I built the 1st version of this MPCNC back in the summer of 2015. After having some problems with my z-axis recently dropping twice while cutting, I have decided to reprint the parts for the upgrade & use the M8 leadscrew instead of the 5/16" threaded rod. I had replaced that plastic part that holds the 5/16" nut & tightened it twice, but still dropped a little during my last test cut. A couple days ago, I was dreading these long print times so I decided to look at changing the Marlin 1.1.8 firmware on my Makerfarm 10" Prusa i3v to klipper firmware. I had tested this last December, but was not entirely happy with it so I saved my settings & went back to Marlin until now. Yesterday after making an image backup of my Pi3B+ with octoprint on it, I installed klipper from https://github.com/KevinOConnor/klipper . Since most of my configuration settings had not changed, I did not have to make much changes to the configuration file. After going thru the pressure_advance calibration tests, I printed the C-Z-Lower.stl, then the C-Z-Motor. Before going to bed I started the long print of the C-XY.STL & it finished before I woke up. I had printed the C-XYZ_T8.stl files before changing to klipper. Based on the print estimate times of Slic3r Prusa Edition, that long print was 30% faster (9:24 actual print time). I really like the idea of letting the Raspberry pi do all the hard work & just having the 8bit electronics on the 3d printer do the simple stuff. If you are not familiar with klipper, here is the page on it’s features. https://github.com/KevinOConnor/klipper/blob/master/docs/Features.md
I am printing these parts using 55% gyroid infill & variable layer height, .2mm layers where horizontal holes are & .3mm for the other heights. Here are the layer heights I used for the C-XY.STL file. Looks like the weights on my parts are a bit less than what is shown in the parts section.
0 4.85 .3
4.85 13.25 .2
13.25 70.45 .3
70.45 92.05 .2
92.05 97.6 .3
11:07:51 Estimate before speed changes
4.6oz 130.4grams (201g on site)
I still have some waves in the sides, but not sure what else to change there. I tried acceleration at 800,1000 & 1500 with little difference. I might try 3000 just to see how it looks. I have never had sharp corners before, so am really happy with that. I know marlin has similar feature to the pressure advance, but I don’t think Marlin can do the smooth acceleration/deceleration calculations that klipper does. After I use the firmware more, I plan to change the firmware on the Folgertech Delta to this. I am using an MKS 8bit board on that machine & this firmware should really speed that machine up.
I am using esun PLA+ Silver 1.75mm plastic with e3d lite hotend & titan extruder. If I run out of silver, I will print the rest of the parts in either brown or black since that is what I have on hand. I really like the PLA+ because it has a little bit of give to it.
I attached photos of the parts I have printed so far & the test prints from the klipper firmware changes.