Levinslaw / Spicy-CR-10

Quest for the limits of a simple ultrapolymer 3D printer
https://levins-law.github.io/Spicy-CR-10/
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Relocating interstitial linear guide supports for Y-axis carriage #5

Open levins-law opened 3 days ago

levins-law commented 3 days ago

With the newly reimagined Y-axis gantry having larger and longer linear guide rails the interstitial supports added to the CR-10 frame a few years ago need to be moved.

Originally these 2040 supports were precariously cut to length with a carbide-toothed miter saw, and mounted using no-drill corner brackets and frame rail nuts. Alignment was a challenge, but this arrangement worked well for a couple of years.

[!WARNING]
Cutting metal on a miter saw made for woodworking is dangerous, and not recommended.

Ideally these segments of 2040 aluminum frame rail would have been drilled and tapped longitudinally with M5 or M6 threads, with matching counterbores in the frame's 2020 rail along the front edge. This is how the front edge rail is attached to the side rails. One can see the heads of the M5 socket head cap screws on either side of the frame as manufactured by Creality. I did not have a milling machine at the time and lacked the ability to make counterbores safely any other way.

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Now that a milling machine is in the shop it occured to me I should not endure the hassle of the 8 corner brackets and 16 cap screws any longer.

Being motivated by a deadline for work-related travel I needed a quick way to pilot-drill and counterbore these holes in the same location on each side of the front rail, and do that twice. I came up with a stack of 1-2-3 blocks on the milling machine table as a way to locate and stop the rail repeatably. This facilitated flipping the 2020 rail around and having the drill bit the correct relative distance from the end of the rail. Productivity boosted!

Steps taken:

  1. A light cleanup face-mill cut was made on the end of each linear guide support rail.

image

  1. The ends of the existing Zyltech 2040 rails were tapped with M6 taps. This was different than the Creality 2040 rails which use M5 threaded holes.
  2. Calculated the dimensions of the center mark of the M6 counterbores and pilot holes.
  3. Placed the frame rail in the milling vise with an M6 clearance hole drill bit positioned roughly where the holes would be.
  4. Stacked up a pile of 1-2-3 blocks, pushed them snug to the protruding rail, and clamped them to the mill table.
  5. Used an edge finder to locate the face of the block stack (end of 2020 rail) and the centerline of the rail, programmed into the mill's digital readout display.
  6. Drilled the holes 20mm apart at the required distance from the end.

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  1. Machined the two counterbores, deburred the edges that could be reached, and cleaned up the Anchorlube and chips.

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