Drawing a gear and a rack
Drawing a gear and a rack
(OP)
I have a gear and rack (these are physical units that I have in my hand) that I need to create a model and drawing for in SolidWorks. For this, I first need to make the relevant measurements on the gear and rack and then figure out how to reproduce in SW. My question is: what measurements do I need to take, how do I take them (i.e. what instruments do I use) and how do I draw them in SW. I have an older version of SW, so I might have to make these from scratch. I think there is a feature "Gear" in newer SW. Your comments will be greatly appreciated.






RE: Drawing a gear and a rack
As far as doing a drawing of a gear, it is not critical to actually draw the teeth (unless you want a pretty picture). The critical areas are typically tabulated on the face of the drawing. These areas are:
1. Diametral Pitch
2. Number of Teeth
3. Pressure Angle
As far as measuring the gears you have, you can count the teeth, and there are formulas that relate the diameter of the gear and the number of teeth to find the dimetral pitch. As far as the pressure angle goes, that deals with the shape of the tooth. I am not sure how you will be able to find that. Somewhat standard for pressure angle is 14.5 degrees
You may be able to check out www.engineersedge.com for more info.
RE: Drawing a gear and a rack
Regards,
Scott Baugh, CSWP
3DVision Technologies
www.3dvisiontech.com
www.scottjbaugh.com
FAQ731-376
FAQ559-716 - SW Fora Users
RE: Drawing a gear and a rack
"I think there is a world market for maybe five computers."
Thomas Watson, chairman of IBM, 1943.
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
RE: Drawing a gear and a rack
The standard way to do accurate measurements of gears is to use three pins. The pins engage opposite teeth, and you measure across the pins. A textbook on gears should explain this all. This will help you confirm the pitch.
Dudley's Gear Handbook (McGraw Hill) has instructions on how to draw a gear involute. It works.
JHG