Cosine Error Explained

Cosine Error Explained
in this video i will demonstrate best practices
and explain why cosine error is no big deal
demonstrate how to use the cosine correction factor
and show you a pear shaped contact point
ray gallant

[@EverettsWorkshop]

Most of the time I have been using indicators for comparative measurements, as you say. Never really needed to use them for direct as much, but the correction factor formulas are handy, thank you.

[@matthubbard8541]

Hi from the UK, thoroughly enjoying all your posts, thanks.

[@shopandmath]

Thanks for watching!
and commenting
Ray

[@jonnyphenomenon]

Thanks for this!

[@shopandmath]

You’re welcome and thank you for taking the time to comment. It is much appreciated.
Ray

[@Androfthegreat]

Keep up the great work Ray!

[@raysfix]

Thank you for your nice comment and also thank you for taking the time to comment. It’s much appreciated.
Ray

[@jdmcritter]

I knew this, but didn't know what it was called. Thanks! I'm a FOG and I really like learning new things.

[@shopandmath]

thank you for taking the time to comment
Ray

[@ShopperPlug]

Well explained.

[@TangentJim]

Excellent presentation --- Two thumbs up

[@shopandmath]

thank you
Ray

[@walkinthelight8740]

For my Mahr and Brown and Sharpe Indicators, the tip should be parallel. But for Interapid DTIs, I believe the proper angle is actually 12 degrees to the surface being measured

[@shopandmath]

Yes you are correct 12° for interapid indicators is the true calibration angle if you are using the original stylist of 0.687 with an 0.08 ball

[@braingrenade]

@@shopandmath a detail like this should be explained better in the video, as most people that I know use the original stylus. If you've put a different stylus on there then what came with it then it can be confusing. I know this video is not about the stylus and more about cosine error, your demo should reflect details about the variables you've introduced that a lot of people won't have to factor in. Good quick video though to help understand the effects of cosine errors and corrections.

[@raysfix]

@@braingrenade
Thank you for sharing and thanks for taking the time to comment. It’s much appreciated.
Ray.

[@vincenteby7509]

Yea you got it right my man. Interapid is different l2 degrees

[@SevenDeMagnus]

Thanks, could you create a video about the Abbe error (I think it's also called Sine Error).
God bless.

[@martincacer7033]

thank you, very well explained, I get it.

[@shopandmath]

Glad it was helpful!

[@beckyschwantes5287]

This is actually not correct. Considering the indicator being used. Interapid indicators require a 12degree angle for a true reading. Although most indicators do require the tip to be 0deg or parallel to the surface being measured this is not always true. You will also find a number of starret indicators requiring a 15deg angle.

[@thrustprop67]

I looked at the part of the clip were you put the 100 thou block in under the indicator thinking the indicator was square with the surface plate but its at 30 degrees

[@thrustprop67]

why did you get a 115 thou increase with a 100 thou block ??????????

[@8931831]

The cosine error of 30° for every hundred thousand is 15
So if you were to draw a triangle out with 30° at the top of the triangle the hypotenuse would be 115 if the back side was 100
I hope that this helps explain it if it does not let me know and I’ll try different way

[@peeeoii2738]

How does setting your protractor to 60 make your indicator at 30?

[@shopandmath]

30° is the complement angle of 60°
In other words, 90 Takeaway 60 is 30 this will be a lot easier if I could draw it out and show you to explain it.
I hope that this explanation helps understand. If not send me another response and I’ll try and do it a different way.
Ray