That's all fine and dandy until you want to make an impact on a customer without showing them a real part first. I think I can decide the relative value of modeling the threads for myself. Obviously I sometimes feel a need to draw them in or else I wouldn't have posted. Some of the replies remind me of the time I wanted a CNC company to demonstrate both absolute and incremental on the same screen and when they couldn't figure out how they instead tried to convince me I didn't need to do it. Even while they were looking at our 15 year old machine that had no problems doing it. Or when I once tried to order a computer from Dell and I asked for a full tower. When the guy didn't have that option he instead tried to tell me I didn't need one. An option to show at least a simple v thread doesn't seem like much of a burden unless you are targeting the Wal-mart laptop CAD market. Plus I know for a fact I'm not the only person asking for it so let's not pretend there isn't a desire to have it. Just make it a feature based toggle. Key features where you want visual impact can have 3D threads turned on while you can slap 2D decals on everything else. It's 2010, not the days of AME and the 386.
Edited by: BillPirschel7709 on Jan 29, 2010 1:36 PM
We do custom threads for mounts for custom optics in instrumentation. The size of an optic is determined by the size of the light beam at the particular point of the optic, so the mounts can be any size and are often limited by space.
This is how I handle custom threads. I have built a spreadsheet that uses the formulas in ASME B1.1 (Unified Inch Screw Threads) to calculate the appropriate values. Input is the nominal diameter, pitch, class of thread, any extra allowance, length of engagement, and any coating thickness that may apply. The output is max and min diameters for major, minor, and pitch diameters in the format of the Threads.xls spreadsheet. I copy the line into a sheet of special threads in the Threads.xls spreadsheet as suggested in other responses to this thread. The diameter of the cylinder that I apply the thread should fall within the max/min of the major diameter of the thread. We have recently acquired a lathe that can turn metric threads, so I will be doing a spreadsheet for ASME B1.13M also. As a bonus, I have a section of the spreadsheet that formats the thread information so I can copy and paste it to the notes section of the drawing.
My complaint in this process is that to get Inventor to read the modified spreadsheet, one has to restart Inventor after a new thread is added. This is second only to the memory leak problem in my book.
FWIW - I also have created a workaround so that I can put real threads in when I need them. If I have lots of small threaded holes in a part, of course cosmetic threads are fine. But, for those of us who design parts where the thread itself is an important feature of the part, cosmetic threads are useless: they don't show up in renders or in drawings.
I have an iPart that I use that can be internal or external, trapezoidal or ISO threadform and it works fine. Sure would be nice to just have the option on the threading tool whether to make it real or Memorex though.
Mikah Barnett All Angles Design Product Design Suite Ultimate 2014 Windows 7 Professional x64 Intel i7-3770k @ 4.5GHz 32GB DDR3-2400 RAM GeForce GTX 670 4GB
I took a similar approach. I got my ifeature to work after looking at CBiss's ifeature. His relies on a table while I just tell it the diameter pitch and length. But mine is just a sharp V with no radius so it gets the point across without taking up more resources than needed. CBiss's is more acurate as it includes the radius. I started but have not had a chance to finish the internal version. But they should match up using the angle constraint. My first attempt still seems to need an extra geometry selection than I think should be needed. I guess we can at least be thankful that Inventor has the tools to work around it's own limitations.