Re: Thread Maker v4
Posted: Thu Apr 28, 2022 9:19 pm
Finally, I've had a chance to do a "deep-dive" into the Fasteners Workbench (FW), after having initially dismissed it as not able to create mating Int/Ext threads with a clearance. This clearance is needed in 3d printed threads, because without it, after the curing process, mating printed threads will generate a mean interference fit during tightening, which turns much of the surface material into powder. I've found 0.1 - 0.2 mm radial clearance between mating thread surfaces gives a tight fit at first, but after one run-in fit, they tighten normally and survive lots of re-tightening afterwards (esp. using "coarse" pitch standards not available in the FW objects).
But I still wanted to come back to FW to discover all of it's functionality, and made note of 4 basic differences between ThreadMaker (TM) and FW.
Wide variety of bolt heads, washers, nut profiles. FW is rich with standardized bolt styles, nuts, washers which are threaded. TM has none of this, generating only Ext thread shafts and mating Int thread inserts.
Variable pitch. FW fasteners are created without user-selectable pitch, except for the "Threaded Rod" object. And that is only available for Ext thread. Also, setting a custom pitch for Threaded Rod will not adjust the diameter if using an alternate standard pitch from the ISO table. TM will generate any pitch entered, on or off the ISO chart; and you pick the diameter to use for it from the chart, rather than entering a "size" such as M10.
Filleted concavities. FW threads are filleted along the concave edges between threads, as allowed in ISO thread standard. This makes for a mechanically stronger thread bolt (or insert). TM threads can be filleted separately (select 1 upper and 1 lower arc edge, then PartDesign->Fillet).
Mating clearance. All FW threads are 0 clearance between Int. and Ext. As mentioned, TM allows user-specified clearance for generating 3d-printable, mating threads.
Clearly there are valuable benefits in both tools for us 3d printer owners trying to break the bonds of our brick-sized max print volume. From the above differences, and in the interest of getting the most out of FreeCAD in it's current form, I suggest and am following these guidelines for printing threads:
** Do it all in FW if you are printing threads to fit non-printed counterparts, and the "standard" pitch for each thread size meets your needs.
** Do it all in TM if you don't require fully formed nuts and bolts, AND [[[ you are printing mating threads (needing clearance); or you are printing threads to fit non-printed counterparts with pitch size not avial. in FW ]]].
** Use both FW and TM to generate complete nuts and bolts with 3d print capability or alternate/non-standard pitch. For example, to make a 3d M10 nut/bolt pair, use FW to generate a threadless bolt head and nut; use TM to generate the mating pair "Ext Chamfer Base" / "Int Bevel Base"; fuse the Ext threads to bolt head; fuse the Int thread insert into the nut.
I wonder if TM and FW could get 'hitched' someday. Just think of all the wonderful children we could have. Awww!
EDIT: Oh, I forgot to mention taper! NPT. If you need to print to fit NPT, you''ll need TM.
But I still wanted to come back to FW to discover all of it's functionality, and made note of 4 basic differences between ThreadMaker (TM) and FW.
Wide variety of bolt heads, washers, nut profiles. FW is rich with standardized bolt styles, nuts, washers which are threaded. TM has none of this, generating only Ext thread shafts and mating Int thread inserts.
Variable pitch. FW fasteners are created without user-selectable pitch, except for the "Threaded Rod" object. And that is only available for Ext thread. Also, setting a custom pitch for Threaded Rod will not adjust the diameter if using an alternate standard pitch from the ISO table. TM will generate any pitch entered, on or off the ISO chart; and you pick the diameter to use for it from the chart, rather than entering a "size" such as M10.
Filleted concavities. FW threads are filleted along the concave edges between threads, as allowed in ISO thread standard. This makes for a mechanically stronger thread bolt (or insert). TM threads can be filleted separately (select 1 upper and 1 lower arc edge, then PartDesign->Fillet).
Mating clearance. All FW threads are 0 clearance between Int. and Ext. As mentioned, TM allows user-specified clearance for generating 3d-printable, mating threads.
Clearly there are valuable benefits in both tools for us 3d printer owners trying to break the bonds of our brick-sized max print volume. From the above differences, and in the interest of getting the most out of FreeCAD in it's current form, I suggest and am following these guidelines for printing threads:
** Do it all in FW if you are printing threads to fit non-printed counterparts, and the "standard" pitch for each thread size meets your needs.
** Do it all in TM if you don't require fully formed nuts and bolts, AND [[[ you are printing mating threads (needing clearance); or you are printing threads to fit non-printed counterparts with pitch size not avial. in FW ]]].
** Use both FW and TM to generate complete nuts and bolts with 3d print capability or alternate/non-standard pitch. For example, to make a 3d M10 nut/bolt pair, use FW to generate a threadless bolt head and nut; use TM to generate the mating pair "Ext Chamfer Base" / "Int Bevel Base"; fuse the Ext threads to bolt head; fuse the Int thread insert into the nut.
I wonder if TM and FW could get 'hitched' someday. Just think of all the wonderful children we could have. Awww!
EDIT: Oh, I forgot to mention taper! NPT. If you need to print to fit NPT, you''ll need TM.