Sovol SV08 Multiple Motion System Upgrade.

dwuk3d

Auto alignment with ball probe complete.

Original plan was to use the electro magnet on the bed - but it is quite weak - despite specs being near to the permanent magnet that works very well.

So switched to having the magnet off the bed grabbing a big circular plate.

Not sure how much it is really needed.

Also ordered a bigger magnet - but not sure if I will need to use it.

Demo video of homing, levelling, deployment of probe and alignment attached.

https://youtu.be/kpVAuKwoTiQ

o_lampe

@dwuk3d Nice video, but I watched it without sound.
The problem with any nozzle touch probes is, you have to make sure the surface is completely clean. (and conductive too?)
I hope your homing macros are ready for "murphy's law"

dwuk3d

@o_lampe Thanks - sorry about the music - will have to get a bit more creative with that - and maybe think about some narration.

Agreed about the nozzles needing to be clean, will have to add in some auto cleaning as part of my start up phase. I've put a cleaning pad on the swing out arm - but haven't done the automation for this yet.

The ball probe is mechanical - so no worries about conductivity.

I think my ultimate solution is likely to be a 3 stage approach - with the inductive probe or an eddy probe to find the ball probe and do some basic alignment, then using a cleaned nozzle pressing on the ball probe for a 2nd phase of alignment, with then a final check using the camera for fine adjustments,

There is some software to do the camera based adjustments automatically - but I suspect that it will be hard to get that to work reliably too - especially in different lighting conditions and with different bits of waste on the nozzle.

dwuk3d

@dwuk3d Added Nozzle cleaning into alignment process, also decided to start making use of Daemon.g for timeouts of things like magnets, servo's, hot ends - which seems to be working ok.

Only issue is with the hot ends - where if the process is left on when a print is about to start then the daemon.g could drop in and switch tools - so will need to disable any tool based timers when prints are started.

Example switch on Servo and Magnet - in Probe Deploy Macro.

M42 P5 S1 ; Servo On

if exists(global.servo5Off) == false
    global servo5Off = 0

set global.servo5Off = state.upTime + 120

M42 P4 S255 ; Magnet on


if exists(global.magnetOff) == false
    global magnetOff = 0

set global.magnetOff = state.upTime + 200

Example Daemon.g

;daemon.g

if exists(global.servo5Off)
    if global.servo5Off != 0 && global.servo5Off < state.upTime

        M42 P5 S0 ; Servo Off
        set global.servo5Off = 0
        echo "daemon.g servo5 switched off"
        


if exists(global.magnetOff)
    if global.magnetOff != 0 && global.magnetOff < state.upTime


        M42 P4 S0 ; Magnet off
        set global.magnetOff = 0
        echo "daemon.g magnet switched off"
        
if exists(global.T1Off)
    if global.T1Off != 0 && global.T1Off < state.upTime
        M596 P0
        T1
        M109 S0
        set global.T1Off = 0
        echo "daemon.g T1 switched off"

if exists(global.T0Off)
    if global.T0Off != 0 && global.T0Off < state.upTime
        M596 P1
        T0
        M109 S0
        set global.T0Off = 0
        echo "daemon.g T0 switched off"

dwuk3d

@dwuk3d Trying out various different options for head cleaner location while still waiting for Nema8 and Nema11 Z lifters to arrive.

Not sure whether to put the cleaner at the front of the gantry - so that it can be wiped in 2 dimensions,
or just on the end of the Y gantry - so can only be wiped in the X direction.

I suppose I could add another servo at the end of the Y gantry, or some sort of 3d printed mechanism to make the Y wiper move backwards and forwards a little bit.

Long thin arms working quite well on low Z heights - as they bend slightly rather than fouling on the bed.

dwuk3d

@dwuk3d NEMA11 stepper arrived.

Doesn't work quite like I expected as there is a thread inside the motor - so the lead screw has to be held for the motor to move.

Also quite heavy and bit big - so think I will hold off until the lead screw NEMA8 arrives.

Motor size comparison

dwuk3d

I think Nema8 might end up working quite well for the Z hoppers.

Decided to try and create some sort of lead screw for the existing NEMA8 I got a few weeks ago.

Took quite a few iterations - but ended up doing my first ever 'captive print' - with an M4 Hex Headed Bolt captured inside a coupler print.

As its a bolt rather than lead screw then it is quite sloppy - but might be able to use that as a slight advantage as will hopefully be able to use a single optical end stop for both
a) The homing of the Nema8 based Z hopper
b) The X axis
c) Z Axis tapping too.

Have replaced Servo on the rear gantry with the Nema8 motor and it is looking good so far.

Comparison photo with the slow soon to be replaced front gantry stepper, rear gantry with almost completely installed NEMA8, with 3 way optical end stop below, plus the NEMA11 motor also included.

Had to move the 1LC tool board about 16mm to the left to accommodate the taller stepper/lead screw combination.

o_lampe

@dwuk3d said in Sovol SV08 Multiple Motion System Upgrade.:

As its a bolt rather than lead screw then it is quite sloppy - but might be able to use that as a slight advantage

Vertical slop is a 1st layer killer.
Although it might have advantages with other stuff, you sure don't want to risk bad adhesion to the bed.
Maybe you can add a spring to reduce backlash?

dwuk3d

@o_lampe Thanks will try a spring over the bolt.

Will be interesting to compare the 'bolt' version with the proper lead screw Nema8 version I have ordered.

dwuk3d

Nema8 motor working quite well as a zlifter on rear gantry - so have ordered a few more for other extruders.

Will create a short video next showing use of a single optical endstop for U,A and Z Axis.

In the meantime - another interesting video from teaching tech with a comparison between Marlin, Klipper and RRF - with another little mention of this project in the RRF section about 9mins30 in.

https://youtu.be/fahU6UXl7g8?si=W7gJpKrv2_YfzKT-

dwuk3d

@dwuk3d Initially I was finding that the Nema 8 motors were not powerful enough to reliably lift the gantry.

The Non Lead screw one was I thought rated at 0.4a and the Lead Screw one at 0.24A.

However it looks like on further investigation that the Non lead Screw one is actually rated at 0.8A - and when I set it to 0.6A in Config.g it is working very reliably.

Before I found this out I ordered some smaller (28mm) Nema11-s however as the Nema8's look ok I have ordered two more of those too

Short video attached of Nema8 in operation, and also showing what may or may not be a good idea - using the same (very cheap) optical sensor for

MicroZ (A Axis)
U Axis
Z Axis tapping

In order to swap the 122.io2.in pin between the 3 axis - I found I had to first swap the other axis to dummy IO pins - so that they would release 122.io2.in - so that it could be assigned to the correct axis using M558 commands.

https://youtu.be/0jkH4YBIZDc