Chapter 10 - In which I cheat a little, and things get back on track

Things are starting to look up - I now have all of the parts I need to finish my reprap, with the exception of some hot end bits (I think). The major cause of the delay was bought on by myself. In a bid to reduce the cost and number of surplus fixings I'd be left with, I opted to purchase the majority of the components I need through the company I work for. We use a vast array of fixings and electronic components, and I was able to get hold of almost everything I needed. Placing the order, and picking all the parts too longer than expected, but now it is all done I can crack on with the build.

Here are the majority of the parts I purchased:

Mechanical parts

Electronics

The microswitches in the first picture have 90 degree arms on them, and will need to be modified before use as endstops. They were more expensive than most of the others I looked at on the web, but they are good parts. They're UL and CSA approved, and are rated to switch 15 Amps. Whilst I'll never need that much, it provides a margin for error, especially if I end up with a firmware that doesn't use the processor's internal resistors. Speaking of processors, I purchased that too but haven't got a photo yet.

I got back to work by attaching the Y axis stepper motor. We don't carry M3 by 10mm screws at work, so I got 12mm long ones instead. I knew that the motor screw holes bottom out and that 12mm would be too long, so I got some spring washers to take up the slack.

The screws fully seated - you can see the slack caused by them being too long. The bottom screw has the spring washer fitted.

Next I fitted the pulley to the motor shaft. I had gotten a couple of pointy grub screws, thinking that flat ended ones wouldn't grip the shaft well, but hadn't looked at the screws Nophead had supplied. These turned out to be pointed as well, so I kept them (thanks Nophead!). I aligned the pulley with the bearing and tightened it into the shaft before checking that it gripped well and didn't turn. At the same tie, I moved the Y axis bearings closer to the middle of the frame. They were a way off to one side, and I was worried about off-centre forces affecting the movement of the axis. I brought them as close to the centre as possible.

I realised I had forgotten the plain washers behind the spring washers. I went back and fitted them.

I wrapped the Y axis belt (the shorter of the 2 supplied) around the bearings and lined it up over the lower sheet. I marked where it lay on the sheet, and started to carefully remove the sheet form the Y axis smooth rods. Then, disaster! - the bushings came off. Whilst the superglue had done a good job of holding it while it was flat, it cracked when I started to move it vertically.

I took the sheet off completely and used the opportunity to mark up the clamp holes and drill them.

I glued the lower tray down to the bushings again, and will continue with the fitting and tensioning of the belt when the glue is dry. The only good thing to come of this is that the movement seems a little smoother now I've reglued it. Perhaps the bushings were misaligned when I fitted them initially.

Whilst waiting for the glue to dry, I figured I'd make a start on the X axis. Here are the ends:

The holes are all the right size, so no need to drill anything out. I fitted the nuts into the traps, which was a little fiddly. I used the end of a file to make them lie flat when needed:

I fitted M3x12 screws into the nuts (again lacking in 10s). These seem excessive (although they may have something important to do later), and I think that M3x8 or even 6 would be better.

The visual instructions say to lay the parts out 500mm apart, but for the suggested X axis smooth rod length of 420mm this was too far:

Anyhow, I fitted the X ends to the rods, and tightened the screws:

I built the X end idler bearing onto a 50mm piece of threaded rod, and fitted it, and that's the X axis done for now:

The next job is to level the printer. Mine was a bit wonky:

A pair of plastic rules provided the bulk of the adjustment required, with folded post-it notes providing the fine-tuning.

After adjustment - nice and level.

I have a snap-on adjustable foot in mind as one of my first upgrades....

The preliminary adjustment of the Z rod fixings went well, and I moved on to the upper fixings. I fitted up M3x25 screws as suggested in the assembly instructions, but found they were too long. I hadn't read far enough ahead to spot the note about this! I was on the brink of turning the screws around and trying them in reverse, when I looked back at my parts list. I realised I had gotten the correct amount of 20mm screws, so I replaced the 25s and the rod restraints now fit well:

I test fitted a motor to make sure the screw threads didn't protrude too far - they don't.

The last part of this evening was spent fitting the z rods and checking them for verticality. It was a slightly painstaking process, but well worth taking time over.

So here is the machine after all of today's exertions. I'll let the glue dry overnight, and hopefully tomorrow will see the mounting of the X axis.

Next up: X's, Z's and leadscrews!