I borrowed a 10mm allen head bolt from 3d warehouse, as I needed a custom length bolt to try
the bolt provided was composed of a head and shank. My challenge is to change the length of the shank, longer or shorter sample bolt shank.skp (488.7 KB)
Of course I can’t use Push-Pull on the shank to adjust length, can I? I made the shank into a solid thinking I’d use trim with a ‘cutter’ to shorten, or add a trimmed section of shank to lengthen. Of course, scale would make a mess of the threaded rod?
Is there a better way to adjust the shank length of the imported model bolt?
The shank of the screw should be smooth and effectively a cylinder. You should be able to use Push/Pull on that part if the head is separate. Then use Move on the head to move it into place. If you have the head and shank as a single component you can select the Head geometry and use Move to adjust the length. If you need to change the length of the threaded portion Scale wouldn’t be the right tool for the job because, as you say, it’ll scale the threads, too. To shorten it, frimming with a cutter and the Solid Tools (or better Eneroth Solid Tools or BoolTools2) would work. To make it longer you can open the threaded component, Turn on Hidden Geometry and use Move/Copy to created additional threads.
When I need to make a screw or bolt component I always make it longer than I need (longest available in the size, anyway) because it’s easier to cut the screw shorter than it is to cut it longer.
There may be some confusion of terminology here. In your model, you labeled the threaded portion as “bolt shank as a solid”. As @DaveR wrote, the term “shank” more often means an unthreaded portion between the head and the threads, which doesn’t exist in your model. It would be easy to add by push-pulling the circular face of the head.
That leads me to think you mean you want a longer threaded screw without a shank? If that’s correct, again as Dave wrote, you can just move/copy a suitable collection of (hidden) edges to add the length. The tricky part is getting all and only the edges you want to copy. Also as he wrote, you can use a solid tool to trim off excess to get a shorter screw. In both cases, you would probably need to scale the screw up by 100 or even 1000 to avoid issues with losing small edges and faces during the trim.