This can make gears bind or function poorly. One of the more common mistakes we see in simplified gear software is the lack of undercut in small tooth count gears. Gear 1 and Gear 2 can have the same or different center hole diameters.Ĭenter Distance – This is the distance between the two shaft centers holding the gears. Another way to think about it is positive profile shift numbers will allow for more backlash between two gears en-mesh.Ĭenter Hole Diameter – Central bore hole in each gear, for standard size we’d recommend the Machinery's Handbook. A positive profile shift represents a theoretical cutter cutting deeper (leaving longer, thinner teeth), while a negative shift would cutter more shallow (leaving shorter, thicker teeth). Profile Shift – Default is 0 for most applications. To convert, use: Module = 25.4 / Diametral Pitch Module (Pitch) – this parameter sets the tooth size. The rack length defaults to the diameter of Gear 2. Gear Type – External spur gears use a positive tooth count, while internal spur gears use a negative tooth count. Tooth Count – is set with the parameter "n" for Gear 1 and Gear 2 Input the following parameters in our free gear dxf generator:.Then select the SPURGEAR.LSP program from where you stored the downloaded files. Use theĪppload facility by selecting Tools / Load Application. These values are updated so the spur gear data becomes that of the prior entries.ĭownload the SPURGEAR.LSP and SPURGEAR.DCL files and save them in AutoCAD's Support directory. The default first-session values are shown as 4" PCD, 12 teeth, and a 14.5-pressure angle. The program draws the gear in the image tile, showing the number of teeth for a quick reference. You supply the pitch diameter, number of teeth, and pressure angle using the Spurgear dialog box (figure 1). In response to requests, particularly from John Hurlburt, to update the routine for AutoCAD 2004/2005, I added a dialog box and corrected some compatibility problems to make SPURGEAR.LSP run in all versions of AutoCAD from 2000 onward.
This month, I was spurred to return to a spur gear program that first appeared for AutoCAD Release 14.