The drawing calls for a taper of 7 deg, 7 mins & 30 seconds.
Length of taper 0.625". (in the sense of the "x" axis).
I've calculated Y axis deflection of 0.078" with this taper over 0.625".
I have a DRO, and taper turning attachment.
So 0.625" in the X axis should give me 0.078" deflection on the tool post, or Y axis, when the angle is correctly set.
It may take several "dry runs" to get the taper right, but does this make sense ?
(I'll need to be careful any backlash is "taken-out")
Thanks
Bob
I'm not sure if someone here is pulling someone's leg here ;-) or not ?
Ok.
My math can sometimes get a bit 'Wobbly" but there's no stated accuracy or precision or tolerance band or + this or - that.
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As a kid I was sent to school where by the age of nine you had to be able to tell military-time and was taught 'math" by a retired RAF Major - "Major Gick's" and his "bendy friend" in the closet if we didn't behave - said "Bendy friend" being a small thin cane that would be revealed from time to time for the express purpose of being shown the instrument with which one would be beaten with if one did not behave. ~ This was at a time when teachers could still smoke in the classroom, cigarettes or pipe either or and there was no actual limit on how much or how loud you could scream at a child (regardless of age). But honestly no-one ever f*cked around and the "Bendy friend" was never used. Pure fear of the imagined consequences seemed to suffice ... But he had incredibly detailed models of steam engines (that he built himself) and displayed in the classroom in a glass case as well as amazing origami-like models of super complex three dimensional shapes hanging from the ceiling ~ which may explain how or why I got into 3d computer graphics and VR systems. + things engineering related / "Machining" related.
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7 degrees , 7 mins, 30 arc seconds ---> 7° 7' 30"
7 degrees ---> 7.0000 degrees.
7 arc minutes ---> [60 mins in a degree of arc ∴ 7/60 = 0.11666666 or 0.1166(reoccurring)*
30 arc seconds ---> [3600 arc seconds in a degree of arc or 60 seconds in an arc minute ] ∴ 30/3600 = 0.008333333 or
0.0083(reoccurring)*
so,
0.16666667(rounded up for calculator people) + 0.0083333 = 0.125 (when taking into account recursion ).
0.125 is an 1/8th of a degree.
So the taper being asked for here is.
7.125 degrees,
7.125°
or 7 and one 1/8th of a degree.
Still wondering about included and non included angles etc. so is it really 14.25° (full included angle) ? 1/2 angle 7.125° - which rings a bell.
Will re-read thread and re-check "Math".
Depending on type of taper attachment - taper per foot ?
Maybe using log tables or your tan function (in deg mode not "rad" mode) on your calculator, or "Machinery's Handbook"
That's
1.5" over a foot.
1.5" over 12".
1.5 inches over a foot,
one and half inches over a foot just so inches and arc seconds do not get mixed up.
1.5000 inches per foot (for example) is not a reliable indication of the actual tolerances required.
Actual tolerances are required or even statements of "tapericity " - but in this case sounds like 1 1/2" over a foot taper = 7 degrees, 7 arc minutes , "And" 30 arc seconds.
1.5" over a foot (taper) = 7°, 7', 30" (exactly).
(I haven't checked to see where or IF any divergence occurs at a much higher number of decimal places (obviously not really practical or actionable to 25 decimal places anyway or achievable in a practical fashion especially in this context of tools used. but hey... whatever. ).
1 arc second is 1 degree divided by 3600 = 0.00027°(reoccurring).
The intent of 30 arc seconds (in the context of ( 7° 7' 30") is unknown or unknowable as an indicator of precision in this case with the information thus far provided.
Maybe @DrCielo is right...
Machinists CAD Tool - Looking for ideas
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* For some reason I can't use any of the superscript notations for reoccurring decimals on this site / forum ?
Repeating decimal - Wikipedia
^^^ Such as these ... to use "R" or brackets would be confusing - (
sorry !)