Is this normal?
I just got done with building the kit and the calibration tests all passed. I have been able to print two of the sample keychains. When the printer begins to print it moves all the way to the front right corner and then hits the rails multiple times for about a minute and then it begins printing. The prints aren’t the greatest so I need to figure that out still.
RE: Is this normal?
I just got done with building the kit and the calibration tests all passed. I have been able to print two of the sample keychains. When the printer begins to print it moves all the way to the front right corner and then hits the rails multiple times for about a minute and then it begins printing. The prints aren’t the greatest so I need to figure that out still.
It is normal that the printer "bangs" the right and front sides a few times to find its precise home position. But it should not take that long. In a well-aligned printer, it hits front, front -- right, right -- front, right, front, right, front, right, front, right. 12 bangs total, takes a few seconds (but still sounds a bit unhealthy...)
If you printer needs much longer to establish its home position, be sure that your gantry is squared and the belt tensions are correct. Updated instructions are here: https://help.prusa3d.com/article/adjusting-belt-tension-core-one_845048.
The new Release Candidate firmware 6.4.0 makes belt tuning easier by implementing a wizard and a stroboscope tuner using the built-in white LEDs; no more strumming and acoustic frequency measurements needed. Despite not being officially released, it works ok on the Core One. But with a newly built printer, maybe you want to stick with the production firmware for now.
RE: Is this normal?
Thank you for your suggestions.
I finally managed to get it to perform a complete homing, but for that to happen the belts have to resonate at around 60 Hz, which seems very strange to me.
However, there’s something else that puzzles me: with the printer turned off, if I manually move the Y axis, the X axis moves the same distance. And if I move X, then Y moves as well.
Is that normal?
Please take a look at this linked video, and if it’s not normal, do you have any suggestions?
RE:
CoreXY printers don't move in a way you would expect. For example if you move the print head where X=Y (0,0) - (220,200) then only the 'X' belt will move
From the Wikipedia Article CoreXY
For movement along the x-axis, both motors must rotate in the same direction. For movement along the y-axis, the motors must rotate in opposite directions. If only one motor rotates, the movement will be diagonal.
The movement can be mathematically described as follows. If A is the movement of the first motor and B the movement of the second motor, the movement in the x and y directions is given by:
Δx=1/2 * (ΔA+ΔB)
Δy=1/2 * (ΔA−ΔB)
RE: Is this normal? (Solved!)
Thanks for your comments, which helped me understand the philosophy behind the Core One in my first venture into the CoreXY world after years of assembling and calibrating “regular Cartesian” printers.
I’ve now solved all the issues; it turns out that the method of tensioning by measuring vibration frequencies with a smartphone is highly inaccurate for Core One.
Fortunately, I downloaded the 6.4.0 Alpha firmware from GitHub, which includes a belt adjustment method by using stroboscopic light emitted by the LED bar; it allowed me to perfectly tune the belts in less than a minute.
Thanks again.
RE: Is this normal?
Thanks for your comments, which helped me understand the philosophy behind the Core One in my first venture into the CoreXY world after years of assembling and calibrating “regular Cartesian” printers.
I’ve now solved all the issues; it turns out that the method of tensioning by measuring vibration frequencies with a smartphone is highly inaccurate for Core One.
Fortunately, I downloaded the 6.4.0 Alpha firmware from GitHub, which includes a belt adjustment method by using stroboscopic light emitted by the LED bar; it allowed me to perfectly tune the belts in less than a minute.
Thanks again.
Try the 6.4.0-RC firmware, not the alpha. It still has a ton of bugs but I've been running it for 6 weeks now and it's good enough (for me). The audio belt tuning is accurate (probably because I have an iPhone and not Android) once you get a routine down for it. I've compared it to the strobe method and they both produce the same results. But yes, the strobe method is easier and more stable way to check the belts.
RE: Is this normal?
Is that normal?
Please take a look at this linked video, and if it’s not normal, do you have any suggestions?
I just carefully looked at your video, and no, this is not normal. The two belts on the left should be moving in opposite directions. Since only one belt is moving, that is why the print head is moving diagonally (it shouldn't be moving in X when you move the gantry only). What that tells me is probably one the toothed pulleys connected to the motor shaft is installed the wrong way.
Refer to this section: 42. Installing the X-axis pulley and confirm that the X and Y axis pulley's are installed the correct way. A common mistake is not installing the X-axis pulley in the correct orientation. There is a hexagonal cutout in the motor mounts where you can visually inspect the orientation.
RE:
I’ve checked it three times, and yes, the pulleys are in different positions and correctly mounted.
Finally, the best solution for calibrating the belts turned out to be the Biqu Belter digital tensiometer, and I’ve decided to forget about the 6.4 RC firmware and iPhone web apps. It’s a pity that Prusa doesn’t provide the tension in newtons. In the end, I had to calculate and deduce the correct tension for the Core One based on the frequencies provided by Prusa: 24–27 N.
Now everything works fine.
TKS for your suggestions
RE: Is this normal?
Finally, the best solution for calibrating the belts turned out to be the Biqu Belter digital tensiometer, and I’ve decided to forget about the 6.4 RC firmware and iPhone web apps. It’s a pity that Prusa doesn’t provide the tension in newtons.
Hmm -- didn't you write earlier that the stroboscope-based tuning using the 6.4.0 firmware worked very well for you? In which way did you find it deficient?
RE: Is this normal?
I've compared the strobe results against the audio results many times and they agree within 0.5hz. I find the strobe based tuning to be accurate and quick.
RE: Is this normal?
Indeed, it was working, but after a few hours it started showing an error again when performing homing.
RE: Is this normal?
I am sure you are considering the initial stretching phase where the belts will keep stretching until they settle more or less permanently (unless you enconter the same weird problem that @hyiger is having with permanently stretching belts). In my case I had to adjust the belts a few times in the first couple of weeks but now they are rather stable.
If you are familiar with string instruments, same effect: change the strings of a guitar and you'll have to tune them for a couple of days as they loose tension inside a couple of hours until they stabilize.
Indeed, it was working, but after a few hours it started showing an error again when performing homing.