Finally, more progress on the 3D printer! With the frame designed, printed, and bolted together, it was time to move on to the moving parts. All part files are up on Thingiverse.
I ended up going through several revisions of both the hot-end platform, and the carriage mounts for the rod-ends. The versions shown in the pictures are not necessarily the latest version. I've kept the Thingiverse file list updated with the latest files.
|Hot-End Platform on the Left, Rod Sleeves on the right.|
|My original, wimpy carriage rod ends|
|Fixture for making the effector rods|
To make the effector rods, I first cut the rods to length (230mm) using an X-acto razor saw. Then, I epoxied the printed rod sleeves onto each end of the six rods. When I epoxied the Traxxas 5525 rod ends into the ends of the carbon rod, I did it one rod at a time, and after applying the epoxy I slid the tie-rod ends over the screws in the fixture. So, when the epoxy finished curing, each rod was almost exactly the same length.
|Finished Effector Tie-Rods, lightweight and strong as heck|
Note the yellow parts in the pictures, different than the original black shown above.
|Assembled frame & platform. I really need a better photo backdrop!|
|Close-up of the frame and effector rods|
Again, the carriage mounts and platform shown in the photos are not the latest and greatest, I did more revisions after they were taken.
Another option would be to use a pair of springs (or rubber bands) on the ends of each arm to pre-load the arms and eliminate the slop. I might try that short term as it's quick and easy.
Next up was to design and print endstop switch and adjustment screw mounts. At least initially I'll use the trusty RadioShack sub-miniature lever switch.
|Mounts seen in yellow. The carriage is all the way up, with the M5 screw triggering the endstop switch|