Spent way way way too much time working on the machine today, but I have it cutting pine again.
Combination of screwing around with both of the trucks and the core and also upping the current going to the steppers.
I also went back to the basics. It looks like part of my trouble may have been trying to take too deep a cut? I was trying to cut 5mm DOC at 400 mm/min. Final cuts that were successful were 3mm DOC at 500 mm/min.
I still think my machine is a bit tight, but at least it’s somewhat working again.
A comment in another post made me rethink something… I’m wondering if I have my wiring screwed up and it’s not in series like it should be. I’m pretty sure I didn’t parallel it, but if any of the other wires were messed up, would the steppers only get partial current, or would they not work at all?
Increasing the current helped with steps, but I’m still not seeing the huge DOC and feedrates that others get. Maybe it’s my 24"x24" cut size?
IDK. I’m going to let it sit a bit and then I’ll look at it again this weekend. I’m almost finished with my current big project and that will free up some time to work on some other tasks for a bit before starting the next big project.
There are wiring configurations that will not work at all. There are others that will split the current between the coils (effectively giving you have as much as you set it to). You could accidentally wire one coil in series and one in parallel. You would get super torque on one step and half on the other step, but it would still run (I think).
Stepper driver’s current, voltage, and resistance is very counterintuitive. Maybe more so for people who know enough about a typical voltage source. A constant current source often acts in completely the opposite way from a constant voltage source. Even though they both have numbers like 12V 1A.
Let me dig a little deeper. The constant current drivers are pushing 1A (to make it easy). If we ignore microstepping, then 1A is going out one wire and back the second wire. If that wire has two coils in parallel, 0.5A will go to one coil and 0.5A will go to the other (not perfectly split, but close). That would be the same as driving one motor and one driver with 0.5A setting. There are two ways for that current to go, and it will travel both ways. The relative resistance between the two coils will decide how much goes where. Since they are about the same, about the same amount of current goes each way.
If you put them in series, the same 1A is going out. But there is only one way for it to go. It has to go through both coils. The driver is still trying hard to put 1A through the circuit. Both coils get one amp and the torque is proportional to the current. That seems like free energy, but it is not. Pushing 1A through two coils in series means the voltage will be higher. But in our case, the voltage is always 12V, and what changes is how long it will be on. In a series circuit, the voltage will be connected to the coils for longer, but the end result is still 1A going through each coil.
If you managed to wire one pair of coils in series and one in parallel, then you could still have a working pair of motors.
If two coils are wired in series, their resistance will be higher than two coils wired in parallel. If you can’t tell from inspection how they are wired, you can unplug them from the drivers and measure the ohms with a multimeter. Compare that to measuring it at a motor. Each coil should be twice the value of a single motor coil. If your first two pins on a motor are measuring 5Ohms, the series resistance should be 10Ohms.
Unplug one motor. If the other one still moves, you’re not in series. (Or you know, if you’re the more cautious tupe, a multimeter will show no conductivity at all from the board end with one motor unplugged.
If you somehow ended up with one pair in parallel and one in series… That would do some weird ****
You’d see that happen if you get conductivity with one pair with one motor unplugged.
I’ve been thinking about ways to reduce the print time as much as possible but I may want to rethink that based on all the issues people are experiencing
Old thread, but in case it helps anyone…
It’s probably been done before, but I saved some time on my prints using a 0.6mm nozzle. Main advice I would give to anyone wanting to go down this road is to make sure your profile is tuned well. I think my parts came out OK, but they were slightly tighter on tolerances than I think they were designed to be. Main place I saw this show up is in the parts that sit on top of the feet…3 out of 4 have small splits at the nut trap, which I’m guessing may have been caused by the nut trap being a little small, and layer adhesion not being as good as it could have been.
Thankfully, those cracks are small, and I don’t think they’re affecting the clamping ability of that joint. Will definitely be keeping an eye on other parts to make sure I don’t see additional cracking.
Another suggestion for folks using Ender 3 printers is to check out Chuck Hellebuyck’s profiles, which seem to do a good job with printing significantly faster while maintaining good quality: CHEP | 3D model uploads | Thangs
Off topic but you can run an Ender 3 pretty fast. It’s all in the profiles and ya you are not going to get Bambu or Voron type speeds but for example here is what my Ender 3 runs and gets great prints. With things like pressure/linear advance, input shaper, etc. has helped a ton in last couple years. The default speeds and accels are way to low. Obviously you have to make sure your hotend can keep up with it but thats a whole different rathole.
I’ll take a look. I run multiple Ender 3s, so I may try these settings with one and tweak from there.
Are you running stock hot-end? I’ve added improved cooling ducts to all of mine (Bullseye on two, and mini Satsana on another), and I’m getting ready to change one over to an all-metal hot-end, as I’ve been having some real struggles with getting PETG to print well lately, so want to give myself a little more headroom on max temp.
I have an ender3 and I wouldn’t have dreamed it would go this fast. I was looking at putting a new direct drive on it to go faster… something like I read about here. What hot end is needed to go faster? I still have the stock. I’ve upgraded to a dual geared extruder and put a better fan setup on it and the blue tube. I’m happy with print quality at the moment, but 40 is way slower than 180…
Do an all metal HE. Dragonfly is what I run as its a drop in replacement but there are plenty of good ones. E3D V6, Microswiss, etc that with a printed bracket will mount very easily. Are you running the stock extruder? It’s not the best but works. I printed a Voron M4 for mine and never looked back. Been running this setup for over 2 years with zero complaints!
