Update printer.cfg

[weaslus]

Reduce speed and accels in printer.cfg. A couple of users on the discord have had issues with skipping on moves immediately after the home routine, and turning down the speeds and accels has solved this. Having a printer work from the get go, i would say is of prime importance, and tuning for silly speeds later should be a choice they can make, not something that causes them issues.

One user is using the BOM OMC stepper online motors and is now running above the values i have set. The other user i'm currently aware of with the same issue, is running cheaper chinese kit motors, and is running a lower value in speed and accels 150/1500. I will attempt to get them to leave comments here.

Thank you Github cherrubs! Hopefully this time i haven't somehow created a file in the root of the repo...

[weaslus]

video: https://cdn.discordapp.com/attachments/461133450636951552/858167239521468446/1080.mp4 (from message: https://discord.com/channels/460117602945990666/461133450636951552/858167247338995732 )

and video: https://cdn.discordapp.com/attachments/696930677161197640/858132146865569822/PXL_20210625_234935844.mp4 (from message https://discord.com/channels/460117602945990666/696930677161197640/858132152335990784 )

hopefully these links works somehow for you guys to see the issues.

[RussellArmstrong]

I am currently using motors from formbot that were substituted. I will try to get the spec on them. Everything I know right now follows:

Hi, Russell

As I checked, the LDO motor is in short supply and it's out of stock now. so far the date of restock is uncertain, could we ship other motors instead, which is also good quality. if you can accept, I'll apply an extra magnetic flexible PEI sheet for you, is that ok?

Best Regards Nicy

sales@formbot3d.com

Sun, Apr 18, 11:01 AM to sales@formbot3d.com

Yes, that would be fine. As long as the motor is equivalent.

Russell

sales@formbot3d.com sales@formbot3d.com via gmail.com Mon, Apr 19, 2:45 AM to russgwen

yeah, they are the same as LDO motor, thanks for your kindness.

[eddietheengineer]

Hey, thanks for the notes.

Looked at the videos, the V0.1 looks pretty clearly like a skip, it would be great to understand more about the motors being used and what speeds are being used as well to diagnose what is going on.

The V0.0 doesn’t look like a layer skip, it looks more like a gcode or config where the printer thinks it’s in the center of the build plate but it’s in the corner. The sound to me is more of a mechanical nature than a stepper skip.

For Formbot motor substitutions, if they are using higher inductance motors it’s very possible they are going to have issues—in this case it would be best to ask for spec motors as replacements as the parts they are providing are not sufficient.

[RussellArmstrong]

Hey, thanks for the notes.

Looked at the videos, the V0.1 looks pretty clearly like a skip, it would be great to understand more about the motors being used and what speeds are being used as well to diagnose what is going on.

The V0.0 doesn’t look like a layer skip, it looks more like a gcode or config where the printer thinks it’s in the center of the build plate but it’s in the corner. The sound to me is more of a mechanical nature than a stepper skip.

For Formbot motor substitutions, if they are using higher inductance motors it’s very possible they are going to have issues—in this case it would be best to ask for spec motors as replacements as the parts they are providing are not sufficient.

The V0.0 is mine. For reference, the cfg had 3000 and 300 or higher for accel settings (whatever the one linked in the docs has). It works at 1500 and 150. I think we surmised it was skipping, but I won't say I know for sure. I am will to run through some testing if you have some ideas. Let me know.

[DanJunior78]

Usually it's always recommended for sensorless homing to use reduced power and reduced acceleration. I would place something like this as hint in the config. Everything else makes no sense, because there will be dozens of different builds with different motors.

[weaslus]

Usually it's always recommended for sensorless homing to use reduced power and reduced acceleration. I would place something like this as hint in the config. Everything else makes no sense, because there will be dozens of different builds with different motors.

no one is using sensorless homing to the best of my knowledge. the recommended build certainly doesn't specify sensorless homing and spec's for microswitches. it's generally not considered a good idea for coreXY.

regardless, you can see on both, they home to the back right corner. the bed moves up and homes. the toolhead then (eventually on the first video) tries to move to the centre of the build, after the bed has reached printing height. it's this movement from the final location towards the centre of the build that is where the issue presents. being a non print move, it is faster than the print moves that follow, and uses a higher value for accels and velocity. the diagonal movement exacerbates the problem by placing all of the work on the 1 motor on the coreXY architecture.

for further details on how the fault was found, please see the voron discord here: https://discord.com/channels/460117602945990666/696930677161197640/858173226755686400 it's a long read,

[DanJunior78]

I thought it was the homing process. Ok ,sorry. I've on my V0 accelerations of 10k adjusted. Stepperonline Motors. Also, no issues loosing steps. Sensorless homing us active. It's working fine on all my CoreXY printers. But yes, it's not as mentioned in the specs.