I really liked the Hold Down clamps by MasterKookus, but it turned out they were not quite strong enough for some of my workpieces. I very much appreciated the Fusion360 file he attached, and so modified the clamps to have a beefier long leg and thicker saddle to avoid cracking. I also re-did the void for the screw shaft and added in a small gap to allow the cylinder to be inserted more easily into the clamp.
Of all the clamps I've used I like this design the best. I just tweaked it for the strength of materials I used for printing it.
Thanks to Masterkookus for his first design! The parametric design he went to the trouble of creating made this straightforward to modify. That's why we do design that way!
I've also attached the Fusion 360 file with the full assembly and joints.
Following MasterKookus's example, I'm also attaching shorter versions of the clamp (1.5" and 1" leg versions), which are easily generate from the parameterized file in Fusion 360.
Update: Since I was interested in the strength of the part, I ran a stress simulation to find vulnerabilities. Looks like I was able to fix the problem on the saddle and the long leg. I have yet to see a problem on the short leg as indicated as the most probably problem how. Simulation run with 50 lb down on the cylinder, which is probably a lot more than I've been seeing in actual use. I may have to measure it.. Note that the simulation does model the deformation along the length, which is expected with these plastics. Picture of stress analysis attached (I could not attach a video showing the progression).
I printed in PETG with 3 perimeters which gives excellent strength. No supports required for either the arm printed on its side and the cylinder on end. Gaps in the middle are easily bridged.