I have recently been speeding up the parameters on my TAZ because it think that it has the structural ability to handle much greater forces than the current settings generate. I have only done 2 upgrades to my TAZ4; I have the Hexagon nozzle installed and this upgrade that erv posted.
https://forum.lulzbot.com/t/linear-bearing-backlash-big-x-axis-issues/966/1
I found that even at slower speeds the bearing upgrade was a necessity to remove a lot of chatter and slop in the tool head. The hexagon nozzle has made a world of difference in my print quality and I think is why I can lay down plastic accurately at higher speeds. All these prints have been done with ABS. Could it be done with PLA or other filaments? I’m assuming that specialty filaments need to run slower based on their unique qualities.
I’ve printed 2 different sets of pieces at what I think could be close to the upper limits of how fast the TAZ can move around with somewhat mixed results. The first prints are of two types of E3D nozzle mounts this one that ogrethetoymaker put up in this threadhttps://forum.lulzbot.com/t/e3d-hot-end-first-pics-and-how-to-guide/704/1
and the type that mushoo designed on page 2 of the same thread.
here is the brim and first layer going on @100mm/s
here is the 3rd layer to get a feel for top and bottom print speed–160mm/s
here is everything in between @240mm/s–it takes about 0.15 seconds to reach max speed!
These parts came out impressively strong. They were really hard to break with a 12oz hammer and didn’t shear very easily. There were very few cracks along a seam and nothing snapped apart. I would say they were as strong as similar parts I’ve printed with LulzBot settings.
The second print was half a chess set. Sorry I don’t have better pictures I accidentally gave them to a friend before I got individual closeups. The pieces came out pretty clean, I think I have to slow down the perimeter speeds some for more intricate parts.
I did notice–you can see it in the videos–that when making some of the weird perimeter curvatures the machine would seem to stall a bit like the processor couldn’t load gcode blocks fast enough. What I think is really happening is that we are seeing the acceleration slowing the nozzle down when it is moving out to the next perimeter layer or going around a tight i.e. high directional acceleration area.
My settings:
I’m printing with this ABS right now. http://www.amazon.com/Filament-Printers-Makergear-Makerbot-RepRap/dp/B00BSW4HDA/ref=sr_1_1?ie=UTF8&qid=1425243143&sr=8-1&keywords=3mm+abs+filament
It’s only $17 a kg so I figured it would be good to use while messing around.
I realize that I have the travel speed set at less then the print speed, I have since upped the travel speed to 250mm/s.
Cura_Work_Speed.ini (10.6 KB)
Additional info on trigonometry and some physics on acceleration–in case you don’t know, if you do skim across:
I have the acceleration set to 2000mm/s^2 which is the most important setting. What happens is the ramp up time is shortened with increasing acceleration and the head can reach its intended speed sooner. For example if you are printing something with lots of curve and hairpin corners and the acceleration is set very low the print head may never be moving at the print speed that you assigned it. This is because any time direction is changed–which is constantly in an arc or circle–there is an acceleration associated with this. This is a good example of what the X and Y axes are doing graphically when they make a circle.
http://i.imgur.com/O0b3H2S.gif
When either axes crosses the 0 plane they are at max velocity and minimal acceleration–even though the line is on a slope it is straight therefore no acceleration is happening. At the troughs and peaks the axes are experiencing max acceleration and minimum velocity–most curved parts of graph, most acceleration. Speeding up the image creates higher velocities due to the higher accelerations through the peaks and troughs–the curves get sharper and the straight lines get longer. Since forces are what cause strain on the physical machine the only way to change these forces are to either change the mass that is moving or the acceleration that it is moving at–F=ma.
My questions:
I’m making the assumption that the acceleration setting units are in mm/s^2 can anyone confirm this?
Are these settings, particularly the acceleration sustainable? Can the TAZ components handle these kinds of forces–I’m thinking the gt2 belts will be the first things to blow? Did I miss anything?