Yes, lots to blog about about.
First, the top piece. I got most of my ideas from hacklab.to for this part. Most of it isn’t interesting, except for an accident in the design I made. I had originally intended to shift the motors outward to allow for room for the nuts. As I was finalizing the design for printing I realized I had neglected to do so. I decided to quickly add another variable called “beforetap”. What I then did was insert this into the radius parameter. So the script would behave as if the hole were 8mm, but it would print a 7mm hole i would tap for M8 during post processing. So the mistake turned experiment was tapping the holes. This could potentially cut the nut and washer count in half. By tapping the hole we are not loosing structural integrity, nor adjustably. As long as the opposing side is adjustable, by using nuts, we are fine. Also considering the “overlap” nature of the design in many of these part, the rods are in contact with each other, which helps aid in structure.
And it is starting to look like a printer :). So far I have designed all the part necessary without building or using advanced CAD software to visualize. I used the other openscad scripts to keep track of parameters. At this point the only thing left to design is the X carriage and maybe extruder and MixTape Mendel version 0.1 will be complete.
Below you can see on the right top piece, there are no nuts holding it together. It is entirely tapped.
Some pictures comparing Mixtape to Isaac.
I think this one has an optical illusion because the Y travel seems identical in person but isn’t so in this picture. It is probably because Mixtape is much more compact.
S. J. Kelly 