I decided to print out some new parts in ABS and did a partial re-work of my Ormerod this morning. New X-carriage, Z-slider and hotend parts. Everything is a lot tighter and more stable, and runs far more smoothly, and I no longer need tape on the Z extrusion or a hacksaw blade on the X extrusion (though I am using a 10mm bearing on the X carriage). Lubricated the Zscrew and runners with 3-in-1. Two things I noticed:
1) The fan would not turn at first (seized) - it turns out that if the two mounting screws are tight, it distorts the fan frame and the blades make contact. I had to slacken off the two screws - which means the cooling block is not held as tightly as I would like to the heatsink, as it uses the same two bolts to press them together.
2) All my Z-probe readings are way lower. My calibration reading used to be 690 at 2.5mm. Now it is 260 at 1mm ! Actually this is much better, because the fast-changing region is closer to the bed, and also it appears to be far less influenced by ambient light.
There is a very good reason for that change - I printed my new X-carriage in black ABS. It all makes sense - the photocell is now far better protected from ambient light and reflections from anywhere except straight down. I doubt many people will want to print out a new part in black, but perhaps a bit of black paint inside the probe recess would achieve the same thing.
Dave
1) The fan would not turn at first (seized) - it turns out that if the two mounting screws are tight, it distorts the fan frame and the blades make contact. I had to slacken off the two screws - which means the cooling block is not held as tightly as I would like to the heatsink, as it uses the same two bolts to press them together.
2) All my Z-probe readings are way lower. My calibration reading used to be 690 at 2.5mm. Now it is 260 at 1mm ! Actually this is much better, because the fast-changing region is closer to the bed, and also it appears to be far less influenced by ambient light.
There is a very good reason for that change - I printed my new X-carriage in black ABS. It all makes sense - the photocell is now far better protected from ambient light and reflections from anywhere except straight down. I doubt many people will want to print out a new part in black, but perhaps a bit of black paint inside the probe recess would achieve the same thing.
Dave