Saturday, December 26, 2009

McWire Build Session 2

Happy Holidays everyone!
I learned a lot on the 2nd McWire Build session. One of the main things is that I have to be more careful when ordering parts online. I messed up on at least 2 items. Oh well it's all a learning process. Also, some of my mistakes worked anyways.

Here are the highlights of the build:

  • Shortly after cutting the aluminum angle for the X supports I discovered it was only 1"x1"x1/8" instead of the 1.5"x1.5"x1/8 called out. Drilling the holes for the bolts to mount it to the X rails would have blown out the edge of the angle. So I drill and tapped for a #10 screw. It worked great.
  • The countersink bit that I had was not big enough for the 5/16" flat head screws. I had to counter bore about 3/16" with a 5/8" paddle blade to get it to work.
  • The 5/16" flat head screws are working by are little short. I ordered 3/4" long but I think 1" would work better. I'm using 0.25" plexi which might be thicker than the original size.
  • The 5/16" washers are too big in diameter. They are bigger than the bearing LOL!. Oh well, I drilled out some #10s that I had for this session and I'll pick some up tomorrow.
  • The bearing arm assemblies like to become loose when moved so I used medium (blue) thread lock to keep the nut from spinning.
  • The original design calls out 10-24 and M5 hardware. I would either choose one or the other and save about  $7. Certain holes would have to change accordingly. The M5 holes for the PTFE bearing were the perfect size to tap for the 10-24 screws.
  • I finally got the assembly together and discovered that the bearing hit the pipes and will not allow the sled to reach it's end-stop locations. Spacers under the X rails are needed to let it slide past.

Here is another time lapse of the epic struggle...

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