Rat Rig Community [Unofficial]•2y ago

VMinion 3 scraping bed after homing

Hey guys, I have a V-Minion based on Ender 3. After the homing procedure, the nozzle, at bed height, shoots straight towards the purge point without lifting at all, often scraping the bed. Assuming the bed is level (it isn't, but I would have expected the machine to compensate for that), is there a way to make it lift up juuuuuust a hair before going back to purge strip? that way there's no risk of it scraping the bed

34 Replies

blacksmithforlife•2y ago

prerequisite reading: https://os.ratrig.com/docs/configuration/includes-and-overrides Then you copy what you want to override into your printer.cfg and change it how you want (in this case adding gcode to lift it up before priming the nozzle, and then once it is at the priming location moving it back down)

miklschmidt•2y ago

That has been changed in v2.0

extended-salmon•2y ago

When was that released?

blacksmithforlife•2y ago

It's still in alpha release

extended-salmon•2y ago

I think I have Alpha 4 @miklschmidt so it might not be fixed. Or my 3D printer didn't get the message. Or the bed is so out of whack it didn't matter

miklschmidt•2y ago

It is, just update RatOS It's travelling along the edge several centimeters above the bed. Go refresh your update manager and update RatOS.

extended-salmon•2y ago

kk ty

miklschmidt•2y ago

btw @airmanepic i don't know if you've seen the announcement but alpha4 will probably stop working within a weeks time. The configurator is already broken if you update it on alpha4. Had to make some major changes, so Alpha5 is out (and requires a reflash). So after this update, i recommend not updating again as long as you're on alpha4.

extended-salmon•2y ago

Ok thanks for this update - I missed that announcement. I am not reading 100% - I updated about half a week ago - ismy configurator already broke? If not, I assume don't update it. but this thing where it doesn't get off the bed is still there (BTW thanks for developing this!)

miklschmidt•2y ago

Nope, breaking change was pushed yesterday, so you're good 🙂 Do you have any macro overrides in printer.cfg? my pleasure

extended-salmon•2y ago

@miklschmidt I do not. As blacksmith suggested though i may add some, I guess I'll need to read up on how though. Tbqh I've never been very good at gcode

miklschmidt•2y ago

I guess I'll need to read up on how though.

You shouldn't need any. I asked because that could've been why it didn't work for you. Please post your klipper.log and printer.cfg and i'll take a look.

extended-salmon•2y ago

Sure. Once I get the chance I'll run it through and send it over. New bed and levelling kit are arriving today so I'll wait to put those on haha closer examination revealed a suspiciously uniform pattern of nozzle crashes lol. I wonder if something's wrong with the sensor or something

extended-salmon•2y ago

The sensor was falling off the edge. However, it still doesn't do the z-hop.

klippy_5.log

extended-salmon•2y ago

printer_1.cfg

miklschmidt•2y ago

When doesn't it do the z-hop? The config output looks correct. This is the part of primeblob that makes it travel along the edge:

    G0 Z{z} F{z_speed}
    
    G1 X{x_start} F{speed}
    G1 Y{y_start} F{speed}
    
    G1 Z0.5 F{z_speed}

    G0 Z{z} F{z_speed}
    
    G1 X{x_start} F{speed}
    G1 Y{y_start} F{speed}
    
    G1 Z0.5 F{z_speed}

Where Z is {% set z = printer["gcode_macro RatOS"].start_print_park_z_height|float %} And that is variable_start_print_park_z_height = 50 in your config So it'll travel 5cm off the bed. I think you need to make a video. Because this works well on my printers (and others), so i need to see exactly where, what and how it fails.

extended-salmon•2y ago

Huh. It may jump 5 cm, I just didnt see it. I do have a a recording but my clumsy ass didnt manage to record the whole thing. Anyway whatever as long as it doesnt scrape the bed who cares

miklschmidt•2y ago

I care! 😂 If there's some situation that breaks the macro, i'd like to know 😄

extended-salmon•2y ago

I'll see if I can send you the recording. It doesnt LOOK like it moved back to 5 cm. It might have. Again the I messed up the angle so you're not looking at the nozzle exactly when the jump happens. But you'll at least see what I'm seeing. http://airmanepic.com/sneaky_jump.mp4 it does the same thing on the way back

miklschmidt•2y ago

That is neither the primeline, nor the primeblob. This doesn't even look like the RatOS start procedure. Did you use the proper start gcode in your slicer?

extended-salmon•2y ago

You know what I didnt check. This might be a facepalm moment. it's got a bunch of gcode but no start_print nor g90 so I'm guessing that might be the issue I assume it just needs the same commands as the VCore 3 to make it work

miklschmidt•2y ago

It is

miklschmidt•2y ago

You need to replace everything in there with this: https://rat-os.vercel.app/docs/slicers

Slicer Configuration | RatOS

RatOS comes with STARTPRINT and ENDPRINT macros that you can call directly from your slicers. This way the printer knows how to start a print, and you can there easily switch between slicers without worrying if you changed anything in another slicer.

extended-salmon•17mo ago

Thanks. I nailed that on my VCore3 but I missed it here somehow. Thanks for the feedback, let's see if I can get everything working with this. One last thing. The z axis is making a LOT of noise, significantly more than the x and y, and getting hot for the calibration. I'm wondering if this is because it is supposed to have 2 z steppers or something

miklschmidt•17mo ago

You'd need custom stepper settings for your creality motors Do not use the stock v-minion stepper settings.

extended-salmon•17mo ago

Any idea a good place to get those?

miklschmidt•17mo ago

Use the klipper standards and find out how much current they’re rated for

extended-salmon•17mo ago

I found some numbers I'm comfortable with trying but it's not accepting them under the stepper files. I'm also trying to find the stepper files in the printer.cfg but I have no idea what to enable. The names don't make sense. I think I have Creality 42-34 stepper motors (the default that comes with the Ender 3 Pro) but can't be sure @miklschmidt ... if I'm not mistaken they're identical to the 42-40 steppers used by the V-Minion A few other problems: the z gantry does not stay up after steppers are depowered such as after the print ends. This leads to the nozzle crashing. I think I just need to increase the z steppers hold current right? Next problem is that the retracts are huge and when they finish the extrusion rarely continues leading to print failure.

extended-salmon•17mo ago

extended-salmon•17mo ago

miklschmidt•17mo ago

This is a mechanical problem, not a firmware problem just comment out all the steppers/ includes and define your own.

extended-salmon•17mo ago

Hmmm. Ok. The numbers that are in the current includes seem to match what I would have put anyway so I dont see the point... other than maybe the hold current if that fixes it when it dips. But you said that wouldnt fix it so who knows. What about the huge retracts? Is that a cura problem?

miklschmidt•17mo ago

when no hold_current is set it's the same as the run current. Your problem is stepper power off. There's no current there.. There's no power. yes

extended-salmon•17mo ago

Thanks for my help with the dumb questions lol

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VMinion 3 scraping bed after homing