Typical math in the shop

[Wreck™Wreck]

This is a typical math calculation that will come up on any given day.

This is the drawing for one feature of the parts that I made today, a simple 45 Deg. angle at the beginning of a bore .15" deep, however there is a .03" radius before the small diameter.

The question is, what is the diameter and depth at the tangent?

The beginning diameter of the taper is twice the depth at X .92" (.62" X .30").

Get the calculators out (-:

 

[Doodle]

The diameter is 0.6246 at a depth of 0.1385

 

[Wreck™Wreck]

Solid Works gave me these dimensions which are what I used to make the parts, this doesn't make them correct however (-:

 

[Terrywerm]

I came up with the same dimensions as Wreck Wreck. 0.129" depth to the tangent, 0.638" diameter at the tangent, and 0.895" diameter at the outer part of the chamfer.

 

[RJSakowski]

SolidWorks is a powerful mathematical tool. I use it frequently to solve math problems that would be difficult or impossible to solve otherwise. When I did drawings with radiused intersections of intersecting angles, I would put a virtual point which was collinear with each of the intersecting lines and dimension to the point. In the actual machining process, the chamfer would be made first, followed by the fillet anyway so this was a logical way of dimensioning. Dimensioning to the intersection of the fillet with the mating surfaces is not a easily verifiable.

Measuring the depth of a chamfer is an interesting task. An optical comparator can be used to determine the diameter of the chamfer at he surface but not every shop has one. My favorite method is to use a known diameter ball bearing and measure the depth to which it seats in the chamfer. It does require knowing the angle of the chamfer but otherwise is a simple and accurate method. When I created part drawings for the shop, I would include a drawing with the ball in place giving the inspection dimension. Again, SolidWorks makes a trivial task out of determining the dimensions.

 

[Doodle]

I measured at the point tangent to the 0.03 radius, if you wanted the edge of the 45 line, to me, that is not the same question.