Archive for November 12th, 2015

3D Printer Nozzle-to-Platform Gap Visualization

Here’s what the 0.35 mm diameter nozzle of my Makergear M2 looks like when printing a 0.40×0.25 mm thread on borosilicate glass with a coating of hairspray:

M2 V4 nozzle - thinwall box first layer

M2 V4 nozzle – thinwall box first layer

The dimensions:

Extrusion Dimensions

Extrusion Dimensions

Some common household objects at the same scale:

Objects vs Thread Comparison

Objects vs Thread Comparison

The accuracy required is literally hair-fine: being off by the diameter of the hair on your head can wreck the first layer of the printed object.

One turn of the M3 screws supporting the M2 platform move the mounting point by twice the thread thickness. Their positions on the platform amplify the motion by about a factor of two, so if you’re tweaking the screws by more than 1/6 turn at a time, you’re overdoing it.

For first-layer nozzle-to-platform distance adjustment:

  • If it increases by 0.25 mm, the plastic won’t touch the platform
  • If it decreases by 0.25 mm, the plastic won’t come out of the nozzle

For platform alignment:

  • If your printer can’t maintain the proper gap to within ±0.10 mm across the entire platform, it won’t produce accurate results
  • Platform alignment that looks good probably isn’t

After you do a coarse alignment and set the Extrusion Multiplier to get accurate thread width, print thinwall hollow boxes and use your trusty digital calipers to make the platform settings & adjustments perfect.

Works for me, anyhow. All I do is slice whatever object I’ve just designed, turn the M2 on, and print it. No muss, no fuss, no wasted motion: It Just Works.

The sketches come from my Digital Machinist column (DM 10.4). They’ve been covering a bunch of 3D printing topics, so if you’re interested in that kind of stuff…

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