TECHNICAL

Quick overview about the production methods of gear cutting. This video illustrates the basic generating method of a gear shaping machine. Several examples of external and internal gears and splines are produced.

In this month’s TechBit we examine a few of the most common ways to produce gear teeth.

Methods of Gear Generation

So you have a gear (or a spline) and you don’t know what it is. Three basic things you should ask, what are the Pitch, Pressure Angle, and Circular Tooth Thickness. In all involute system gearing, these features define how the gear is made and are useful to understand when discussing gear and spline projects.

Gear & Spline 101

Have you ever wondered what the difference is between a “gear” and a “spline”? Or what a “Stub Tooth” is? If so, you might find the attached TechBit useful and informative. Please consider Doppler Gear for your next gear cutting, broaching or splining requirement.

Gear & Spline 201

In previous TechBits we discussed the basic features of “spur” (straight toothed) gears and splines. What if your gear teeth are “helical” (angled) or you have a “worm”? How is that defined? How is it measured? The following TechBit explores the concepts of Lead and Helix and should be useful to anyone working with gears, worms, and even basic threads.

Gear 301, Helix & Lead

If you’ve ever wondered how gear teeth are cut, this one-minute video on hobbing is for you.

Due to numerous requests, we put together this simple decoder to help identify the basic features of this common type of German spline. DIN 5480 can be confusing to those familiar with ANSI and ISO involute splines as it is based around the concept of a “Reference Diameter” with limited outcomes rather than a linear set of uniform ratios covering all tooth and Module combinations. This TechBit addresses some of those common misunderstandings and describes the basics of DIN 5480.

DIN 5480 Spline Decoder

This TechBit expands on international spline standards by examining the Japanese Industrial Standard JIS D 2001:1959 We hope you find it useful and, as always, please feel free to contact us if you have any splining requirements.

JIS D 2001:1959 Splines

Due to the popularity of our spline series of TechBits we have added the French Industrial Standard NF E22-141. We hope you find it useful and, as always, please feel free to contact us if you have any splining requirements.

NF E22-141 Spines

Estimated measures of machinability for steel, stainless, aluminum, cast iron, bronze, tool steels, and specialty steels and relative Machinability vs. Material Harness.

Machinabilty Tables DGC

So you want to know how much that 1 inch diameter gold bar sitting on your desk is worth…

With Doppler Gear’s handy Material Calculator it’s easy to do. You measure your gold bar and find it to be Ø1.00” in diameter and 4.00” long. You look up the today’s price in pounds and find it to be $19,993.74. Entering that into the calculator yields a material value of $43,780.09. This calculator is also helpful for calculating weights and cost on a variety of other materials like Steel, Aluminum, Bronze, and Titanium.

Material Calculator PDF

Material Calculator XLS Weight & Cost Worksheet

Over time we have found that a handful of keyboard shortcuts make technical communications more efficient, accurate, and effective.

Please download the list on the right of commonly used shortcuts and contact Doppler Gear Company for help with your gear, spline, and power transmission component needs.

Key Shortcuts

Well, since the definition of cog is “a toothed wheel whose engagement transmits force” we narrowed that down to pulleys. Should you need a toothed wheel to mesh with a synchronous belt, give us a call!

Timing Belt Pulleys

Space Sprocket Standard we do have ANSI B29.1M and ANSI B29.2M. If you come across chain sprockets you might find this information useful. Keep an eye out for our next TechBit on Cogs!

Sprockets

Gear hobbing is a highly accurate and very economical way to generate shapes in a part piece. These shapes could include gear involutes, splines, straight sided lugs, serrations, and a variety of other profiles.

Hobbing Toolpath Calculator XLS

Hobbing Clearance

Broaching is one of the most highly productive machining processes. It removes a significant amount of material in a precise and repeatable way. Generally a long tool called a broach is pulled through a hole in the part removing material with each successive row of “teeth” on the broach.

To the right you will find some information for download regarding stocked broach tooling. If you don’t see a tool that matches your requirement, contact us. We have hundreds of additional broaches including most standard keyways.

Broaching

Gear & Spline Broaches Partial List

Square & Hex Broaches Partial List

Straight Spline Broaches Partial List

Occasionally we have found that carburized parts will appear softer than they actually are when measured at the surface with too much penetrator weight. This can be easily remedied by using a different hardness scale and converting the data back up. You will find a reference chart to to the right to help explain the process.

Case Hardness Testing