Sweep command rotating "swept" object

Well to be honest it was over 2 years ago that you sent me the tutorial files and I followed the tutorial. Since then, I've done helical threads a only a couple of times here and there. Recently, after not doing it for quite some time, I just glanced over your tutorial to remember the basic steps.

I'll have to come back to this tomorrow as I have to leave for a doctors appointment. I will also do my drawing up so that it follows your tutorial drawing more closely to rule anything else out. What I don't understand is, why when I draw the stud with "flat" 90 deg angles on the end (before revolving) it works, but if I add the 45 deg bevel at the end it doesn't create the threads. That's part of the reason I assumed I must be overlooking something that would be obvious to people more skilled at this.

I'll try to make less assumptions and be more prepared next time.

Thanks again.

Actually JD, I misunderstood what you meant about the hidden layers. I was aware of the layers in the drawing, but I somehow read that to mean there where duplicate layers of the 2d geometry that were hidden already in the tutorial file, that I didn't remember seeing.

I haven't had time to redo my drawing yet as today has a bit hectic, but I'll make sure and set DELOBJ=0 before drawing and uploading.

Ok, so I don't see anyone offering a real answer here. When you choose your sweep object look at the command line, 4 options appear.

Alignment is set to yes by default, choose no and select your helix. Your triangle will now extrude properly around the helix and your thread will look proper.

I am trying to create helical threads based on this tutorial by JD Mather: http://home.pct.edu/~jmather/content/CAD238/AutoCAD%202007%20Tutorial%204.pdf

 

I have done this in the past successfully, but now I can't figure out what I am doing wrong. If I draw the stud so that ends are tapered at a 45 deg. angle as in Mr. Mather's drawing, when I try to sweep the triangle along the helix it rotates the triangle which cuts into the tapered end a little but then only creates lines along the rest of the stud.

 

If I draw the stud so that is is flat on each end, just a plain cylinder, it sweeps properly and once subtracted, gives the proper helical threads.

 

Does anyone have any idea what causes this? Originally I thought maybe I was putting too little height between turns and tried several things before getting the idea that maybe it was the tapered end causing the issue... which seems to be the case.

 

I would also like to note that I am not drawing it to JD Mather's "specs" from the tutorial, I am using the Machinery's handbook to get measurements for diameter, pitch, etc... I made a 5/8 stud, and didn't have an issue, however on 3/4, and 7/8 I have the same problem.

 

 

*Edit*

If it helps any it appears that the triangle is rotating so that the side of the triangle is parallel with the base of the stud.