #f0f0f0" class=xl71> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl72> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66>D</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl74>0.1728</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65 height=20> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65 height=20> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65> </TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Transverse pressure angle:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>Ad=DEGREES(ATAN(TAN(RADIANS(An))/COS(RADIANS(h))))</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>34.10320</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Transverse circular tooth thickness on pitch diameter:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>td=Tn/COS(RADIANS(h))</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>0.18108</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Helix angle on base diameter:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>Ha=DEGREES(ATAN(TAN(RADIANS(h))*COS(RADIANS((Ad)))))</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>26.90400</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Transverse pin diameter:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>dD=D/COS(RADIANS(HA))</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>0.19377</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Pitch diameter:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>PD=N/(DP*COS(RADIANS(h)))</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>5.86414</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Base diameter:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>BD=PD*COS(RADIANS(Ad))</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>4.85568</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Involute function of Ad(rad):</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>InAd=TAN(RADIANS(Ad))-Ad*PI()/180</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>0.08192</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: #f0f0f0; mso-ignore: colspan" class=xl67 colSpan=4>A=td/PD</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl69> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>0.03088</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: #f0f0f0; mso-ignore: colspan" class=xl67 colSpan=4>B=dD/BD</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl69> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>0.03991</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: #f0f0f0; mso-ignore: colspan" class=xl67 colSpan=4>E=PI()/N</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl69> </TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>0.06283</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Involute function of Bd(rad):</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>InBd=A+B+InAD-E</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>0.08987</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Pressure angle to pin center Bd:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>InBd (HELP?)</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75> </TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Diameter of pin centers:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>CC=BD/COS(RADIANS(G20))</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>4.85568</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Dimension over pins Even #:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>DE=CC+D</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>5.02848</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Dimension over pins odd #:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>DO=COS(RADIANS(90)/N)*CC+D</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75>5.02608</TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: #f0f0f0; BORDER-LEFT: #f0f0f0; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: #f0f0f0; BORDER-RIGHT: #f0f0f0" class=xl65 height=20>Pressure angle to point at tangency:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>F (HELP?)</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl75> </TD></TR><TR style="HEIGHT: 15pt" height=20><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext 0.5pt solid; BACKGROUND-COLOR: #f2f2f2; HEIGHT: 15pt; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: windowtext 0.5pt solid" class=xl66 height=20>Radius to point of tangency:</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: #f2f2f2; BORDER-TOP: windowtext 0.5pt solid; BORDER-RIGHT: black 0.5pt solid" class=xl67 colSpan=5>RT (HELP?)</TD><TD style="BORDER-BOTTOM: windowtext 0.5pt solid; BORDER-LEFT: windowtext; BACKGROUND-COLOR: white; BORDER-TOP: windowtext; BORDER-RIGHT: windowtext 0.5pt solid" class=xl73> </TD></TR></TBODY></TABLE>
'

Thanks, Again!

 

[Michael M]

Geez, I walked into that one.
I was hoping it was a simple error...and probably is, but my trig is, shall we say mediocre !!

What answer are you getting ? as opposed to the 35.06197301664947 from the online calc.

 

[zach454]

Sorry, haha its got me for a loop. Yea it is spose to be 35., and what I get using this formula

=DEGREES(TAN(InBd)-InBd*PI()/180)

is 5.07343.

I've tried every combination, using radians, degrees, etc... I'm out of idea's on what I'm doing wrong. I'm so close.

Thanks, again!

 

[Michael M]

Yea, well based on the info provided, I get the same thing....but, what is BD and Bd.
I see the BD in the table but not the Bd, which I'm guessing is the reverse or opposite of each other. I'm not helping much, mainly 'cause I'm Excel, not engineer....I guess while were discussing, you're getting Bumped back to the top of the list

 

[MikeWx]

At the link that Zach refers to in his first post, you can click on the icon in the upper right corner and it will show a chart of the various angles and other values referred to in the different formulas. I am still not sure how to find angle bD, which is the key to determining the remaining values.

 

[VoG]

Your angle needs to be in Radians = Degrees/2*Pi

 

[zach454]

I belive the number I using is in radians, but I did try converting using degrees and radians, or did I misunderstand? How should the formula be written? Maybe I've done it right, but just haven't got the right numbers, here is the websites way to calculate it, but I don't know javascript, only vba:

//Pressure angle to pin center
var i
var A = pi / 4
var B = A / 2
var Tet1
for (i=1; i<= 100; i++) {
Tet1 = Math.tan(A) - A;
if (In_Bd < Tet1) {
A = A - B;
} else {
A = A + B;
}
B = B / 2;
}
var B_d=A/pi*180;
document.gearcalc.Bd.value=B_d;

 

[Norie]

Zach

I thought it was a degrees/radiant thing at first but after looking at the script and your formulas that doesn't seem to be an issue.

When I tried recreating the formulas in Excel I tried both the RADIANS function and the conversion with 180...

Didn't notice any difference.

Did you use named ranges?