Proper way to detail an ellipse
Proper way to detail an ellipse
(OP)
Hello All,
I've created an ellipitical plate needed for an assembly. My probelm is what do I need to fully define it as a 2-D drawing that a machinist to understand. Right now all I have is the major and minor diameters and axes, as well as the overall centerpoint. If I gave this to a machinist would that be enough or do I need to find other points and radii. If so could someone lead me in the right direction of what I need to dimension.
Thanks,
Jason
I've created an ellipitical plate needed for an assembly. My probelm is what do I need to fully define it as a 2-D drawing that a machinist to understand. Right now all I have is the major and minor diameters and axes, as well as the overall centerpoint. If I gave this to a machinist would that be enough or do I need to find other points and radii. If so could someone lead me in the right direction of what I need to dimension.
Thanks,
Jason





RE: Proper way to detail an ellipse
Just Wandering.
The rentapen
RE: Proper way to detail an ellipse
Good Luck - You might be pleasently surprised.
RE: Proper way to detail an ellipse
But I would also include the GD&T tolerance of the profile, if it has to match another part. Of course it all depends of what are you designing.
gearguru
RE: Proper way to detail an ellipse
Could a simple (metal, wood, paper ?) template suffice?
If so, you can have a discussion with your better shop-guy(s) and have one template made up to meet your needs, and save a LOT of possible confusion.
Of course, if a template won't work, you may need to have a trained worker, or spend some training time on the workers (plural) that will need to do the job.
Curmudgeon
RE: Proper way to detail an ellipse
RE: Proper way to detail an ellipse
An approximate ellipse is obtained by using the major and minor radii and and the X and Y overall dimensions. Some blending may be required at the intersections of the radii. There is a standard drafting procedure for constructing and dimensioning these.
To obtain a true ellipse you have to project points from a circle and spline them. EG: Using basic descriptive geometry draw two views of the circle, plan and side ( a line), slice the plan with planes then project the intersections from the side view at the angle required to obtain the ellipse. Again, any descriptive geometry book should show this procedure.
Al Kirby
askkkf@avci.net
RE: Proper way to detail an ellipse
If you are making this piece with a CNC machine, output an iges file to the CAM operator. They should be able to program from this. Some machines will have the function built in.
If this is being done by a flame cutter, then do a plot on mylar.
If the poor sucker has to do this by hand on a milling machine, then use a spreadsheet to generate an xy table of values.
If sending this out to a blacksmith . . .
Crashj 'your lucky day' Johnson