Worm gears--small

[newcomer]

The basic idea is this: a driven gear, about 2" (or 50mm) in diameter connected to a "something" (details don't matter).  A worm gear is the driver gear, connected to a stepper with either a 5mm or 8mm shaft (to be determined).  The Inventor worm gear mechanism presumes I know the meaning of all lthe parameters, but I couldn't find any one place where these parameters were explained with a drawing.  The worm gear will be driving this will drive the gear, which will be about 5mm-8mm thick.  As I've played with the worm gear stuff, I can't get it to create a worm less than 72mm long.  Since I can't find a reference drawing, and am not a mechanical engineer, I need some help in how to create a nice, small worm-driven gear and its worm.

One of the more fascinating features about the Inventor documentation is it says "do this" but does not say how to get to the place where "this" can be done.  It is often very hard to figure out what I have to do to get to the conext for doing what the help page describes (any Autodesk people reading this, remember that help is not just a book that is read from cover-to-cover; hypertext documents are often entered at random places and therefore do not give context.  And the "parent link" isn't adequate for figuring how to get from wherever I am to wherever I need to be)

      joe

[JDMather]

Since you aren't familiar with gears - can you use two simple cylinders to represent the gears?

[newcomer]

That idea would work up to the point where I have to create the gears themselves, whether by 3D printing (probably not useful) or CNC manufacturing from blocks of metal.
joe

[JDMather]

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@newcomer wrote:
...I have to create the gears themselves, ....

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...

Gear geometry (especially worm gears) is very complex.  The Inventor Gear Generator Design Accelerator only creates simplified representation (there is a way to use the info to create the complex geometry - but it isn't easy or automatic).

Gears are usually purchased off-the-shelf or by giving parameters to a company that specializes in gear manufacture.  You have a long learning curve ahead to design and make them on your own.  Probably cheaper to contract this out (or purchase existing off-the-shelf item).

[Paul-Mason]

The may be a way to get the length of Worm that you want by

Create the Worm & Gear as normal accepting that the worm is to long then :-

1) Open that worm & Gear assembly

2) Highlight the assembly RMB select open, now this may look like the same assembly but it is not

3) In the second iam file that opens highlight the worm RMB and open again, this I think take you to the part level, if not

3a) Highlight the worm and RMB and open

4) In the part level there are one or possibly two imate/constraints that need to be deleted, I can remember off hand which., to allow the worm to be easily edit to the desired length.

Then you can create two offset work planes from the center work plane and use the SPLIT command to trim the worn to the length that you want using the new offset planes. Also while in at the part level you can add the drive shafts etc. To the part save then, if you finished, close the part update the two assembly files

I've used this method on this ,these attached worm & gear file Design Accelerator.zip, that's if IE 11 is not playing up again, they are in Inventor 2013 format, as the worm was way to long for what I needed so by comparing the worm gear in that you should be able to ID the constraints that I deleted to get the length and diameter that I required, like you say you can't always get the length to diameter sizes that you need in the Gear Generator.

Hope this is of some help to you.

The final assembly/project is available at https://grabcad.com/library/hand-reversing-gear-1/files/Hand%20Reversing%20Gear.zip you may have to register to get sasses to them.

The edited worm

The final assembly