So I’ve gotten my layer alignment better by properly tensioning my x and y belts, I haven’t bothered with retraction yet, haven’t installed my fan yet, but I have a weird problem with speed. In using slicer 0.9.10b
All my accelerations are at 80mm/s2
All my normal speeds are around 1000mm/s
Small perimeters are 50%
External perimeters are 75%
Solid infill is 100%
Top solid infill 80%
Travel is 1200mm/s
First layer is 60%
2 top solid layers, 2 bottom
2 perimeters
.1 infill
I know, these speeds are insanely high, but hear me out. The first later on the need is decently quick, the second even faster, both having solid infill. Then when I get to the third layer, it’s super slow.
The reason I kept cranking the speeds up is that the third layer and beyond appear to be at 20mm/s peak. Since my acceleration is so low, smaller moves don’t reach the 1000 speed, but the 2nd and third layer perimeters should be the same speed. Any ideas why the drop in speed?
Are you sure you don’t have those numbers reversed? Default acceleration in Marlin is 3000mm/s^2 - 80mm would be some insanely slow acceleration…and you’re not hitting 1200mm/s for travel moves, those numbers are high but you’re reaching a cap in the firmware. Max feedrate in Marlin is 500mm/s by default.
Sounds like you were messing with settings that you didn’t quite understand at the time. Go with some sane defaults and try again.
I figured I was hitting a firmware velocity peak. I’m positive the acceleration is that low, I’ve purposely be dialing it down because my y stage is incredibly heavy, and atrociously constrained, which has been leading to the whole be wobbling like crazy. It’s definitely working that low as well, as I can see the slow accelerations. Even if I am hitting firmware velocity limits, even my first layer is much faster than my third+ layers. My second layer is a great speed, with no wobbling bed since my accel is so low. my confusion lies in the fact that after such a perfect 2nd layer, the rest of the layers are a snails pace. I crank the feedrate multiplier in repetier host to 300% and the speed is still slower than the first layer. Luckilt the accelerations stay yhe same and I have no wobble, but the prints are SLOW due to the oddly low speed.
@John_Ecker_GeoDroidJ I can’t put my accelerations anywhere above 120 at the moment without really awful ringing, due to a poorly constrained y stage. Once I finish a mod I have the parts for, I’ll be able to increase, but currently that’s not possible. But like I said, my first 2 layers are fine, it’s just the third and higher that are slow.
As for the stringing, I’ll give that retraction a shot, but I think it may be my extruder, which is just a gear preloaded into a 608 bearing. I had it at 3mm before, but I was getting underextrusion when it finished it’s move, as I think the extruder slipped a bit on the filament that already had tooth marks in it. I think there’s a correction for this either in slicer or firmware, but I was going to change my extruder anyways
@John_Ecker_GeoDroidJ Ahh, cooling rules. It’s currently set to 30 seconds, AND the 3rd layer is the first to use infill instead of solid infill. I’ll set it super low to test that theory. Thanks!
@Eric_Moy then it looks like you know exactly the problem. Fix your overconstrained machine, and get closer to some normal values. You’re off in far left field here. If the cooling thing doesn’t help, I’m afraid there’s not much people are going to be able to do.
Also, what machine do you have? Why is your Y stage “really heavy”? I know a guy that was pushing around a 5lb copper plate on his Sells Mendel at way higher accelerations and speeds than that.
I have an eventorbot from a Kickstarter. The designer enlarged the bed as a stretch goal, then during production changed the printed parts to steel sheet metal. The x stage is solid as a rock. The z stage holds up the y stage. The y stage hills the bed. Unfortunately the y stage is only held up on one side, so when the y stage accelerates too fast, the bed swings around due to the connection between the z and y stages being too flexible. I intend to couple the y stage better to the z stage so it doesn’t rotate anymore. Just a poor design that the other builders have been able to find workarounds for. Good learning experience though
@Stephanie_A I described this pretty poorly. The y stage is moved up and down by the z stage. It’s a novel design, I had some concerns, but I assumed it was coupled well from videos of the original design running. Unfortunately, when the parts were changed to steel, it wasn’t done by an engineer. The additional mass was not accounted for and the design of the sheet metal parts made no account for direction of stresses. But being an engineer, I’m also super critical on design flaws. There are sine super clever folks on the eventorbot forums and we’ve been sharing our personal fixes. I would honestly just scavenge the parts and build a more rigid bot, but my budget does not allow it. I honestly was seduced by the $600 pricetag that this had last November. Of course 2 months later, solidoodle released gen 3 and dropped the price of the gen 2. I would’ve picked that up. I had wanted to build my own open source, but quickly realized that self sourcing for one kit is very cost prohibitive. I have access to skycraft surplus, but I didn’t want to rely on their ever changing inventory, plus I didn’t want to spend every weekend searching for parts in that labyrinth of a store.
So I’m slowly Frankensteining my machine in true reprap fashion, just a slow process I guess
