Thanks for the feedback! I'll keep pushing through on the assembly. I just didn't want to get "done" and have to back up so far to fix something. Also, thanks for the link to the tensioner. I like that design better than the others I've seen that simply clamp onto the belt. However, the part I'm talking about is the screw used to hold the center lever down. If you look at this picture:
It's the screw/nut that you can see on the right side of that block. As you can see in the picture the little piece of wood is thinner than the slot it sits in (it's all the way up at the top of the slot in that picture with a big gap underneath). The gap under the piece of wood is where the nut ends up. So when I'm trying to tighten the screw the nut just spins. If the piece of wood were the same size as the slot then the nut would stay captured down in the vertical groove and not spin. Oh well. Again it's something I can easily work around.
I think one of the first things I do (after printing the standard upgrades) is to design new blocks for the XY gantry. I don't understand why proper linear bearings are used in the head itself but copper bushings/slides are used on the fixed axes. I think I will design some blocks that use 8mm linear ball bearings and include a more robust tensioner system. The laser cut design is really cool and well thought out but something much easier to assemble/adjust could be printed pretty easily.
Edit: On a positive note.... I measured my fixed axes with my CMM and they are within a few seconds of square and parallel. Very impressive considering it's all located by laser cut wood The right and left axes were out of parallel the most.. only about 1 minute though.
1) Yeah I thought that was a bit silly myself when I read that step. Personally I used another part (or was it some of the scrap bits, I can't remember) instead to get a square edge on both ends. Then I simply got it as close as I could and it seems to work fine. I'd say get it as square as you can, try to print a few things and see how it goes. If you need to you can always print something to use as a squaring tool
2) My machine is also quite stiff. I think there's a video in the wiki that shows someone moving the print head around very very easily with just the tip of their finger. I think this was filmed with an early version and they stiffened up the whole mechanism quite a bit. As long as the motors don't have any trouble moving things around or it is extremely stiff I don't think you need to worry. My machine is far from silky smooth when moving it manually but the prints are great (at least I think they are ).
3) I honestly don't remember how this step went for me so I can't comment.
4) Yup, had the same problem. I later replaced them with these:
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