While waiting for the bits for my extruder to turn up. I have been tweaking the parts a little. If you look at the fully assembled images in an earlier post, I originally used toothed pulleys that came with the belts at the top of each axis thinking these would be better. The problem was that I could not really tighten the belts as these pulleys simply had too much drag. Although it worked, if things went too fast it would occasionally skip during a move, so I had to slow things down.
That'll learn me fer thinkin.
I decided to replace them with F6o08zz Flanged Ball Bearings (see link below).
Wow! what a difference. Now the belts are so tight that I can play a nice base riff and the movement is silky smooth. I was able to increase the movement speed by almost 50% over the older setup and I will get a lot less backlash.
I have included a picture of the top part of the axis. There are two of these flanged bearings on each one. They are only flanged on one side so you place 2 face to face. In the image I have put a couple on top of the printer in this photo so you can see the profile.
Now I am just waiting for the mounting plate for my hot end and the PTFE tubing for the Bowden Extruder.
I am doing the same double flange bearing on mine (I'm not even really sure what was originally intended, doubling them up seemed to make sense though. My Rostock build uses mostly Mcmaster parts, and will have close to a 445mm build height.
ReplyDeleteHi Andrew,
DeleteI cant imagine ever building something that high. But thats just me. my existing printer is only about 85 build height max. At the moment, my build height on the rostock will be about 200. I have the extra 200 sticking out the top and can always extend by getting longer belts. Thats one of th things I like about this design.
Thanks again for blogging your Rostock build.
ReplyDeleteI was going to assemble this as Johann outlined with only one flanged bearing. But, after seeing that you used two - it made sense and I used my extras. I will also twist the belt as you mentioned in another of your posts.