Wednesday, December 31, 2014

Prusa i3 Rework: Build Log #7- X and Y-Axis Motions

Moving on to the next part of the build log- attaching the timing belts. Without a doubt, this step was the most painstaking part of the build process. Tightening, loosening, and re-tightening the belts was time-consuming and rather dry. Hopefully you can pick up some tips from my build process.


Here are the only items you need for this step- the belts and some small zip ties. I used flush cutters to trim off the ends of the zip ties. They are very cheaply priced (made by Hakko) and they work very well.



Here is the very first part of this step. Inserting the belt through the X End Idler was tough due to the screw poking into the part (upper right, above the pulley). I recommend pushing the belt through on the upper side, and letting it snake out the bottom.


After getting the belt around the side with the idler (bearing) and the side with the pulley, here is the carriage with the belts wedged into the proper spots.


Here you can see what the belts look like. There are small teeth in the top of the carriage part that allow the belt to stay put.


Here is the carriage after pulling hard on each side of the belt, and wedging more length of belt in the teeth each time. When the belt became taut, I put two zip ties on each side, lining up the teeth with each other.


Here you can see how the belt lines up with itself. The zip ties were then clipped, without trimming the belt at all.


Now the X-Axis assembly is complete.


For the Y-Axis, I tilted the printer on its back to get easier access to the necessary parts. The belt here was much easier to install than the one on the X-Axis.


After lining up the Y Idler, Y Motor, and the Y Belt Holder, I pulled the belt taut through the belt holder and zip tied it. It is important that the screw in the Y Idler is all of the way in at this point.


I then moved the zip ties over, so that they wouldn't get caught when the bed was fully extended or fully retracted.


A close up of the zip ties on the belt. It doesn't really matter if the belt isn't tight at this point- that's why there is a tightening screw on the Y Idler.


Again, the belt here is slack. Here the motor pulley is shown with the belt attached.


Finally, I tucked the excess belt pieces between the zip ties and the Y Belt Holder parts. I didn't really want to cut them off, because I might need to modify the printer in the future.


Here I made sure that all of the Y-belt carrying parts were lined up. I then adjusted the Y Idler's tensioning screw until the belt was taut.


Another step closer to a complete build!

This post is the seventh of ten that goes over my Prusa i3 Rework build. These posts are in the order given on RepRap's wiki page for the Prusa i3 ReworkAll of the images from the build are in this Flickr photo album.

My build log: