kas006 Posted September 4, 2011 Posted September 4, 2011 Hello! I have a pretty anoying problem. I want to sweep the "cuttingtool" through the helix to create a inner thread of my nut. When i set "Align" to "NO" it refuses to sweep. If i set "Align" to "Yes" it works perfectly but the result is ofcourse totaly wrong. Can anyone help me? Pic http://i60.photobucket.com/albums/h11/kas006/sweep.png Quote
ReMark Posted September 4, 2011 Posted September 4, 2011 Have you tried EXTRUDE using the Path option too? Quote
kas006 Posted September 4, 2011 Author Posted September 4, 2011 Yes i've tried that also, it ends up in a ugly corkscrew. This is pissing me off. Quote
nestly Posted September 4, 2011 Posted September 4, 2011 (edited) Orient your UCS so the Z axis is running though the centerline of your helix. Edited September 4, 2011 by nestly Quote
kas006 Posted September 4, 2011 Author Posted September 4, 2011 It worked! Thanks alot! do you mind telling me why it matters where my Z axis is? Quote
nestly Posted September 4, 2011 Posted September 4, 2011 It worked! Thanks alot! do you mind telling me why it matters where my Z axis is? Truthfully, I have no idea, I only know that it does matter as I suffered through the same frustration you've just encountered. Quote
kas006 Posted September 4, 2011 Author Posted September 4, 2011 Finished product http://i60.photobucket.com/albums/h11/kas006/finished.png Thanks again. Quote
kas006 Posted September 5, 2011 Author Posted September 5, 2011 Now it doesnt work again... this is so damn frustrating.... Quote
nestly Posted September 5, 2011 Posted September 5, 2011 Post a sample drawing of one that won't work. Quote
JD Mather Posted September 5, 2011 Posted September 5, 2011 http://home.pct.edu/~jmather/content/CAD238/AutoCAD%202007%20Tutorial%204.pdf Quote
ShawnTTCoop Posted September 6, 2011 Posted September 6, 2011 I get the unable to sweep message if the object created intersects itself. I.E. if i just make a triangle to cut out the screw threads, and the triangle base ends up too big. This shouldn't be a problem if you are making a realistic thread, but sometimes something goes wrong. Might be worth checking out Quote
kas006 Posted September 8, 2011 Author Posted September 8, 2011 Im using the exact exact measurement of a m10x1.5 thread. Helix height is 1.5. If i want to make an inner thread, i point the tip of the cuting tool to the center of the circle(hole). from here it refuses to sweep. If i change the angle of the cuting tool just a few degrees away from the center it works perfectly but the finished product isnt a exact m10 since the cutingtool now is not aligned with the center.. If i try to extrude the cuting tool with the helix as path, it makes a weird looking waistshaped helix (With cuting tool aligned with center) .... how can 2 parts perfectly straight make a curved helix? I guess this is what makes the sweep not working. As you said "it intersects itself".. but why? Sorry for my bad english. Quote
ShawnTTCoop Posted September 8, 2011 Posted September 8, 2011 I think i know the waist shaped helix you are talking about, but I had the same problem with my dwg, and was unable to correct it. I, unfortunately, just shortened the width of the triangle i was sweeping(from the exact measurement), and it worked to create the threading. I just correctly labeled it in the 2D drawings I made of the models and showed it to the fabricator to make sure he knew the threads. The self-intersection, I believe, was do to the base of the triangle, used to make the object, (which I then subtracted from the rod to make the thread) being to large. I don't really know why it turned out that way when I was using factory specs for the triangle creation, but there are tolerances for a reason I guess. Sorry I can't be of more help. I am an AutoCad newbie, and Inventor has a screw creator lol Quote
SuperCAD Posted September 8, 2011 Posted September 8, 2011 The problem when doing threads like this (and I've done a lot of them) is when you use the exact measurement of the thread and try to sweep it along the helix, the edges of the threads may be touching each other and ACAD doesn't like that. Make sure that you have enough separation/gap between the treads before you sweep the profile. Quote
kas006 Posted September 8, 2011 Author Posted September 8, 2011 Okey.. event tho i think it VERY weird that the worlds most used CAD program cant make a proper thread, i guess it simply cant... Quote
JD Mather Posted September 8, 2011 Posted September 8, 2011 Okey.. event tho i think it VERY weird that the worlds most used CAD program cant make a proper thread, i guess it simply cant... In the first place AutoCAD is a 2D program that has had some 3D clumped on top. You should be using a next-generation 3D MCAD product like Autodesk Inventor for something like this. But whether you are using AutoCAD, Inventor, SolidWork, Pro/E or .... you will need to make the triangle 1.499 for a 1.5 pitch. (see the thread tutorial in my signature) Quote
nestly Posted September 9, 2011 Posted September 9, 2011 But whether you are using AutoCAD, Inventor, SolidWork, Pro/E or .... you will need to make the triangle 1.499 for a 1.5 pitch. Did you just say you can't make a true 1.5 pitch thread with Inventor? Quote
JD Mather Posted September 9, 2011 Posted September 9, 2011 Check your Machinerys' Handbook for the true toothform depth. In the real world nothing can be made to exact sizes - there are tolerances associated with every dimension (which you can enter in Inventor). Offset your cutting tool if you wish to mimic real world rather than create a mathematically perfect helix. Quote
nestly Posted September 9, 2011 Posted September 9, 2011 I'm not asking about machining tolerances, I'm asking whether Inventor has the ability to draw a perfect thread in 3D. Quote
JD Mather Posted September 9, 2011 Posted September 9, 2011 I'm asking whether Inventor has the ability to draw a perfect thread in 3D. Yes, as defined by the Machinerys' Handbook. As does AutoCAD. You might see the Threading tutorial in my signature for instructions. As I recall it is an M10 x 1.5 Quote
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