Friday, February 29, 2008

Drill Bits

Spent the evening drilling out the corner blocks. Four vertical holes with a 5/16" bit (roughly 8mm). Five horizontal holes (one around back) to clean out the trapped nuts using a 5/32" bit (roughly 4mm), followed by an M5 screw to clean up the threads.

Bits and Pieces

Ran into some problems with the corner blocks for the XY frames. Each of the blocks has 3 trapped nuts. I did the same thing as before: drill with undersized bit and self-tap with grub screw. It just now occurred to me that I could use an M5 screw to do this instead of a grub screw. I overtightened one of the grub screws and cracked a block. Superglued it back together. Fingers crossed. Need to drill out the vertical holes in the blocks. I'll have to dust off the drill press. Hoping a 5/16" bit will do.

Also noticed that the diagonal tie brackets don't have trapped nuts. Not sure how I'm going to attach those to the frame. I'll have to improvise.

Tuesday, February 26, 2008

X Axis

Turns out Home Depot has 3' lengths of 5/16" rod. I picked up 3 to make up for the metric/imperial problem with the ones from McMaster (1 metre > 3 feet). Should be good enough for use in the XY frame.

Assembled the carriage and X motor bracket. Did the drill-and-self-tap thing with the grub screws again. The rods were difficult to push into the motor bracket. Required a "tap gently with hammer while cringing" approach. Used a store-bought pulley on the motor.

Monday, February 25, 2008

X Idler and Constraint Bracket

Unpacked the plastic parts and started assembly. Y opto flag seems to have snapped during shipping. Easy enough to glue back together.

Noticed that Mcmaster-Carr sells 3-foot lengths of 8mm rod instead of 1-meter. Kinda screws up the cuts. Will need to order 3 more rods.

Assembled the X Idler and Constraint Bracket. Used a C-clamp to press the rod into place. The grub screws gave me a bit of trouble. Had to pre-drill with an undersized drill bit, then force them through using a hex bit in a screwdriver. Alternated driving it in, then backing off until the grub screw broke through.


The plastic parts arrived today from BitsFromBytes. I'd been tracking in on the UPS site for the past few days, watching hop from town to town:

Bristol->Barking->Stansted->Philadelphia->West Columbia->Raleigh

This afternoon at about 1:00, the status changed to "Delivered". Unfortunately, I still had 4 hours of work until I could come home and check it out. Took 6 days door-to-door, by the way.

As you can see, I chose basic black. I also chose the regular finish, so I've probably got some drilling to do. Currently cleaning up and setting aside the electronics and extruder to make room for the hardware build.