Experimental Y carriage

This evening I built a new Y carriage for the printer under construction, making it wide enough to hold the pyroceram glass without cutting. In order to facilitate this I rejigged the printer to 250mm wide instead of the Prusa standard 235. The threaded rod is all long enough to support this width (barely).
I also decided that the Y bearing bracket over at Thingiverse is an interesting idea, allowing the Y carriage bottom plate to be mounted upside-down. This should give at least another 10mm of Z print area. After printing the part and assembling, the problem is that with a 608 bearing the belt hits the bottom threaded rod a bit. I won't allow that, I think what I will do is to redesign the bracket to move the bearing up enough to barely clear the rod. Then I'll print a belt clamp that's tall enough so that the belt coming off the top of the bearing will line up perfectly with the clamp so it's a linear pull.
The bearing only needs to move up about 5mm for the belt to pull the bottom rod; I think this can be accomplished and still let the bottom of the print bed come down all the way to the LM8UU bearings.
I don't like wingnuts as leveling adjustments on the bed so I printed up some knobs from my parametric knob script. Given the extra long length of those bed-to-bed screws, I sized them up to #10 screws.

RepRap demo at the high school tomorrow

I am doing a 3D printing demo for the high school Robotics club tomorrow morning (Tom is on the team). The shop manager that mentors the group has a DIY 3 axis CNC router so he's pretty familiar with the concept and the tool chain, and he teaches 3D CAD at the school.

I got the full toolchain installed on the new laptop and just picked everything up from the basement and put it on the kitchen counter and did a test print, so I think I'm ready to go. The printer is looking a little ratty right now but I think that's a good thing; it shows that this is definitely a DIY thing and I'll emphasize that the reason it's all ratty looking is that I keep taking bits of it apart and making changes and doing experiments.

I'll also bring along my in-progress printer and if any of them want to talk more I can show the different stuff I'm changing, and point out that I haven't even finished it yet and I'm already thinking about changes to make after I get it done, and I'm kind of thinking about a 3rd printer (but only after I sell the first one) - I want a bigger form factor, not so much for wider/deeper things but taller. I'd like to be able to go a full 200mm high, and that just needs more threaded rod, modified vertexes and some longer drill rod and a firmware tweak.

The school actually has a couple of 3 axis mill/router things but they're industrial bots and without the industrial software to match them they're just sitting there. I spent an hour last Saturday talking with him and poking at the bots and we started thinking that we could rip the existing electronics off of them and hook up RepRap electronics, or some other applicable drivers. They're just standard bipolar steppers on all three axes.

New thing (variant) posted

I posted a new variant of a thing up on thingiverse. Y axis bearing bracket very similar to one posted a few days ago but parametric to be able to change where the bearing goes.